Lecture Notes 305 Learning Objectives PDF

LECTURE 1: Introduction to Human Neuroscience ============================================= **LEARNING OBJECTIVES:\ ** 1. 2. **OBJECTIVE ONE:\ ** - - - - - **OBJECTIVE TWO:** - a. i. b. - Our discipline only really works in the case of one-to-one and many-to-...

LECTURE 1: Introduction to Human Neuroscience ============================================= **LEARNING OBJECTIVES:\ ** 1. 2. **OBJECTIVE ONE:\ ** - - - - - **OBJECTIVE TWO:** - a. i. b. - Our discipline only really works in the case of one-to-one and many-to-one mappings; however, we may solve the other problems as time moves on. +-----------------------------------------------------------------------+ | LECTURE 2: Foundations of Human Neuroscience | | ============================================ | +=======================================================================+ | **LEARNING OBJECTIVES:\ | | ** | | | | 1. Identify some of the major conceptual milestones in the history | | of human neuroscience and some of its philosophical underpinnings | | | | 2. | +-----------------------------------------------------------------------+ | **Antecedents of Human Neuroscience** | +-----------------------------------------------------------------------+ | **RENÉ DESCARTES (1596 - 1650)** | | | | - - - - | | | | - - - - - - | | | | **THOMAS WILLIS (1621 -1675)** | | | | It makes much more sense to think of the STUFF of the brain as more | | important than the ventricles themselves (given the fact that after | | brain damage, their behaviour may change despite the ventricles being | | undamaged). | | | | - - - | +-----------------------------------------------------------------------+ | **Dubious Origins: Phrenology (-- and Localisation!)** | +-----------------------------------------------------------------------+ | - - - - - - | | | | - | | | | **IDEAS & EVALUATION:** | | | | 1. 2. 3. | | | | What went wrong? Probably the measuring tool? Somewhat -- but rather | | **they completely guessed / intuited the psychology!** | | | | - | | | | Consider reading The New Phrenology (misguided but helps as a | | reminder) | | | | - | | | | **"SCIENTIFIC PHRENOLOGY"** | | | | - - - - - | | | | - - - - - | | | | - | | | | - - - - - | | | | - - - | | | | - - - - | | | | **JOSEPH WHITWORTH, ALFRED KUPP, JAMES PARIS LEE, and TATSUJI | | INOUYE** | | | | - - - | | | | - - - | +-----------------------------------------------------------------------+ | | +-----------------------------------------------------------------------+ | Roy and Sherrington (1890) noticed that blood volume in local regions | | of the cerebral cortex increased in response to nerve stimulation. | | | | - - - - | | | | - - - - | +-----------------------------------------------------------------------+ | **Microanatomy** | +-----------------------------------------------------------------------+ | **CELL THEORY --** 1830s biology | | | | - - - | | | | | | | | - - - | | | | - | | | | **Santiago Ramón y Cajal** conducted more experiments with Golgi's | | stain, exploring the architecture of the central nervous system in | | multiple animals and carefully logged + drew what he saw. | | | | - - - - | | | | **THE NEURON DOCTRINE** | | | | - - | +-----------------------------------------------------------------------+ | **CYTOARCHITECTURE** | +-----------------------------------------------------------------------+ | **Korbinian Brodmann (1868 - 1918)** took the Cajal project one step | | further -- he looked for anatomical variation from region to region | | across the brain | | | | - - - | | | | - | | | | The **thickness** of these layers differed from region to region of | | the brain, and had different layering structures (tldr; different | | microanatomy) -- suggesting these portions had different functions / | | priorities! | | | | - | | | | Brodmann's areas are still used as a navigational tool (e.g. we might | | say a person has a lesion in area 10). | | | | - | +-----------------------------------------------------------------------+ | ### **THE ELECTRICAL BRAIN** | +-----------------------------------------------------------------------+ | **HANS BERGER & EEG (ELECTROENCEPHALOGRAPHY) --** | | | | - - - | | | | - - | | | | - - - | | | | Lord Adrian recreated the study in Oxford some time