Psych 377 Final Exam Part 2

left brain

-analytical-logical-see details rather than the whole-reading, writing, arithmetic-language-intelligence-dominant hemisphere

right brain

-holistic (big picture)-intuitive-artistic-music-emotional intelligence (able to read other peoples emotions and chose correct emotions for yourself)-spare hemisphere

right hemisphere anatomy

-extends farther anterior (frontal lobe further forward)-larger and heavier (more myelination/white matter)

left hemisphere anatomy

-more grey matter (more higher cortical area)-extends farther posteriorly-gentler slope of sylvian fissure

temporal lobe asymmetry

-planum temporale (wernickes area) larger in left hemisphere-heschl's gyrus (primary auditory cortex) larger in right hemisphere

commissurotomy

-surgical procedure of severing corpus callosum (L and R hemispheres can't communicate anymore)-done to reduce seizures that medication doesn't help (so seizure won't spread to other hemisphere)

vision tracts

-temporal hemiretinal tracts stay on same side-nasal hemiretinal tracts cross to other side of the brain-contralateral relationship between visual field and hemisphere of processing (L visual field to R hemisphere)

split brain experiment

-get person to stare at middle point-quickly flask info to 1 visual field so info only goes to 1 hemisphere-ask them to name to object-info in RVF goes to L hemi --\> can tell you what they say-info in LVF goes to R hemi--\> R hemi doesn't have language so they can't respond but they can use L hand to pull out the object you saw just using touch-R hemi can also demonstrate functional use of known objects

divided visual field technique

-RVF--\> LVC-LVF--\> RVC-bilateral presentation-unilateral presentation-perceptual asymmetries (reaction time and errors)

right hemisphere

faster at recognizing faces

chimeric face

-mix 2 faces together to create one face-fixate on center so a different half of the face goes to each hemisphere-get them to chose the face they saw-will chose the face that corresponds to their R hemi

wada technique

-test each hemi to look for primary functions-use for surgery planning-anesthetize 1 hemisphere with sodium amobarbital-results in contralateral paralysis

auditory laterality

-contralatreral dominance (more connections, more rapidly conducting)-superior olivary complex --\> sound localization

dichotic presentation

-simultaneously present 2 different auditory stimuli 1 to each ear-can test to see which hemi is dominant for language-demonstrates ipsilateral suppression-R ear advantage fro language since info is going to the same hemisphere that is dominant for language-L ear advantage for music

direct access theory

-input hemisphere processes the information-performance varies based on the output you are looking for

callosal relay model

-information is transferred to best side (this degrades performance because it takes longer if its not already in the preferred hemisphere)

activating-orienting model

-attentional bias leads to information saliency-if R hemi dominant for faces, then focus your LVF on the face

spatial frequency hypothesis

-hemispheres receive different frequencies of information-low frequency wave processed better in R hemi, look at whole picture, L ear advantage, match by apperance-high frequency wave processed better by L hemi, look at details, R ear advantage, match by function-these are relative not absolute frequencies (pattern stays the same even in different ranges)

global vs local processing

-R hemi damage = see the more detailed information, lose holistic shape-L hemi damage = see overall shape, impaired ability to see the details

chimeric figures experiment

-created figures so that you could match them based on appearance or function-show 1/2 of pic to each hemi and see what object they match to the object they see (do they match based on appearance (using R hemi) or function (using L hemi))

transfer of sensory information between hemispheres

-electrodes in occipital lobe, fixate on middle cross-when LVF figure shifts, info goes to R hemi (O2) first = O2 starts processing first-when RVF figure shifts, info goes to L hemi (O1) first = O1 starts processing first-no difference between pointing with L or R hand because we are measuring occipital lobe and info hasn't even gotten to motor planning yet

interhemispheric interaction

-use divided field technology, measure rxn time-easy task: is the bottom item the same as either top items, perform best when matching numbers are in same VF-difficult task: does the bottom item + 1 of the top items = 10 or more, perform best when the numbers adding up to 10 or more are in different VFs-interaction of 2 hemi's affected better performance in this task

confabulation

-make up a plausible story to explain why they did something because the language side of the brain didn't have access to the information given to R hemisphere-spontaneous production of false memories (events that never occurred or events that are displaced, elaborate, bizarre or mundane)-not lying deliberately

aphasia and apraxia

usually a consequence of left hemisphere damage (motor planning linked to our ability to produce language)

hemineglect and prosopagnosia

usually a consequence of right hemisphere damage

70%

% of left handers with left lateralized speech

10%

% of population that is left handed

15%

% of left handers with right hemisphere dominant for language

behavioural utility

-proposes that left hand is better for certain activities ex: holding a shield with L to protect your heart-is right handedness a cause or consequence of this?-do they already have right hand dominance or do they become right handed because of these behaviours

environmental reinforcement

-bias in environment for right handedness-environmental cues make it easier for right handers-ex: learning to write, swing a bat

environmental accident

-genetic bias towards right handedness (R handed= dominant, recessive= no preference)-left handedness develops through a cerebral deficit --\> more common in children with neurological disorder and twins with more stressful birth-creates R handed dominance

women superior at:

