Sensation and Perception PDF

Chapter 5: Sensation - act opf using sensory systems to detect environmental stimuli Perception - teh conscious recognition and identification Synestesia - involuntary and consistent links or intermixing between their sensory systems Sensory receptor cells - specailized cells that convert a specif...

Chapter 5: Sensation - act opf using sensory systems to detect environmental stimuli Perception - teh conscious recognition and identification Synestesia - involuntary and consistent links or intermixing between their sensory systems Sensory receptor cells - specailized cells that convert a specific form of environmental stimuli into neural impulses Sensory transduction - the process of converting a specific from or environmenal stimuli into neural impulses The limits of the senses: Our sensory receptors can be activated by weak stimuli. A stimulus must reach a certain threshold before it can be detected. The minimal threshold is called the absolute threshold. It varies from person to person. Difference threshold - the minimal difference between two stimuli necessary for detection of a difference between the two Signal detection tjoeyr - theory that teh response to a signal in every situation depends on the individuals ability to differentiate between the signal and the noise Signal detection tehoyr - teh response to a signal in every situtaion depends on an individuals ability to differentiate between two stimuli Surrounded by stimuli:sensory adaptation  - Our senses are generally rganized to detect change. Sensory adaptation - the process whereby repeated stimulation of a sensory cell leads to a reduced response Olfactory adaptation - occurs when a change in sensitivity to a particular odour reaches a point where the odour cannot be distinguished after a prolonged exposure to it Processing sensory information - Perception can occur through bottom up processing, which begins with the physical stimuli from the environment and proceeds through transduction and of those stimuli into neural impulse. - Top down processing - involves previously acquired knowledge, as a result when you look at your best friend face, brain regions that store information can recognize who it is - Perceptual set - readiness to interpret a certain stimulus in a certain way - Perceptual sets may come into play whe we are faced with ambiguous stimuli stimuli that can be interpreted in different ways The senses - Sensory systems are a part of the nervous system consisting of sensory receptors that receive stimulus information and conduct information to parts of teh brain responsible for processing sensory information - Aristotle was the first to claim the 5 senses - Proprioceptive feedback is the unconscious awareness of yeh self and spatial orientation arising from stimulation within the body The chemical senses: smell and taste Olfactory sense - our sense of smell Gustatory sense - our sense of taste Odurants - airborne chemicals that are detected as odours How they work (smell and taste) - Begins when chemicals called odorants enter the nose, they are converted to neural signals at sensory receptors (cilia) located in the nasal mucosa - Olfactory receptor neurons - sensory receptor cells that convert chemical signals into odorants - When odorants enter the nose, these chemicals bind to specific receptors located on the olfactory receptor neurons like a lock and key - When enough odorant molecules bind, the combination starts off an action potential - and this goes to the brain Types of tastes - Smell is closely related to taste, so what we taste is flavour - The tongue is covered in papillae, bumps of taste buds on the tongue  - Taste buds - clusters of sensory neurons that convert chemical signals from food into neural impulses to the brain 5 major types of taste receptors - Sweet, sour, bitter, salty and umami (pleasant savoury taste) - The inputs of the taste receptors is relayed to the brain - Capsaicin - activates pain receptors from the tongue (chili peppers) this combines with smell and taste so the falvours can be pleasant How the brain processes smell and taste - How the Brain Processes Smell and Taste - Olfactory Processing: Smell signals come from olfactory receptor neurons. - Signals travel to the brain via the olfactory nerve. - First stop: olfactory bulb (at the front base of the brain). - Then sent to the piriform cortex for recognizing smells. - Changing Smell Recognition: - The piriform cortex can adapt based on experiences. - People can learn to distinguish similar smells through conditioning (e.g., pairing a smell with a shock). - Emotional Connections: - The olfactory bulb sends signals to the amygdala (emotions) and indirectly to the hippocampus (memory). - Certain smells can trigger memories (e.g., baking reminding you of childhood). Taste Processing: - Taste receptor cells connect to sensory neurons on the tongue. - Taste signals go to the thalamus, then to the cerebral cortex. - The thalamus acts as a relay for most senses (except smell). Reward and Aversive Tastes: - Pleasant tastes (like sweet and salty) activate similar brain areas. - Unpleasant tastes (like bitter and sour) activate different areas. - Integration of Taste and Smell: Taste and smell are processed through separate pathways. - They converge in the prefrontal cortex. - Disgust Response: - The insula cortex processes taste and is linked to feelings of disgust. - Activates with unpleasant tastes, smells, and even repulsive images Development of Smell and Taste Smell at Birth: Newborns can recognize their mother’s scent within hours of birth. They show a preference for their mother’s amniotic fluid odor even before birth. After birth, babies quickly learn the smell of their mother’s milk, which calms them during minor pain. Other scents associated with the mother (like her perfume) can also have a calming effect. Taste at Birth: Newborns have a well-developed sense of taste. They prefer sweet tastes and dislike bitter and sour ones. Babies react positively to sweet substances (leaning in and sucking) but grimace at bitter/sour substances. Changing Taste Preferences: By around 7 years old, children start to prefer sour tastes. Bitter taste aversion usually lasts until young adulthood, when foods like dark chocolate may become favourites. Developmental Changes in Taste Buds: Taste buds develop before birth; newborns have more taste buds than adults. Children have taste buds in more areas (palate, cheeks) than adults, which may contribute to picky eating. The high number of taste buds makes certain flavours seem stronger to children, helping them avoid potentially harmful substances. Individual Differences in Smell and Taste Sensitivity to smells varies widely among people. Some individuals are more sensitive to odours, while others may be less so. Exposure to certain smells in childhood can reduce sensitivity to those smells in adulthood. Individual Differences in Smell and Taste Variation in Smell Sensitivity: ○ People differ greatly in their ability to detect smells. ○ Some are insensitive to strong odors, while others are very sensitive. ○ Early exposure to certain smells can lessen reactions to them in adulthood. Gender Differences in Smell: ○ Females generally have a higher sensitivity to smell than males. ○ Sensitivity can vary with the menstrual cycle, peaking around ovulation. ○ Women’s smell sensitivity decreases after menopause, possibly due to hormonal changes. Variation in Taste Sensitivity: ○ People are categorized into three taste sensitivity groups: Non-tasters (25%): Don’t notice bitter tastes. Medium tasters (50%): Notice bitter tastes but aren’t bothered by them. Supertasters (25%): Strongly dislike bitter tastes. ○ These differences are linked to the number of taste buds on the tongue. Gender Differences in Taste: ○ More women are supertasters compared to men.  ○ Greater sensitivity in women may help avoid harmful foods for themselves and their children. Age-Related Declines: ○ Taste buds begin to decline around age 50. ○ Sense of smell may decline starting at age 60. ○ These declines can lead to reduced interest in food, which can be countered by using spices and offering varied flavors. Smell and taste disorders Ageusia - inability to tase Dysgeusia - taste leaving a foul aftertaste - temporary and associated with cancer treatments Hyposima - reduced ability to detect odours Anosmia - inability to detect odours Migraines, epilepsy and the sensory systems - Specific odour can start a migraine - Some ppl with reflex epilepsy have a seizure after a specific smell - Some people have hallucination called auras during migraine headaches or epileptic seizures The tactile or cutaneous senses: touch, pressure, pain and vibration Free nerve endings - located near the surface of the skin and function to detect touch, pressure, pain and temperature Meissner’s corpuscles transduce information about sensitive touch and are found in the hairless regions of the body, such as the fingertips, lips, and palms. Merkel’s discs transduce information about light to moderate pressure on the skin. Ruffini’s end-organs are located deep in the skin. They register heavy pressure and movement of the joints. Pacinian corpuscles are also buried deep in the skin and respond to vibrations and heavy pressure. Tactile senses and the brain The touching brain - Touch signals travel up the psinal cord to the brain, touch information is first received in the thalamus amd yhen routed from there to the somatosensory cortex - If u touched something on the right ur left side of the brain processes i Pain and the brain - Pain info travels to the brain via two different pain fibres - Fast pathways, which uses myelinated axons - Pain sensed using the fast pathway uses more unmyelinated axons - these inputs communicate with brain regions involved in processing emotions Development of Tactile Senses Tactile Senses at Birth: ○ Tactile senses are present at birth. ○ Fetuses can respond to touch even early in development. Importance of Physical Contact: ○ Physical touch is crucial for healthy infant development, as shown by Harry Harlow’s research. Post-Birth Development: ○ Recognition of different tactile stimuli improves with brain development and learning. Tickling: ○ Tickling can be enjoyable for children, often causing laughter. ○ The reaction to tickling is due to unexpected sensory input activating somatosensory pathways. Sensory Sensitivity: ○ We notice unexpected touches more than familiar ones (e.g., noticing someone else's leg brushing against yours more than your own). Surprise and Defense Mechanism: ○ Reacting strongly to unexpected touches serves as a defense mechanism. Diminishing Enjoyment with Age: ○ Enjoyment of being tickled decreases as we grow older. ○ Adults can better anticipate touch, making them less sensitive to surprise. ○ Tactile sensitivity may also decline with age. Tactile senses: Individual Differences Gate control theory of pain - theory that certain patterns of neural activity can close a gate to keep pain information from travelling to parts of the brain where it is perceived Disorders of the tactile senses Chronic pain -pain that lasts longer than 3 months Researcjers have identified two groups pf chemicals naturally produced by our nervous systems that have pain relieving properties: endorphins and enkephalins - class of molecules called opiates Acute pain - short pain No pain- cannot respons to certain things Phantom limb sensations and pain - People with amputated limbs report non painful tactile hallucinations or phantom sensations of neuropathic pain, including touch, pressure, vibrations, pins and needles, heavy, cold and pain in the body part that no longer exists - When a body part is removed the part of the somatosensory cortex is still in use, instead somatosensory inputs from intact body parts expand to occupy those regions of the cortex The auditory sense: hearing - Converts sound waves into neural impulses - Frequency - the number of cycles the wave completes in a certain amount of time, it is measured in units called hertz - Amplitude - strength of a given cycle, waves with higher peaks and lower bottoms are of higher amplitude that those that do not reach such extremes Tympanic membrane - the ear drum Ossicles - tiny bones in the ear called maleus (hammer), incus (anvil and stapes (stirrup) Oval window - a membrane separating the ossciles and the inner ear, deflections of which causes a wave to form in the cochlea Cochlea - fluid filled structure in the ear containing hair cells Basilar membrane - structure in the cochlea where the hair cells are located Hair cells - sensory receptors that convert sound waves into neural impulses Tonotopic map - representation in the auditory cortex of different sound frequencies Identifying frequency and pitch - Frequency theory suggested different sound frequencies are conveyed into different rates of action potential sor firing in our auditory nerves, so according to this high frequency sounds produce a more rapid firing than do low frequency sounds - Place theory accounts for a greater degree of auditory perception. Difference in sound frequency activate different regions on the basilar membrane - Absolute pitch - the ability to recognize or produce any note on a musical scale Drowning out the noise - Adaptation - adpaty to sounds that we hear over and over again - Hair cells become less sensitive to continuous noises Sounds in space - General loudness - we learn from many early experiences taht loud sounds are usually closer to us that are quiet sounds, so that evntually we automatically use the loudness of a sound to assess the distance between ourselves and teh source of sound - Loudness in each ear - because of the distance between our ears and the presence of the head between our ears, there are slight difference between each ear in the loudness of the same sound wave. The ear closer to the sound hears it louder, good for detecting the place of a sound - Timing - another cue used ot localize the sound is the times each sound waves hit both ears, sound waves reach the closer ear first. Development of hearing - Capable of transducing sound waves before we are even born - Foetuses respond to loud noises with a startle reflex and after birth, they are capable of recognizing some sounds they heard in utero, like their mothers voice Sound adaptation Cocktail part effect - brain picks up on relevant sounds even in a noisy environment Hearing loss - Conduction deafnessoccurs when there is some soty of occlusion or break in the various processes by