Cognitive Neuro PDF

Sept 4th PSY50 cool sounding class Cognitive neuro is FUNCTIONS OF BRAIN AND WORKINGS/BIO OF MIND Various biomedical tech (MRI) Animal and human neuropsychology (patients with brain injury) Understanding natural dynamics of the Brain The Power of Cognitive Neuro ○ The S...

Sept 4th PSY50 cool sounding class Cognitive neuro is FUNCTIONS OF BRAIN AND WORKINGS/BIO OF MIND Various biomedical tech (MRI) Animal and human neuropsychology (patients with brain injury) Understanding natural dynamics of the Brain The Power of Cognitive Neuro ○ The Stroop Task Involves a lot of cognition Perception of colour Decoding if colours, word meaning Inhibit colours word interface Response effector Respond Monitor appropriateness of response, integrate feedback Taken for granted subconscious processes ○ Challenges and opportunities Examining effects of psychoactive drugs for public policy(weed bad for the brain?) Mapping cognitive development to neurological development Theory of mind/ how thinking changes as brain does  Rehabilitating the injured brain and mapping its progress ○ How? What parts of the brain Rehab? Mapping progress of the brain in rehab. Huge implications for neurology Identifying biomarkers(Alzheimer’s disease) HOW?WHY? Biomarker is a biological signature of a condition Allows for treatment earlier Allowing diagnosis as soon as possible COURSE LEARNING OUTCOMES ○ How Cognitive psych and neuro helps promote a more rigorous understanding of human cognitive process than either field alone might ○ The core elements of a range of neurocognitive tools and research designs- including strength/weaknesses. Application of this knowledge ○ The core tenets of major theories in various domains in cognitive neuro (ex., Memory), How to create experiments to test and evaluate ideas ○ How and why primary research articles are organized the way they are, and to develop and apply strategies to effectively understand and consume info within ○ Evaluate whether conclusion reached in studies are appropriate ○ Conceptualize content ○ Identify and articulate the value and contribution of this course MIDTERM 1 (27%) ○ First 4 lectures MIDTERM 2 (33%) ○ Next 4 lectures FINAL (40%)  ○ All lectures, post-midterm 2 textbook readings, and one journal article Multiple choice and short answer Lecture (⅔-¾)> textbook (¼-⅓) weighting Demonstrating foundational knowledge of core ideas, theories and supporting research Applying knowledge of theories and methods to new situations. WHEN IN DOUBT CHECK SYLLABUS Lecture 1 Lecture objectives ○ Describe value and challenges of studying the mind ○ Describe HOW and Why localization of function is an important way of thinking in neuro ○ Articulate multiple, clear examples where localization of function appears to accurately describe brain function ○ Describe concepts of cortical networks and hierarchy in the brain and how they make the LoF idea more sophisticated ○ Articulate why it is fair to characterize cog neuro as a heavily interdisciplinary field, and to provide multiple examples to that effect ○ Educated thoughtful inferences to how the mind works Method of inquiry : introspection(via structuralism) ○ Introspection can’t be used to study mental intricacies ○ Self insight can help better understand emotional processing ○ William Wundt/ Edward Titchenner Method of inquiry: Behaviorism ○ Older theory (psych is the science of behaviour) ○ Shifted towards not the mind as it was believed to be unobservable ○ Value placed on associative learning, forms of conditioning ○ Detailed analyses of behavioural accuracy, reaction time  ○ Referred to as the DARK AGE of psych ○ Allowed for a lot theories still used today but lacking in most Method of inquiry: Cognitivism ○ James McClelland, David Rumelhart (have a book) ○ “Cognitive revolution” rejected the notion that only behaviour should be subject to study ○ Developing complex models of cognition Serial and parallel processing Parallel distributed processing (1986) ○ Serial was the first theory but was found to be too slow for all processes ○ Parallel is believed to be a form of parallel thinking that allows for how fast we compute Lessons from what we’ve learned about cognition ○ Usage and Utility Cognitive resources appear limited( cannot do everything at once) Cognition is important for functioning well in the world ○ Variability There are within-subject differences in cognitive functioning(Within oneself) There are between-subject differences in cognitive functioning( Between 2 or more people) ○ Flexibility Cognitive abilities often change, for better or for worse, with development and/or disfunction  Most cognitive abilities are malleable, at least to some degree Understanding the profile of ability allows us to research next steps. FIRST MEDICAL DOCUMENT ON TREATMENT FOR TRAUMATIC INJURY ○ Edwin Smith papyrus 2500-3000 BC( egyptian) ○ Most early on studies were on soldiers who suffered injuries of war ○ Hinted at localization of function (LoF) ○ Brain has no space to swell When brain swells it leaves no space for metabolic functions Tracking down the seat of the mind ○ Cardiac hypothesis( Aristotle) ancient Egypt Heart was thought to be the seat of intelligence Heart provides oxygen to brain (Brain takes 1 quarter of oxygen) ○ Brain hypothesis (Alcmaeon of croton (490-430 BC) Galen (129-199)) Current way of thinking ○ Descartes(1596-1650) Rationalism Dualism (vs monism) Dualism is when mind and brain are too different to be the same ○ Separate processies Monism (same as brain hypothesis) ○ Brain gives rise to the mind ○ Workings of brain generate mind The pineal gland Reflexes, vision Allows for dualism hypothesized by descartes ○ Only part of the brain that's not (right or left) ○ Reasoning is because there is only 1 pineal gland ○ Didn’t capture really how things worked in the mind ○ Really is just hormonal control The Brain, Blood flow, and cognition ○ Angelo Mosso Study(1846-1910)  What he observed is that anytime something was going on in the environment the brain blood pressure chart would go wild on chart compared to when nothing was happening( Whenever there was a mental task to be done the brain would show activity Blood pressure changes when brain is under activity Brain reacting to info processing This finding turned into critical knowledge for the invention of fMRI, among other things How is the brain organized? ○ Rejection of Golgi’s syncytium proposal ○ The synapse and neural communication (communication between neurons through neurotransmitters) Allows for neurons to communicate with each other electrically or chemically ○ Layers of cerebral cortex Progression of neurodevelopment ○ Two possible theories Aggregate field theory (i.e Pierre Flourens) Localization of function LoF  ○ Pseudoscience of phrenology(Franz Josef Gall 1758-1828) Entire map above^ is wrong Correlation does not always equal causation Awful practice and map Motivated Good science and people to prove it as a false notion ○ Histologically- defined regions (brodmann’s map of the cerebral cortex 1868-1916) Identified histologically defined regions and gave them a number Two areas that are differently numbered means that they are differently layered to each other Evidence for localization of function (1) (Paul Broca 1824-1880) ○ Found subjects with lesions to the brain ○ All patients had damage to the left frontal lobe ○ A portion of the left frontal lobe (Broca’s area) ○ Damage -> Broca’s aphasia Non-fluent output despite intact comprehension (damage can’t speak but can understand Carl Wernicke(1848-1904) ○ A portion of the left temporal lobe (Wernicke’s area) ○  Lecture 1 practice q Sure! Let's solve the questions step by step. --- ### **Multiple-choice Questions** 1. **Which of the following is FALSE regarding the history of psychology and neuroscience?