Lecture Notes on Neuroscience: Brain, Behaviour, and the Mind PDF

Lecture 2; how can we study the brain, behaviour and the mind? Friday, 15 March 2024 11:38 AM We might: Ask questions Observe what you are doing Measure your performance on a speciﬁc task See how damage to the brain can impact performance Measure activity of healthy brains Observation Observation comes naturally to humans helps us understand processes inside the mind Example: investigating food preference in meerkats (Brox et al., 2021) Independent variable: food type Dependent variable: number of meerkats present at each site Tells us about which food animals prefer when they are given a range of foods to choose from Creates a preference hierarchy Measuring performance on a speciﬁc task The Stroop Test The next slide will show a grid ﬁlled with names of colours. Your job is to say the names of the colours that the words are printed in from left to right as fast as possible The next slide will show a grid ﬁlled with names of colours. Your job is to say the names of the colours that the words are printed in from left to right as fast as possible this time the colour of the word will not match the colour the word is printed in (if the letters are in green and the word says pink, say green) This leads to theories on how attention works: Automaticity theory: the word interferes with the colour naming when the word and colour doe not match because reading is an automatic process and recognising colours is a more controlled process Selective attention process: reading requires less attention compared to identifying a colour, that’s why it takes us longer to identify the colour of words in incongruent trials. The impact of damage on the brain Example 1: Clive Wearing and short term memory Clive Wearing contracted a virus (herpesviral encephalitis) which caused damage to parts of his brain involved in memory Unable to store new memories Lost most of his memories from before he became ill Retained his knowledge of music Example 2: Language and Aphasia Language disorder that a[ects a persons ability to communicate The result of a stroke or brain injury People with aphasia may ﬁnd the following tasks di[icult: 1. Talking 2. Comprehending spoken, or written language 3. Writing 4. Using numbers, for example calculating answers to problems Aphasia can present di[erently depending on the area of the brain e[ected: Broca's Area Involved in speech production Di[iculty in producing language Comprehension abilities relatively conserved Wernicke's area Involved in language comprehension May speak ﬂuently Spoken language often lacks meaning Di[iculty with language comprehension Observing brain activity during mental tasks fMRI (functional magnetic resonance imaging) Safe and non-invasive Detects changes in the ﬂow of blood Increases in blood ﬂow are correlated with neuronal activation TMS (transcranial magnetic stimulation) Non-invasive technique that disrupts speciﬁc brain activity for a fraction of a second Allows us to investigate the role of these areas in human functioning In summary Many di[erent methods are used by researchers trying to understand the brain, behaviour and cognitive processes Method used depends on the question being asked and the approach being used New methods are constantly evolving, and technological advances have given us many more ways to investigate questions relating to brain, mind and behaviour. Online lecture 1; the biological basis of behaviour Friday, 12 July 2024 2:58 PM Lecture 4; the biological basis of behaviour continued Wednesday, 17 July 2024 10:56 AM Learning objects for week 2 1. Describe how signals travel within a neuron 2. Describe how signals travel between neurons 3. How certain substances can alter how signal travels within and between neurons The neuron: signals received by the dendrites, travels towards cell body Two kinds of signals can travel into the cell body: 1. Excitatory signals: make the cell more likely to ﬁre 2. Inhibitory signals: make the cell less likely to ﬁre When the signal reaches the axon hillock a process called summation occurs Summation The sum of all incoming signals (inhibitory and excitatory) determines whether the neuron ﬁres Threshold value at which the neuron ﬁres: -55 mV (millivolts) Value the neuron starts at before any signals arrive: -70mV All that has to happen for the cell to ﬁre is the excitatory signals have to be 15mV stronger than the inhibitory signals Resting membrane potential Inside of the cell is more negatively charged (-70mV) compared to outside the cell Questions we need to answer before we can go further 1. What are these charged particles that reside inside and/or outside the cell? These 2 ions are crucial to sending signal down an axon, both are positively charged As the ions leave the cell the more negative the cell becomes, the more of these ions that enter the cell the more positive the cell becomes 2. How do these charged particles get into/out of the cell to make it more positive or more negative? Ion channels; doors within the membrane Some of these are always open/closed, some only open in certain situations Potassium channels, only potassium can travel through these channels 3. Why don’t these charged particles just stay where they are? Concentration gradients and electrical gradients The dash lines represent semi-permeable membranes, such as the membranes within the cell The goal is always to be in equilibrium Resting membrane potential continued There is a higher concentration of K+ inside the cell, therefore the K+ will move outside of the cell to cause equilibrium, while it will also move inside of the cell to keep the charges equal inside Resting membrane potential is achieved when both forces are equally strong And then the cell ﬁres- the action potential What is an action potential? An action potential is a change in the voltage inside a cell relative to outside of the cell taking place at one section of the cell at a time (not the whole cell at once) A chain reaction Action potential propagation Na+ A channel that only allows sodium in it triggered by a certain voltage At -55mV the doors are triggered to open This causes the cell to ﬁre Na+ wants to enter the cell in order to create equilibrium This causes a chain reaction as Na+ enters the cell, triggering the next channel to open Action potential propagation K+ Na+ enters the cell very quickly, causing the cell to become more positive This means K+ rushes out of the cell as Na+ enters Action potential- change in voltage across time Depolarisation to repolarisation It is more negative outside the cell, causing K+ to continue to move outside of the cell through the leaky channels The refractory period The Na+/K+ pump throws 3 Na+ outside of the cell while bringing 2 K+ into the cell Is able to slowly regulate the cell back to -70mV This requires energy, it is not passive di[usion Is this di[erent for myelinated axons? In myelinated neurons the action potential jumps from one node of Ranvier to the next This jumping is referred to as saltatory conduction (node to node conduction of this action potential) This allows the signal to move faster (increased the rate of propagation) Is energy e[icient with 100x less movement of ions, because the action potentials occurring only at the nodes, not along the whole axon Summary Lecture 5; biological basis of behaviour continued Thursday, 18 July 2024 9:54 AM Learning objectives 1. How signal travels between neurons (how cells in the nervous system communicate) Synaptic transmission (synaptic communication) Neurotransmitters (inhibitory and excitatory) Receptors (ligand gated ion channels) Reuptake 2. How di[erent substances people consume can impact syntactic transmission Agonists Antagonists Reuptake inhibitors Some history Santiago Ramón y Cajal (1852-1934) Spanish Neuroscientist First illustrations that showed how the brain was structured Believed that the neurons within the brain are not connected, they are all separate cells (he was right) Camillo Golgi (1843-1926) Italian neuroscientist Believed the neurons within the brain are all connected Neuronal communication is electrochemical The generating of action potential/travel of action potential is electrical process The process of sending the message to the other cell is a chemical process This chemical process takes about 1 millisecond for chemical transmission to occur The space between neurons is 20 nanometres (1 million times smaller than a millimetre) Myelinated neurons can send action potential 50 - 120 meters per second This means myelinated action potentials move 1000x faster than synaptic communication How signal is transmitted from one neuron to another Synapse means 'to join' The post-synaptic cell is the one that is receiving the information The pre-synaptic cell is the one that is sending the information Main structures of the synapse The synaptic cleft is just an empty gap Neurotransmitters are chemicals that carry the signals to the next cell Vesicles contain neurotransmitters- they are the vehicles that have the neurotransmitters in them Types of synapses Synapses can also form to multiple parts of another neuron When neurons connect from axon to dendrite we call that axodendritic synapses They can also connect to the cell body (the soma), and so these are axosomatic synapses Axoaxonic synapses connect axon to axon 2 more ions Cl- is essential for understanding how neurons send inhibitory signals Ca2+ is essential for allowing chemicals in presynaptic cell to exit the cell and enter the synaptic cleft Chemical synapse- steps of synaptic transmission 1. The action potential travels down the axon 2. The action potential arrives at the presynaptic terminal 3. Voltage gated Ca2+ channels open, allowing an inﬂux of Ca2+ 4. Ca2+ allows vesicles to merge with the membrane (fuse) and neurotransmitters release out to the other side 5. Neurotransmitters bind to the receptors, causing ligand gated ion channels to open (or close) 6. This allows ions to enter the channel into the next cell, causing excitatory or inhibitory postsynaptic potential to be generated 7. Neurotransmitters are removed by glial uptake (or enzymatic degradation) Inhibitory and excitatory synapse Glutamate- Excitatory Synapse When glutamate neurotransmitters open the channels, the opening only allows Na+ and Ca2+ (positive) ions through This means the cell is depolarised and is more likely to ﬁre GABA- inhibitory synapse When GABA neurotransmitters open the channels, the opening only allows Cl- (negative) ions through This means the cell is hyperpolarised and is less likely to ﬁre Reuptake The pre-synaptic cell membrane has neurotransmitter-speciﬁc transporter proteins that transport neurotransmitters back into the presynaptic cell Means that the neurotransmitters can be reused Neurotransmitters Chemical messengers that transmit signals across synapses from one neuron to another neuron (or to a muscle cell or gland cell) We do not know how many there are, there have been over 100 di[erent kinds so far They are synthesised inside the neuron (in the cell body or axon terminal) There are di[erent categories of neurotransmitters: 1. Amino acids (glutamate, GABA) 2. Monoamines (dopamine, serotonin, histamine) 3. Peptides (endorphins, oxytocin) Dopamine Can be excitatory or inhibitory depending on the receptors