Cognitive Neuroscience - exam 1

mind-body problem

the relationship between the mind and body - is there a physical basis for mental processes?

ancient methods

many folks thought that the heart was the organ of the mind; trepanation

trepanation

you drill a hole into the skull... either letting out 'bad spirits' or to remove intracranial pressure

Galen

father of experimental physiology

vivisection

surgery on living animals to see what happens (results on behavior, mental processes)

Galen's experiment

attempting to dissect vagus nerve to see how it affects pig's respiration; discovered a branch of the vagus nerve that is responsible for speech production (laryngeal branch)

cell doctrine/ventricular theory

medieval idea that memory and cognition are stored in the brain's ventricles; ventricles create a substance which controls the body ('psychic pneuma')

Rene Descartes

said the brain controls the body via biochemical processes, but the mind is something separate. Mental processes are not physical in nature, are controlled by self-determination & consciousness, and that the mind is uniquely human

Cartesian Dualism

the mind & brain are made of different substances - the mind exists in a separate realm from the physical realm

reductionism

psych constructs can be explained entirely in terms of simpler (or biological) constructs; modern view which explains the mind through using the physical body

Andreas Vesalius

started dissecting humans; tried to determine brain functions based on underlying structures

Thomas Willis

said the brain's gray matter is where mental processes happen & white matter is how gray matter communicates

Franz Gall

separate mental processes can be localized to specific regions of the cortex and are therefore physically determined - the mind is a collection of independent entities housed within the brain; phrenology inventor

Johann Spurzheim

phrenology contributor - individual differences in cognition can be mapped onto differences in skull shape

Jean Pierre Flourens

Used lesion studies of pigeons to investigate the claims of phrenology (Gall)

Karl Lashley

taught rats to run a maze - vivisection to 'cut out memory' - unable to do so (rats could still do maze); goal to identify engram - said memories are stored throughout the cortex

engram

location of stored memories in the brain

Donald Hebb

cells that fire together wire together; during memory recall, neurons that fire together are activated together

George Miller

founder of cognitive psych & cognitive neuroscience

cognitivism

learning is an active mental process involving the acquisition and organization of knowledge; George Miller

cognitive neuroscience

explores the relationship between the brain & cognitive processes; George Miller

localizationist perspective

mental processes can be localized to specific parts of the brain

Paul Broca

had a patient with problems with speech production (could understand others, no other issues) - damage/cyst to Broca's area; localizationist

John Hughlings Jackson

patients struggled with regular speech production, but had intact emotional speech production; localizationist

Carl Wernicke

had patients who could produce speech fine, but couldn't understand what others were saying (speech reception); can produce superficially appropriate speech, but it lacks depth; localizationist

connectionist perspective

mental processes are caused by a distributed network of brain parts

Norman Geshwind

studied disconnection syndromes - damage to white matter; connectionist

Fritsch & Hitzig

discovered the primary motor cortex; vivisection & brain stimulation on dogs

Roberts Bartholow

first to do vivisection & brain stimulation on human brains (primary motor cortex)

Phineas Gage

railroad worker who survived a severe brain injury that dramatically changed his personality and behavior; case played a role in the development of the understanding of the localization of brain function (frontal lobe - personality)

Sir Victor Horsley

had the first theater for legit safe neurosurgery post-civil war (with anesthesia)

Walter Freeman

performed first lobotomy in the US

Wilder Penfield

-stimulated brain with electrical probes before patients underwent surgery for epilepsy

-created maps of sensory and motor cortices (humunculus man)

Brenda Milner

founder of clinical neuropsych; studied memory & cognition, worked with HM

patient HM

medial temporal lobe (hippocampus) removed; showed that hippocampi are responsible for memory, separate from perceptual & cognitive abilities; Brenda Milner worked with him. could not form new memories

pyramidal cell

A neuron characterized by a pyramid-shaped cell body and elongated dendritic tree; found in the cerebral cortex. primary excitatory messaging neuron

glial cells

cells in the nervous system that support, nourish, and protect neurons (don't directly participate in neural communication)

oligodendrocytes

type of glial cell in CNS that forms myelin sheath

myelin sheath

fatty layer, made of oligodendrocytes, that covers the neuron's axon. MS attacks myelin

astrocytes

type of glial cell in CNS that are star-like in shape and support neural communication (tell vascular system when neurons are firing to increase O2 & glucose, which increases blood flow). this cell either restricts or dilates arteriole, thus adjusting blood flow

microglia

type of glial cell that act as 'scavenger cells' where they clean up damaged cells in the CNS (synaptic pruning)

action potential

primary source of neural communication; brief polarization (+) then repolarization (-) in axon - all or nothing firing

EPSP

caused by influx of positively charged ions into postsynaptic cell; depolarize cell, making it more likely to fire action potential