later and | | pronounced it brain activity, so then EEG became 'mainstream'. | | | | **NEURAL ELECTRICAL FIELD** | | | | Pyramidal cells in layer 3; one part of the cell is positive/negative | | with respect to the cell (generates an electrical field that can be | | recorded) | +-----------------------------------------------------------------------+ +-----------------------------------------------------------------------+ | LECTURE 3 + 4: The Functions of Neural Oscillations | | =================================================== | | | | IAN | +=======================================================================+ | **LEARNING OBJECTIVES:** | | | | *Lecture 3* | | | | 1. 2. 3. 4. | | | | *Lecture 4* | | | | 1. 2. 3. | +-----------------------------------------------------------------------+ | **Oscillations** | +-----------------------------------------------------------------------+ | - - - - - | | | | **WARD (2003) --** available on canvas in modules, overview on | | oscillations | | | | - | | | | Different oscillation frequencies integrate activity over different | | distances; | | | | - | | | | | | | | - | | | | **Background Reference Signal for Cell Discharge** | | | | - | | | | *PLACE CELLS* -- "Place cells are **neurons in the hippocampus that | | fire when an animal visits specific regions of its environment"** | | | | - - | | | | **Phase Precession** -- **The** **gradual shifting of preferred | | neural spiking relative to local field potentials** (LFPs) | | | | - - - | | | | Coding in *Time* -- a rat has been trained to par press for a reward, | | but they only get a reward after a certain amount of time has passed. | | The cells in the hippocampus will code for this passage of time by | | precessing on the background theta wave. | | | | **TIMING / COINCIDENT ACTIVITY** | | | | - - - - | +-----------------------------------------------------------------------+ | **Integration, Segregation (Segmentation) -- Lecture 3 Objective 4** | | | | - - | | | | - - - - - | | | | There is also a theory that working memory in humans is controlled in | | a similar way -- the separate gamma rhythms hold different memory | | components; all of these lump together on a theta wave | | | | - - | +-----------------------------------------------------------------------+ | ### **OSCILLATION GENERATION** | | | |  | | | | **Oscillation Generation** involves three mechanisms: | | | | 1. a. | | | | 2. b. c. | | | | 3. d. | +-----------------------------------------------------------------------+ | ### **DELTA \> 4 Hz** | | | | Delta appears to involve neocortex (generation) and can be easily | | generated by excitatory excitation and recurrent inhibition. You | | don't even really need a whole brain to generate delta signals. | | | | - - | | | |  | | | | **Delta in dream recall** | | | | There appears to be a frontal reduction in delta activity period to | | successful dream recall. | | | | **Go / No-Go Task** | | | | - | | | | **Non-related Words** | | | | - - | +-----------------------------------------------------------------------+ | ### **THETA 4-7 Hz** | | | | - - - - | | | | Theta is an important presence as a 'background' wave | | | | - - - | | | |  | | | | **Is there a relationship between grid cells and place cells?** | | | | - | | | | Theta waves help bind regions of the brain together; **MISSING NOTES | | HERE** | | | | **THETA AND SPATIAL MEMORY IN HUMANS** | | | | Maguire et al.'s taxi driver studies (1996) | | | | - - - - | | | | Kahana et al. (1999) -- is theta involved in navigation? | | | | - - - - | | | | Student study - asked participants to navigate through Doom maps, | | although they were actually given a trail | | | | - | | | | Scientific community has reasonable evidence that the human | | hippocampus performs similarly to a rat hippocampus. | | | | **THETA AND RECOGNITION MEMORY** | | | | Aggleton and Brown (1999) vs Most of North America (heated debate) | | | | - - - | | | | Squire suggested there is no difference between these two processes - | | they're the same thing (memory) at different strength. | | | | So, two tasks were devised to test whether these are separate | | processes: | | | | **RECOLLECTION TASK:** words or pictures serially presented, % repeat | | in trial. Make an old/new judgement. | | | | **RECALL --** make