Plays diverse roles in the nervous system Involved in thoughts, feelings, motivations and behaviours Associated with the experience of pleasure Learning to associate particular behaviours with reward (the reward pathway) Attention, mood regulation, emotional responses Coordinating movement (Parkinson's disease is caused by a progressive loss of dopamine producing neurons) Serotonin Involved in regulation of mood, sleep, eating, arousal and pain Depression associated with reduced serotonin (thus, antidepressants target neurons that produce serotonin) Other ways to increase serotonin levels include sunlight exposure, sunlight exposure stimulates production of vitamin D in the skin, which is involved in serotonin synthesis The eLects of drugs in the nervous system Alcohol Alcohol acts as an agonist (for GABA) and an antagonist (for glutamate) Binds to a speciﬁc part of GABA receptors to make them even more inhibitory Essentially it makes neurons that release GABA way stronger at inhibiting the ﬁring of the next neuron, leading to sedation and anxiolytic e[ects (anxiety reducing) Also binds to glutamate receptors preventing the glutamate from exciting the cell Targets the reuptake, meaning there is a bunch of neurotransmitters left in the synapse increasing the likelihood of the cell ﬁring Online lecture 2; introduction to the brain and nervous system Thursday, 18 July 2024 3:49 PM Why should neuroscience matter to psychologists? Humans and animals are biological systems The basic assumption of all modern neuroscience and psychology: mental functions are the product of activity in the nervous system Cognitive neuroscience: the scientiﬁc study of biological and neural processes underlying mental processes Or in other words: the science of how the brain creates the mind Understanding the mind requires an understanding of the nervous system What functions does the nervous system perform? Receives sensory information from the environment Integrates and processes information Regulates internal functions Produces motor actions Living beings: levels of observation Body, measuring motor activity Systems, measuring speciﬁc systems Organs, measuring the brain Tissues, within the organ Cells Genes All of these are di[erent levels of observation on the same organelle The organisation of the nervous system The peripheral nervous system Composed of nerves, a bundle of axons Includes: 1. Autonomic nervous system (internal regulation) A nervous system that works automatically and involuntary Controls and regulates blood vessels, organs including the heart and glands 2. Somatic nervous system (skeletal muscles) These are the nerves that form synapses onto muscles The autonomic nervous system can be broken further into: 1. Sympathetic nervous system (arousing) Increases arousal Prepares the body for survival-related action Fighting, ﬂeeing, feeding, mating 2. Parasympathetic nervous system (calming) Reduces arousal Returns the body to a resting state, slowing down heart rate and redirecting blood These are not completely separate systems, they operate in coordination with each other The central nervous system Includes: 1. The brain * 2. The spinal chord Nerves come out from between the 2 vertebrae Gray matter: tissue made of mainly cell bodies White matter: tissue made of mainly myelinated axons Information coming into the spinal chord enters dorsally Information exiting the spinal chord enters ventrally *The brain Part of the central nervous system Just like the spinal chord the brain is made up of grey and white matter There are 3 main divisions: 1. The hindbrain Phylogenetically ancient, its been with us for many years Coordinates information ﬂow to/from the spinal cord The medulla Extension of the spinal cord Controls heart rate, circulation and respiration Reticular formation Regulates sleep/wake and arousal Cerebellum Controls ﬁne motor activity Doesn’t initiate movements but reﬁnes and smooths them Pons Relays information between the cerebellum and the rest of the brain 2. The midbrain The midbrain coordinates basic functions related to perception and action Tectum (dorsal) Spatial orienting to the environment Superior colliculi- vision Inferior colliculi- audition Substantia nigra (part of the tegmentum) High level of dopamine gives it dark colour Tegmentum (ventral) Movement Arousal and pleasure seeking 3. The forebrain Made up of cortex and sub-cortical structures: 1. The subcortical structures Basal ganglia Plan initiation of intentional movements Not involved in ﬁne calculations or reﬂexive movements Thalamus Relays and ﬁlters information from the senses to the cortex Pituitary gland Regulates hormones the limbic system- The hypothalamus Regulates internal bodily functions- temperatures, hunger, and the 4Fs the limbic system- The hippocampus Spatial navigation Creates and integrates new memories but not long-term storage The limbic system- the amygdala Emotional processing and memory- particularly fear 2. The cortex The outside of the brain (the cortex) is very folded The forebrain has 2 hemispheres, and they are not entirely independent of each other, connected by the corpus callosum which is made of white matter Each of these hemispheres has 4 lobes Occipital lobe Vision The primary visual cortex Temporal lobe Semantic knowledge Word meanings Object identiﬁcation Audition Parietal lobe Spatial attention Sensory integration Object location Numbers/quantities Frontal lobe Planning Abstract thinking Executive control The Skull, meninges and cerebro-spinal ﬂuid (CSF) The brain ﬂoats in a pool of CSF, which provides shock absorption when the brain moves against the skull This CSF is located in the arachnoid membrane The CSF is produced within the brain Terminology Neuraxis The central axis of the nervous system The spinal chord is vertical The brain is horizontal You have to keep in mind what part of the human nervous system you are talking about to use the right terminology Rostral or anterior The front of the neuraxis (the front of the nervous system) Caudal or Posterior The back of the neuraxis (the back of the nervous system) Dorsal Anything above/behind the neuraxis Ventral Anything below/in front of the neuraxis Lateral Towards the side, the outside surface of the brain Medial Towards the middle Horizontal/sagittal/coronal Horizontal slices (of the brain) are parallel to the ﬂoor Sagittal is a plane parallel to the proﬁle Coronal is a plane parallel to the face Neurosurgery: brain stimulation In the 1950s, Penﬁeld stimulated exposed cortical surface with an electrode during surgery He found that this caused sensation/movement/memories etc This allowed us to map functions Provided us with knowledge of the brain Necessary for individual patients as brains are like ﬁngerprints, all are slightly unique Context After accidents involving blows to the back, 3 di[erent patients have di[erent symptoms: 1. Has lost all sensation to the left arm but is able to move it 2. Cannot move his right arm but can feel it 3. Cannot move or feel his legs What damage to the spine or near it would you suspect in each case? Lecture 7; branches of the nervous systemc Lecture 7; neural activity and networks Wednesday, 24 July 2024 10:38 AM Lecture 8; branches of the nervous system Thursday, 25 July 2024 12:46 PM The peripheral nervous system: The somatic nervous system Consists of the nerves that have synapses onto/into muscles Unconscious a lot of the time: we don’t think about walking we just do The peripheral nervous system: The autonomic nervous system Internal regulation Controls internal organs and physiological arousal Mythbusting Myth: polygraph machines detect lies Status: incorrect Polygraphs measure arousal- they assess the autonomic nervous systems activity Measures blood pleasure, heart and breathing rates and skin conductance (sweat) The idea of polygraph machines is based on the assumption that lying is stressful and therefore increases arousal, however: 1. Some people have a high arousal threshold (for example psychopaths) 2. Some people get around very easily (just being interrogated is enough) This means there is a high chance of both false negatives and false positives There is also a possibility of countermeasures The central nervous system: the spinal cord A challenge: Online lecture 2; introduction to the brain and nervous system After accidents involving blows to the back, three di[erent patients have di[erent symptoms, what damage to the spine would you suspect in each case? Patient 1: has lost all sensation to the left arm but is able to move it We know its on the left, so it will be the left part of the spinal chord The dorsal nerve is in charge of sensation Therefore: it happens from C6/C7 and is on the dorsal horn on the left side Patient 2: cannot move his right arm, but can feel it Movement is impaired so it will be the ventral nerve It is also on the arm (though this time to the right) so it will also be around C6/C7 Patient 3: cannot move or feel his legs Both the ventral and dorsal nerves will be damaged As its in the legs it will be around L1/L5 The central nervous system: the brain Functional specialisation in the cortex Mythbusting Myth: the right hemisphere is artistic and intuitive, the left hemisphere is logical and rational Status: distortion, exaggeration, oversimpliﬁcation Hemispheric di[erences do exist But its not divided by logic/intuition or art/science or anything that simplistic, and both sides work together Most prominent lateralisation is language (lateralised usually to the left hemisphere), but there is also: 1. Left = details and Right = holistic 2. Left = sequences and Right = spatial arrangement Myth: we only use 10% of our brain Status: NOT TRUE, not even a little bit We use 100% of our brain Di[erent brain regions are more/less active at any time, but none are completely inactive All neurons ﬁre- a neuron that does not ﬁre is a dead neuron A challenge Functions like memory, object recognition etc could happen without consciousness (such as in a computer) What function creases consciousness- our subjective experience of the world? And at what point/level does consciousness enter the system? The hard problem of consciousness Online lecture 3; sensation and perception Friday, 26 July 2024 9:22 AM The sense organs: 1. Eyes 2. Ears 3. Nose 4. Tongue 5. Internal Organs 6. Skin Gateways for information to get in, so that the brain can understand what is happening in the world around us transduction The physical energy from the physical world around us has to be translated into a neural code Each sense organ is full of receptors When something touches or contacts those receptors they create action potentials That action potential can now send a signal to the brain Perception How we make sense of the activity in the brain brought through transduction and how we experience it The process of creating, taking that neural signal and creating a psychological reality Psychophysics: the relationship between the physical world and the psychological world (via the neural world How we experience the world The experience you have of the world is determined by the types of sensory receptors that you have, for example: The sense of smell molecules (chemicals) given o[ by fragrances are a part of the air that is around us Enter the nose when we breathe chemoreceptors (neurons) within