Cognitive Neuroscience unit 1

Mind-Body Problem

how can the tissues and cells of the brain underlie thoughts, emotions, and decisions, ect.

Pure insertion

that adding or subtracting a cognitive operation does not change the other operations being measured

Cognitive subtraction

technique in which brain activity is measured while a person engages in a task.

activation map is generated by subtracting the activation that occurred in an experimental condition from that which occurred in a control condition

What imaging techniques use cognitive subtraction

fMRI, PET and MRI

factorial designs

usually two levels of an independent variable

parametric design

expand the range of the independent variable you’re observing

Event-related Design

random ordering of the stimuli

Block Design

similar stimuli are grouped together

Stereotactic normalization

average out brain structure, average out activation, put average activation onto average structure

measured in terms of voxels

smoothing

spreads activation of voxels to neighboring voxels

enhances regions where neighbors are active

deemphasizes regions where neighbors are not active

When a particular cognitive process is performed and an assortment of nonadjacent voxels are active what would diminish one’s ability to detect this activity

correcting for head movement

faces are associated with what type of representation

localized

PET vs fMRI temporal and spatial resolution

PET is better at spatial

fMRI is better at temporal

what is a part of the medial temporal lobe

the limbic system- hippocampus, amygdala, thalamus

neurotransmitters are released from what and are picked up at what from another neuron

from the terminal button to the dendrite

If you have two neurons which will respond to objects presented in its visual field when they fire in synchrony

when a single object extends across both of the neuros’ visual fields

What technique was Hubel and Weisel using when they discovered feature detectors in the visual cortex of cats

single cell recordings

what area is dominant with regard to language processing

left hemisphere

Patient with corpus callosum completely severed is called

split brain

Descartes on the mind body problem

dualism

dualism

the mind and brain/body are made of different substances

mind- no physical and immortal, can be passed to different people

body- physical and mortal

Dual aspect theory

Spinoza

the mind and brain are two different ways to explain the same thing

maybe similar to the duality of the wave/particle aspects of an election

MEG vs EEG for spatial resolution

MEG is better

current understanding of cognition

Reductionism

Reductionism

describing emotions and thought processes will eventually be understood at the neuron level

reduced psychology to a subfield of biology

Aristotle’s contribution to cognitive neuroscience

believed the cognition resided within the human heart

Galen’s contribution to cognitive neuroscience

made the connection between the brain and mental experiences

thought that the action was in the ventricles, not the tissue of the brain

Phrenology

Gall and Spurzheim

the sections of the brain housing specific functions vary in size based on ability

this is measurable on the skull surface

Functional Specialization

first introduced in phrenology

the idea that different areas of the brain perform different functions

Neuropsychology

helping people with brain damage

examining deficits in function of those with acquired brain damage to learn about typical cognition and functional specialization

Examples of neuropsychology

Broca- damage in the posterior frontal lobe related to deficits in speech production

Wernicke- damage in the posterior temporal lobe related to comprehension difficulty

When was their a break in studying cognition

early 1900s until late 1950s

due to dominance of behaviorism

Cognitive revolution

a surge of new research on cognitive processes in the late 1950s

began thinking of the brain as an information processing device much life a computer

Information processing used what two types of models

box and arrow models

also those featuring interactivity

these help to explain cognitive processes but they are not constrained by neuroscience

Computational and Connectionist models

use parallel distributed processing (PDP) methods

use a series of nodes that are interconnected

the strength of the connections are strengthened or weakened based on experience

debate over how much these models are related to neuron networks

Interactivity

work on a process can be occurring across many stages at one time

“later” stages can influence processing in “earlier” stages

parallel processing

Cognitive Neuroscience as a discipline

relating structure to function

bridge between cognitive psych and neuroanatomy

exploring damage

recording brain activity

examining reactions to stimulus

Electroencephalography

EEG

electrical activity across brain and get ERP

Single cell and multi-unit recordings

drill a hole in skull and put electrode into individual neuron

collect activate signals

many trials

common in animals models not human

Magnetoencephalography

MEG

magnetic and electrical activity

do task and see where is active

Positron emission tomography

PET

radioactive isotope is put in brain to trace flow when doing a task

measure glucose activity

functional magnetic resonance imaging

measuring blood flow- activation

measure through magnetic properties through iron in blood

no injection needed for anything just do task and measure blood flow

transcranial magnetic stimulation

TMS

magnetic field that manipulates neurons near it

task before stimulation- measure- task during stimulation- measure

can have therapeutic benefits

Transcranial magnetic stimulation

manipulate current from one side of brain to the other

Temporal Resolution

the accuracy of the measure for when the event is occurring

what methods are best at measuring temporal resolution

MEG, ERP, TMS

spatial resolution

the accuracy in terms of where in the brain the activity is occurring

methods that are good for spatial resolution

single cell and multi unit

Why bring in the brain?