** - **a.** Introspection is a useful yet imperfect tool for analyzing the workings of mental processes. - **b.** Cognitive functions may be modifiable under the right circumstances. - **c.** Controlling for other factors, parallel processing tends to be more efficient than serial processing. - **d.** Behaviorism was deeply damaging to the field of psychology and contributed little to nothing to our understanding of human functioning. - **e.** None of the above. **Answer: d. Behaviorism was deeply damaging to the field of psychology and contributed little to nothing to our understanding of human functioning.** - **Explanation**: While behaviorism had limitations, it wasn't "deeply damaging" to psychology. In fact, behaviorism contributed significantly to our understanding of learning, reinforcement, and conditioning. The statement is exaggerated and false. 2. **The most consequential outcome from the end of phrenology was the:** - **a.** Advancement of the concept of localization of function. - **b.** Division of the cerebral cortex into 52 distinct regions based on histological properties. - **c.** Rejection of the brain hypothesis for localization of the mind. - **d.** Accurately identifying the function of a variety of brain regions. - **e.** None of the above. **Answer: a. Advancement of the concept of localization of function.**  - **Explanation**: Phrenology was debunked as pseudoscience, but the idea that different brain regions have specialized functions persisted and led to the scientific exploration of brain localization, which is one of its main legacies. --- ### **Short-answer Questions** 1. **Cognitive psychology and neuroscience operated separately for quite some time before coming together as cognitive neuroscience. Explain how each field could operate independently of the other and argue why it is optimal for them to operate together (8 points).** **Answer**: - **Cognitive Psychology's Independence**: Cognitive psychology could operate independently because it focused on understanding mental processes like perception, memory, and decision-making. Early cognitive psychologists used behavioral experiments, introspection, and computational models to infer the workings of the mind, without needing to reference the brain’s biological mechanisms. - **Neuroscience's Independence**: Neuroscience, particularly before modern imaging techniques, focused on studying the brain’s anatomy, physiology, and biochemistry without needing to understand how these structures correlated to specific mental functions. Techniques like lesion studies and electrophysiology allowed neuroscientists to explore brain function independently of cognitive theories. - **Optimal Together**: It is optimal for them to operate together because cognitive neuroscience bridges the gap between mind and brain. This combination allows us to: - Map specific cognitive processes to brain structures and functions (e.g., using fMRI to see which areas of the brain activate during memory tasks). - Gain a deeper understanding of both the brain’s biological basis and cognitive processes.  - Move beyond mere behavioral observations to a mechanistic understanding of how the brain enables cognition, thus giving us a more comprehensive picture of human behavior. 2. **(a) Provide three distinct, compelling pieces of evidence in support of localization of function (3 points), and then (b) make a clear and compelling argument about whether the idea of localization of function is compatible with Luria’s notion of cognitive networks (6 points).** **(a) Evidence for Localization of Function**: 1. **Broca’s Area (Speech Production)**: Damage to Broca’s area, located in the left frontal lobe, leads to Broca’s aphasia, where individuals struggle to produce speech but can understand language. This shows localization of language production. 2. **Wernicke’s Area (Language Comprehension)**: Damage to Wernicke’s area, located in the left temporal lobe, results in Wernicke’s aphasia, where individuals can produce fluent speech, but it lacks meaning, showing the localization of language comprehension. 3. **Phineas Gage Case (Personality and Executive Functions)**: Phineas Gage, who suffered damage to the frontal lobe, experienced drastic personality changes. This case supports the idea that the prefrontal cortex is responsible for personality and decision-making, providing evidence for localization of executive functions. **(b) Argument: Compatibility of Localization of Function with Luria’s Cognitive Networks** - Luria’s notion of cognitive networks suggests that while certain brain regions have specialized functions, they do not act in isolation. Cognitive functions are the result of interactions among multiple brain areas that form functional networks. - **Compatibility Argument**: The idea of localization of function is compatible with Luria’s model. While specific areas, such as Broca’s or Wernicke’s area, are essential for certain cognitive tasks, they work as part of larger networks. For example, language processing involves not just Broca’s and Wernicke’s areas but also other regions involved in auditory processing, memory, and attention. - Localization identifies the "hubs" or key areas for specific functions, but Luria’s networks emphasize that cognition is more complex and distributed across the brain. The two concepts are not contradictory but rather complementary: brain regions can have specialized roles within broader, interconnected networks.  Lecture 2 Lecture objectives ○ To explain the overall process by which neurons send signals using both electrical and chemical transmission ○ To describe how MS, ALS and stroke impair neurotransmission ○ To identify the major pathways (and functions) of the spinal cord in the central nervous system ○ To identify some of the major regions(and their associated functions)of the human cerebral cortex, as well as various subcortical areas ○ To understand anatomical directional terms (e.g, dorsal) and to apply this knowledge to discuss where a brain region is relative to another ○ To describe the roles of the ventricular and cerebrovascular systems in supportings brain functioning The “glue” of the nervous system: glial cells ○ Glial cells are thought of as the glue of the nervous system ○ They help bind together the brain to facilitate neural functioning and help neurons do their job ○ Astrocytes Functions Helps compose the blood brain barrier Chemical gating mechanism by which you can keep out things that may be toxic to our nervous system Early versions help create a scaffold to help build the brain in babies as the nervous system matures in the mothers womb Response to injury ○ Will release certain chemicals that will facilitate the stopping of the injury and trying to stabilize neurological functioning as best as possible (stroke or trauma) ○ Oligodendrocyte  Supports neuronal transmission Insulates neuron transmission and helps ensure that signal reaches end of axon ○ Schwann Does the same insulations but outside of the brain and the spine(arms and legs) ○ Microglial cell Scavengers of the neuro Gobble up dead and dying neurons to remove problematic neurons ○ Neurons ○ Transmits signals from one part of the neuron to the other Motor neurons Carry motor information Sensory neurons Carry sensory information and turn it into a neural signal Interneurons Wide variety of information Power house unit of the brain Makes up 90% of the neurons ○ ○ Triggering an action potential The signal being sent is always to the same degree It’s not how strong the signal is it's always how many(e.g, when something is loud more signals are sent not a higher signal) ○ Propagation of the signal down the axon  If signal starts at the beginning it would start from left to right Myelin sheath insulates the signal (oligodendrocyte) As the signal travels through the axon it beings to become weaker so the nodes of ranvier are there to reinforce the signal This makes it seem like it's jumping from node to node otherwise known as saltatory conduction ○ Myelin degradation and neural failure Multiple sclerosis(MS) Myelin degradation presumably due to autoimmune disorder ○ As it degrades and weakens not only does it itself fail but it may also cause underlying damage to the axon itself neurodegenerative ○ 55000-75000 in canada Canadians have one of the highest rates of multiple sclerosis in the world Symptoms depends on the area of myelins being degraded ○ Degradation in temporal lobes will result in loss of memories ○ Can affect motor pathways which can affect being able to walk or move Important our myelin works well  ○ Motor neuron disease and neural failure Amyotrophic lateral sclerosis (ALS) Rapidly progressing upper and lower motor disease that results in death ○ 2500-3000 in canada ○ Steven hawking had ALS ○ Electrical failure and neural failure Ischemia When someone has a stroke it is a massive issue to the brain, the brain takes up about a quarter of total oxygen and as a result it is very sensitive to lack of oxygen Ischemia is the most common form of stroke ○ Through lack of exercise or diet arteries develop plaque which don't allow for enough blood to pass to the brain  When a blood vessel is blocked the downstream neurons get into trouble quickly, because they need oxygen to create action potentials, if we deprive oxygen then the ion fluxes(actions potentials) enter a dark period called electrical failure If action is not taken immediately it leads to neural death ○ Chemical transmission The process by which one neurons communicates to an adjacent neuron When action potential travels down the axon and reaches the terminal: ○ The terminal allows in calcium ions It's important because calcium comes in and binds to vesicles ○ Then it moves its way into the terminal and dumps out its neurotransmitters into the synapse(space between 2 neurons)  The neurotransmitters migrate across the synapse to the other neuron that the initial neuron wants to communicate with This causes a membrane potential change that may excite it or prohibit it Neurotransmitters ○ Dopamine Sites of production Substantia nigra Ventral tegmental area (VTA) Select links to cognition/behaviour Higher order cognition ○ Short term memory, working memory ○ Plays a crucial role in protecting our ability to focus on a certain piece of information and keeping it in mind to use it E.g Remembering a phone number to call it later Voluntary movement ○ Basal ganglia Plays a role in choosing to move or not Like gas to a car Reward/reinforcement learning  ○ When you do something and it feels good it would make a lot of sense to remember that that happened so that if you can do it again you do. Dysfunctional levels associated with Parkinson’s ○ A disease that destroys the substantia nigra which is where dopamine is produced leading to movement impairment or loss Psychotic thoughts/behaviour ○ Schitzo hypothesis is that high levels of dopamine attribute Addiction ○ Altered levels of dopamine is apparent in various forms of addiction ○ Norepinephrine Site of production Locus coeruleus ○ Projected broadly in the corpus and cerebellum Select links to cognition/behaviour Cognitive arousal/attention ○ Crucial role in control of attention Memory and mental flexibility ○ Being able to pay attention facilitates ability to remember something  ○ Plays an important role in recognizing if you have to change a decision or action norepinephrine facilitates the ability to contemplate other options and change your behaviour as appropriate Mood ○ Plays a crucial role in mood regulation Dysfunctional levels associated with Alzheimer’s disease ○ Not just attention and memory but mood changes and irritability that come with dementia Mood disorders ○ Depression and bipolar Lower levels in depression Higher in bipolar Visuospatial neglect ○ Serious attention impairment Not aware of most things going on in their world ○ Associated strongly to degradation or damage to the norepinephrine distribution system ○ Serotonin Site of production Raphe nucleus Select links to cognition/behaviour Mood ○ Antidepressant helps serotonin work in the synapse longer than it would otherwise Seems to help boost mood ○ Plays a crucial role in mood Dysfunctional levels associated with Mood disorders Psychotic thoughts/behaviour ○ Certain psychedelics can cause massive surges in serotonin that can affect your understanding of reality ○ Acetylcholine(Ach) Site of production Basal forebrain Select links to cognition/behaviour Sensory processing/attention ○ Analysis of visual information ○ Ability to control attention in your mind Learning and short term memory ○ Plays crucial role in learning and long term and short term memory Movement (peripheral nervous system -PNS) Dysfunctional levels associated with Alzheimer’s disease ○ Biggest link Most common med given With cataclysmic drop to ACH it creates alzheimer Medicine is given to increase those levels Myasthenia gravis (PNS)  The “game” of psychopharmacology ○ The challenge An individual's baseline level of a neurotransmitters may vary from person to person Neurochemical levels can be affected by a multitude of things such as hormones ○ Yerkes dodson curve What this shows is that “medium” amount of neurotransmitter is the best for optimal life and performance The graph shows that we can have problems if we have too much of a neurotransmitter or too little as well ○ Interactions with other NTs If I increase the level of serotonin i may increase the level of dopamine as well If I throw a boulder into a pond I would also get the splash ○ Effect of other factors (e.g, hormones)  The cycling of hormones Women as a function of their menstrual cycle have oscillating hormone levels that can interact with certain neurotransmitters ○ Some considerations Where does a person fall along the curve? Because there's variability across people that's not always easy How to figure out best medication Prescription ○ Using already known information we can prescribe medication thats the best possible start Observation ○ Patient observes whether the medication is working and how they feel Refinement ○ If it doesn’t work or it’s not good enough we may prescribe either more or less Major descending motor tracts ○ Corticospinal tract (Pyramidal tract) Starts in frontal lobe/cerebral (motor) cortex and descends into spine, descends down through medulla, then crosses over the body through the medullary pyramids ○ Rubrospinal pathway Smaller but may be a part of the reason why we are able to recover function when having a injury ○ Tectospinal Helps control head and neck movement ○ Vestibulospinal Important for helping you balance ○ Reticulospinal Important role in muscle tone Keeping muscles ready to take action when receiving signals  ○ Major ascending somatosensory tracts ○ Touch information ○ Medial lemniscal tract Plays important role in helping you transmit touch information to the brain Also carries proprioceptive information Sense of knowing where your body is in space ○ E.g knowing if you're standing up ○ Even if you can't see at the time ○ Lateral spinothalamic tract Carries pain information as well as temperature information ○  Gross anatomy of the spinal cord ○ Ventral refers to motor information ○ Dorsal refers to somatosensory information ○ Dermatomes of the human body ○ At the top of the spinal cord you have motor and touch fibers that carry info for