the nose have certain shapes that correspond to di[erent smells When a chemoreceptor locks in with one of these speciﬁc chemicals it generates as action potential, sending a signal to the brain Humans can distinguish around 50,000 di[erent smells, meaning we have around 50,000 di[erent shapes of chemoreceptors within our nose Chemicals don’t actually smell until they attach themselves to a receptor in a nose, and the nose takes the action potential and creates the feeling of smell This means that things you smell are determined by whether your nose has receptors for them Light/colour Light is made up of di[erent wavelengths Di[erent colours are made up of wavelengths of di[erent lengths Light is part of electromagnetic radiation, di[erent wavelengths of radiation which ﬂoat around the world We can only see electromagnetic waves that are within a speciﬁc range of lengths; this is colour This means we have receptors in our eyes that can change the electromagnetic radiation of those waves into the experience of colour, meaning colour does not exist in the physical world, it exists in our mind Temperature Temperature is the minds interpretation of kinetic energy We have hot and cold receptors Hearing Our hearing is at its best in a range of about 4 to 8,000 hertz, which is exactly the frequency that matches human voices Our ears have receptors for a speciﬁc range of sound wave lengths, very similar those that allow us to perceive light/colour If a tree falls in a forest and no one is around, does it make a sound? No, pressure waves will be created from the act of the tree falling but if there is no one close enough to receive those pressure waves then it will not be converted into sound No ears, no sound Measuring sensations; behavioural methods Many perception studies use detection/discrimination experiments Detect whether or not a stimulus is present Discriminate which of 2 stimuli is more intense The absolute threshold: how low can you go? For example: how dim can I make that circle so that I can still see it? Ask the participant to guess whether the stimulus is present or not Signal detection theory example: A circle is there 100 times and it isn't there 100 times This looks like their perception is really good, however we also have to look at when they say the circle is there when it isn't Sensitivity: how well you can distinguish between when the stimulus is present or absent, meaning you have a high hit rate AND a low false alarm rate Response bias: presented with the same stimulus intensity, di[erent participants might respond di[erent not because they have di[erent perceptual sensitivities, but because they are more/less biased in responding to the task Signal detection theory allows us to separate sensitivity from response bias An example: absolute threshold of human hearing depends on frequency Depends on age and the frequency of the sound we are listening to Our auditory system is evolved to be most sensitive to stimuli most useful to us humans 9the range in which humans speak) The discrimination threshold: can you tell the di[erence? Discrimination thresholds depends on how intense the original stimulus is The just noticeable di[erence (JND) = smallest perceivable di[erence, the discrimination threshold JNDS exists for more complex decisions too Weber's Law/Weber Fraction Discrimination threshold increases proportionally to baseline/reference stimulus increase K = JND/Baseline = ΔI/I For example: (50-54)/50 = 0.08 so an 8% change Lecture 10; vision Thursday, 1 August 2024 9:54 AM Visual Light Electromagnetic spectrum showing the broad range of energy and the small range within this spectrum that we can see (visible light) Photons: particles of light that get captured by a receptor, which triggers the polarity of the photon and causes an action potential Our eyes Rods: many rods, mostly in the periphery Respond to light of all wavelengths: they are colourblind High sensitivity/low resolution: responds to everything so really good in dim light, but are not tightly packed Makes up the most of your peripheral vision; which is colourblind Cones: centred in the middle of the retina (fovea) Respond to di[erent wavelengths (red/green/blue), they are how we see colour High resolution/low sensitivity: tightly packed together but they do not respond to everything, a lot of photons are required to activate a cone Trichromatic theory Colour perception is mediated by cones, with there being 3 types: 1. S-cones are most sensitive at short wavelengths (blue) 2. M-cones are most sensitive at medium wavelengths (green) 3. L-cones are most sensitive at long wavelengths (red) Your brain perceives colour based on the combination of photoreceptors that are activated in a speciﬁc location Colour-blindness There are 2 basic forms: 1. Monochromat, where the person has only one type of cone (this is very rare) 2. Dichromat, where the person has 2 types of cone Someone who doesn't have colour-blindness is a trichromat We can test for colour-blindness with the Ishihara plates In the animal world: The callitrichids: Marmosets, tamarins and capuchins The males are dichromats The women are dichromats and trichromats Dark adaptation When you are in a dark area overtime the rods become more sensitive, meaning your threshold lowers and you can see more things Dark adaptation is the transition of the retina from the light-adapted to the dark- adapted state Colour Colour opponency Colour perception involves opponent processing of 2 pathways: 1. Red/green 2. Yellow/blue Colour opponency is another mechanism of colour perception that works in addition to the photoreceptor-based mechanism Perceptual constancy: objects maintain their properties even when the context changes their physical characteristics We know that all these bananas are yellow but when out of context these bananas all have di[erent colours: The dress Overall, 57% of subjects described the dress as blue/black and 30% as white/gold This proves how we all have entirely di[erent perspective experiences to each other without realising If you assume that the dress is outside and in shadow, your brain will take the outside shadows into account and you will see it as white and gold If you assume the dress is indoors in artiﬁcial light, your brain will see it as blue and black Lightness constancy: our brains take the shadows into account when creating the perception of light and dark Visual pathways Most vision doesn’t happen in the retina but actually in the brain The left visual ﬁeld projects to the right visual cortex and the right visual ﬁeld projects to the left visual cortex Visual cortex is retinotopic Online lecture 4; vision continued Thursday, 1 August 2024 8:21 PM Visual pathways and the split brain The fovea is the centre of our vision, where our vision is best There is the left and the right visual ﬁeld Left visual ﬁeld projects onto the right visual cortex, right visual ﬁeld projects onto left visual cortex The visual cortex is retinotopic: each area of the visual cortex corresponds to a di[erent area of the retina (our visual ﬁeld) The lateral geniculate nucleus: bundle of cells in the thalamus, where information from all of our senses ﬁrst comes into the brain before being sent out From the thalamus the information gets sent to the primary visual cortex Where the left and right visual ﬁelds cross over is called the optic chiasm, and it’s where the information from the nasal hemiretinas crosses Once the information is in the visual cortex, it travels through the di[erent hemispheres corpus callosum: the thick band of nerve ﬁbres that connect the 2 brain hemispheres The 2 hemispheres of the brain Both hemispheres contribute to our uniﬁed sense of consciousness Both work in slightly di[erent styles, processing information in slightly di[erent ways Perceiving depth The problem: the retina is ﬂat, like a photo/paining, yet the world feels 3D. How does the brain create the feeling of depth out of a 2D (ﬂat) image on the retina? Binocular cues Cues that depend on us using both eyes Everything in the world that isn't the object being ﬁxated on will not land directly on the fovea Your brain takes these ques about disparity to understand what is close or further away from us than the ﬁxation point, causing us to be able to perceive depth Disparity = depth Another binocular cue is vergence, when we turn our eyes inward in order for us to be able to see them/ﬁxate on The signal the brain receives from the muscle in the eye allows it to understand the level of vergence, therefore it is able to understand how close the object we are looking at is to us which in turn creates depth Binocular cues require our 2 eyes to be monitoring the same part of the world from slightly di[erent perspectives Monocular cues Cues that only require us to use one eye Linear perspective: parallel lines come closer together the further in the distance they are Relative height: things that are closer to us are in the bottom of our visual ﬁeld and things that are further away are at the top of the visual ﬁeld Relative size: things get smaller as they are get further away from us (they make smaller projections on our retina) Texture gradient: things that are closer to us are higher in resolution, so we can see more details Arial perspective: water molecules in the air around us mean things that are further away from us tend to be less colourful and a bit hazy Interposition/occlusion: things that are closer to us are going to block things that are further away Light and shade/shadow: our brain takes the shadow into account when understanding the world, allows us to understand where light is coming from Motion parallax: when ﬁxating on one object while moving, everything that’s further away than that object will seem to be moving with you, while objects closer to you feel like they are quickly moving past us in the opposite direction Bottom-up and top-down perceptual processes Bottom up processing (data-driven processing) Using incoming information to drive perception Top-down processing Conceptually driven Using our knowledge or experience to drive perception This phenomenon also happens with auditory stimuli- think about misheard song lyrics Bistable images: have more than one perceptual interpretation Although these images can be interpreted multiple ways, our brain chooses one and that is the one we experience Lecture 12; attention Wednesday, 7 August 2024 10:48 AM Your attention is a limited capacity system Change blindness: perceptual phenomenon that occurs when a change in a visual stimulus is introduced and the observer does not notice it. Failure to detect changes to people during a real-world interaction- a study by Daniel Simons and Daniel Levin, found that 50% of people did not notice when the person they were talking to changed, with younger adults being more likely to notice the switch, however when the researchers were dressed as construction workers 75% of young adults did not notice the change People pay more attention to those in their "in-group" compared to those in their "out-group" Automatic and controlled processes The Stroop e[ect (again) Lecture 2; how can we study the brain, behaviour and the mind? Looks at the conﬂict between automatic and controlled processes Reading = an automatic process Colour = a controlled process Congruent means word and colour