Lecture 1: Cognitive Neuroscience

Neuroscience

study of the nervous system

Cognition

process of knowing, reasoning, and understanding

Cognitive Neuroscience

the neural basis of cognition; interdisciplinary, specialized, major developments, new

Our Main Assumption

all our thoughts (the mind) arise from the brain; the mind is the product of the brain

Brain Assumption

the brain is divided into regions, that we created; it's a model that we have of the brain

Brain Region

1) visual distinction, landmarks, 2) cytoarchitecture, 3) distinct function, 4) gene distinction

1) Landmarks

visual distinctions;

2) Cytoarchitecture

ex. Brodmann; shape, density, size of cells; requires microscopy

3) Function

requires neuroimaging + clinical studies

4) Genetics

requires advanced tools, many regions

NBA

network-based approach; brain areas with networks of correlated activity; some excitatory or inhibitory

DMN

group structures active during wakeful rest, daydreaming, mind-wandering; correlated activity, fMRI

Barriers to BR

1) results, 2) disagreement over brain regions in network, 3) nomenclature, 4) generalization, n

1) Inconsistent Results

need for more + better brain imaging; Replication Crisis → early studies, df,

3) Inconsistent Nomenclature

need standardization, different working is complicated/more-less specific

Key Development

1) brain-behaviour correlate 2) biological tech 3) experiment approach 4) tech development

1) Brain-Behaviour C

hippo, galen, vesalius, willis/wren, dax, wernicke/broca, gall, spruzheim, phrenology

Hippocrates/Galen

physicians; brain injury asw impairs; brain → behaviour; limited, no anatomical data

Drawings

vesalius → produced high quality drawings; willis/wren following afterwards

Post-Mortem Brain

severe psychological impairment asw brain injury; Dax and Wernicke/Broca

Dax

left hemisphere damage and language impairment → aphasia

Wernicke/B

regional damage; wernicke → meaningless speech, broca → difficulty speaking; why? MCA

Opposition

opposed to idea that brain → behaviour; implications on views, will, agency, culture, religion

Gall

localized brain function; diff regions have diff functions; both are true

Holistic View

all brain regions, all together, do everything

Spurzheim

experience-dependant neuroplasticity; brain areas are developed with use

Phrenology

brain areas related to mental traits change in size with use; brain changes = cranium changes, measure cranium = predict traits → pseudoscience;

Phrenology Conclude

brain changes with experience, but are subtle + not in cranium, often undetectable

Neuroplasticity

neurons and their connections change; more connections, more gray matter

2) Biological Techniques

exam brain; stain cells → shape, distribution; brain not homogenous → mosaic

Brodmann Map

neuron structure organization (cytoarchitecture), 52 diff cell groups; imperfect

New Maps

talairach + MNI → coordinate maps used in delicate procedures and surgery

Thought Changes

LBF → single area, multiple func. any behaviour, multiple areas. reorganization w injury

3) Experimental Approach

correlations, causation, Donder, Mental Chronometry, Ebbinghaus, Behaviorism

Correlations

btw brain damage + behaviour, limited → no causation; need controlled experiment

Controlled System

manipulated IV/brain → measure DV/behaviour; all other variables constant

Manipulating Brain

de/activate; Fluoren, lesions to NS in birds; Fritsch/Hitzig → dog stim, specific mvmts

Donder’s Study

perception vs. perception + decision task; click J when you see light vs. press J for left, K for right; complex task longer because of decision-making; time diff related to decision-making process

Mental Chronometry

measurement + comparison of time (RT) to infer mental processes;

Ebbinghaus’ Experiment

memorize non-sense syllables in order, test after delays → decline (forgetting) in 2 days, with stabilization afterwards; nonsense syllables because if they make sense → scaffold/link concepts

Mental Processes

focus of cognitive scientists; thoughts; thought to be impractical + unnecessary

Structuralism

identify contents of mental processes through analytic introspection - what are you thinking?

Functionalism

purpose (adaptive function) of mental processes, not their contents

Psychoanalysis

focused on mental processes but not experimental

Behaviouralism

ignored mental processes, focused on how to modify behaviour

Behavioural Thought

change in the environment → mental processes → activity (reinforcement/punish)

Blank State

anyone can be anything if you change their environment

Behaviouralisms Weakness

1) language development, 2) infant attachment, 3) MH risk, 4) Tolman’s Map

2) Infant Attachment

good childhood → more likely to leave but shouldn't you be more likely to stay

3) MH Risk

same event could happen to two people but only one of them gets depression

4) Tolman’s Map

animals have mental maps; rat → food on right; but placed in diff location, makes left

4) Technological Developments

Computer Tech, Broadbent, Cognitive Revolution (late 60’s)

Computer Tech

1) Simon + Newell AI program (Dartmouth) 2) Miller number 7, IP (MIT); IPM

Broadbent’s Model of Cognition

input → filter → detector → memory; filtration + limits on processing

EEG

electroencephalography; measures electrical activity, analyzes functional in short window

PET

positron emission tomography; measures metabolism of glucose, analyzes function

fMRI

functional magnetic resonance imaging; measures blood oxygenation, analyzes structure and function

Neurons

excitable cells, generate + conduct electrochemical signals (AP); integration, speed, specificity

Gray/White Matter

gray → cell bodies, nuclei (dense-cortex); white → axons, tracts (myelinated-inside)

The Brain

forebrain → tel, di; midbrain → mes; hindbrain → myt, myel

Tel

forebrain, cortex (outer layer); basal ganglia , limbic system (Hp,A, Olf)

Cortex

outer layer of cells; gray matter, really thin; neocortex (6 layers, 90&, new, high order), allocortex

Surface of Brain

frontal (more motor), pre-frontal (everything in the front that’s not motor)

Longitudinal Fissure

divides hemispheres (left and right) (language and spatial)

Central Fissure

divides frontal/parietal; pre-central (frontal-motor), post-central gyrus (parietal-touch)

Lateral Fissure

top half (parietal + frontal) from bottom half (temporal)

Limbic System

cingulate cortex, hippocampus, amygdala, mamillary body, septum; lot functions (mem/emo)

Basal Ganglia

caudate + putamen (dorsal striatum), globus pallidus → movement; nucleus accumbens (ventral striatum) → reinforcement learning, habit, addiction

Diencephalon

thalamus → relay centre for sensory info (not olf); hypothalamus → drive centre (emo), four F

Mesencephalon

superior colliculus (vision), inferior colliculus (auditory), substantia nigra (motor), reticular formation (arousal), periaqueductal grey (nociception/pain)

Metencephalon/Myeliencephalon

Met → pons and cerebellum; Myel → medulla;

3D-Axis

medial-lateral (middle-outer), rostral-caudal (ant-post) (front-back), dorsal-ventral (top-bottom)

Visualizing Brain

coronal (frontal), horizontal, sagittal