-fine motor tasks and intricate hand movements-computation-more sensitive to all sensory stimuli, except vision (facial expressions and body posture) --\> lower thresholds and greater speed-spatial memory (landmarks and changes)-verbal abilities (fluency, memory)

men superior at:

-throwing and intecepting objects-mathematical reasoning (word problem to mathematical form)-more sensitive vision-spatial location/navigation (route knowledge)-mental rotation-drawing mechanical objects

planum temporale asymmetry

-larger left than right-larger asymmetry in males

sylvian fissure asymmetry

-longer horizontal section in L hemi compared to women (to accomodate longer PT)-larger asymmetry in males

interhemispheric connection asymmetry

-females have more connections (more networking between hemi's)-females have larger spenium (vision info, temporal lobe, parietal lobe) and anterior commissure (base emotion, temporal lobe) --\> more connections-male has more intrahemispheric connections-when there is less asymmetry maybe there needs to be more connections to other hemi because the hemi's need to work together more instead of function being localized to one hemi

planum parietale asymmetry

-twice as large asymmetry in males than females-larger in R hemi (since PT is larger in left)-large PT= small PP in L hemi-small PT = large PP in R hemi

fingerprint asymmetry

-typically right hand has more ridges from core to trimedial point-females more likely to show atypical pattern (less asymmetry in females)

interhemispheric differences

-males: left lesion= greatest deficit in verbal IQ, right lesion= doesn't affect verbal IQ but does affect performance IQ-females: left lesions= greatly affects verbal and performance IQ's, right lesions= didn't really affect either IQ

Intrahemispheric Differences

-females: more likely to be apraxic and aphasic when damage is in L frontal area-males: more likely to be apraxic and aphasic when damage is in L posterior area

EEG

-electrical potentials recorded at the scalp (summation of millions of neurons firing)-blind to more detailed signals-quantified by time (measured by frequency and voltage) and frequency (frequency and power)-ERP (time locked activity)

event related potentials

-deflections in EEG as a result of some event-time locked activity-neurotransmitter binding-exogenous= changes related to things happening outside of the body (more perceptual)-endogenous= changes related to events happening inside the body (more cognitive)

10-20 system

-normalization process since everyone's head and brain is shaped differently-used to control for variability-measure distance from nasion to inion-all electrodes are 10-20% of this distance away from each other-electrode placement-"z" = zero, on midline-odd \# = left-even \# = right

alpha rhythm

relaxed9-12Hz

beta rhythm

alert15Hz

delta rhythm

sleeping1-4Hzhave bursts of high frequency activity

ERP study

-electrode feeds to amplifier (needed in order to visualize them)-auditory stimulus causes deflections in EEG-average across all deflections-(+) voltage goes down-time in log scale-time zero= stimulus onset-brainstem potentials= roman numerals-50-1000ms range--\> most cognitive functions

signal averaging

-makes it easier to quantify waves (time, size and location)-noise gets blurred out-more participants= clearer results, more stable, easier to quantify, get a smoother line-average won't look exactly the same as individual (large variation in responses between participants but within subject variability is small)

Galton

-serious criminals must look different from the rest of us such that we can use it to identify them-took photos of convicted murders-superimposed the pictures so common features would become clear to find out key facial signals-didn't work

ERP vs behaviour

-ERP can elucidate specific cognitive processes underlying overt behaviour ex: stroop test suggests either perceptual or motor related interference, use LRP to determine its likely motor interference-online measure in absence of overt behaviour (automatic processes, below awareness threshold, correct responses vs errors)-small amplitude of erp necessitates greater number of trials than behavioural experiments

advantages of ERP

-non-invasive-temporal resolution (ms level) --\> how close it is to real time-cost (once you have it, it doesn't cost a lot to run)