match Incongruent means word and colour do not match Response time is shorter when it is congruent compared to when it is incongruent- the congruency eLect This only happens when the words in in a language that we are ﬂuent in, as we need to be ﬂuent in the language to be able to read words automatically Is reading automatic? Reading individual words in automatic constructing meaning out of the individual words is controlled processing Feature integration theory- the Red X experiment Searching for one feature (colour, shape) can be done automatically. It "pops out". It takes the same amount of time, no many how many items to have to search- bottom-up process Searching for a combination of features requires controlled attention. You need to apply attention to each item, one at a time. More items requires more time- top-down process Automatic processes Fast E[ortless over time Occurs without intention Inﬂexible Uncontrollable Examples Texting Stereotyping/impressions Facial recognition Handwriting Instruments Sport Driving Walking Advantages/disadvantages Advantages: long repetitive tasks can be streamlined, requires less e[ort, dual tasking, e[iciency Disadvantages: hard to break bad habits, lack of control, outside awareness, error prone Controlled processes Slow E[ortful Requires intention Flexible Controllable Lecture 13; models of attention Thursday, 8 August 2024 9:55 AM "everyone knows what attention is. It is the taking of possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalisation, concentration, or consciousness are of its essence… it implies withdrawal from some things in order to deal more e[ectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrained state which is called distraction" William James, 1890 William James wrote the very ﬁrst psychology book, focused on the mind Believed attention was one of the functions of the mind Selective Attention- the dichotic listening experiments The ability to prioritise some information while ignoring other information Attention narrows the ﬂow of information into awareness Attention as a ﬁltering mechanism Cherry (1953)- Dichotic listening experiment One message being played in each ear Shadowing- one person listens to both messages at the same time and repeats one of them back, very attentionally demanding Asks what do you remember from the other ear If attention is a ﬁlter, what happens to everything we are not focusing on Broadbent (1958)- dichotic listening experiment Presents pairs of numbers as shown in the diagram Asks people to report back what they heard People would report one ear then the other ear- so for example, 1,7,5 then 8,9,3 This lead to Broadbent's ﬁlter theory Attention narrows the ﬂow of information into awareness based on physical characteristics Moray (1959)- dichotic listening experiment Treisman (1960)- dichotic listening experiment People switch to the other ear to continue focusing on the message that makes sense This formed the basis for Treisman's attenuation model Attended messages pass through clearly Unattended messages are weakened, however they sometimes break through breakthrough happens when the unattended message reaches a threshold Relevant/expected/important messages have a low threshold while irrelevant/unexpected/boring messages have a high threshold MacKay (1963)- dichotic listening experiment Ambiguous words: have two meanings, such as the word BANK, can mean building or river In the other ear they played one of the 2 meanings for the ambiguous word to see if it inﬂuences the persons understanding of the sentence Found that it does This explains subliminal attention This created the Deutsch and Deutsch late selection model We process everything for meaning, but only selected information makes it into our awareness Nilli Lavie's Load Theory- a solution to the debate? Attention is a ﬂexible pool or resources Perceptual load If the primary task is demanding (high perceptual load): No resources left Leads to early selection and no distraction If the primary task is easy (low perceptual load): Leftover capacity Leads to late selection and distraction Forster and Lavie (2008)- distraction experiment When we move to the high perceptual load experiment, we are so focused on what we are doing that the distracter does not e[ect our reaction time When our world is busy we are less distracted Implies that your mind must be full at all times- if its not full with everything you want it to be full with it will ﬁll up with other things around us Summary Online lecture 5; distraction Friday, 9 August 2024 11:00 AM Bottom-up attentional processes involuntary Attention can be grabbed by things in the environment that are salient (di[erent) to the things around it However when you are focusing on something your attention might be less easily focused on these salient things Stimulus driven attention Salience: things that stand out from their background Colour Movement Size Loudness Pitch Top-down attentional processes Voluntary Goal driven Focused on current needs such as goals, tasks, relevance and motivation The biased competition model of attention Bottom-up mechanisms feed into sensory competition We can bias things towards things that are relevant to our goals using top-down modulation Example study- how emotion e[ects processing People tend to prioritise things that have emotional value Suggests that another form of salience that can attract our attention using bottom-up processing is emotional value, things that carry threat or things that have the potential for rewards When motivation was increased to pay attention to the letters (and decrease distraction) through monetary rewards, the participants were able to override their distraction, meaning emotions have less e[ect during top-down processing Sana et al. (2013) experiments Experiment 1 All participants took laptop notes Multitasking condition also gad online tasks to complete whenever they wanted such as: ﬁnd out what time a movie was playing, shop for an item, check the weather in another city etc A test was taken at the end of the lecture Experiment 2: does multitasking e[ect the attention of those around you You can be distracted easily by what others are doing around you The costs of multi-tasking What you miss Attention is limited Dividing your attention results in poor attention for everything The switch cost When we switch tasks, we have to activate a while new set of cognitive processes Switching takes time (seconds to minutes) Computers in human behaviour Online study with over 200 participants Assigned them to 1 of 4 experimental conditions: 1. People are going to get notiﬁcations on their phone as usual 2. Batched notiﬁcations hourly 3. Batched notiﬁcations 3 times a day 4. No notiﬁcations at all Dependant variables (studied daily) Well-being Attention Phone use FOMO Star means signiﬁcant di[erence in that group Beating distraction Decreasing bottom-up distractions Put away devices Turn o[ notiﬁcations Choose a good location Increasing top-down control Take notes (ideally on paper) Use video recordings Write questions/summaries Keep your goal in mind (objectives) Use focus apps Lecture 15; introduction to memory Wednesday, 14 August 2024 10:57 AM Sensory memory Apart of our perception Iconic memory: visual memory a type of short-term sensory memory in which one can recall visual images for just a few milliseconds after the physical image has disappeared. Echoic memory: auditory memory A brief sensory memory of audible sounds Allows the brain to retain spoken syllables in order for the brain to process them into intelligible speech. Short term/working memory Consciousness The thought bubble; the things we are thinking right now What we are aware of in the moment Long term memory Declarative (explicit) memory Semantic memory: Knowledge, there's no event its just knowledge that we have Episodic memory: Events These are memories that we can talk about Nondeclarative (implicit) memory Procedural memory: skills, motor sequences, priming Autobiographical memory Your personal history Events you remember from your life and knowledge that you have about your life Our identities Really important to sense of self The modal model of memory, Atkinson and ShiLrin (1968) encoding is the process of moving information from your short term/working memory to your long term memory Rehearsal allows us to keep information in our short term/working memory for a longer period of time, takes up space within our working memory Reporting (action) uses our short term/working memory Sperling (1960) study on reporting Full report: people can report 1-2 items Hypothesised that the sensory memory of the letter list fades away too quickly which is why people cannot report them all Partial report: people an report 2-3 items no matter which row is cued This shows us that for a brief period of time you have a complete mental image of the thing you just say Our sensory memory has a larger capacity than originally believed Delayed partial report: people lose the ability to report in 1-4 seconds Same is found to be true of auditory memory This report concludes that sensory memory has a capacity of 5-10 items and a duration of < 1-4 seconds What is the capacity of short-term/working memory? George miller; described the capacity of short term memory with The magical number of seven, plus or minus two: the limit of our short term memories capacity (for numbers) Chunking words together allows us to remember them better, allows us to increase the capacity of our short-term memory by creating meaning Increasing the capacity of short term memory: Chase and Ericsson (1981) Practiced digit span 4 days/week for 2 years Digit span increased from 7 to 79 They have created an ability to chunk numbers into something meaningful This does not transfer to something they have not been able to chunk, meaning the capacity of short term memory has not increased, they have simply found a successful strategy Our mind works with chunks of information Chunking theory: Chase and Simon (1973) Focuses on spatial memory using a chess board Used chess players and novices during this study When the spatial arrangement was a game move, the chess player's expert knowledge allows them to more successfully remember the spatial arrangement When the places are random, the novices and chess players are just as bad at memorising the spatial arrangement as the novices Lecture 16; memory continued Thursday, 15 August 2024 12:47 PM The duration of short-term memory; Peterson and Peterson (1969) Working memory model: Baddeley and Hitch (1974) Central executive: controls ﬂow of information into and out of LTM Phonological loop: auditory store, mostly language based Visual-spatial sketchpad: visual store, mostly imagery based Episodic bu[er: mental workspace that holds together all parts of our current perception or thought Comparison of sensory and short-term/working memory Anatomy of a memory experiment Levels of processing Encoding phase Structural: upper or lower case? Phonemic: does it rhyme? Category: living or non-living? Sentence: does it ﬁt in this sentence? The levels of processing theory: Memory is a side e[ect of thinking The strength of encoding depends on the level of elaborative rehearsal: 1. Amount of attention paid 2. Amount of meaning information extracted 3. Connection to pre-existing