the entire body ○ At the bottom of the spinal cord you have nerves that control the bottom half of the body ○ Dermatome map is the map of spine nerves Dermatome is each nerve ○ Can be helpful for doctors to identify problems The brain ○ Gyrus (plural: gyri) Bulges in the cortex ○ Sulcus(plural:sulci) Creases in the cortex  ○ Cerebral cortex and white matter tracts White matter is myelinated axons and neurons Gray matter is the unmyelinated pars such as cell body ○ A look at inter individual cortical variability Study tried to keep 4 same sex same age same mental history subjects and yet brain is still not even close to similar Important to create maps of the brain to think about how cognition works An approximate map that idea relates to more people than not ○ The four lobes of the cerebral cortex Frontal lobe Constitutes ⅓ of the brain Voluntary motor control Speech production Higher order cognition ○ Working memory ○ Controlling behaviour Parietal lobe Somatosensory cortex ○ Touch information Attention control and construction of mental space Occipital lobe Only dedicated to vision Temporal lobe Important to auditory processing ○ Consists of the auditory cortex Crucial role in speech comprehension ○ Wernicke's area Crucial role in memory ○ Creating new memories as well as helping represent those memories for years to come  ○ Watch lecture for more info on this ○ In frontal lobe motor control gets more space ○ In sensory cortex senses get more space ○ We know less about the association areas because of how complex the areas are  Navigating the human brain ○ Planes of view Sagittal Profile view of the brain ○ Side view Axial/horizontal Top down/ birds eye view  Studies often show brain orientation through this view Coronal The view through the front or the back The human limbic system ○ Corpus callosum Band of white matter or myelinated axons that connect the right and left side of brain ○ Thalamus Sensory relay station Every sense except for smell synapses onto the thalamus before going to the cortex Associated with the ability to be conscious ○ Hippocampus Crucial role in creation of new declarative or conscious memories Part of a memory circuit ○ Damage to a different part of that circuit affects memories aswell ○ Amygdala Important to emotional processing ○ ○ Coronal and transparent views of the brain showing the basal ganglia Basal ganglia Made up of 3 structures ○ Caudate nucleus ○ Putamen ○ Globus pallidus Plays a crucial role in control of voluntary movement ○ This is where the substantia nigra projects its dopamine to ○ Needs dopamine to control voluntary movement in a purposeful deliberate and consistent way Procedural knowledge is controlled by the basal ganglia ○ Plays a big role in learning new skills Swinging a baseball bat, playing guitar, etc If it doesn't have dopamine the way it normally does diseases like parkinsons may show up  ○ Hindbrain(cerebellum) Motor control and motor coordination area Helps smooth out movements ○ E.g plays a crucial role in appropriate reach distance when reaching for something Contributes to cognition as well Involved in ○ Language ○ Memory ○ Higher order cognition You are able to rewire the brain when born without a cerebellum Protecting the brain ○ Ventricular system A set of chambers in the brain filled with fluid Help keep brain buoyant ○ Shock protection mechanism ○ Mitigates likelihood of damage from non traumatic movements ○ Plays a role in waste removal and even delivery of nutrients in some cases  If a person has a bleed in the brain you can test for that through the spine because you share the same fluid system between the brain and the spine Lateral ventricle Third ventricle Fourth ventricle ○ The Brain’s power supply ○ Cerebral vasculature Anterior cerebral artery Front ○ Medial part of frontal and parietal cortex Middle cerebral artery Covers the entire lateral surface of the cortex ○ Covers the frontal lobes ○ Parietal lobes ○ Almost occipital area ○ Temporal lobes ○ Biggest cerebral distribution Most of the blood flow goes in the brain relative to the other two distributions Posterior cerebral artery Covers entirety of the occipital lobe and most of the medial temporal lobe  If there was damage to the posterior cerebral artery we may see problems with vision and blindness These arterial distributions supply blood and oxygen rich nutrients to different parts of the brain, and those distributions being distinct as they are helps doctors hypothesize or speculate about where an injury might be Lecture objectives ○ To understand how neurons send signals using both electrical and chemical transmission ○ To describe how MS, ALS, and stroke impair neurotransmission ○ To identify the major pathways(and functions) of the spinal cord in the central nervous system ○ To identify some of the major regions(and their associated functions) of the human cerebral cortex, as well as various subcortical areas ○ To understand anatomical directional terms (e.g, dorsal) , and to apply this knowledge to discuss where a brain region is relative to another ○ To describe the roles of the ventricular and cerebrovascular systems in supporting brain functioning Lecture 2 Summary: Cellular and Gross Neuroanatomy **Main Topics Covered:** *Neurons and Neurotransmission (Micro Level):** ○ Neurons send signals through both electrical (action potentials) and chemical (neurotransmitter release) processes. ○ Glial Cells**: Support cells of the nervous system, playing roles in maintaining homeostasis and supporting neuron function. - **Multiple Sclerosis (MS)**: An autoimmune disorder affecting myelin, causing neural failure. - **Amyotrophic Lateral Sclerosis (ALS)**: A progressive motor neuron disease, leading to neural failure and eventual death. - **Stroke (Ischemia)**: Disruption of blood flow leading to electrical failure in neurons. 2. **Neurotransmitters:** - **Dopamine**: Produced in the substantia nigra and ventral tegmental area, linked to cognition, movement, and reward. Dysregulated in Parkinson's disease, addiction, and psychosis. - **Norepinephrine**: Produced in the locus coeruleus, associated with arousal, memory, and mood disorders. - **Serotonin**: Produced in the raphe nucleus, influencing mood and disorders like depression. - **Acetylcholine**: Linked to sensory processing, memory, and movement. Dysfunction in Alzheimer's disease and myasthenia gravis. 3. **Psychopharmacology Considerations:** - Focuses on how neurotransmitter levels influence behavior and cognition. - **Yerkes-Dodson Curve**: Indicates that optimal performance occurs at a moderate level of arousal, too much or too little impairs function. 4. **Spinal Cord Pathways:** - **Motor Pathways**: Include descending tracts responsible for voluntary movement. - **Sensory Pathways**: Include ascending tracts transmitting sensory information to the brain. 5. **Cerebral Cortex and Subcortical Structures (Macro Level):** - Discussion of the **cerebral cortex** regions (lobes) and their functions: frontal (decision-making), parietal (sensory processing), occipital (vision), and temporal (auditory processing). - **Limbic System**: Key to emotion and memory. - **Ventricular System and Cerebrovascular System**: Vital for protecting the brain and supplying it with nutrients. 6. **Brain Anatomy:** - Directional terms (e.g., dorsal, ventral) and their use in navigating brain structures. - Imaging methods for understanding brain structure (DTI, MRI, etc.). 