Cogntition and emotion key words

the DRC

a model of reading in which excitatory and inhibitionary signals are used withing hte 3 routs of reading

3 routes

• phonological

• orthographic

• semantic

semantic

understanding the meaning of a word

orthographic

understanding the physical properties of a letter or word

Phonological

understanding the individual sounds of a letter

excitatory connections

allows one representation to exite related representations

feed forward

light up and activate other related letters or sounds - linked to excitation

inhibitionary connections

allows for suppressions of non related representations

Feedback

suppresses other letters or sounds that are not related to the representation - linked to inhibition

regular words

can be read by

• phonological

• orthographic

• semantic

irregular words

can be read by

• orthographic

• semantic

non-words

can be read by

• phonological

the visual word form area

is in the left ventrial occiptotemporal cortex

reading method

• information is recieved by both visual feilds and is processed by opposite hemipheres

• information is transfered into the left occipital lobe

• 230 ms - activity moves to both temporal hemispheres

• 300 ms - activity extends into the prefrontal cortex

u fibers

convey information from port to port - short distance

inferior longitudinal fasculas

long distance form occipital pole to temporal pole

repetition suppression

stimuli repetition can lead to a reduced neurol responce

familiar word repetitions suppression

are words coded in letters or in full words

• if words changed a single letter it should increase neural activity by a bit

• if words then changing a letter it will dramatically increase the neural activity

• words are coded as full words

engagement

if the brain region is able to deal with / is involved with the processing of this information

effort

the amount of effort/ oxygen required to process stimuli

the more effort / difficult the stimuli, the higher the BOLD signal

BOLD signals

the blood oxygen level required to process a stimuli

words - engagement and effort

non words - no engagement

low frequency words - more effort required

high frequency words - some effort is required

(uses subtraction logic)

Lexico-semantic pathway - effort and engagement

• testing semantics

• low frequency words - high activation

• high frequency words - lower activation

• non words - no activity

imput lexicon - effort and engagement

• testing orthography

• low frequency irregualr wards - high activity

• high frequency regualr wrods - low activation

• non words - no activity

conversion phoneme output buffer - effort and engagement

• testing phonemes

• non words - irregular words - high activity

• regular words - low activation

• non words (letter strings) - no activation

Peripheria dyslexia

occuring before parallel reading can take place

central dyslexia

occurs during parallel reading in semantic, orthographic or phonological routes

Pure alexia

• letter by letter reading

• length effect - takes longer if the word is longer

• damange in the visual words form area

Attentional dyslexia

• can’t identify letters when in the presence of other stimuli

• can lead to migration of letters

• assoicated with a left parietal lesion

neglect dyslexia

• faliure to identify or read the first or last letter of a word

• some letters or numbers are substituted

• a result of spacial neglect

• assoicated with a contralateral parietal lesion

phonological dyslexia

• inability to read non words

• prefer concrete words

• assoicated with a temporal lobe lesion in dominant hemisphere

deep dyslexia

• inability to read non words

• will make semantic errors - only relies on semantic knowledge

• assoicated with a lesion to the dominant hemiphere

surface dyslexia

• comprehension is based on pronunciation

• can read regualr and non words

• casued by damange to multiple sections of the orthographic DCR

semantic dyslexia

• unable to comprehend the meaning of words

• cannot name objects

• assoicated with neurological disease

modulation of the visual system - 2 system pathway

information is seen and is then process at the back of the brain

after this there are separate anatomical brain regions htat process different information

doral stream

• the where pathway

• understands spatial infromation

• located in the periatal lobe

ventrial stream

• the what pathway

• involved in object discrimination

• located in the occipital/temporal lobes

what and where in m onkey visual cortex

• was the first evidence of a double dissociation

• lesions to infreotemporal cortex impares object recognition (what) (dorsal)

• lesions to the perietal cortex impares spatial recognition (where) (ventral)

what and where in human neurophisiological evidence

found different patterns of activation between spcail and object recognition

• location tasks = more activation in the ventrial temporal cortexc

• object tasks = more activation in the dorsal crotex

however - this destinction is not so simple - case study fo JS

why is the what vs where system organised like this

• evolutionary reasons

• soical reasons

visual form agnosia

an imparememnt in visual perception leading to an inability to group or intergrate shapes or objects

assoicated agnosial

an inability to recognise or identify an object and cannot accoiated an item with its fucntion - can however draw a copy of the object

object recognition

• modular - separate systems per process

• constructive - representations are based on differnet courses of contextual information