knowledge Generation e[ect the generation e[ect is a phenomenon whereby information is better remembered if it is generated from one's own mind rather than simply read Actively producing material during encoding improves memory Organisation e[ect Memorization or learning depends on organization and the organizational variables determine memory. memory and organization are not only correlated, but organization is a necessary condition for memory. Imagery Method of Loci: 1. Imagine to-be-remembered items in familiar locations 2. Retrace your steps Online lecture 6; retrieval and forgetting Friday, 30 August 2024 12:40 PM Retrieval from long-term memory Your memory weaves a path- one memory leads in some logical way to another memory in a way that only makes sense to you This illustrates that our memory is organised in ways that make relationships between memories, like a 3D spiderweb- each individual memory can be accessed by following the strands that lead to that memory Example experiment: listen to the words and recall, Tulving and Pearlstone (1966) Free recall: participants study a list of items on each trial, and then are prompted to recall the items in any order Cued recall: retrieval of information from memory with the help of cues/hints (in this case using categories) Manipulated the list length and number of categories Free recall doesn't really increase much as the number of items increases, generate your own retrieval cues Cued recall does increase as the number of items increases This tells us that on the 48 item list people did encode the words they just weren't able to ﬁnd them within their memory, so when the cue is used it allows them to ﬁnd the memory Example experiment: availability vs accessibility of information in memory, Tulving and Pearlstone Availability: item is in memory Accessibility: item can retrieved from memory Forgetting: failure of availability Retrieval failure: failure of accessibility Sometimes the best cue you can give someone is the actual memory itself (Eg: some of these words were on the list and some of them weren't) Example experiment: state dependent memory, Godden and Baddeley (1975) 1. Study words either on land or underwater 2. Recall words either on land or underwater What matters is matching the context- when retrieving on land you will remember what you studied on land better than in water This is true for many things including mood, when you are sad you more easily recall memories you encoded while you were sad and this is thought to be one of the mechanisms that leads to depression Cue dependency principle The strength of a memory depends on the number and informativeness of its cues Encoding speciﬁcity principle Cues are most e[ective if they are encoded along with the to-be-remembered information Forgetting Hermann Ebbinghaus (1885) Early pioneer of psychology Did all his research on his own memory, using himself as his only research participant He created lists of random sets of nonsense syllables such as Pab, Dax and Russ with the point of this being to use things with no meaning has he believed that if what he was using had meaning we would start to use the meaning to help us understand things, and he wanted to study what happens if we don’t have any meaning to rely on He would vary the number of items on the list and repeat the list to himself and then test himself on it until he could recite the list perfectly- the learning phase He would then test himself on the list after di[erent intervals Red line: learn the list once, rapid forgetting Green lines: relearning the list, more gradual decline in memory Repeat process, each time you relearn there is less forgetting Overlearning leads to stable remembering Each time Ebbinghaus relearned a list, it took less time Savings: the reduction in time required to learn a second time How long do we keep memories? Forgetting happens all the time, usually for poorly encoded information Memories are strengthened every time we retrieve them If you learn information well, how long can you keep it? Bahrick et al (1975) Tested memory using high school yearbooks Participants ages 18 to 70 1. Free recall 2. Recognition (choose the right name) 3. Recognition (choose the right face) Recognition memory tests are pretty stable with age, especially compared to free recall Overlearned information can be retained over a very long period of time, you just might have di[iculty accessing it without the right retrieval cues Lecture 18; forgetting and amnesia Wednesday, 4 September 2024 10:38 AM Reminders Availability- item is in memory Loss through poor encoding/consolidation or decay Accessibility- the idea can be retrieved from memory Loss through retrieval failure or interference Causes of memory failure 1. Failure to encode/consolidate; consolidation can occur through dreaming or rehearsal 2. Decay? Memories decay/fade away- the neuron connections weaken causing the memory to be lost, this is very hard to prove that it actually happens. 3. Retrieval failure; things get lost in memory, can occur because we haven't encoded the memory well Interference 1. Retroactive interference Recent memories interfere with the ability to retrieve older memories 2. Proactive interference Old memories interfere with the ability to retrieve newer memories Intentional forgetting - the think-no-think task Given a list of paired associated words, for example Garden-Bakery If the cue word is written in green, recall the target and think about the word If the cue word is written in red, don’t recall the target word, try to keep your mind blank Findings: 1. Facilitation (FE) Words that have been recalled during testing are better recalled than baseline words 2. Suppression-induced forgetting (SIF) Words that have been suppressed during testing are more poorly recalled than baseline words Suppression vs Repression Repression: Freud's psychoanalytic theory, proposed that when we have traumatic experiences we can subconsciously lock them away and that in order to heal we have to unlock and talk through these memories Memory itself is perfectly intact Maladaptive process Not supported by experimental evidence Suppression: consciously keeping memory out of awareness Adaptive Supported by experiential evidence A famous case: Patient H.M. and amnesia Removal of hippocampus in 1953 for treatment of seizures at age 27 Single most inﬂuential case in the history of neuropsychology For the rest of his life, H.M. did not form a new memory Anterograde Amnesia Amnesia for events after the trauma (amnesia going forward) What H.M. developed after the removal of the hippocampus Retrograde Amnesia Amnesia for events before the trauma What was lost? The ability to form new episodic memories (anterograde amnesia) The ability to learn new words (with a few exceptions) Events several years before the surgery (retrograde amnesia) What was preserved? Short term memory (for example digit span, he can carry on conversation, continuous sense of current time) Semantic memory for everything he knew before the surgery Intelligence Personality Memories for childhood and young adulthood Sense of self Implicit memory The mirror tracing task with H.M.- implicit memory Tracing an image by looking at a mirror instead of the paper Number of errors decrease He does not recall doing the task but his performance was improved due to a previous experience Memories he cannot access Lecture 19; memory in the real world Thursday, 5 September 2024 9:55 AM The hippocampus Not where memories are stored Creates memory traces by binding ideas together Consolidates these memories Transfers memories to cortex Memories are us reconstructing/reliving the original event The war of the ghosts (1932)- Bartlett Research participants were given a story to read; a native American folktale called war of the ghosts The story was unfamiliar to the participants beforehand Recall was to write out the story as you remember it With repeated reproduction: Narrative gist remained the same as ﬁrst report Omissions: stories got shorter and culturally unfamiliar details omitted Normalisations: details were changed to match participant culture, with canoes and paddles turning into boats and oars and seal hunting turning into ﬁshing Schema Theory- Bartlett Schemas are semantic memory structures that help people organize new information they encounter Memories are not reproduced, they are reconstructed We use Schemas to understand the world Later, we use schemas to remember the world Bransford and Johnson (1972) How much of this do you understand? Then another group gets the same piece of writing along with the title "washing clothes" When you understand the context, it ﬁts into your schema and you are suddenly able to understand the text When it is encoded with the schema in mind, it is easier to memorise Brewer and Treyens (1981) Spend 35 seconds in an o[ice while "waiting" for an experimenter The o[ice contains: Schema consistent items (chairs, typewriter, posters) Schema inconsistent items (skull, frisbee, wine bottle) Shift to a new room where they complete either: Verbal recall Drawing recall Recognition Results: People were more likely to remember items in the room that were consistent with their schema than things that were inconsistent with the schema People also remembered things that weren't in the room (such as books), but they inferred were in the room as the object is consistent with their schema The recognition memory test: Shows that the participants used their schema to help them remember things Bower et al. (1971)- the dentist A script tells us how to behave: we have scripts for di[erent situations which tell us what we should expect to occur When something outside the script occurs, it becomes an especially salient event 1. Group 1 generates components of the script High agreement across people 2. Group 2 read stories using scripts: recall/recognition Script-consistent events in the story Script-consistent events not in the story Salient non-consistent events Memory construction and reconstruction Encoding We encode items/events We encode our inferences/assumptions drawn from our scripts and schemas New information is incorporated into our existing memory Retrieval We reactivate components of the memory We reactivate the script/schema Every time we retrieve a memory, we revise it based on our current script/schema Cognitive psychology for the win: study skills inspired by research in attention and memory In order to enhance encoding we require: Deep processing Organisation Generation Spacing Interleaving: Study all the topics together Allows you to ﬁnd links between the knowledge E[ective strategies Minimise distractions and multi-tasking Active engagement/notetaking during lecture Link new knowledge to existing knowledge Organise your information Generate your own study materials Space learning episodes and use interleaving Create retrieval cues Practice retrieval Online lecture 7; the characteristics of language Saturday, 7 September 2024 2:06 PM Language is organised hierarchically Phonemes (sounds) Acoustic speech sounds that express meaning Around 200 di[erent types of human made sounds are used in language Single unit of sound that changes meaning Phonemic di[erences signal di[erences in meaning Languages may di[er in the sets of phonemes that make up that language: for example