an old/new judgement from a previously learnt | | list. | | | | FINDING: In the recollection vs. familiarity; there were quite clear | | and significant differences in where these were occurring, consistent | | with the pathways devised by Aggleton and Brown... | | | | **THETA AND MEMORY SCANNING** | | | | - - - - - | | | | - - - | | | | If we gave more items, the theta amplitude was higher | | | | - - - - | +-----------------------------------------------------------------------+ | ### **ALPHA** | | | | - - | | | | Worden et al., 2000 | | | | - - - | | | | - | | | | Alpha is also shown to reflect temporal **resolution** of perception | | -- | | | | - - - - | +-----------------------------------------------------------------------+ | ### **BETA** | | | | Seems to be involved in motor tasks. | | | | - - | | | | Also present during higher level object perception / | | conceptualisation | | | | - | | | | Two generation loops: | | | | 1. 2. | | | | - | | | |  | | | | **Go / No-Go --** | | | | - - | | | | - | +-----------------------------------------------------------------------+ | ### **GAMMA** | | | | Involved in segregation of place cells and working memory segregation | | of items (see gamma/theta nesting). | | | | - - | | | | Experiment compared whole and broken grating | | | | - - - | | | | Tallon-Baudrey and Bertrand (1999) | | | | - - - | +-----------------------------------------------------------------------+ +-----------------------------------------------------------------------+ | LECTURE 5: Synaptic Mechanisms of Memory | | ======================================== | +=======================================================================+ | **LEARNING OBJECTIVES:\ | | ** | | | | 1. 2. 3. 4. | +-----------------------------------------------------------------------+ | **MEMORY --** | | | | - - - | | | | - | | | | **DISTRIBUTED MEMORY STORAGE** | | | | - - | | | | | | | | - | | | | | | | | - | | | | The picture of Eric codes in this network such that the outputs of A, | | B and C get altered | | | | - - - - | | | | - - | | | | | | | | - | | | | Below -- a visual demonstration of this storage and memory strength | | | |  | +-----------------------------------------------------------------------+ | ### LONG-TERM POTENTIATION | +-----------------------------------------------------------------------+ | **How do these weights get stored at synapses?** | | | | Donald Hebb suggested memories are stored by coincident pre and | | post-synaptic activity | | | | - | | | | **HEBB'S FIRST POSTULATE:** | | | | - - - - | | | | **HEBB'S SECOND POSTULATE:** | | | | - - | | | | **TIM BLISS & TERJE LOMO** | | | | - - - - | | | | ***LTP --** Activity dependent plasticity resulting in long-term | | enhancement of synaptic strength following co-activation of neurons | | in a network* | | | | - - - - | | | | **INDUCTION OF LTP** -- can be done in vivo (electrodes in rat | | itself) or in vitro (electrodes in slices of rat brain)! | | | | - - - - | | | | **MOLECULAR MECHANISMS OF LTP** | | | | - - - | | | | Early research -- in vitro and in vivo studies on rabbit and rat | | hippocampus | | | | Further research -- other areas of the brain (but hippocampus the | | best for navigation), human cortical tissue, and focus on different | | forms of LTP (e.g. NMDA independent) | | | | **But how do we study LTP in humans?** | | | | - - - - - | | | |  | | | | In this case tetanus refers to a tension or stimulation. | | | | This example found a significant amplitude increase in the N1b | | component of visual evoked potentials following photic tetanus | | | | "But maybe the N1b just shifted to appear bigger?" -- "well, the | | sources that generated it didn't shift around, so it's just the | | response that's getting bigger!" | +-----------------------------------------------------------------------+ | **LTP of Auditory Evoked Potentials** | | | | - - - - | | | | **Localising LTP using fMRI --** | | | | **"SPECIFICITY" --** LTP theory is quite specific; you don't want | | your brain to increase potentiation in response to every stimuli, but | | rather specific stimuli | | | | - - - | +-----------------------------------------------------------------------+ +-----------------------------------------------------------------------+ | LECTURE 6: LTP and Brain Disorders | | ================================== | +=======================================================================+ | **LEARNING OBJECTIVES:\ | | ** | | | | 1. 