7. **Approaching Exam Questions:** - Multiple-choice questions often require careful reading and eliminating false options. - Short-answer questions benefit from outlining and focusing on key elements, using strategies like RIOT (Read, Identify, Outline, Transition). --- ### Study Notes: #### 1. **Neurons and Neurotransmission:** - **Electrical Transmission**: Action potentials triggered by ion exchange. - **Chemical Transmission**: Neurotransmitter release at synapses. - **Diseases**: - **MS**: Affects myelin sheaths, disrupting signal transmission. - **ALS**: Targets motor neurons, causing muscle paralysis. - **Stroke**: Interrupts blood flow, leading to neuron death. #### 2. **Key Neurotransmitters**: - **Dopamine**: Movement, reward; dysfunction in Parkinson’s and addiction. - **Norepinephrine**: Arousal, attention; dysfunction in mood disorders. - **Serotonin**: Mood regulation; dysfunction in depression. - **Acetylcholine**: Memory and movement; dysfunction in Alzheimer's. #### 3. **Spinal Cord and Brain Pathways**: - **Motor Tracts**: Control voluntary movement. - **Sensory Tracts**: Relay sensory information to the brain. #### 4. **Brain Anatomy**: - **Cerebral Cortex Regions**: - **Frontal Lobe**: Executive function, decision-making. - **Parietal Lobe**: Sensory integration. - **Occipital Lobe**: Vision. - **Temporal Lobe**: Hearing and memory. - **Limbic System**: Emotion and memory center. - **Ventricular System**: Cerebrospinal fluid circulates to cushion the brain. - **Cerebrovascular System**: Supplies oxygen and nutrients to brain tissue. #### 5. **Approaching Exams**: - **Multiple-Choice**: Focus on eliminating wrong options through careful analysis. - **Short-Answer**: Use RIOT: Read, Identify, Outline, and Transition from outline to structured response. --- By reviewing these points, you can better grasp both the cellular and gross neuroanatomy aspects discussed in this lecture, as well as strategies for effectively tackling exams in cognitive neuroscience.  Lecture 2 prac questions Here’s a solution to the questions from your Neurotransmission and Neuroanatomy practice document: --- ### **Multiple-choice Questions:** 1. **Which is FALSE regarding glial cells?** - **a.** Microglia help remove dead or dying neurons from the nervous system. - **b.** Schwann cells myelinate neurons in the spinal cord and the peripheral nervous system. - **c.** Astrocytes help form the blood-brain barrier, which protects the brain from many foreign toxins. - **d.** Oligodendrocytes and Schwann cells have a similar overall function with respect to supporting neurotransmission. - **e.** Options A, B, C, and D are all true. **Answer: b. Schwann cells myelinate neurons in the spinal cord and the peripheral nervous system.** - **Explanation**: Schwann cells **only** myelinate neurons in the **peripheral nervous system (PNS)**, while oligodendrocytes myelinate neurons in the **central nervous system (CNS)**, which includes the brain and spinal cord. 2. **With respect to neurotransmission:** - **a.** The neurochemical cause of Parkinson’s disease seems to be a lack of acetylcholine. - **b.** The only neurochemical linked with mood is serotonin. - **c.** Dopamine is the only neurotransmitter associated with memory functioning. - **d.** Overactivity of histamine at the neuromuscular junction could cause twitching and spasms. - **e.** None of the above.  **Answer: e. None of the above.** - **Explanation**: - Parkinson’s disease is associated with a lack of **dopamine**, not acetylcholine. - **Serotonin** is linked to mood, but other neurotransmitters like **dopamine** and **norepinephrine** are also involved. - **Dopamine** plays a role in reward and motor control, but **acetylcholine** and other neurotransmitters like **glutamate** are crucial for memory. - Histamine doesn’t act at the neuromuscular junction; **acetylcholine** does. 3. **If Patient K.J. had a stroke in a major cerebral artery that resulted in damage to the primary visual cortex, it would be fair to hypothesize that the stroke may have occurred in this distribution:** - **a.** Anterior - **b.** Posterior - **c.** Middle - **d.** Lateral - **e.** None of the above. **Answer: b. Posterior.** - **Explanation**: The primary visual cortex is located in the **occipital lobe**, which is supplied by the **posterior cerebral artery**. --- ### **Short-answer Questions:** 1. **(a) Describe the difference between primary and association cortices (2), and (b) explain where each type of cortex may be found in the brain (4). (c) Offer three distinct impairments that could result from primary cortex damage, and three for association cortex damage (4).**  **Answer:** - **(a) Difference**: - The **primary cortices** are directly responsible for processing basic sensory input (e.g., vision, sound) or motor output. They handle direct information from sensory organs or motor neurons. - The **association cortices** integrate and interpret this information. They are involved in higher-order processes like recognition, decision-making, and planning. - **(b) Locations**: - **Primary cortices**: - Primary visual cortex (occipital lobe). - Primary auditory cortex (temporal lobe). - Primary motor cortex (frontal lobe). - **Association cortices**: - Visual association cortex (next to the primary visual cortex in the occipital lobe). - Prefrontal cortex (involved in executive functions, part of the frontal lobe). - Parietal association cortex (involved in integrating sensory information). - **(c) Impairments**: - **Primary cortex damage**: 1. **Blindness** from damage to the primary visual cortex. 2. **Deafness** from damage to the primary auditory cortex. 3. **Paralysis** from damage to the primary motor cortex. - **Association cortex damage**: 1. **Agnosia**: Inability to recognize objects (e.g., visual agnosia from damage to visual association areas). 2. **Aphasia**: Language impairment (e.g., damage to Broca’s or Wernicke’s area). 3. **Executive dysfunction**: Difficulty with decision-making and planning (from damage to the prefrontal cortex). 2. **(a) Name and briefly describe the meaning of the six anatomical directions we described in class (3), and (b) use only the following neurological structures to demonstrate correct use of each of the directional terms: frontal lobe, parietal lobe, occipital lobe, temporal lobe, basal ganglia (3).** **Answer:** - **(a) Anatomical Directions**: 1. **Anterior (Rostral)**: Toward the front of the brain. 2. **Posterior (Caudal)**: Toward the back of the brain. 3. **Dorsal (Superior)**: Toward the top of the brain. 4. **Ventral (Inferior)**: Toward the bottom of the brain. 5. **Lateral**: Toward the sides of the brain. 6. **Medial**: Toward the middle of the brain. - **(b) Examples**: 1. **The frontal lobe is anterior (rostral) to the parietal lobe**. 2. **The occipital lobe is posterior (caudal) to the temporal lobe**. 3. **The parietal lobe is dorsal (superior) to the temporal lobe**. 4. **The temporal lobe is ventral (inferior) to the parietal lobe**. 5. **The basal ganglia are medial compared to the occipital lobe**. 6. **The temporal lobe is lateral to the basal ganglia**. --- Let me know if you need further explanations or additional details!  