English uses around 45 phonemes, Tongan used 17 phonemes We can tell that a phoneme is used within a language because when that phoneme is changed, the meaning of the word is changed: for example bat doesn't mean the same thing if you change the /b/ phoneme to /p/, as that now means pat Languages may have similar speech sounds but use them in di[erent ways to signal meaning: for example the use of aspirated and unaspirated /p/ in English and Thai Aspirated [ ph ] and unaspirated [p]: spill and pill Allophonic: acoustically di[erent but not functionally di[erent Morphemes (words) Morphemes are the smallest language units that carry meaning Words, su[ixes and preﬁxes Words carry content/semantic information within a sentence Content morphemes Semantic processing relies on processing content words Content words map onto concepts Concept is a unit of semantic memory Expresses ideas Organised into categories Grammatical function morphemes Syntactic processing relies on function words (unbound morphemes) Examples: and, or, but, a, the, she, it They have a functional role Bound morphemes: get added to another morpheme to change the meaning, but doesn't mean anything when it stands alone Plural (-s) Possessive (-s) Third person singular (-s) Regular past tense (-ed) Comparative (-er) Superlative (-est) Syntax/semantics distinction Semantic processing relies on processing content words such as nouns, verbs, adjectives and some adverbs Syntactic processing relies on processing function words such as pronouns, prepositions and conjunctives Context: Broca's Aphasia An important characteristic within Broca's aphasia is the inability to process syntax Broca's area is located near areas that control speech muscles- in right handed people it is found in the left hemisphere, mostly lower edge if the frontal lobe and upper edge of the temporal lobe Syntax: Sentences and phrases Syntax refers to the structure of language Rules for ordering words are learned implicitly; some sequences of words are allowed, but others are not Syntax is cued by: 1. Morphology, for example: I talk vs he talks He (subject/doer) hit him (object/receiver) 2. Word order, for example: Subject - object - verb (mele the apple ate) Subject - verb - object (mele ate the apple) Verb - subject - object (ate mele the apple) 3. Word class, such as adjective, nouns and verbs Word order helps us identify the word class Context: Wernicke's Aphasia The language appears ﬂuent, but there are very few context words and very little meaning within the sentences, di[iculty in understanding language Wernicke's area is located near the temporal lobe, next to the primary auditory cortex, which is where sound is translated into meaning Mapping between phenology and semantics- the connection between sounds and understanding the meanings those sounds produce Language conveys meaning Syntax cues meaning, semantics Structure of language maps onto "who is doing what to whom" Proposition: the statement that expresses and idea The action = verb Performers = doer and receiver of action (semantic roles) Lecture 21; language part 2 Wednesday, 11 September 2024 10:47 AM Early infant speech perception Newborns are able to perceive may basic phoneme contrasts (the di[erences between sounds) This is not restricted to the sounds in the language they are growing up in Detection of phonemic changes "ba" vs "ga" Between 1 and 4 months old HAS: high amplitude sucking procedure; allowed us to discover that infants can use their environment to control their sound, measured through sucking response Habituation: they have habituated/gotten used to the sound and so their sucking pattern goes down, the boredom threshold When a new sound is played the infants interest goes up again, as they can hear the di[erence between the 2 sounds; they recognise that the sounds are not the exact same Categorical speech perception Perception of constant sounds becomes categorical: di[erent categories of sound VOT: time interval between release of consonant and onset of voicing, "ba" and "pa" have a 25msec di[erence in VOT Detection of phonemic change is modiﬁed by experience By 9 months old children ﬁne tune their perception to the language they are growing up in Older infant speech perception Detection of phonemic change and categories is modiﬁed by experience Producing language Learning language is a social experience Infants make a limited set of sounds: 1. Cooing: 2 months 2. Replicated babbling: 6-7 months, the same syllable over and over At 10 months the baby's sounds have adapted to the language it hears, meaning adults can tell which language the baby is leading 3. Variegated babbling: 11-12 months, syllables with di[erent consonants and vowels Producing speech sounds The limited set of sounds created by infants is due to the shape of the infant vocal tract and the development of the motor cortex Early sounds are all made at the front of the mouth Comprehension vs Production Word comprehension (receptive vocabulary) precedes productive vocabulary by an average of 4 months initial acquisition rate for comprehension is twice that of production Even phoneme production lags behind phoneme comprehension (discrimination) The vocabulary burst Major increase in productive vocabulary acquisition rate after the ﬁrst 50 words are learned This is due to the symbolic nature of language, control over articulation and easier retrieval The overextension and under-extension of meaning Under-extension example "dog" only for family dog but not for other dogs Overextension example "dog" to refer to dogs and cats "moon" for orange, lamp, ﬁngernail clipping "milk" for white blanket, puddle When are words overextended? Within the ﬁrst 1-25 words acquired, 45% are overextended When 50 words are acquired, 35% are overextended By 75 words being acquired, 20% are overextended Overextension is more common while infants have very limited vocabulary Why are overextensions made? Words that are easy to produce and are common within the infants environment The word they are trying to look for (cat) has similar characteristics to what they know the word for (dog) Learning to communicate beyond single words Protowords Non-verbal functions of language Such as turn-taking and pitch Holophrases A single word that stands for an entire statement When a child says "water", what do they mean? Early sentences Around 2 years children begin to combine words Children have speciﬁc meaning (semantic) relations they like to convey such as: 1. Possession: my toy 2. Naming: that ball 3. Attributes: big cat 4. Action: go home Later syntactic development By 4 years syntax beginning to resemble adult language is developing Some examples of a 4-year old's language: 1. What planet is England on? 2. I'm going to kick mummy into the sky. Then we'll have no more mummy Todays outcomes Description of sound system: Child ﬁrst learn to perceive and categorise the phonemes in their language, and this knowledge is modiﬁed by experience Children's early babbling forms the basis of their ﬁrst words Description of early developmental language stages Comprehension of words precedes production Word production takes o[ after the ﬁrst 50 words Children's early words or holophrases convey more complex statements Children's initial word combinations convey speciﬁc meaning relations before developing into full adult grammar Lecture 22; language part 3, the origins of language Thursday, 12 September 2024 9:56 AM Nativist views of language Children are biologically predisposed to learn language Language acquisition device (LAD)- core language knowledge, Noam Chomsky- there is already innate capability/mechanism in order to learn language, not enough information to learn it from the environment alone Linked to the theory of the universal Grammer Poverty of the stimulus: linguistic input (stimulus) is not rich enough to explain why children show competence in language, yet: 1. Children acquire language rapidly 2. Children acquire language e[ortlessly 3. Children acquire language without being taught Nativist views: Children resistant to feedback Explicit teaching and imitation is proven to be not how language is learnt Language bioprogram hypothesis children are innately predisposed to acquire the syntax of language, "part or all of the human-speciﬁc capacity for syntax"- Derek Bickerton, 1984 Sensitive period: ideal time for acquiring certain parts of language, with maturational constraints Sensitive period ends by puberty once lateralisation occurs Evidence for sensitive period Isolated children Deaf signers Case study for isolated children: the case of Genie Isolated for the ﬁrst 13 years of her life Struggled to vocalise; not even babbling It was noticed that she didn't understand the need for language Rehabilitation: Intensive language training over many years Di[erent rates of progress seen in acquiring words versus acquiring syntax Content words were there but she was struggling with the Grammer Her bioprogram hasn’t been able to mature and develop which allows her to learn language Case study for deaf signers: Newport 1990 Nicaragua 1998, a school was established for deaf children Main form of communication was lip reading School created community/culture in which sign language was developed by the children in order to communicate with each other Full syntax, less content based language Caused by exposure to other deaf children Understandings Native: exposed to sign from birth Early: exposed to sign at 4-6 years Late: exposed to sign at 12 years Late signers had far more issues and couldn’t reach ﬂuency as easily, proving that the time period you learn language really matters especially when looking at syntax These results were similar when looking at those learning a second language, with a big population that shows this is adult immigrants General learning capacities Alternative views to nativist accounts Children use domain general skills Children have highly developed pattern recognition systems, with evidence from word boundary studies and forming categories Counterargument to poverty of the stimulus claim Learning about word boundaries, Sa[ran et al (1996) Statistical learning; conditional probabilities Children notice patterns and get excited when the patterns di[er Children have highly developed pattern recognition systems Allows children to form language categories through picking up on regularities without resorting to innate language categories Frequent frames: forming language categories from data You _ it: the gap will be ﬁlled by a verb The _ and: the gap will be ﬁlled by a noun Suggests that the children can build these syntactic categories Social learning Argument is that children spend most of their time around other people, and this could be su[icient in allowing them to learn language Response to innate explanations to language learning- poverty of the stimulus argument Parentese: simpliﬁed speech and exaggerated intonation, how parents talk to children Social responding to infant's language attempts Children's vocabularies are strongly associated with the amount of language parents use with their children Social contexts of early word learning Parents let child's behaviour guide their talk Words refer to things; children learn that gaze and objects are connected Early words emerge as parts of social routines Feedback to children