which sound is transmitted through teh inner ear, wax buildup, infection, ear drum damage or water in teh ear can cause temporary or permanent deafness - Cochlear implants that help individuals work with deafness to hear sounds. - Tinnitus - rining in the ear, due to abnormalities The visual sense: sight - Each sensory system is most receptive to some form of physical energy, taste and smell response to chemical stimuli, touch to changes in temperature or pressure and hearing to vibrating air molecules Seeing the light: - When light enters the iris (colour) adjust the size of the pupil to let in more or less of the light reflected from objects around this - Muscles also adjust the shape of the lens enabling it to bring both near and far objects into focus near and far objects - Retina - contains sensory receptors for vision - Transductions - converts stimulus energy into neural impulses that can be interpreted by the brain Rods and cones Rods - no colour Cones - colour receptors Photoreceptors - the sensory receptor cells for vision, located in the retina Optic nerve - bundle of axons of ganglion cells that carry visual infomrtaion from the eye to the brain Fovea - centre of the retina, containing only cones, where vision is mostly clear Seeing in colour - Hue - experience of colour based on teh wavelength of light that the visual stimulus emits or reflects. Mpost basic aspect of colour, red green orangle blue yellow or some other colour - Saturation - purity of a colour, how bright or how vvid the colour appears - Brightness - how much light emanataes from it Theories of colour perception - Young helmholtz trichromatic theory - maintains that there are three dffernet receptos fir colour and that each type of receptor respons to a different range of wavelengths of light. Correct in people with normal colour vision have three receptor types (cones), eahc senstitci to a particular wavelength. One responds to yellowish red, one to green and one to bluish purple hemi- neglect - damage to the where pathway, people ignore one sid eof their visual field. - Opponent process theory - maintains that colour pairs work to stio one another in teh perception of colour. In the retinal ganglion cells, as well as the thalamus and visual cortex, colour information is analysed in terms of antagonist opponent colour pairs: red-green, yellow-blue and black-white. Colour blindnes s- missing certian cones The brain and sight - Basic visual info is transmitted through the brain via a partially crossed set of axons - Visual info from the middle part of your visual field closest to your nose is sent via axons to the other side of your brain - Once visual info reaches the primary visual cortex it is processed to enable the detection of very simple features such as lines and edges - Directions of complex visual stimuli occurs as a result of circuitry that involves association areas of visual cortex Prosopagnosia - see others like this and would need to recognize their friends by feature other than their face Hemi neglect copies only teh right side of each image Visual perceptual organization Sigure ground perception is used to identify whether something in the visual field is the main object or the background. Proximity - indicates that visual stimuli near to one another tend to be grouped together. Continuity - the law of closure indicates that we tend to fill in small gaps in objects so that they are perceived as whole objects Similarity - the law of similarulity indicates that stimuli resembling one another tend ot be grouped tgetehr so AAaa is viewed as two groups because of the dissimilar appearance of upper and lowercaseletters Binocular and monocular cues Binolaur - uses both eyes Monocluar - uses one eye - We do not see exactly the sam rthing with each eye, this retinal disparity, the slightly different stimuli recorder by the retina of each eye provides is with a binolcuar cue of depth. Our brains use the discrepancies between the visual info from both eyes to help us judge how close an object is - Retinal disparity - slight different in images processed by the retinas of each eyes - Convergence - inward movement of the eys to view objects close to oneself - Monocular - Interposition - when one objects blocks part of another from our view, we see the blocked object as further away - Relative height - see objects yhat are higher in our visuals plane as farther away that those that are lower in the visual plane - Texture gradients - see details of textured surfaces such as the veins in leaves when things are closer - Linear perpseoctives - parallel lines eem to get closer together as they recede, creating the illusion of depth or distance - Light and shadow - we use light as a cue to distance. Objctes that are bright are perceived as closer, whereas shadowed objects are perceived further - Clarity or aerial perspective - we see closer objects with more clarity - Familiar size - once we have learned the sizes of objects such as people or buildings we assume that they stay the sane size, so objects that lok smaller than usual must be farther away than usual - Relative size - when we look at two objects we know are about the same size, if one seems smaller than the other, we see the smaller object as further away - Motion parallax - this monocular depth cue requires that the observer be moving. The relative movement of objects that are stationary against their background gives us an idea of the relative distance Seeing what we expect to see: perceptual constancies Perceptual constancies - our top-down tendency to view objects as unchanging despite shifts in the enviornmental stimuli we receive Size constancy - helps us in depth perceptions. Once we have learnt the size of an object we expect it to stay the same. How sight develops Babies visual acuity is much less than it will be after a few months. By the time babies are 2 months old, visual acuity has improved and infants seem to focus on intently faces, bu their focal range is limited - Continues to improve so by the end of the 8th month their vision is more similar to normal adults Visual loss Strabismus - Typically both eyes coordinate and look in the same direction at the same object at the same time, sending a focused image to the brain. However, in 2 to 4 percent of cases, the eyes are misaligned. This misalignment is called strabismus. Ambylopia - partial or complete loss of vision due to abnormal development of the brians visual cortex in infancy. Caused by one eye focusing better than teh other due to a number of causes, including an extreme refractive error in one eye. Strambismus - lack of coordinated movement of both eyes Chapter 7: Learning Learning - lasting change caused by experience. - Associate learning - learning that involves forming associations between stimuli - Dogs associate their barking as the cause of the retreat of the mail carrier, indicating that not all associations are necessarily accurate reflections of reality. The mail carrier would have moved on whether the dog was barking or not, however the dog associates the mail carrier leaving with its own behaviour. - Making connections - Classical conditioning - Associate two stimuli, eventually responsingbthe same way to both - Operant conditioning - Examine after classical conditioning, we