DVs from neuroimaging as another DV on the level of reaction time and accuracy

how the evidence from neuroimaging studies is found to coincide with RT and accuracy measures

Why shouldn’t CogNeuro replace cognitive psychology

cognitive psychologist typically have a different skill set and different training in terms of experimental methods and designing experiments without confounds, but sufficient power

Is CogNeuro brain mapping?

no, it has modularity

modularity

certain cognitive processes (or regions of the brain) are restricted in the type of information they process

connectome

a comprehensive map of neural connections in the brain that may be thought of as its “wiring diagram”

graph theory

a mathematical technique for computing the pattern of connectivity from a set of correlations

Nodes

help to move faster

allow the propagation of the action potential

Resting potential

more negative ions inside cell than outside

change of -70 millivolts

action potential

the electrical changes occurring when neuron fires

anions

negative

cations

positive

when going through action potential the change becomes

positive

from -70 to +40

Steps of neural impulse

1. dendrites receive excitatory neurotransmitters which open the voltage-gated Na+ channels

2. sodium gates open- depolarization-negative potential is reduced

3. neurotransmitters released from terminal buttons- outward flow of K+

absolute refractory period

immediately after firing

the neuron cannot produce another action potential regardless of the strength of the excitatory input

relative refractory period

after the absolute refractory period

a stronger than normal excitatory input is required for that neuron to produce another action potential

Acetylcholine

excitatory

involved in muscular activity, memory, and attention

Dopamine

inhibitory

related to schizophrenia (high levels) and Parkinson’s disease (low levels)

GABA

major inhibitory neurotransmitter in the brain

low levels is related to anxiety

Gray Matter

neuronal cell bodies

exterior

White matter

myelinated axons

glia

interior

Glia

support cells of the nervous system consisting primarily of axons and support cells

Types of projections that interconnect different parts of the brain

association tracts

commissures

projection tracts

Association tracts

connect different cortical regions within same hemisphere

white matter tracts

Commisures

white matter tracts

connect across hemisphere

corpus collosum

Anterior

towards the front

rostral

Posterior

towards the back

caudal

Superior

towards the top

dorsal

inferior

towards the bottom

ventral

lateral

the outer part

Medial

in

towards the middle

Coronal cross section

slice the vertical plane through both hemispheres

Sagittal

slice in the vertical plane going through one of the hemisphere

Axial

slice on the horizontal plane

Projection tracts

connect between cortical and subcortical

Cortical

outer/cortex

4 ways in which regions of the cerebral cortex may be divided

1. regions divided by the pattern of gyri and sulci

2. regions divided by cytoarchitecture

3. regions divided by function

4. regions divided by connectivity

Diffusion tensor imaging

measures movement of water molecules that cannot escape due to myelin

Cerebrospinal fluid (CSF)

carries waste, protective cushion

analysis can predict Alhiemers’s and dementia

Gyri

raised surfaces

sulci

dips inside the folds

cytoarchitecture

individual neuron cells are different in structure related to different types of functions

Types of Cortical divisions

cytoarchitecture and functional (cortexes)

Subcortical regions

basal ganglia

limbic system

diencephalon

Basal Ganglia

involved in motor activity, skill learning, and reward learning

programming action

terminating action

Hypokinetic

poverty of movement

Parkinson’s

difficulty moving and stopping to move

Hyperkinetic

excess of movement

Huntington’s

being stimulated when its not intentional

Limbic system

related to processing information from the present and past

amygdala, hippocampus, cingulate cortex and mamillary bodies

Diencephalon

thalamus and Hypothalamus

thalamus

sensory relay station

sensory info comes in and is redirected out depending on what it is

hypothalamus

basic bodily processes

hunger, thirst, hormone levels, ect.

Superior Colliculi

Midbrain

integrates information from vision, hearing, and touch

also programming fast eye movement

around first evolutionarily compared to occipital lobes

Inferior colliculi

auditory

Midbrain