varies between cultures Self-construal: self perception Independent cultures Focuses on child-centred talk: caregivers adopt to talked to child's level Internal attributes most salient Self concept separate from group Personal goals will take priority over group goals Interdependent cultures Focuses on situation-centred talk: child learns to adopt to situation Social role most salient Self concept is part of the group Group goals take priority Relationships are crucial Todays outcomes Introduced three theories of how children acquire language 1. Language is innately acquired 2. Children learn language through general learning mechanisms 3. Language is learnt through social interaction Online lecture 8; thinking and decision making Saturday, 14 September 2024 10:54 AM Part One Humans are smart. Why do we sometimes get it so wrong? Salience bias Assessing something as more prevalent if it comes to mind very readily Conformation bias Looking for information that conﬁrms what they already believe, not just stereotyping Conﬁrmation bias in research: testing for a favourite theory Conﬁrmation bias in the diagnostic setting: bias when understanding the cause of distress Darley and Gross (1983): showed participants a video of an oral test, 2 participant groups: Group A: was told girl was from a middle class background, they reported more examples of good answers Group B: was told girl was from a poor background, they reported more examples of bad answers Why do we make these errors: Tversky and Kahneman (1972): suggested that we base most judgement/decisions on heuristics Heuristics: the process by which humans use mental shortcuts to arrive at decisions, quick rules of thumb that work well in most situations, useful as they can be applied rapidly and without a lot of conscious intentional thought The representativeness heuristic: to classify something, we assess how closely it matches our "prototype" for that group Tversky and Kahneman (1982) This shows us the operation of a heuristic, which is not leading us to the optimal decision in this instance, as surely it is more likely for L to be a bank teller than a feminist bank teller Proposed that participants matched L to a prototype, in this case a feminist prototype ﬁtted her far better than a bank teller prototype. If you make the bank teller a feminist, the prototype appears to match better People are making this judgement based on a quick rule of thumb about the likely match between the persons description and some prototype Prototype: a mental representation of an object or concept. A real life example of the representativeness heuristic Woman who had heart attacks we much less likely to have been correctly diagnosed with a heart disease before their attack than men Shows us that woman are less likely to be given the correct information that they are at risk of a heart attack Biases within the diagnoses for a heart attack itself The prototypical heart disease patient is an overweight, middle aged man Doctors are applying what is a prototype of a heart disease patient to match the diagnoses to the person The availability heuristic: the tendency to assess outcomes as more probably if it comes to mind readily This is the core principle underlying the salience bias Can cause us to over assess probability But most of the time heuristics work! Consider this scenario… An experienced driver is chatting to a passenger. A pedestrian appears near the side of the road. Without missing a beat in the conversation, the driver tightens her grip on the steering wheel and gently squeezes the brakes to slow the car; then after a short moment, she releases the brakes and returns to her previous speed Logical thought costs time and mental resources Dan Kahneman's thinking fast and slow Proposes that we have 2 modes of thinking: 1. System 1 (fast) Automatic Draws on concepts, routines and rules of thumb acquired through extensive practice 2. System 2 (slow) Slow, e[ortful Needed in unfamiliar situations, where creativity is called for and where precision is paramount "fast" thinking and expertise Experience builds richer knowledge structures and rules of thumb Visual pattens, patterns of movements/sequential information We can draw on this automatically to shape our behaviour, allowing us to free up our conscious ﬂow of thought to where we most need it Some terms Heuristics: rules of thumb about the world Schemas: mental knowledge structures based on experience Scripts: common action routines Is there a cost to expertise? Berner and Graber (2008) Heuristics are rapid, they may confer overconﬁdence Doctors with over 10 years experience were given case descriptions Each doctor was asked to come up with what they believed to be the diagnoses Some led to high disagreement amongst doctors Asked the doctors to rate their conﬁdence in their diagnoses, with each individual doctor being conﬁdent that they were correct In conclusion Fast/automatic routines guide an enormous amount of our behaviour and judgements They are essential for our day-to-day functioning But we need to be aware of their limitations Part two Thinking In the sense of conscious thought Often experienced as inner speech Can also involve images, music, action sequences or even complex scenarios Makes up only a tiny fraction of all mental activity A working deﬁnition: thinking is the conscious experience of generating mental representations and operating on them in some way So conscious thought is: Resource-intensive Requires e[ort, ﬁltering out distractions What is a thought? When people are at rest in an fMRI scanner, a network of structures "talk" to each other, the "default mode network" The default mode network Mind wandering Integrating past and present Imagination, creative thinking Creating scenarios for future actions, "episodic future thinking" In major depressive disorder the default mode network shows hyperconnectivity Goal-directed thinking A simple example: working memory tasks Main maintain information "online" and work on it in some way Requires mental e[ort such as concentration and avoiding distraction More complex problem solving tasks The tower of Hanoi problem: move the discs to the right peg in as few moves as possible You can only move one disc at a time You cannot put a larger disc on top of a smaller one These tasks engage a wide network of brain structures Two modes of thinking These two modes of thinking involve 2 di[erent networks: 1. Open ended reﬂection: the default mode network 2. Goal directed thinking: the executive control network A neuroscience perspective A thought is a pattern of activity across a widely dispersed range of brain areas At any time, one pattern dominates For many tasks, we need to switch between states Lecture 24; thinking and decision making continued Friday, 20 September 2024 11:55 AM Hot cognition The mental processes involved in making judgements and decisions in situations involving strong emotion Making choices based on preference Responding appropriately in socially sensitive situations Understanding how others might be feeling in a situation Hot cognition can facilitate rapid decisions in these situations Damasio's somatic marker hypothesis This brain region binds memories together with their emotional and physiological associations When faced with a decision, we recall emotions from previous similar actions/situations Bad associations deter us from that action, good associations encourage us Damasio says we use these emotional markers in everyday situations Putting it all together Emotions play a key role in judgement and decision-making by: Guiding our emotions Shaping our decisions Facilitating inferences about others emotional states Ensuring we behave appropriately in social situations Online lecture 9; learning and conditioning Friday, 20 September 2024 12:00 PM What is learning? The most accepted deﬁnition is: "An experiential process resulting in a relatively permanent behaviour change that cannot be explained by temporary states, maturation, or innate tendencies"- Klein, 1996 According to this deﬁnition: 1. There must be a change in behaviour Development of new behaviours Modiﬁcation of old ones Reduction in behaviour 2. The change is relatively permanent 3. Learning is the result of experience Therefore, many instances of behaviour are not examples of learning such as: genetically predetermined behaviours (reﬂexes), changes brought about by maturation and temporary states The major goal of the learning researcher is to establish general principles of behaviour Discovering rules and laws that govern learning across di[erent settings, situations and even species This approach is similar to that of other areas of psychology and science generally Some special features of the area: An emphasis on e[ect of environmental events on behaviour as opposed to genetic inﬂuences Typical subjects are individuals (as opposed to groups) and many studies employ non-human animals as subjects An emphasis on external/observable phenomena (the only way we can infer that learning has occurred is by actually seeing an observable behaviour change) Classical conditioning Classical conditioning is all about learning to associate stimuli (an unconditioned stimulus and a conditioned stimulus) such that we now react to the conditioned stimulus in a way we never did before Through classical conditioning we learn to react to stimuli that predict important events are about to occur In many cases this can be adaptive but it can also be maladaptive An example (Ikemi and Nagakawa, 1962): A person with hypersensitivity to the Japanese wax tree is told: "I'm going to touch your arm with leaves from a wax tree" A harmless leaf is applied to the person's exposed forearm Possible outcomes: A. Person jerks their arm away B. Person reports that their arm itches C. Redness develops on their arm D. Subject develops blisters on their arm Turns out all of the above occur, with this being an example of the basics of classical conditioning Ivan Petrovitch Pavlov Made the observation (through the study of dogs) that a stimulus that should be neutral can come to elicit the same reaction as a stimulus that elicited a reﬂexive reaction John Watson and Little Albert can more complex human behaviours such as emotions and thoughts be conditioned in this way? Little albert was conditioned to fear rats and this was generalised to a fear of everything white and ﬂu[y Basic features of classical conditioning Acquisition Although conditioning can be established in a single trial, typically a number of pairings of a conditioned stimulus with a unconditioned stimulus are required before a conditioned response emerges as a response to the conditioned stimulus alone Stimulus generalisation and discrimination Generalisation: Once a conditioned stimulus has been established, other similar stimuli will also elicit the conditioned response Discrimination: not all stimuli elicit the conditioned response Generalisation allows learning to carry over to new situations/stimuli without requiring further learning while discrimination restricts new learning from being inappropriately applied to all situations Extinction If the conditioned stimulus continues to be presented without the unconditioned stimulus occurring then the conditioned response is eventually eliminated This extinction of the conditioned