2. 3. a. b. c. | +-----------------------------------------------------------------------+ | ### The Diathesis-Stress Hypothesis | +-----------------------------------------------------------------------+ | **Essentially, stress = gene x environment** | | | | - - - | | | | | | | | - - - | | | | **STRESS AND LTP --** Stress causes metaplasticity; the threshold at | | which you get potentiation vs. depression (could be any stimuli to be | | honest) is **shifted towards depression(?)** | | | | - - | +-----------------------------------------------------------------------+ | DEPRESSION | | ---------- | +-----------------------------------------------------------------------+ | - - - | | | | - - - - - | | | |  | | | | **What does this have to do with plasticity?** | | | | - - | | | | - - | | | | Aguilera et al. explored the idea that there is probably a whole list | | of genes that influence our probability of developing depression | | | | - - | +-----------------------------------------------------------------------+ | ### BDNF, Memory and LTP | +-----------------------------------------------------------------------+ | **Human LTP paradigm relative to different alleles in BDNF** | | | | - - - - | | | | **BDNF & STRESS** | | | | - - | | | | **Stress, BDNF, Ketamine & Depression** | | | | - - - | +-----------------------------------------------------------------------+ | ### LTP & BIPOLAR DISORDER | +-----------------------------------------------------------------------+ | - - | +-----------------------------------------------------------------------+ | SCHIZOPHRENIA | | ------------- | +-----------------------------------------------------------------------+ | **Positive symptoms** -- delusions, hallucinations, disorganised | | speech, generally disorganised behaviour | | | | **Negative symptoms** -- reduced expression of emotion, poverty of | | speech, difficulty in initiating goal-directed behaviour | | | | - - | | | | **SCHIZOPHRENIA + DOPAMINE** | | | | - - - | | | | Neuroleptics (treatment drugs) tend to be dopamine antagonists | | | |  | | | | **COMT x cannabis use** | | | | - - - - | | | | **GLUTAMATE & PCP** | | | | - | | | | **REDUCED NMDA RECEPTOR EXPRESSION IN MICE →** Mice behave more | | antisocially following reduced expression | | | | *Figures on lecture slides 28 and 27 were glossed over quickly* | | | | - | | | | **Cavus et al.** had a group of people with schizophrenia in the Yale | | medical facility who often came in, and she performed LTP | | measurements on these people versus controls | | | | - | | | | **Mears and Spencer (a terrible study)** used the auditory LTP | | paradigm and found that in people with schizophrenia, the LTP-like | | effects were reduced | | | | - | +-----------------------------------------------------------------------+ | AUTISM SPECTRUM DISORDERS | | ------------------------- | +-----------------------------------------------------------------------+ | - - - - | | | | - - | | | | Wilson et al. (2017) -- Increase LTP found in those with ASD, | | evidence of hyper-plasticity in adults with ASD | | | | - - | +-----------------------------------------------------------------------+ | LTP, MCI & ALZHEIMERS | | --------------------- | +-----------------------------------------------------------------------+ | Progressive neurodegenerative disease, expected to impact 1:85 people | | by 2050. | | | | - - - - - | | | | The Problem -- to find endophenotypes (biomarkers) to see if a person | | has MCI | | | | Alzheimer's is believed to be characterised by the formation of | | Amyloid plaques; | | | | - - | | | | **What does this have to do with LTP?** | | | | - - - | | | | Matter of quantity -- do people with Alzheimer's have less LTP than | | those without? The answer is yes, but we don't have a great enough | | distinction to understand what actually is happening. | | | | - - - | | | | **MCI and vsLTP** | | | | - - - | | | | - - | | | |  | +-----------------------------------------------------------------------+ +-----------------------------------------------------------------------+ | LECTURE 7: Frontal Lobe Functions | | ================================= | +=======================================================================+ | **LEARNING OBJECTIVES:\ | | ** | | | | 1. a. b. | | | | 2. | +-----------------------------------------------------------------------+ | **Dorsolateral (top) and ventrolateral (bottom) prefrontal cortex.