come to associate stimuli witn the consequences that follow - Non-associative learning - learning that does not involve forming associations between stimuli - Simpler, following repeated exposure to a single stimulus or event - Most basic form of learning - Habituation - Organisms decrease response to a stimulus after repeated stimulus presentation, behvaiour. - Dishabituation - Full strength recovery of the habituated response in the presence of a novel - Allows organisms to ignore stimulus Sensitization - Non-associative learning that involves an altered response following the presentation of a single sensory cue. A strong stimulus results in an exaggerated response to the subsequent presentation of weaker stimuli Classical conditioning The association fo events in teh envriionment, therefore when you hear a song you immediately think of a specific event in your life thats associated with that event - Associate learning between two previously unrelated stimuli - Disocved by ivan petrovich pavlov - naturwla reflexes are present at birth and do not need to be learned, hardwrieed into species, like dogs salivate when theres food nearby, but he noticed dogs will start salivating when food isnt present, and they learned classical conditioning. How does classical conditioning work? Unconditioned Stimulus (US): A stimulus that naturally and automatically triggers a response without any prior learning (e.g., food). Unconditioned Response (UR): A natural, unlearned reaction to an unconditioned stimulus (e.g., salivation in response to food). Neutral Stimulus (NS): A stimulus that initially does not elicit a response. When presented together with the unconditioned stimulus, it begins to elicit a response after repeated pairings. Conditioned Stimulus (CS): The neutral stimulus that, after being paired repeatedly with the unconditioned stimulus, eventually elicits a response on its own (e.g., a bell that signals food). Conditioned Response (CR): The learned response to the conditioned stimulus; it is typically similar to the unconditioned response but is acquired through experience (e.g., salivation in response to the bell). Processes of classical conditioning - Pavlov identifiex a number of important porcesses related t classical conditioning. The first of these processes is related to teh acquisition of the assoicared between the conditioned stimulus. - Learning is more robust when the number of CS-US pairings is high. - Timing also plays an important role, occurs when the CS and US occur at the same time Stimulus generalization - what occura when stimuli similar to the original conditioned stimulus trigger the same conditioned response - Sometime important for a difference to be made - like some plants are poisonous and in order to survive we need to be able to differentiate between the two Stimulus discrimination - what occurs when an organism learns to emit a specific behavior in the presence of a conditioned stimulus - Considering pavlovs dog, each dog was conditioned to salivate to the arrival of the lab assistant. - Following the acquisition of the learned association between the lab assistant (CS) and the (US) lets say the bell on teh door becomes apried with the arrival of the lab assistant, even though the bell has never been paried with the meat power, the dogf begins to salivate at the sound of the bell. Higher order conditioning - what occurs when a previously conditioned stimulus functions as if it were an unconditioned stimulus for further conditioning - Observed in advertising, where advertisers often paur their products with sexual imagery Extinction - reduction of a conditioned response after repeated presentations of the conditioned stimulus alone - Information about the CS and US still exists after extinction training is observed by allowing time to pass with no training after extinction has occurred. In this case the CR will often re-emerge at a later date, at up to half the intensity of its original conditioned level, a phenonomien called spontaneous recover. - For example, if the assistant hasnt bbrough food for several visits, and the dogs salivation response has been inhibited by extinction, the dogs might still salivate a week after extinction, when the assistant arrive indicating that the response was not unlearned Spontaneous recovery - re-emergence of a conditioned response sometime after extinction has occurred Classical conditioning and drug dependency - Shepard Siegel at McMaster University focuses on the role of classical conditioning in drugu dependency. Drudge use begins when an individual expefiences the effects of a drug as pleasurable. Drug dependecu involves the psychological and physiological experiences that occur as the individual continues to use the drug; the  body adapts tro the presence of the drug and the idnivudal experiences withdrawl if the drug is reduced to stopped. - Tolerence develops in drug users and abusers as they require increasingly large doses of the drug to obtain the same intensity of effect initially obtained by a smaller dose. Compensatory responses - the enviornmnetal context in which heroin addicts inject thesmelves becomes assocated with their bodies compernsatory responses to the heroin. - The nervous sysetm expects the heroin from the environmental cues Classical conditioning and fears - Involved in drug tolerance, also plays a role in allergic reactions and fear conditioning - John B Watson and roslaie rayner emphsized teh role of environment in the shaping of individuals - He rejected introspection and the study of the conscious and unconscious mind as unscientific, instead advocating for behaviorism, which focuses on observable behavior that can be studied objectively. - Conducted little albert, conditioning albert to fear a white rat by pairing with a loud noise. - After several pairings, Albert began to cry and avoid the rat. Watson also observed that Albert’s fear generalized to other furry objects, like a rabbit, a dog, and even a Santa Claus beard. Ethical and moral reasons - Alberts mother was not informed of this experiment, conducted even the risk of emotional state Phobias - a persistent, irrational, or obsessive fear of a specific object or situation that may arise as a result of fear conditioning - Some belive fear conditioning the the basis of the development of a category of anxiety disorders called phobias. - Extreme, irrational and persistent fears of specific objects or situations, many of which pose little real danger Systematic desensitizatin - a process used to contion the extinction of [hobias through a gradual exposure to the feared object or situation Classical conditioning and taste aversions - Wehn someone learns to associate a specific food with being sick - For example, if you eat something and then feel nauseous or get sick, you might develop an aversion to that food, even if the sickness was caused by something else, like the flu or alcohol. - The food you ate becomes a conditioned stimulus (CS), and the nausea or sickness is the unconditioned response (UR). After this experience, just seeing or thinking about the food can make you feel sick again, even if you know the food wasn't the actual cause of the illness. - Happens very quickly Phobias and the brain - this coloured brain scan of a cross section