• semantic - meaning of an object is automatically processed

modules for specific object recognition

• different processing of faces comapred to objects - the tatcher effect only works on faces

• faces are processed configurally / holistically

• performance at recognising faces is worse when you can only see parts of the faces

• the same occurs with the coomposite face illusion (misaligned faces)

fMRI evidence for mappign functions to structures in the brain

• as neurons show sensitivity to complex aspects, the further from V1 they are

• tge primary visual cortex (V1) is retinotopic (the visual feilds are integrated)

• lateral occipital complexity - there is high activation for novel / familure objects

mapping functions to structures in the ventiral visual pathway

it is rare to find pure and small lesioned case studies

• V1 - sensitive to simple visual features

• Lo - sensitive to more complex shapes

• V5 - sensitive to motion processing

prosopagnosia

a deficite in face recognition due to brain damage

but it is difficult to idenitfy lesions assoicated with this as lesions are large and can extend across anatomical boundaries

fMRI evidence for the FFA - Kanwisher

• the parahippocampal place area - PPA - activates when seeing scenes

• the Extriate body area - activates when seeing human bodies

challanges to the FFA model

• expertiese activation evidence from greebles and some birds

• patterns of activation in other brain regions

• developmental prospagnosia

• multivoxal pattern analysis (looks at individual patterns of activation and compare / predicts activation levels)

fMRI adaptation

• fMRI is aused to asses the sensitivlity of neurons to different object properties but the nerons acticity will decrease asa reuslt of increased exposure

• neurons however arnt effected by orentation

defigning attention

• Harlod Pashler - no one knows what attention is

• William James - withdrawal from somethings in order to deal effectlive with others

• attention is difficutl to defign as it is not just the result of looking at something

Selective attention

the ability to choose what we are focusing on

• an example of the monkie business illusion

Inattentional blindness

we can be looking at something but not selectivly attending to it

covert attention

paying attention to somethings while appearing to pay attention to something else

Overt attention

turning the head to orent to the stimuli

late selection

semantic understanding of a stimuli before attention descriminates between it

attention opperates like a spotlight and stimuli in the spotlight are given porcessing prefference

early selection

attention opperates at an early stage and sematic knowledge occurs after attention selects the relevant information

this donst explain the cocktail party effect

Cherry 1953

used the diachotic listening task where participants had to repeat one imput stimuli and ignore a second input stimuli

subjects could note the physical attributes of the unattended stimuli but could not recall the content

strokes

• cuased by a build up of fatty materials in the corroted arterties -

• limits blood flow to specific areas of the brain - symptoms depend on the site of the lesion

clinical presentations of MCA stroke

• inability to move opposite side of body

• inability to feel other side of body

• loss of vision to opposite side of space

changeblindness

involves comapring responces between changes in location and object

found tht attention opperated within objects supporting the late selection hypothesis

nural basis of attention

attention occurs in the same brain regions, in individuals neurons and si thereofre competative

temporal cortex shows selective attention cof specific stimuli at 180 ms - is stimuli is liked, then actvity is continued, if not then activity is supressed

properties of neglect

• object centred frame of reference

• internal representation

• late stage processing

• competative process

• may not be a unitaty system

object centred frame of reference

only attending to one side of an object instead of the full object even it if can bee attended to fully on the correct side

internal representation

information of effected side is neglected in the mids eye - ipsilesional

late stage processing

kanizsa figures - extinction was reduced when illusions were formed

extinction is reduced with fearful or emotional stimuli

competative process

it can be difficult to disengage attention from onw side to the other - hence competition

may not be a unitary system

competition between stimuli can occur at different lelevs of processing eg visual features, object sematics and emotions

neglect

a disroder of spacial or attentional representatinos

• cant conciously responde to a stimuli on one side

• more common for the right hemisphere in the temporal/ periatal area

• is not a form of blindness as it can be mulitsensory

• tests for it include - cancelation tests, copying tests and line bisections tests

extinction

a mild form of neglect where attention is only given to one side at a time

fMRI and the primary visual cortex (V1)

occurs through retinotopic mapping where attention enhanises performance for primed participants

fMRI for the V4

v4 is colour sensitive

there is more activity when stimuli was presented sequentially vs simulteniously

too much informaiton will lead to activity supression

biased competition model of attention

fMRI studuies suggest that the source of attentioal signals come from - only correlational data