** | | | | - - | | | | | | | | - | | | | **EXECUTIVE FUNCTIONS** | | | | - | | | | | | | | - | +-----------------------------------------------------------------------+ | ### PHINEAS GAGE | +-----------------------------------------------------------------------+ | **PHINEAS P. GAGE** | | | | - - | | | | Statement from Dr John Harlow: | | | | *"**The equilibrium or balance, so to speak, between his intellectual | | faculties and animal propensities, seems to have been destroyed**. He | | is fitful, irreverent, indulging at times in the grossest profanity | | (which was not previously his custom), manifesting but little | | deference for his fellows, impatient of restraint or advice when it | | conflicts with his desires, at times pertinaciously obstinate, yet | | capricious and vacillating, devising many plans of future operations, | | which are no sooner arranged than they are abandoned in turn for | | others appearing more feasible. **A child in his intellectual | | capacity and manifestations, he has the animal passions of a strong | | man.** Previous to his injury, although untrained in the schools, he | | possessed a well-balanced mind, and was looked upon by those who knew | | him as a shrewd, smart businessman, very energetic and persistent in | | executing all his plans of operation. In this regard **his mind was | | radically changed,** so decidedly that **his friends and | | acquaintances said he was \'no longer Gage'**."* | +-----------------------------------------------------------------------+ | ### THE FRONTAL LOBES IN EXECUTIVE FUNCTION | +-----------------------------------------------------------------------+ | **ANTERIOR CINGULATE CORTEX --** Involvement in... | | | | - | | | | | | | | - - | | | | | | | | - | | | |  | | | | #### STROOP INTERFERENCE TASK | | | | - - | | | | *"It is traditionally suggested that the ACC performs attentional | | allocation and monitoring, AND error detection, AND resolves conflict | | at the attentional (input) and response (output) stages of the Stroop | | task."* | | | | - | | | | *"More recent fMRI work has suggested the Attentional allocation is | | performed by the dlPFC, and the ACC is involved in error detection & | | performance monitoring **(NB: our data does NOT support this).**"* | | | | - - - | | | | **Source Localization in the Stroop** | | | | - - | | | | - - - | | | | Now that we have a control, we are able to look at a variety of | | differences using Global Field Power (GFPs, data technique which | | gives us a better handle on when and where things are happening). | | | | - - | | | | | | | | - - | | | | So we essentially have "Oh, there's two sources of information, we | | have to be careful!" and "Oh! One of these information sources is | | wrong, so we need to look out for that too!" | | | | Found ACC activation when assessing streams of information, different | | set of activation in LPFC in conflict resolution -- which is pretty | | much expected | | | | - - - - - - - - | +-----------------------------------------------------------------------+ | ### WORKING MEMORY | +-----------------------------------------------------------------------+ | ***"Transient representations of task relevant information."*** -- | | Gazzaniga et al., 2002 | | | | The WM buffer integrates various bits of information about objects, | | events, etc. that it then retrieves from various other regions in the | | brain. | | | | - | | | | Animal maze experiment (spatial WM task), where the animal has been | | injected with a radioactive ligand such that we can see the areas of | | the brain working the hardest (because more radioactivity is there) | | once the brain is sliced. | | | | - | | | | **NEURONS IN THE PREFRONTAL CORTEX** | | | | - | | | | **TESTS OF WORKING MEMORY** | | | | - - - - - | | | | **TESTS OF HUMANS;** Sternberg probing -- Was this letter in the list | | you just saw? | | | | - | | | | **Two general theories for what the LPFC is doing during these | | working memory tasks...