response only happens if the conditioned stimulus occurs but the unconditioned stimulus does not Therefore a learned conditioned response can persist a very long time if the conditioned stimulus only happens very rarely Lecture 26; learning and conditioning part 2 Wednesday, 25 September 2024 10:35 AM Introduction to operant conditioning (also called instrumental conditioning) Many behaviours are inﬂuenced by the consequences that follow behaviour This type of learning is called operant conditioning Operant conditioning is learning about the relations between environmental stimuli and our own behaviour The basic principle underlying operant conditioning is that "we tend to repeat behaviours that lead to desirable outcomes and we tend to stop performing behaviours that lead to undesirable outcomes" Edward Thorndike and his puzzled cats An animal was placed in puzzle box and the food was placed outside the box, so the cat would have to do a certain action to escape and get to the food Eventually the cat would understand the pattern and what action would get it out Thorndike's law of e[ect If a response in the presence of a stimulus leads to satisfying e[ects, the association between that stimulus and response is strengthened This is still considered a valid description of operant conditioning, however the term 'satisfying e[ects' has been replaced with the term 'reinforcement' B.F Skinner and his rats and pigeons Operant chambers Skinner was interested in how changing environmental events such as the payo[ for level pressing resulted in changes in behaviour Operant changer is a very controlled environment in order to rule out confounding inﬂuences The 3-term contingency: Skinner Describes the relationship between environmental events and behaviour A = antecedent stimulus or discriminative stimulus (a phone ringing) B = the behaviour (answering the phone) C = the stimuli that occur as a consequence of the behaviour, normally just called 'consequences' (a friend starts to talk to you) Stimulus control The relationship between A and B Antecedent/discriminative stimuli set the occasion for responding, as in they signal what behaviour is now appropriate Schedule control The relationship between B and C Skinner said the reason you continue to perform particular behaviours in the presence of particular antecedent stimuli was because you had gained desirable consequences when performing those behaviours in the past We call such desirable consequences Reinforcers However, aversive consequences that reduce the occurrence of a learned behaviour are called punishers Types of consequences Positive Reinforcement A consequence that causes an increase in the rate of responding Although positive reinforcement seems at ﬁrst glance to only apply to very simple aspects of learned behaviour, it also underlies very complex learned behaviours It also forms an important part of many everyday educational practices and intervention techniques for numerous developmental disorders such as autism Negative reinforcement Where responding is maintained or increases as the result of the termination of an aversive stimulus For example: taking aspirin to remove aversive feeling of a headache Positive punishment Also called 'punishment' or 'aversive punishment' When responding decreases as a result of the delivery of an aversive stimulus Punishment, like reinforcement is deﬁned in terms of its e[ects on behaviour- this is di[erent from the way we tend to use such terms in everyday language Problems with positive punishment Most e[ective forms cause pain or discomfort Induces fear and hostility Learn to escape/avoid punishing situation Only teaches you what response not to make Alternatives to positive punishment Use extinction Remove antecedent stimuli that precede the undesirable behaviour Use response cost Response cost Also called 'negative punishment' or 'omission training' A decrease in the frequency of a response that is followed by the termination of, or lack of access to, positive stimuli or events What makes an event a reinforcer or punisher? 1. Primary reinforcers/punishers are events that satisfy an inherent survival need and punishers that are inherently aversive 2. Conditioned reinforcers/punishers are established by our past learning history via classical conditioning Notes The stimuli that acquire reinforcing or punishing properties may be quite removed from primary reinforcement/punishment via second-order conditioning Reinforcers/punishers can also be 'behaviours'. According to Premack (1971) if an organism prefers to engage in response B compared to response A then response B can reinforce A Experimental evidence Premark (1959) Behaviours that result in a preferred response are strengthened Kids were given the choice between eating candy or playing pinball Kids who preferred candy over pinball would play more pinball if it meant they gained access to candy Kids who preferred pinball over candy would eat more candy if it meant they would gain access to pinball Premark (1971) Behaviours that result in a less preferred response are weakened Water deprived rats (rats who preferred water) were put in a motorised running wheel When they drank water, the wheel would start to move. Drinking (preferred behaviour) led to running (less preferred behaviour) Rats stopped drinking even though they were thirsty No matter what the source of reinforcement/punishment is, how reinforcing or punishing it is is determined by: 1. Deprivation 2. Magnitude of event 3. How immediately the consequence is applied after the behaviour Summary tables for exam revision: Reinforcement is when you want to see more of the action Punishment is when you want to see less of the action Lecture 27; introduction to learning and behaviour Thursday, 26 September 2024 9:22 AM Where do new behaviours come from? Are new behaviours: A product of prior learning? Independent of prior learning? Example study Wolfgang Kohler's demonstration of insight in learning in chimps in the 1920s insight means the sudden appearance of an appropriate behaviour without any obvious shaping Shaping Describes the process by which new behaviours emerge For example, learning how to write letters Relies on a couple of things: 1. Di[erential reinforcement of appropriate behaviours and/or punishment of wrong behaviours 2. Natural tendency for behaviour to vary from instance to instance Basic steps 1. Identify pre-shaped behaviour 2. Identify potential reinforcers/punishers 3. Apply di[erential reinforcer/punishment 4. Reinforce successive approximations to a desired behaviour (as behaviour starts to alter change the criterion before reinforcement is given again) The end product may look nothing like original behaviour Behaviours can become more elaborate via chaining A series of behaviours that are functionally linked- engaging in behaviour X provides access to behaviour Y (a secondary reinforcer) which then provides access to a primary reinforcer Shaping underlies all kinds of behaviour For example, shaping also underlies the emergence of superstitious behaviours- behaviours we continue to perform even though they are not really the cause of positive outcomes Behaviour naturally varies, so purely by chance a behaviour can sometimes be accidentally reinforced How does learning transfer to new situations- Generalisation Generalisation is the process by which our behaviours transfer to new situations or stimuli that we did not directly learn about It is an important part of learning (both classical and operant conditioning) by allowing our learning to be adaptive For example, we don’t have to learn separately about every set of tra[ic lights we come across Extent of generalisation depends upon: Physical similarity of stimuli How salient (obvious) the stimuli are Presence of other stimuli Our past learning history Biological constraints on learning What we learn about it not just determined by the environment, genetic factors also inﬂuence what is learned Seligman's (1970) concept of preparedness suggests that though evolution all animals are biologically prewired to easily learn behaviours related to their survival as a species Example A: Taste aversion, Garcia and Koelling (1966) Showed that classical conditioning underlies many taste aversions Organisms are biologically predisposed to associate certain events with others, for example in the case of rates, taste with being sick or visual/auditory appearance with painful event. This is useful in terms of survival Example B: biological constraints on operant trained behaviour, Marian and Keller Breland Observed a number of instances of instinctive behaviours interfering with conditioned responses- instinctive drift For example, pig trained to drop coin in 'piggy bank' would drop coin on ground and root at it with trotter Main overall points from last 2 examples: 1. Sometimes genetic predispositions conﬂict with environmental control over behaviour 2. This does not mean organisms can only learn to associate things we are genetically prepared for, only that it is easier to learn about some things than others 3. Both genetics and environment work interactively to shape out behaviour Know the following for the exam 1. Deﬁne classical conditioning and operant conditioning 2. Be familiar with terminology in both types of conditioning 3. Be able to recognise examples of both types of conditioning and generate your own examples 4. Know how basic conditioning processes can help us understand insight and more complex forms of learning 5. Be able to identify the factors that inﬂuence conditioning Online lecture 10; what is an emotion? Thursday, 26 September 2024 3:38 PM What are emotions? They are adaptive Activate survival mechanisms (for example the feeling of fear) Motivate adaptive behaviour Optimise use of cognitive resources Communicate needs and intentions Classifying emotions Discreet models Basic categories; happiness, anger, sadness, fear, surprise, disgust Blended categories; jealously, awe, contempt, pity, delight Social emotions; embarrassment, shame, empathy, love Intellectual emotions; boredom, curiosity, insight, confusion Homeostatic emotions; hunger, pain, thirst, itch Dimensional models Valence; positive/negative, pleasant/unpleasant Arousal; high/low Motivation; approach/withdraw The basic emotion theories Darwin 'the expression of the emotions in man and animals' When looking at facial expressions and characteristic behaviours there's a lot that would suggest that many animal species have things that look like emotions Not the full range of emotions shown in humans, but at the fundamental core there's a set of emotions that seem to be critical for survival that are adaptive and therefore evolutionarily preserved These same basic emotions appear early in life, which gives us a cue that these may be part of our human genome to promote our survival Ekman- what makes an emotion basic? Emotions are discrete neural/physiological/behavioural states triggered by deﬁned evolutionarily relevant situations Distinctive universal signals Distinctive physiology Distinctive subjective experience Automatic appraisal Distinctive universal triggers Presence in other primates Presence in infants Psychological constructionist theories Emotions emerge from the combined actions of core

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