EEG studies - long distance interaction between enurons via frequence occilation syncronisation

load theory

tests high vs low loads of infmoation with congruent and ingongurent distractors

• low load - dosnt use up capacity of attention meaning it can percieve distractors - late selection

• high load - perceptual capacity is used up on the stimuli meaning it cannot percieve the distractor - early selection

• cheakerboard example - greater activity in the visual cortex for low cogantive load becuase it has free attention to percieve the cheakerbaord

FFA and PPA evidence

activation in brain region increased depending on attention to stimuli

memory consolidation

any way in which memories are retained in the brain once the coding of information is finished

can be

• cellular level

• system level

Mueller and pilzeiker 1900

experiment in which list of paired assoicated sylables were leart and cued

found a temporal gradient - if learning new information was close to learning old information then recall was impared

lists of information did not need to be similar to eachother

the clay sculpture metaphore

memeory is fragile when it is first made and becomes resistant to forgetting the longer it is maintained

the shape of forgetting (wixted 2004)

we do not forget as a constant rate

we forget information less as time goes on - a lot of information is lost in the first unit of time btu the the rate of forgetting decreases as time goes on

Jost 1897

if two memories have equal strength but different ages then the older tree will decay at a slower rate

cellular consolidation

occurs are the neuron level - neurons talking to eachother to consolidate information

• the hippocampus is used to remember episodic declaritive (concious) memories

long term potentiation

a way to encode and stabalise information

• electircal stimulation in the presynaptic neuron = the post synaptic neuron will listen more

retrograde facilitation

factors that prevent mental exertion protect information from being frogotten e.g. sleep

system consolidation

when regions of the brain are talking to eachother

e.g. HM case study with retrograde and anteriorgrade amnesia

Bayley 2006

declaritive memeories Bedouin independant from the hippocampus and more dependant on neocortical regions = system consolidation

temporal gradient of semantic memory

bayley - compared memory recall with historical events - old memoriess were preserved so therefore they are not stored in the hippocampus

smith and squire 2009 - neuroscietific markers for memeory redistribution

hippocampus was not active for old memories but the neocortex was

investigated memeores over 24/48 hours

the brain reactived differently based on the age of information

working memory case studies - HM

• bilateral removal of the temoral lobe

• had sever amnesia - couldnt form any new long term memories

working memory case studies - KF

• lesion to the parietal occipital cortex

• poor short term memory and digit span

HM and KF

provided a double dissociation

Baddley and hitch - 1974

• came up with a computer model of working memory

• suggested the existance of separate stores for different types of information

articulatory supression effect

impares short term memory of words

concurrent short term memory

impares spatial tasks

general intelligence

found a correlation between acedemic ability and sensory discrimination - an underlying factor common to performence “g” - accounted for individual differences in performance

g factor

fluid inteligence - reasoning and problem solving

crystalised intelligence - general knowledge

Kyllonen and christal -

• what underlies out ability to perform reasoning task

• found a high correlation between working memory and reasoning ability

Kyllonen and christal - critisism

the tasks used did not differentiate between storage and information manipulation

• short term memory only stores information

• working emeory stores and manipulates infromation

Kane and Engle

given different types of tasks - simple or complex where complex tasks required storage and manipulation

constructed an equation model - working memoey was highly correlated with fluid intelligence

John duncan

carried out research to suggest tht is the ability to follow a complex set of task rules that underlies fluid inteligence

• used the rule working memory task

• found a correlation between IQ and rule task performance

monkey neurophysiological studies - WM

suggested the key role of a prefrontal cortex in working memory

neurons in the PFC shows sustained elivated responces the delay period of the working memory task (food in tray)

neurons hold a representation of the location of the food

Goldman - Rakie 1987

sustained delay activity in the PFC = baddleys working memory model storage buffers