** | | | | 1. a. | | | | 2. | | | | **Digit Span Tests --** repeat the numbers in working memory | | forwards, or *backwards*; e.g. if asked to remember "3 6 7 5", the | | person may be asked to recite it backwards | | | | - - | | | | #### VENTROMEDIAL PREFRONTAL CORTEX | | | | - - - | | | | - - - - - - | +-----------------------------------------------------------------------+ +-----------------------------------------------------------------------+ | LECTURE 8: Evolution of the Human Brain | | ======================================= | +=======================================================================+ | **LEARNING OBJECTIVES:\ | | ** | | | | 1. a. b. c. d. | | | | 2. e. f. g. h. | +-----------------------------------------------------------------------+ | ### HOMININ EVOLUTION + HOMO HABILIS & ERECTUS | +-----------------------------------------------------------------------+ | **HOMININ EVOLUTION** | | | | - - - - - - - - - - | | | | - - - | | | | **HOMO HABILIS** | | | | - - - - - - - - | | | | **HOMO ERECTUS** | | | | - - - - - - | | | | **H. HABILIS VS. H. ERECTUS** | | | | - - - - | | | | **WHY WAS H. ERECTUS SO SUCCESSFUL? -- 1.9mya to 27k yBP** | | | | - - - - - - - - - - | +-----------------------------------------------------------------------+ | ### HOMO NEANDERTHALENSIS & HOMO SAPIENS | +-----------------------------------------------------------------------+ | **HOMO NEANDERTHALENSIS** | | | | - - - - - | | | | **NEANDERTHAL CULTURE** | | | | - - - - | | | | **WHAT HAPPENED TO NEANDERTHALS?** | | | | - - - - | | | | - - | | | | **HOMO SAPIENS** | | | | - - | | | | - - | | | | - - - | | | | **CRO-MAGNON MAN** | | | | - - - - - | | | | **ARCHAIC H. SAPIENS CULTURE** | | | | - - - | | | | - - - - | | | | **UPPER PALAEOLITHIC -- Hotbed of Culture** | | | | - - - - - | | | | - - - - - | | | | - - | +-----------------------------------------------------------------------+ | ### ENCEPHALIZATION -- Evolutionary Trends | +-----------------------------------------------------------------------+ | At some point we became more advanced. | | | | - | | | | EQ -- Encephalization Quotient | | | | - - - - - | | | | **TRIGGERS TO RAPID BRAIN SIZE GROWTH?** | | | | - - - - | | | | Many other genes that have altered in our recent evolutionary history | | are also candidates for causing significant brain changes: | | | | - - - | | | | | | | | - | | | | | | | | - - - - | | | | The **neocortex shape** also changed as we evolved (sulci, fissures, | | gyri). | | | | - - | | | | **More specific changes:** | | | | - - | | | | **Brain areas that grew:** | | | | - - - | | | | Our connections in our frontal lobe became much more sophisticated. | | Relative to chimps, our white matter connections are much more | | complex. | | | | **Brain Asymmetries:** | | | | - - | | | | **What primarily "non-genetic factors" might have led to brain | | changes (although these factors might have their influence through | | genetics) & re recent changes** | | | | - - - - | +-----------------------------------------------------------------------+ | ### NON-GENETIC HYPOTHESES | +-----------------------------------------------------------------------+ | #### **CHANGE IN ENVIRONMENT** | | | | *[The Savanna Hypothesis] --* we developed bipedalism in | | response to extensive savannas | | | | - - - | | | | *Sahelanthropus tchadensis* | | | | - - - | | | | *[We travelled!]* -- extensive migration may have driven | | cultural changes that then drove evolutionary changes | | | | - | | | | #### **CHANGE IN DIET** | | | | *['Expensive Tissue' Hypothesis]* | | | | - - - - - - - | | | | *['Man the Hunter' Hypothesis]* | | | | - - - - - | | | | - - | | | | *[Shoreline Foraging]* | | | | - - - - | | | | *David Horrobin -- "The Madness of Adam and Eve"* | | | | - - - | | | | #### **THE SOCIAL BRAIN HYPOTHESIS** | | | | - - | | | | - - - | | | | - - - - | | | | - - - | | | | **The hypothesis →** A larger brain is only adaptive once social life | | is complex. | | | | - - - | +-----------------------------------------------------------------------+ +-----------------------------------+-----------------------------------+ | LECTURE 9: Human Brain Electrophy | | | siology -- EEG, ERP, VEP | | | ================================= | | | ======================== | | +===================================+===================================+ | **LEARNING OBJECTIVES:\ | | | ** | | | | | | 1. 