CAT/CT Scan

-pic taken in axial plane-uses x-ray technology and then use computer programs to make a 3D rendition-dark regions= low density regions-light regions= very dense-oblique slices (angle tipped upward)--\> numbered in ascending order, need multiple slices to get proper image of the brain, acquisition done in ascending order

MRI

-3 magnets: radio frequency coil, gradient magnet around head, large static magnet on outside-static field: constant magnetic field (0.5-7 tesla)-radio frequency field pulse sequence: transmitter coil (perturbation of static field-H atoms-excitation- resonance), receiver coil (reception/realignment-image acquisition)-gradient field: spatial info-H atoms line up on a particular way, then they get excited, when turned off they must return to alignment position and as they do so they give off energy and time of decay used to create MRI signal

functional imaging

-study how the brain is working-fMRI is the \#1 technique for cognitive neuroscience

anatomical imaging

-study what the brain looks like-CAT, MRI

angelo mosso

-first functional brain experiment-perfectly balanced board-get people to try and balance board while lying on it-asked them math questions or asked to conjure up a very emotional memory-caused the board to tilt down towards head (displacement of blood redistribution to head)

fMRI

-measures BOLD signal (blood oxygenation level dependent signal)-indirect measure of neural activity-increased neural activity= increased blood oxygen= increased fMRI signal-lower resolution (don't see anatomical details)-overlay fMRI images onto MRI image or else you don't know where the blood flow is in the brain

control head movement

-if head moves between fMRI and MRI then the images wont match up-bite bar: makes it hard to move head-plastic mold bolted to table

MRI safety

-appropriate risk level for a research participant is much lower than for a clinical patient because they don't receive any benefits

anatomical contrast

ability to distinguish between 2 or more different properties of tissue

functional contrast

-contrasts should be considered as "contrast to noise"-how effectively can we decide whether a given brain region has property X or Y

voxel

-small cubic prism that is the basic sampling unit of fMRI-anatomical one: 1mm^3-functional one: 3mm^3-spatial resolution

MRI incidents

-pacemaker malfunctions leading to death (at least 5)-blinding due to movements of metal in the eye (from working in construction for a long time, 2 cases)-dislodgment of aneurysm clip-projectile injuries (most common)-gun pulled out of policeman's hand, hitting wall and firing

permanent magnet

-fixed field-can't be stopped

resistive magnet

-controlled by electrical system-can be switched off at any time

super conducting magnet

-to create higher level electrical field-flows continuously-forms static magnetic field-can be shut off at any time

vermis damage (cerebellum)

-disrupts balance, posture, walking but not reaching or grasping-show few symptoms when lying down-fall ipsilaterally to damage

intermediate zone damage (cerebellum)

-difficulty in smooth movements-action/intentional tremors: once they get to more detailed/end of target the tremor occurs-nose test: touch finger to nose

lateral zone damage (cerebullum)

-ballistic movements (quickly grabbing something) and overshooting target--\> knock over object-multi-joint movement (compensatory strategy): decomposition of movement, slower movement, take away ballistic action

overshooting

-hypermetria-flexion of arm: agonist muscle must allow bending but then stop movement once you get to end antagonsits kicks in-causes very disjointed, unsmooth movements-alcohol produces similar effects

prism goggles experiment

-normal person: throw darts without goggles= good, then put on goggles= bad at first because you must readjust using feedback to compensate, get better with time, then take off goggles= throw too far in opposite direction so must readjust again-lateral zone damage: throws initially off, with goggles=they don't compensate, don't use feedback to alter motor program, throw badly, goggles off= no rebound effect, just go right back to how well they were throwing before

neurotransmitter systems

-dopamine (DA): excites basal ganglia (from substantia nigra)-acetylcholine (Ach): produced in basal ganglia, in balance with GABA-GABA (inhibitory): regulate activation-glutamate: excitatory

hyperkinetic disorders

excess movement

hypokinetic disorders

decrease in movement

huntington's disease

-genetic (dominate allele, 100% penetrance)-onset= 30-50 yrs old-destroys cells in caudate putamen = involuntary and exaggerated movements, chorea, athetosis-cortical atrophy as it progresses= results in cognitive deficits, more severe atrophy in basal ganglia= more severe atrophy in rest of brain

chorea

-twitching-brief, abrupt, irregular movements

athetosis

-writhing-slow, convoluted movements

tourette's syndrome

-genetic and environmental factors-onset= 2-15 yrs old-dysfunction in cortical and subcortical regions (not just basal ganglia)-involuntary motor tics (blinking, licking lips, face tics, occurs amidst normal motor activity)-involuntary vocal tics (inarticulate and articulate, echolalia, coprolalia)-possible abnormalities in cognitive functions supported by right hemisphere (visuospatial)-decrease connectivity along motor pathways