IPSP

caused by influx of negatively charged ions into postsynaptic cell; polarizes cell, making it less likely to fire action potential

membrane potential

determined by permeability of membrane to ions & ionic distribution inside/outside of cell; generally at resting state, changed by NTs

neurotransmitters

molecules stored in vesicles at the end of an axon, released when action potentials force these to be released into the gap/cleft. then the post-synaptic/receiving neuron takes these in via dendrites

glutamate

primary excitatory NT - most common NT, important to everything in the brain

GABA

primary inhibitory NT - super common; plays a role in weakening & slowing neural connection (issues with sleep, anxiety disorders)

serotonin

mood, hunger, sleep regulation (low - MDD, high - hallucinations)

dopamine

mood, emotion, arousal (high - kinda Schizophrenia, low - Parkinson's)

endorphins

natural, opiate-like NTs linked to pain control and to pleasure; modulator - can increase & decrease amounts

acetylcholine

modulator NT associated with muscle function, learning, memory (low - Alzheimer's (begins in basal forebrain, where this is often produced))

glial reuptake transporters

NT taken into glial cells and broken down (glutamate --> glutamine (deactivated) --> sent back to neuron for reuse)

agonist

a molecule that, by binding to a receptor site, stimulates a response (makes NT work better, activates receptor site)

antagonist

acts on the receptor but does not activate it (can be competitive - blocks receptor, noncompetitive - blocks reaction)

sulcus

groove in gray matter

gyrus

raised portion of gray matter (generally, more = better intelligence)

cortical layers

cortex/gray matter is organized into 6 distinct layers with different cell types

pyramidal cells & cortical layers

primarily in layers 2, 3, & 5. excitatory cells & deal with communication

Broadmann's map

organized chunks of similar tissue/cells in the cortex into 52 areas

gray matter

tissue with higher concentration of neurons & glial cell bodies

white matter

mostly myelinated axons bundled together; unclear organization but deal with neural communication

basal ganglia

cluster of neurons at the brain's foundation which serve a critical role in motor activity, decision making, inhibitory control

Parkinson's disease

basal ganglia inhibits motor activity (neurons in BG die, resulting in a loss of dopamine & norepinephrine). symptoms are motor related, sometimes associated with Lewy Body Dementia (~20-50%) - first LBD then parkinson's

limbic system

associated with fighting, fleeing, feeding, fornicating. includes cingulate cortex, hypothalamus, thalamus, hippocampus, amygdala, mammillary body; forebrain

hippocampus

memory formation & retrieval (esp. spatially)

thalamus

relay center for sensory info that reaches the limbic system

hypothalamus

regulates bodily functions & is involved with emotional responses; formation of new memory

cingulate cortex

coordinates attention, memory, emotional control; motivation

amygdala

emotion processing, especially fear

mammillary body

emotion regulation & memory consolidation, limbic system structure

corpus callosum

connects the hemispheres & allows communication - middle of the brain; forebrain

midbrain

auditory & visual processing; process before signals are sent to occipital/temporal lobes

hindbrain

coordinates autonomic functions essential to survival; made of spinal cord & brainstem (medulla oblongata, pons, cerebellum)

cerebellum

plays a role in perception of time & motor control; common stroke location (motor control problems, still good cognition)

ventricles

let the brain float in CSF (buoyancy); nutrient delivery & waste removal, helps regulate intracranial pressure

meninges

3 layers that cover the brain; dura mater (tough outer layer), arachnoid mater (middle), pia mater (tender, delicate inner layer)

spatial resolution

how specifically/detailed can you see neurons, see what the brain looks like - even in broader areas

temporal resolution

correspondence between neuro change & brain signals changing

intracellular recording

method of taking measurements of cell firing by inserting a fine-tipped electrode into the cell; ex - grandma neuron; aka single-unit recording

grandma neuron

one hypothetical neuron that responds only to your grandma (or one specific thing) - you can see the neurons fire more when shown pics of specific people

single-unit recording

direct measure of neural activity - placing electrode outside of cell; high spatial & temporal resolution; invasive & largely restricted to animal research

Hans Berger

A German physician, he was the first to observe and report human brain waves in 1930, including alpha waves and the fact that brain waves changed with sleep onset.

EEG

measures gyral activity - measured in voltage

EEG & pyramidal cells

neurons are lined up so axons are pointed down into the brain, dendrites are pointing up to cortical surface -- EEG measures LOTS of these

dipole

2 opposite charges (-+) separated by a small distance to represent the neuron's electrical activity

multiple dipoles

electrical charge from tons of pyramidal cells creates a larger dipole, measured by EEG; this measurement can be pos/neg (excitatory/inhibitory)

EEG brainwaves

low hz = slower brain activity/less cognitive activity (fewer cycles/sec); high hz = more activity

event related potential (ERP)

high temporal resolution, cheap-ish; low spatial resolution; primarily associated with cortical activity (gyri > sulci)

Magnetoencephalography (MEG)

measures magnetic differences that are caused by electrical activity; magnetic equivalent to EEG; measures sulcal activity

event related field (ERF)

a bunch of MEGs - magnetic equivalent to ERP

MEG pros

high temporal resolution, moderate spatial resolution, direct measure of neural activity (better spatial > EEG)

Angelo Mosso

experimental neurophysiologist; measured pulsing blood vessels on dura mater (outermost layer)

perfusion

process of increasing blood flow to bring in nutrients (O2, glucose)

cerebral blood flow (CBF)

changes in volume of blood that is delivered to the brain

cerebral metabolic rate of glucose (CMRGIc)

the rate at which glucose is utilized in (brain) tissue

position emission tomography (PET)

measures CMRGIc; uses radioactive tracers (invasive). high spatial resolution (similar level to MRI), direct measure of metabolism in brain, can image NT receptors; poor temporal resolution

functional imaging with PET

take many pics of the brain over time (as the brain eats glucose, tracers are detected) - you can see dynamic changes over time as the brain eats glucose

cerebral metabolic rate of oxygen (CBRO2)

brain fires more, increase O2 in brain, increase blood flow in brain (so it doesn't run out of O2) → increase in deoxyhemoglobin where there is increased neural activity, changing magnetic properties of brain