2. | | +-----------------------------------+-----------------------------------+ | ### WHAT IS THE BIOPHYSICAL BASIS | | | OF EEG? | | +-----------------------------------+-----------------------------------+ | **NEURAL ELECTRIC FIELD** | | | | | | - | | | | | | The voltage experienced by the | | | electrode at a particular point | | | is the sum of all electrical | | | fields being generated (by | | | neurons) at that point of time | | | | | | - - - - | | +-----------------------------------+-----------------------------------+ | **OPEN FIELD** | **CLOSED FIELD** | +-----------------------------------+-----------------------------------+ | Population of cells is oriented | Cells are randomly oriented, so | | similarly. Electric field | electric field summates | | summates constructively. | destructively. That is, the | | | electrical fields can cancel each | |  | other out. | +-----------------------------------+-----------------------------------+ | Cajal's slices and staining of | | | the brain --\ | | |  | | | | | | - - - | | | | | | - - - | | | | | | | | | | | | - | | | | | | EEG signals = Cortical signals | | | | | | **NEURAL POTENTIALS** | | | | | | - - - - - | | | | | | - - | | | | | | **GENERATORS OF EEG** | | | | | | *Based on the above evidence...* | | | | | | - - - - | | | | | | - - | | | | | | - | | | | | | But nobody has definitive proof. | | | | | | If we look through EEG Frequency | | | bands again.. | | | | | | - - - | | | | | | - | | | | | | **CORTICAL RESPONSES** | | | | | | - - - | | | | | | - - - - - | | | | | | - - - | | | | | | - | | | | | | **VISUAL EVOKED POTENTIAL (VEP)** | | | | | | - - - - - | | | | | | - - - - - | | | | | | **ASTROPHOTOGRAPHY -- stacking as | | | technique** | | | | | | - - - | | | | | | Example checkerboard test with | | | numerous trials: | | | | | | - - - - | | | | | | **CONVENTIONS IN RESEARCH** | | | | | | ***Which way is up?*** | | | | | | In an apparent effort to baffle | | | newcomers: | | | | | | - - - - | | | | | | ***What do we call the peaks and | | | troughs?*** | | | | | | In an apparent effort to baffle | | | newcomers: | | | | | | - - - | | | | | | - - | | | | | | **SCALP DISTRIBUTION** | | | | | | - - - | | | | | | **"MULTIFOCAL" VEP --** Change | | | different quadrants of the | | | checkerboard, so we can ask about | | | the contribution of different | | | parts of the visual field to this | | | response | | | | | | - | | +-----------------------------------+-----------------------------------+ +-----------------------------------------------------------------------+ | LECTURE 10: Multifocal VEP; VEP in Maladaptive Plasticity; Face-speci | | fic ERPs (N170, P200, N250); Cognitive ERPs - P300 and N400 | | ===================================================================== | | =========================================================== | +=======================================================================+ | **LEARNING OBJECTIVES:\ | | ** | | | | 1. a. b. c. | +-----------------------------------------------------------------------+ | **TERMINOLOGY** | | | | - - - | | | | - - - - | | | | - | | | | - | +-----------------------------------------------------------------------+ | **"MULTIFOCAL" VEP --** Change (pattern reverse) different quadrants | | of the checkerboard instead of the checkerboard as a whole, so we can | | ask about the contribution of different parts of the visual field to | | this response | | | | - - | | | | | | | | - - | | | | | | | | - | | | | | | | | - | | | | **Optic Neuritis in MS** | | | | - - - | | | | ### **Visual activation of auditory cortex reflects maladaptive plast | | icity in cochlear implant users --** | | | | - - | | | | - - - - - - | | | | - - - - | | | | - | | | | #### **STUDY: *Does neural reorganisation interfere with therapeutic | | interventions?