Lecture 3 Neurophysiology: Single cell recordings ○ Electrophysiological methods are used to identify the response characteristics of cells in the visual cortex ○ ○ Not only can you study sensory processing you can study cognitive if you're careful with it ○ Neurophysiology: lesion studies  ○ Damage can make it hard to understand which areas cause the problem Lesion studies allow for specific damage to certain parts of the brain which allows for greater experimental control Parietal lobe lesion Affects ability to reach Affects ability to link what we see to our motor function ○ Lesion studies allows to see cause and effect of partial damage to certain areas which allows for better diagnosis on larger brain lesions Cognitive neuroimaging ○ Medical uses [Clinical] Identifying pathophysiology(cause of neurological impairment- e.g., tumor) Focusing on identifying a medical condition that is problematic Localizing anatomical and/or functional disruption(s) Identify how brain networks work differently after brain injury ○ Basic research uses [experimental] Examining healthy (and impaired) brain topography [structural analyses] Looking at structure doesnt mean its working the way you might neuro typically expect Examining healthy (and altered) brain functioning [functional analyses] Computerized Axial Tomography (CT scan) ○ Computer needed to reassemble all information ○ Axial: a way of viewing our brain (birds eye view) ○ Tomography is a slice, scanning slices of your brain ○ 3d x-ray Gives detailed information about body tissue and allows for the ability to reconstruct the model of tissue in more depth Different tissues in our body absorbs different amounts of radiation Able to recreate an image that reflected absorption rates ○ Enormously important to emergency medical aid On a ct scan if you are bleeding in the brain it shows white Crucial way of getting a quick and non invasive view into the brain ○ Limitation  Not a sharp image Doesn’t show grooves Exposing patient to radiation Unable to do such scans repeatedly ○ White is skull Black is fluid glands Structural Magnetic Resonance Imaging (sMRI) ○ Transformative on all aspects of the body ○ Structural: physical aspects of the body ○ Magnetic : relies on powerful magnetic properties ○ Imaging: getting a picture of body or brain ○ Resonance: a signal given off body tissue ○ Incredibly complex Patient is in a strong magnetic field (very very powerful 60k times more powerful than earth's magnetic field) When inside the protons in the body begin to go along with the magnetic field Introduce a radio frequency pulse to knock them out of alignment(resonance)  And by doing this we are measuring the signal resonance gives off when you knock protons out of alignment Takes 90 seconds 7 tesla scanners 200k times more powerful than earths magnetic field  Correlating brain structure (using sMRI) with behaviour ○ ○ Brain space quantifiable in voxels(volumetric pixels) ○ Specifying the size of a brain lesion using voxels To learn how big an injury can be To learn the size of a brain area ○ Correlating brain lesion size to neurobehavioural phenomena ○ Lesion overlap method : common impairment, common damage  Overlap heatmap scans on top of each other to find commonalities ○ Invaluable to understanding the brain Diffusion tensor imaging (DTI)(still uses MRI machine) ○ Water generally moves freely when unrestricted but will move more readily along a path. Able to look at water diffusion by voxels and create a brain pathway imaging ○ Indirect measure of brain pathways ○ Able to isolate specific white matter tracts in the brain ○ Able to track neuro development ○ Able to track brain injury ○ Quantifying fractional anisotropy(FA) on a voxel by voxel basis Way to put a number on it scientifically so you're able to quantify it Stronger FA value should be a stronger neural pathway Electroencephalography(EEG) ○ Listening to electrical signals ○ Ceph is the head ○ Electrodes placed on multiple areas of the scalp Each electrode generates a recording channel More electrode, more recording channels Means more to analyze Solid temporal resolution( but weaker spatial resolution) Important to epilepsy and seizure research Doesn't tell you exactly where brain activity is coming from(spatial resolution) ○ Can’t tell you specifically which gyrus its coming from ○ Computing event related potentials (ERPs) from EEG data By having lots of trials it increases validity of experiment Averages the electrical activity to create an ERP Allows for elimination of outliers Crucial importance of many trials, trial averaging Exploring ERP signal properties  N400 is a brain wave that recognizes when a language mistake happens Electrocorticography (ECoG) ○ EEG Directly on brain ○  Functional Magnetic Resonance Imaging (fMRI) ○ Neurovascular coupling Blood flow and neural changes happen together Brain needs more oxygen to do more things The magnetic properties of oxygenated and deoxygenated hemoglobin differ (~1990s) The BOLD signal Blood Oxygenation Level dependent How much oxygen rich blood is going to the brain ○ More blood more neural activation ○ Solid spatial resolution, weaker temporal resolution Can only take a scan once every second which is a lifetime in the brain ○ More dominate ○ The challenge of interpreting brain data  ○ ○ Yellow increased BOLD signal ○ Blue is decreased BOLD signal ○ Always going to see activity but if we don't have a study or research method its useless Applying the subtraction method ○ If you showed 2 pictures and the second one (control) has no colour we are able to control brain activity/see brain areas that are sensitive to colours when seeing different colours.  Studying patients with brain injury ○ Just because brain areas become active doesn't necessarily mean it is used ○ When studying brain injury you are able to eliminate random correlations and are able to deduct that a particular part of the brain serves a particular function Studying brain dysfunction: Transcranial Magnetic Stimulation (TMS) ○ Creates a magnetic field  ○ Knowledge of pre-”injured’ state Temporary induction of dysfunction, repeatable ○ Able to disrupt or enable brain activity as if the brain was damaged To then see what that disruption results in E.g finger twitching Able to measure how good you are at certain abilities right now and then you can measure how much it impairs yourself, Able to use this to study particular parts of the brain that brain injury simply wouldn't allow ○ ○ Would not qualify if you have a history of seizure or epilepsy  Lecture 3 Prac Questions Here are the solutions to the Cognitive Neuroscience Methods practice questions from your document: --- ### **Multiple-choice Questions:** 1. **Which is FALSE regarding how structural neuroimaging methods could be used to link to cognition?** - **a.** You could measure the link between white matter thickness and typical cognitive changes. - **b.** You can examine if temporary disruption of one brain area affects other brain areas. - **c.** You could work to correlate the volume of a brain lesion to the degree of cognitive difficulty someone is experiencing. - **d.** You could examine whether a common brain structure is damaged in a given acquired neurological disorder (i.e., unable to create any new memories). - **e.** Options A, B, C, and D are all true. **Answer: b. You can examine if temporary disruption of one brain area affects other brain areas.** - **Explanation**: Structural neuroimaging methods, such as MRI or CT scans, focus on the anatomy of the brain, like volume, thickness, or lesions. Temporary disruption of brain areas (which suggests techniques like TMS) would be studied with functional methods, not structural methods. 2. **ECoG allows you to:** - **a.** Monitor blood flow changes for a given brain region. - **b.** Examine how disruption of a brain region alters cognition and behavior. - **c.** Quantify the size of a brain lesion after an injury has occurred. - **d.** Examine brain activity without the signal loss that occurs through the skull.  - **e.** None of the above. **Answer: d. Examine brain activity without the signal loss that occurs through the skull.** - **Explanation**: ECoG (Electrocorticography) measures brain activity using electrodes placed directly on the cortex, avoiding the signal loss that occurs when using EEG, which places electrodes on the scalp. Options a, b, and c refer to other methods (fMRI for blood flow, TMS for disruption, and structural imaging for lesion size). --- ### **Short-answer Questions:** 1. **Prof. T.R. is interested in exploring the neurological basis of memory creation. Use this context to demonstrate the goal/value of each of the following techniques, and then how each could be used to serve his cause: DTI, fMRI, and TMS (12 points).