of the brain reveals increased activity in a phobic individuals amygdala, while the person is looking at a feared object Producing a taste aversion - John Garcia and his collegues used classical conditioning to condition taset aversions in laboratory animals by giving them sociefic foods to eat or drink, and then inducing them with nausea though injection or radiation. - The rats quickly learned taste aversion and this is referred to as the garcia effect. - Form quickly and are very specific, why dont we form an aversion instead to the friends who were with us? We are biologically prepared to form aversions between taset and illness, this biolgical readiness is adpative and rooted in evolutionary history Conditioned aversions and visual cues - birds use visual cues to develop conditioned taste aversions such as aposematic colouring to identify butterflies that produce an illness when eaten Operant conditioning - Passive learning, where the person doesnt know its happening - For example, if a light flashes and then a shock occurs, an animal or person will learn to associate the two, but this learning happens involuntarily. In contrast, most real-life learning is active, where people or animals modify their behavior based on the consequences of their actions. This is called operant (or instrumental) conditioning. - Behaviours that lead to positive outcomes are rpewated and behaviours that lead to negative outcomes are avoided - Thorndikes puzzle box - used a puzzle box to study ooperant conditioning in cats. When the cat accidentally steppedf on a pedal that pulled a string, the cat escape from the box and received a fish rewards. Once the cat has done this once, it cntoniued to repeat the action How does operant conditioning work? - Because of the dominant school in psychology being behaviourism, the systematic study of observable beahviour. Behavioursists believed that behaviour could be objectively studied and measured. They believed that all behaviour could be elarned through stimulus - response associations via either classical or operant conditioning. - Skinner believed that organisms didnt simply respond to the environment; instead they exerted influence on the environment Reinforcemnet - an experiment that produces an increasement in a certain behvaiour - Stimuli are provided in response to the animals bejavour - maing it more or less likely that the animal will engage in the behaviour again. - For example, if a laboratory rat presses a lever and receives a food pellet rewards, the food works as a reinforcer, a consequence that increases the likelihood tat the rat will repeat the bahvaiour or press the lever again. Law of effect - behavouros leading to rewards are more likely to occur again while behaviours producing unpleasantness are less likely to occur Positive reinforcement - presentation of a pleasant consequence follwooing a behvaiour to increase the probability that the behaviour will reoccur Negative reinforcement -removal of an unpleasant stimulus after a response to increase the probability that the behaviour will reoccur Punishment - Decreases the likelihood a response will reoccur, weakening the tendency to make the same response. - Negative punishment - the removal of a pleasant stimulus as a consequence of a behaviour to decrease the probability of the behaviour being repeated - Positive punishment - presnetation of an unpleasant consequence following a specific behaviour to decrease the probability of the behvaiour being repeated Types of reinforcers and punishers Types of reinforcers - Most reiforcers have survival value for organisms and include food, water, sexual partners otr the ability to terminate pain. - Primary reinforcers - satisfy biological needs and are therefore intrinsically pleasurable; that is, if they are rewarding by their very nature - Secondary reinforcers - neutral stimulus that becomes rewarding when associated with a primary reinforcer Types of punishers - Punishers can also be distinguished by whether or not they ae naturally aversive or whether they are learned - Primary punisher - a stimulus that is naturally averisve to an organism - Secondary punisher - a stimulus that becomes averisev when associated with a primary punisher - More effective that punishment as punsihment suppresses the behaviour, but doesnt show them what they should do instead - Reinforcement teaches them what to do in the future - Spanking has ethical concerns, causing them more likley to be aggressive in the future - People start to fear not only the punishment but also the perosn adminestering the spanking - Assocations between the punishment nad the parent Schedules of reinforcement - Continuous reinfocemnet results in rapid learning, but can be easily extinguished Intermittent or partial reinforcement - a schule of reinforcement whether the behaviour is followed by reinforcement only some of the time Continuous reinforcement - what occurs when behaviour is reinforced every time it occur Ratio schedule - reinforcement is based on the number of behavioural responses. In a fixed ratio schedule, a person or animal is rewarded everytime they make a predetermined number of responses. - Fixed ratio schedule - a schedule of reinforcement that occurs after a specific number of responses - Variable ratio schedule - a schedule of reinforcement that occurs when the numbero freposnses required for reinforcement is unpredictable Interval schedule - reinfoecment is based on elapsed time, rather than on the number of behavoural responses. - Fixed interval schedule - a schedule of reinforcement that occurs every time a specific time period has elapsed - Variable interval schedule - a schedule fo reinforcement that occurs after varying amounts of time - Takes longer to train but more effective that continuous reinforcement at maintaining behvaiour Using operant conditioning to teach new behaviours - Instead of waiting for the exact behavior to happen by chance, shaping rewards small steps that lead closer to the desired behaviour - For example, when training a dog to roll over, you might first reward it for lying down, then for turning slightly, and eventually for completing the full roll. This gradual process helps build the complete behavior. - Shaping - introducing new behaviour by reinforcing close approximations of the desired behaviour - Biological constraints - can limit how much an animal can learn. For instance, in a classic study by Keller and Marion Breland, they trained raccoons to put a coin in a piggy bank. But when given more than one coin, the raccoons started rubbing the coins together due to their natural instinct to "wash" food, which interfered with the training. - Breland and breland referred to this inability to produce a conditioned response due to a return to instinctive behaviour, called instrictive drift - Shaping is effective in modifying the behavour of animals and can be used to teach people too - teachers use it all the time Behvaiour modification - Employed to shape the behaviour of people, the behaviour of individuals can be shaped to teach them new academic ro athletic skills or to modify behaaviours that are undesirable - Behaviour modification - a systematic approach to change new behaviours using principles of operant conditioning - Sometimes our prior