*** | | | | - - - - - - - | | | | - | | | | **THE INVERSE PROBLEM** | | | | - - | | | | - - - | | | | **THE FORWARD PROBLEM** | | | | - - - - | | | | - | | | | Estimated P1/N1 sources -- most likely being generated in the visual | | cortex, but not the primary VC (extra striatum VC instead -- areas | | outside PVC) | | | | - | | | | MODEL: Assuming there is a dipole responding to visual stimulation in | | the visual cortex, operating at P1, where would it generate responses | | on the head. | | | | - - | | | | | | | | - - - | | | | Clinical Parameters -- better speech intelligibility correlates with | | *lower* VEP amplitude from right *auditory* cortex | | | | - - | | | | Most of the time neuroplasticity is considered to be a good thing | | (the brain is able to rewire and fix itself) | | | | - | +-----------------------------------------------------------------------+ | ### **STIMULUS SPECIFICITY** | | | | - - - - - - | | | | | | | | - - - - | | | | Can we adapt the face response? Can you saturate a person with lots | | of faces such that their responses become weaker? | | | | - - - - | | | | Many labs have observed that N170 is followed by a positive response | | - P200 (P2) response that varies in amplitude depending on how | | 'typical' the face is | | | | - - - - - | | | | - - | | | | **FACE IDENTITY - N250** | | | | - - - - | | | | So we have face detection (N170) → face typical? (P200) → face | | recognition (N250) → semantic processing (meaning of the face) | | (P300/N400) | | | | **"ODDBALL" -- Discovery of P300** | | | | - - - | | | | | | | | - - - | | | | **P3a (distractor) and P3b (target)** -- three stimulus oddball | | paradigm | | | | - - - | | | | | | | | - - - - | | | | | | | | - - | | | | **PHYSICAL INCONGRUITY** | | | | - | | | | **SEMANTIC INCONGRUITY --** elicits N400 in sentences where word that | | ends a sentence doesn't make sense (e.g. "Take coffee with cream and | | engine.") | | | | - - - - - - - | | | | - - | +-----------------------------------------------------------------------+ +-----------------------+-----------------------+-----------------------+ | | | Clinical Application | +=======================+=======================+=======================+ | P100 | Occipital/parietal | Assess visual | | | electrodes -- Visual | processing abilities | | | areas | | | | | | | | Early visual | | | | processing | | | | | | | | Reflect initial | | | | detection of stimulus | | +-----------------------+-----------------------+-----------------------+ | N170 | Specifically related | Assess conditions | | | to face processing. | like prosopagnosia, | | | Reflects initial | ASD → reduced/ | | | detection of | atypical N170 in face | | | face-like stimuli | processing | | | | | | | Occipital / temporal | | | | regions → visual | | | | processing | | +-----------------------+-----------------------+-----------------------+ | P200 | Face processing. In | Assess visual | | | response to | processing disorders | | | typicality | or neurological | | | | conditions | | | Parietal / occipital | | | | + frontal/cental | | +-----------------------+-----------------------+-----------------------+ | N250 | Face recognition. | Assess | | | | face-processing | | | | conditions | +-----------------------+-----------------------+-----------------------+ | P300 | Reflects violation of | Impaired P300 often | | | expectancy; | associated with | | P3a | allocation of | imapired cognitive | | | attention | function -- assess | | P3b | | conditions like ADHD, | | | Physical incongruity | schizophrenia, etc | | | = enhanced P300 | | | | | Impaired P3a = | | | Detection of | impaired attention | | | unexpected stimuli -- | allocation | | | respond to something | | | | that captures | Impaired P3b = | | | attention (unusual or | impaired memory | | | is target) | retrieval + | | | | recognition | | | Frontal / central | | | | | | | | Relates to updating | | | | behavioral context | | | | (eg make a response | | | | -- target evokes P3b) | | | | or addressing errors | | | | | | | | Parietal | | +-----------------------+-----------------------+-----------------------+ | N400 | Associated with | Assess | | | semantic processing; | cognitive/consciousne | | | semantic incongruity | ss | | | = enhanced N400 | of person who may be | | | | unresponsive | +-----------------------+-----------------------+-----------------------+ +-----------------------------------------------------------------------+ | LECTURE 11: "Cognitive" Potentials in Theoretical and Applied | | Contexts | +=======================================================================+ | **LEARNING OBJECTIVES:\ | | ** | | | | 1. a. b. | | | | 2. c. d. e. | | | | 3.