** **Answer**: - **DTI (Diffusion Tensor Imaging)**: - **Goal/Value**: DTI maps the diffusion of water molecules in the brain to study white matter pathways, which are critical for connecting different brain regions. - **Application**: Prof. T.R. can use DTI to examine the integrity of white matter tracts involved in memory creation, such as the pathways connecting the hippocampus to other memory-related structures (e.g., prefrontal cortex). - **fMRI (Functional Magnetic Resonance Imaging)**: - **Goal/Value**: fMRI measures brain activity by detecting changes in blood flow (BOLD signal). It can be used to identify brain regions active during specific cognitive tasks, such as memory encoding and retrieval.  - **Application**: Prof. T.R. could use fMRI to monitor brain activity in real-time while participants engage in memory tasks. This would help pinpoint the brain regions involved in memory creation, such as the hippocampus and medial temporal lobe. - **TMS (Transcranial Magnetic Stimulation)**: - **Goal/Value**: TMS temporarily disrupts activity in specific brain regions by applying magnetic pulses. This allows researchers to test whether certain areas are necessary for a cognitive function. - **Application**: Prof. T.R. could use TMS to temporarily disrupt the activity of the hippocampus or related areas to see how it affects memory formation. This would provide causal evidence about the role of specific brain regions in memory creation. 2. **Prof. M.S. is interested in studying emotion regulation. (a) Offer a conceptual definition of what emotion regulation is (3), and (b) provide two distinct operational definitions for how you might implement a manipulation of emotion regulation (8). (c) How might you measure emotion regulation (as a dependent variable) to distinguish between poor and effective regulation (4)?** **Answer**: - **(a) Conceptual definition**: Emotion regulation refers to the ability to manage and modify one’s emotional responses to achieve desired outcomes. This involves consciously or unconsciously influencing which emotions one experiences, when they are experienced, and how they are expressed. - **(b) Operational definitions**: 1. **Cognitive Reappraisal Task**: Participants could be asked to watch emotionally charged video clips. One group is instructed to use cognitive reappraisal (reframing the content to lessen emotional impact), while a control group watches without any instructions. This manipulates emotion regulation by instructing participants to consciously alter their emotional responses. 2. **Suppression Task**: Participants could be instructed to suppress their facial expressions while viewing emotionally provocative images. This measures emotion regulation by seeing how well participants can control their outward emotional displays.  - **(c) Measuring emotion regulation**: 1. **Self-report scales**: After the tasks, participants could complete a questionnaire, such as the Emotion Regulation Questionnaire (ERQ), to assess their perceived success in regulating emotions. 2. **Physiological measures**: To objectively distinguish poor from effective emotion regulation, physiological indicators such as heart rate variability (HRV), skin conductance, or cortisol levels could be measured. Effective regulation might be associated with lower physiological arousal, while poor regulation would show heightened arousal. 3. **Prof. K.B. is interested in exploring brain regions that support visual recognition. She designs an fMRI study with three conditions where participants see either pictures of human faces (HUMAN), pictures of animal faces (ANIMAL), or a control condition where participants stare at a blank screen (CONTROL). (a) Comment on the overall scientific value of her research aim (3), and (b) If you conducted the subtraction method by performing [HUMAN – ANIMAL], what would the resulting brain activation reflect (and why?) (5).** **Answer**: - **(a) Scientific value**: - The research aim is valuable because it explores how the brain processes different categories of visual stimuli. Visual recognition is a crucial cognitive function, and understanding how the brain distinguishes between human and non-human faces can provide insights into specialized neural processing. This study could also shed light on areas like the **fusiform face area (FFA)**, known to be involved in facial recognition. - **(b) Subtraction method [HUMAN – ANIMAL]**: - The resulting brain activation would reflect brain areas specifically involved in recognizing human faces, but **not** animal faces. This is because subtracting the brain activity from viewing animal faces removes the common elements of face processing (e.g., shape, eyes), leaving activation related to what distinguishes human faces from animal faces. Likely, this would highlight the **fusiform face area (FFA)**, which is known to be more responsive to human faces than non-human faces. --- Let me know if you'd like further details or clarifications on any specific part! Lecture 4 Lecture Objectives ○ To describe how visual information goes from transduction in the eye to terminating in primary visual cortex(V1) in the occipital cortex, and to describe how disruption along the way can affect vision ○ To understand the engagement properties of V4 and V5 using both functional neuroimaging and a patient approach ○ To articulate how information complexity changes along the pathways towards the temporal lobes ○ To describe the idea behind the phenomenon of synesthesia, and identify how structural and functional neuroimaging may help us elucidate the mechanisms behind this experience ○ To apply your understanding of conceptual and operational definitions to task creation that could be compatible with neuroimaging From sensation to perception ○ Distinction between sensation and perception  Sensation is the physical process of taking energy from the environment and turning it into a neural signal, a message or a form of info the brain can understand Transduction is the description of that exact process ○ We have this processes for all of our senses, different senses have different types of neurons designs to capture that energy ○ E.g we have specific neurons in our eyes to capture different light energy Perception is our brains interpreting the transduction signals so that we understand what is in the physical environment ○ How does the brain do this? Seems so easy and so effortless But is quite complicated when we sustain damage to our neurological system ○ Gross anatomy of the eye ○ Retina is incredibly good at capturing information Light info enters eye to the back of the eye called the retina ○ Image refracts through lens into the photoreceptors of the eye through the optic nerve The reason we don't lose informations through neuron transfer is because the neurons are translucent so light can pass through them The Info is then lead to reception through receptor cells which is aggregated through axons ○ We have fewer axons leaving the eyes because information is consolidated by bipolar and ganglion cells We lose a modest amount of info through this but not a high degree of loss It exits the eye though the blind spot ○ ○ If a retina fully detaches you will develop blindness in that eye Can happen with high blood pressure, diabetes, etc ○ Device meant to mimic what the retina would do Allows restoration of vision in ways we haven't seen before ○ Primary projection pathways of the visual system Visual fields captures in both