echolalia

-repetitive repetition of a word-automatic and immediate repetition of what others say

coprolalia

-rude, crude words shouted out (rare)-involuntary utterance of obscenities or inappropriate remarks

parkinson's disease

-genetic and environmental factors-onset= 60 yrs-loss of dopamine cells in substantia nigra-tremor at rest, muscular rigidity, involuntary movement (akathesia), postural movements-difficulty initiating and performing movements-akinesia: poverty of movement (trouble initiating)-bradykinesia: slow movement-cognitive impairments with progression (dementia)-waxing and waning of symptoms-no cure, only some treatments

akathesia

-create other movements to compensate for tremor-inability to remain still; motor restlessness and anxiety

apraxia

-problem with skilled, sequential, purposeful movement (not due to paralysis)-usually due to damage in L hemi-not due to lower level motor problems (subcortical)

oral (buccofacial) apraxia

-particular to face and mouth-can speak still-can't imitate specific movements of the face-caused by frontal-temporal lesions-damage to planning of actions

ideomotor (limb) apraxia

-problems with pantomime-can show how to perform an action when they have the tool, but can't imagine what action would be when they don't have the tool-tool faciliates motor planning so without it they have trouble putting together the action/behaviour-left parietal-temporal lesions (where planning and intend to plan areas are)

selective effector problem

-moving the incorrect body part when asked to perform an action-make sure it's not due to a language problem (aphasia)-ex: move R foot when told to raise R arm

specific disorders

-focal damage to brainExamples-gun shot wounds: confines damage to path of bullet-stroke: specific brain regions deprived of oxygen-lesion method: inference about normal brain function

generalized disorders

-distributed/diffuse brain damage-affect more than one cognitive system at a time and their effects are not identical-emphasis is on making subtle, but observations in their neuropsychological manifestationsExamples-closed head injury (falls, car accidents, sport injuries)-dementing disorders: pathological changes in brain-demyelinating diseases: multiple sclerosis-exposure to toxins

ischemic stroke

-blockage in vessel delivery blood to brain, deprivation of O2 to areas of brain-often due to an embolism--\> clot somewhere else that breaks off and travels to the brain

hemorrhagic stroke

-vessel breaks, blood leaks out of vessel, later regions get deprived of O2 and get build up of blood in brain--\> too much can produce intracranial pressure on brain

transient ischemic attack (TIA)

-serious but temporarily resolves itself and passes-episodes last a few minutes-indication of serious potential for a more serious attack at a later time-transient = come and goes

treatment for a ischemic stroke

-releive clot (dissolve it)-use tPA (tissue plasminogen activator)--\> needs to do it within the first 4.5hrs-door-to-needle time (time from when they get to the hospital to when they get tPA) --\> need to reduce time it takes to diagnose type of stroke --\> difficult for those living in rural areas (since they're so far away)

stroke ambulance

-called when a person in a rural area is having a stoke-goes out to the rural hospital to pick up the person-has a CT scanner in it so they can diagnose the patient in the ambulance and administer tPA on their way to the hospital

endovascular recanalization (thrombectomy)

-stent retriever-within first 6 hrs and only after tPA

QuICR

-if clot was early in branching of arteries (larger branch) it can have major impacts and may not be able to dislodge with tPA-run a catheter from femoral artery to brain, use stent around clot to pull it right out of the vessel

surgery for stroke

-especially for hemorrhagic stroke-seal up vessel using a stent or to relieve intracranial pressure

life style risk factors for stroke

-these increase plaque formation-poor cardiovascular health-not active-high fatty diet-overweight-smoking (increases elasticity of vessels, cant strech as much)-alcohol-long term stretch ( increase production of cortisol over extended time)-genetic (family history factors)-medications

symptoms of stroke

-face drooping-cant face arms-speech slutrred or jumbled-FAST-sudden numbness, confusion, trouble seeing, trouble walking, or severe headache

occipital lobe medial surface

-no clear division on lateral surface-parieto-occipital sulcus-calcarine sulcus/fissure: contains much of V1, separates upper and lower visual fields-V1 divided into upper and lower regions: upper region=lower VF processing, lower region= upper VF processing

occipital lobe ventral surface

-lingual gyrus: V2 and VP in posterior regions-fusiform gyrus: V4 in posterior region (colour)-areas often respresent brodmann's areas