experiences can cause problems with later learning situations - Learned helplessness - aituatin in which repeated exposure to inescapleble punishment eventually produces a failure to make escape attempts  - If rats couldnt escape the tail shocks initially failed later to learn how to stop a shock to the foot, if rats are given the option of escaping a foot shock by moving to a different area of the cage, many of them fail to do so - Learned helplessness - a situation in which repeated exposure to inescapable punishment eventually rpoduces a failure to make escape attempts Observational learning and aggression - Albert bandura - interested in whether children learn aggression by observing behaviour - Showed children a move of a woman beating up an inflatable clown called a bobo doll, and after the kids played in a room w a bobo doll, those who had previously watched the movie were more aggressive - called vicarious learning - Neuroscientists link observational learning to mirror neurons, which are brain cells that fire both when we perform an action and when we see others perform the same action. Learning and cognition - Implicit learning - the acquisition of information without awareness Spacial navigation - tested through lab rats, trained to navigate through a maze by providivdng them with reinforcement as they move through the maze - Learning that involves forming stimuli relevant to navigating space - Without a reinforcer rats arent motivated to find the quickest route out Latent learning - a form of learning not expressed until there is a reward or incentive Ah-ha - psychologist wolfgang kohler conducted pioneering studies on insight learning - Kohlers chimpanzrrs piles three crates on top of a banana that had been placed out of reach - First contemplated, then stacked and climbed Insight learning - a sudden reliazation of a solution to a problem or leap in understanding new concepts Factors that facilitate learning Timing - Learning facts, known as semantic learning, differs from learning personal experiences, called episodic learning. To improve semantic learning, repetition is key. Multiple exposures to the same material, like reading, attending lectures, and reviewing notes, make learning more effective than just one exposure. Spaced learning, where study sessions are spread out over time, is more effective than massed learning (cramming), which happens all at once. Cramming doesn't give your brain enough time to fully absorb the material and often leads to sleep deprivation, which negatively impacts memory and learning. Context  - Study same place you take test - Studying in a few different places = strong form memories abt the info - Learning in one place and test taking on another makes you less likely to rmbr the info Awareness and Attention - Learning is often enhanced by awareness and attention, though it can occur without them. Many types of learning, like semantic and episodic, require attention. Psychologists have found that attention works differently depending on the situation. - Some attention processes are automatic, like "pop-out", where a stimulus that stands out from its surroundings grabs attention quickly. However, in complex scenes, we use active searching to find relevant stimuli, drawing on memory and cognition (top-down processing). - Attention can sometimes hinder learning when conflicting information is present. A good example is the Stroop Effect, where participants struggle to name the color of a word when the word itself is a different color (e.g., the word "red" written in blue ink). This happens because reading the word is automatic and interferes with the task of naming the color. Stroop effect 1. Identify relevant information: Focus on key topics, especially those emphasized by your professor, and seek out related material during your reading. 2. Avoid multitasking: Focus on one task at a time to improve attention. Avoid distractions like answering texts or watching TV while studying. 3. Active searching: Use this method to locate important material, especially when your professor repeatedly mentions certain topics. 4. Minimize distractions: Studies show multitasking, like using laptops during lectures, lowers comprehension compared to focused learning. Social network and multitasking - Ppl who use social media have fewer hours of studying - Social media in the background negativielly impacts academic performance - A study by Farina Sana and colleagues found that social media use in class not only harms the user’s learning but also affects peers nearby - Students believe the opposite Sleep - Sleep deprivation impairs ability to learn and pay attention - Sleep well Prenatal and Postnatal Learning - Nonassociative learning can occur before birth - In one set of studies, for example, infants who had been prenatally exposed to garlic—through their mothers’ digestion—showed evidence, after they were born, of recognizing the garlic odour. They did not try to avoid the smell, as babies new to garlic typically do (Schaal, 2016). Infant imitation - in a seties of classic studies, meltzoff and moore found that new borns could imitate facial movement such as tongue protrusion mouth opening and lip pursing - Can mirror someone Specific learning disorder - Overly smart ppl too - Overachievers - Many dont have hs diploma - Undetected until grade 5 Specific learning disorder - a disorder that interferes with the acquisition and use of one or more of the basic psychological processes involved in the development of academic skills; oral langugae, reading, written langiage and math Studying reading disorder - Dyslexia - Deficiys in reading comp, written spelling ad word recommendations Mathematics disorder - international diagnotis classifications of dyscalculia Individuals with this have difficulty preforiming simple mathematical equations, recalling math symbols. Counting numbers accurately and quickly recalling mathematical fats or solving word problems. Disorder of written expression - Least understood - Dysgraphia - difficulty communicating in writing, exhibit poor handwriting, struggle w spelling and grammar and have difficulty organizing and expression occurs independently of reading anc communication disorders Disorder of written expression - a disordder experienced as impairment in the ability to create the written word Chapter 8: - Memory is the faculty for recalling past events and past - Encoding - getting information into memory in the first place - Storage - retaining memories for future use - Retrieval - recapturing memories when we need them When you attend a concert, you transform the sights and sound into a memory code and record them in your brain for later, thai will remain in your brain until later retrieval Information processing model - view of memory, suggesting that information moves among three memory stores during encoding, storage and retrieval When we first confront a stimulus, our brain retains a sensory image or sensory memory of it for less than a second. Sensory memories help us keep items that we briefly experience alive a bit longerSensory memories are basically copies of the sensory data we have just received. Visual sensory memories is also called iconic memory, meaning, it is like a small copy of the visual event we java just encountered. Echoic