eyes Optic chiasm  Responsible for peripheral vision When you develop pituitary gland tumors it pushes down on the optic chiasm leading to tunnel vision showing us it's responsible for processing peripheral vision Simplifies visual processing ○ Chiasm allows for processing to be on one side (E.g, left visual field fully processed on right side of brain Through crossing Lateral geniculate nucleus ○ Part of thalamus responsible for visual processing ○ If you sustain damage to this area you would not be able to see through your right eye as the information would not be properly processed Pulvinar nucleus ○ 15% of visual information goes through this and into a brain stem called the superior colliculus Superior colliculus ○ Important for controlling eye movement and reactivity with the pulvinar pathway Right visual field is processed in left hemisphere and vice versa ○ Blind spots caused by brain injury  Retinotopic mapping on primary visual cortex Reflects what retina has captured information ○ The middle part of retina is called the fovea which is what you clearly see/look at Lot of machinery dedicated to analyzing that information Injury to the retinotopic map results in scotoma corresponding to that location ○ Scotoma is a blind spot ○ The map between where I damage on my brain and the effect it has on vision is perfectly predictable ○ If entire left occipital lobe is destroyed you would lose vision to the right ○ If the entire occipital lobe is damaged you would have something called cortical blindness which is blindness through the brain not the eyes Hemianopias caused by visual system damage  ○ DO NOT NEED TO KNOW BUT GOOD TO KNOW ○ Congenital blindness (eye dysfunction) and possible brain reorganization When born without being able to see When they learned braille later in life they used the occipital lobe ○ The lobe got remapped for touch when normally it would only be used for vision The resolution was so good that you can map which part of the lobe was responsible for which body part ○ If you are born with vision and lose it you will never be able to have this form of neuroplasticity as your brain was already beginning to create specializations for vision ○ Discovering the colour processing center(V4)  How does our brain process colour? What does the brain do when eyes are open vs closed ○ When open and taking visual info in compared to reyes are closed you are activating the occipital lobe A study was done by Zeki in which he showed participants 2 pictures, one with colour and one in grey scale ○ When he did the subtraction he identified a specific part of the occipital lobe called visual area 4 (v4) Exceptionally important for visual analysis of colour ○ Isolating colour processing center of the brain ○ Follow up research show the v4 area is sensitive to colour constancy E.g, if you change the light around a cup the colour of the cup doesn’t change V4 area is crucial for recognizing that an object doesn’t change colour despite different lighting circumstances  When you show correct correlative colours to an object such as blue on a blueberry vs a red blueberry you activate additional areas including V4 Areas that help understand what the object is you’re looking at or it looks good etc When shown false colours your brain doesn't understand what it's looking at ○ The more we pay attention to a colour the more activation we see in the V4 The more attention we give something the better we’ll be able to process it Attention can help v4 more intricately analyze colour More attention you pay more it activates  Able to map on v4 where we see colour in visual space Location of where the colour happens in space matters too ○ Just like vision if we have colour in the right side of the visual field we process it in the left side of the V4 and vise versa, just like vision Cerebral Achromatopsia ○ When damaging only one side of the V4 you would have cerebral achromatopsia in which you would only be able to interpret colour on the side that's undamaged. You would still see it through your eyes but not be able to interpret it due to damage  Almost always caused by stroke ○ If you have this kind of damage You don't enjoy eating because it looks disgusting “You eat with your eyes” No sexual interest desires as flesh “looks disgusting” ○ You can even have specific damage to part of v4 and just have only part of the field be impaired Arrow represents lesion Graph shows the only difficulty ○ Lesion overlap technique Allows us to see that although the damage is in similar areas it still doesn’t fully result in same results ○ Discovering the motion processing center (V5) Important in processing of visual motion When people think that something that isn't moving is actually moving they activate V5 E.g, illusory hypnotic circles ○ When shown such pictures brain scans show that V5 activation even though the photo is not moving at all V5 activation overlaid on an sMRI scan V5 is on the lateral part of the cortex so we can use brain stimulation to see what happens when we tweak an areas (TMS)  ○ When stimulating V5 using tms and asking subjects to determine which direction an object is moving we see the answer plummets to chance(luck). ○ Disrupts the ability to understand motion ○ When stimulating other visual areas you don’t come across that problem ○ Specificity of V5 neurons ○ Neurons code(judge) Direction Speed Speed is coded by how many signals sent ○ Faster is more signals  ○ Severe cerebral akinetopsia Rare and usually not the only damage Usually occurs with damage to both frontal lobes You cannot judge movement reliably If you only damage V5 on one side you don’t get akinetopsia Everyday things become difficult and you can’t live independently It would look like snapshots of reality instead of continuous smooth movements Visual information gets increasingly complex as we march through the visual pathway  ○ Synesthesia ○ One sensory experience is automatically crossed with another sensory experience Developmental condition Far more common in females than males Far more common in left handers Prevalence estimates vary widely ○ A few of many types Grapheme colour (letter to colour) You are able to see colors in letters (E.g, A is red) ○ Brain reconstructs visual feedback as if those letters are those colours Chromesthesia(sound to colour) Hearing things and seeing colours Spatial sequence synesthesia See numbers in space ○ As if they are just floating in front of you Auditory tactile When you hear something and then feeling something very different Mirror touch synesthesia When you see someone else being touched you feel like you're being touched as well  ○ Linking fMRI and DTI in grapheme colour synesthesia People with GCS have a stronger connection between colour area of the brain and the letter area of the brain If the connection can be formed in GCS then maybe it can be formed in the other types of synesthesia as well ○ It appears to be true (E.g, sound and touch sensory areas seem to have a stronger connection) Multisensory integration ○ The McGurk effect When you see one thing and hear another you tend to reply on vision more than what we hear Designing experiments ○ Suppose im a researcher interested in working memory(WM) load Why is it important to study? Working memory is important is because it allows us to understand how we hold information in mind in order to use it to make decisions and guide action Articulating a clear conceptual definition (dictionary definition), and then operational definition  Conceptual definition of working memory is your ability to hold information in your mind from moment to moment in the service of making a decision Operational definition is how you might consider it in the context of an experiment