memory - auditory system tha hold info for a short time Sensory memory - the initial stage, briefly holding sensory information from the environment Working memory - working memory is often confused with short tern memory, Proposed by Baddeley and Hitch (1974) as a more complex system for temporary storage and manipulation of information. Subsystems: Central Executive: Manages attention and coordinates tasks. Phonological Loop: Processes verbal information. Visuospatial Sketchpad: Handles visual and spatial information. Episodic Buffer: Integrates information from other subsystems and links it to long-term memory. Role of attention - attention is vital for enhancing specific info while ignoring distractions and maintaining focus during a task Parallel Processing The Parallel Distributed-Processing Model differs from the sequential processing of the information-processing model: ○ New information connects with existing knowledge, forming networks (McClelland, 2011). ○ Baddeley and Hitch found that people could perform different tasks simultaneously without a decline in performance, but struggled when tasks were similar. How do we encode information into memory? - U only rmbr encoded stuff, so dont rmbr the first thing you said today - Automatic processing - encoding of infomrtaion with little conscious awareness of efforts Effortful processing - encoding of inofmrtaion through careful attention and conscious effort - Acquiring new information from a textbook, easily disrupted when you attend to other tasks Encoding information into working memory: transferring from sensory memory  - When we first confront a stimulus, our bran retains a very brief sensory image of it - an image called a sensory memory. - memory involving a detailed brief sensory image or sound retained for a brief period of time - Sperling wanted to demonstrate the presence of a brief visual storehouse - equivalent to the buffer memory of a computer - that would hold a picture of our environment for a very brief period of time, he also wanted to measure how long this buffer would last - In Sperling's study, participants viewed a grid of letters for less than a second and could recall about half immediately. When a tone indicated which row to report and was played within half a second of the letters disappearing, participants recalled all the letters in that row. However, if the tone was delayed by more than half a second, recall declined significantly, showing the limits of sensory memory. Working memory - a short-term memory store that can hold 5-9 items at once. - Rehearsal - repeating info helps ensure its encoded Encoding information into long term memory: transferring working memory inot long term memory. - Eventually reherasah; memory is either passed onto long term memory, or its lost. Best methods of effortful encoding - Understand - we rmbr things better when we can understand what it means - Elaborate - the more we can elaborate teh meaning and make their info personally relevant the better we understand it - Mnemonic devices - Chunking - PQRST (prview, question, read, self-recitation, test) - Use schemas - organize new information according to the categories created by previous experience and learning Long term memory - the memory system in which we hold all of the information we have previously gathered, available for retrieval and use in a new situation or task. - Information is more likely to become long term memory when our rehearsal sessions are spread out over a period of time. This is an example of the spaced practice effect. Spaced practice effect - facilitated encoding of material through rehearsal situations spread out over time In what form in info encoded - phonological code - repeating the sound so the numbers again and again - Visual code - holding an image of how the digits would look in written down - Rely on phonological when recording verbal info and visual when its non verbal info Phonological and visual codes flawed as often the memory of the info is flawed Semantic codes - for verbal info in long term memory. We ;ink the new things we learn to the things we have already memorised. It is defined as cognitive representation of information or an event based on the meaning of the information. - The more meaningful a personal event, the more readily it is encoded and later remembered. The day your grandpa went to the hospital is one you might remember, but going to the mall a random day isn't. - Less meaningful info can become memory if adding meaning to it. - Mnemonic devices - techniques used to enhance the meaningfulness of information as a way of making them more memorable Organising and encoding - When we add or try to elaborate on the meaning of certain pieces, we organise them - Schema - knowledge bases that we develop based on prior exposure to similar experiences or other knowledge bases How do we store memories? Storage in working memory: - Sensory info is briefly stored and then lost or sent on to working memory - Mental maths and working memory - working memory helps us do mental computations The storage limits fo working memory: - Once information enters working memory, it can be stored for just a limited period of time. Rehearsal can strengthen the availability of infomration in owrking memorym but eventualy its either passed into long term memory or its lost. Memory span - maximum number of items that can be recalled in teh correct order Enhancing working memory Chunking - grouping bits of information together to enchacne ability to hold that ifomration in working memory Storage in long term memory - The sensory memory and working memories deal with a limited number of short term meoyr. - Memory must be encoded and briefly stored in wokrng memory, and then encoded inot long term memory, before they can be stored in this memory system What types of memories do we store in long terms memory: Explicit memories - memory that a person can consciously bring to mind, like your middle name Implicit memory - memory that a person is not conscioursly aware of, such as learned motor behvaiours, skills and habits Semantic memory - persons memory of general knowledge of the world - General knowledge and facts Episodic memory - a persons memory of personal events from his life - Personal episodes from our life, like when we leaned to ride a bike How are our long term memories organized? - Pieces of info stored in long terms memory are linked to eachother How do we retrieve memories? - When retrieving info form long term moery, it becomes available again in the working memory system Recalling the past - looking at old family photos is a good way to retrieve infomrayion about family events from previous generations. The photos can serve as retrivela cues for accessing particular episodic memories. - Theoritss believe thst retrieval is like an activation process in which the questions people pose to themselves a tivitate relevant peopoeuce of infomrationthat have been stored in long terms memory. - The reteirval od information from memory is facilitated by retrieval cues, words sights or other stimuli remind us of the information we need. Priming and retrieval - Priming - action of one piece of information, which in turn leads to activation of another piece, and ultimately to the retrieval or a specific memory - Sometimes occurs unconsciously - Recognition tasks - memory task in whic people are asked to identify whether or not they have seen a particular item before - Recall tasks - memory tasks in which people are asked to rpodcue infokrmation using no retrieval cues. Context and retrieval - Easier to retrieve particular inofmrtaion when we return to the setting or situation in which we first encoded it.  - Context - the original location where you first learned a concept or idea rich with retrieval cues that will make it more likely you will be able to recall that information later if you are in that same location or conext - Encoding specificity principle - a theoretical framework that asserts memory retrieval is more efficient when the ifnomrtaion available at retrieval is similar to the information available as the time of encoding Specific retrieval cues - Godden and Baddeley asked trained divers to memorise three list of word son land or 20 feet underwater - participants wrote down 15 digits and then waited for minutes before being asked to retrieve the words that could be recalled, 24 hrs ;ater the participants were asked to recall them, either in the same context or in a different connect. It shows that context is crucial - State dependent memory - memory retrieval facilitated by being in the same state of mind in which you encoded the memory in the first place Emotional memory: rehearsal, elaboration and orgnization - If an event made us particularly happy or distressed, we are better abel to retrieve that information - Important to distrungusih between then direct and deferred effects of emotion on memory - Modulation hypothesis - long lasting emotional effects on memory can eb attrubuted to the activation of teh amygdala, during the encoding of emotion events. Special emotional memory Flashbulb memories - detailed and near permanent memories of an emotionally significant event or of the circumstances surrounding the moment we learned about the event Why do we forget and misremember Theories of forgetting; Decay - theory that suggests that memories fade over time due to neglect or failure to access over long periods of time - Can't account for the repeated finding that people learn seemingly forgotten information or skills much more rapidly the second time around than teh first time Interference - forgetting is influenced by what happens to people before or after they take in the information  - Proactive interference - competing infomrtaion that is learned before the forgotten material, preventing its subsequent recall - Retroactive interfeenrece - learning of new infomrtaion that disrupts access to porviously recalled information Motivated forgetting - we fogret unpleasant embarrassing or painful things - Avoided cues for it, like the walkway it occurred - Repression - process where we unconsciously prevent soem traumatic events from entrerig our awareness so that we do not have to experience the anxiety or blows to our self concept that the memories would bring Distorted or manufactured memories - Our memories can be subject to distortions. Source misattributions - remenbring information but not the source it cam from: can lead to remembering information from unreliable sources as true Exposure to misinformation - retroactive interference often causes us to forget something when we are later exposed to new competing information The effects of imagination - Memories cna also be destroyed by our imaginations, not just from info from others - In one study, a team of researchers asked the parents of undiveristy students to list events that had occurred during the students childhood. - The tsudents were asked to recall these events, along with another event that hadnt actually happened - ¼ students claimed to remember it Memory and the brain Anatomy of memory - No specific place or storehouse - process rather tha [plcae. - Neurons - Prefrontal cortex - important brain structure located just behind the forehead and implication in working memory - Hippocampus - important for teh transfer of memories into long term memories Biochemistry of memory Neural cicuits - Communication throughout the brain processes from neurons to neuron - A give message arrives ta a neuron as an impulse, which travels down the axons ot the neurons, and is then carried by a neurotransmitter across the synaptic space to another neuron - Memory consolidation - process by which memories stabilize in the brai - Potentiation - synchronous networks of cells firing together Long term potentiation- a phenomenon where repeated stimulation of a certain nerve cells in the brain greatly increase the likelihood that the cells will respons strongly to future stimulation - Glutamate - key neurotransmitter in the formation of memories. Memories in the young and old - Babie scan recognize certain objects, even without knowing what teh object is - Babies prefer looking at objects they haevent seen before - preferatial looking - Develop skills hat require memory like stacking blocks. - procedural knowledge which is rarely forgotten - Toddlers forming meoris, but not stored as they wont remember it in a few months time - Your earliest childhood memory is probably linked to something emotional - postively or negatively Prospective memory - ability to rember content in teh future Retrospective memory - ability to remember content from teh past - Hippocampus develops slowly Disorders of memory Amnesic disorders - Loss is the primary sysmption, edperiec e retrograde amnesia, anterograde amnesia or both retrograde amnesia is an inability to rember things that occured before the organic disorder ot event that triggered amnesia - Amnestic disorders - organic disorder in which memory loss is the primary symptom - Retrogade amnesia - inability to rember thinsg tgat occurred before an organic event - Anterograde amnesis a- ongoing inability t form new memoires after an amnesia inducing event Dementias  - Sevre memory problems combine with loss in atleast one other cognitive function such as abstract thinking or language. - Mid neurocognit8ive disorder (MND) is a category resevre for individuals who demonstrate moderate cognitive e declines but who are still able to mange their own everyday activities. - Alzheimers disease - gradully porgressive disease occurs usualyy ftr th age of 65 - Begins with mid memory problems, lapses of attention and difficulties in language an communication, as it gets worse the person cant complete complicated taks or remembering important appointemnets - Neurofibrilary tangles - twisted protein fibres found within teh cells of the hipposcampys and certain other brain areas - Senile plaques - sphere shaped deposits of a protein known as beta amyloid that form in teh spaces between cells in the hippocampus, cerebral coretetx and certain other brain regions. As well as in some nearby blood vessels - Only diagnosed with certaunty after death Gender and ementai - Older woman more liely to dvelelp dementia than men. - As we age, certain conditions in men and women may increase the likelihood of dveleoping demnetai. - Depression and diabetes in woman increase the risk for demntia - Brains of wiman with the disease have more neurofibriliary tangles than men do. - ,en more aggressive and woman more likely to become depressed