Psy270 flashcards quizlet anoxic brain injury mri

Object being interpreted from the viewer’s standpoint, where the object can be identified from almost any viewpoint.

Involves mental representation of objects that is used as a frame of reference for the viewer

Match between current and stored pattern of activation or interpolating between currently seen and stored views

Viewing objects causes a pattern of neural activation that is juxtaposed against the brain’s stored presentation of that object

Flyer experiment

Method: present participants with above objects; ask them to imagine they were making a flyer with these objects and should give customers best possible impression of objects


Task: which view would you choose?

Store representation: natural viewpoint, most easily identified = canonical views

anoxic brain injury mri

Results: average view participants chose: oblique viewpoints

Evidence: largest response to upright stimuli (most activation)

Pros:

Canoincials (easily identified) views exist; explanation why object recognition slows as the viewpoint departs from the canonical view

Cons:

Requires a lot of stored representations

Two stages

1) paralell pre-attentive stage

– small set of primitive visual features maps are handed to a master map containing all of the locations in space for each feature map.

– uses parallel/disjunctive search function of selecting only 1 feature at a time, where the feature is selected by monitoring the master map and is NOT dependent on the number of distractors present

– pre-categorical stage b.C before each both these features is grouped into categories, which emphasizes the fact that the parallel search function occurs before attention takes place

anoxic brain injury mri

2) serial focused attention stage

– several features are combined though the master map (like colour and orientation)

– both of these sensory features are active and send signals that are combined to detect the target

– attentional resources are used here, as the spotlight of attention os focused in an scan the master map — serial/conjunctive search function

– takes longer than disjunctive

– attention serves to bind: these features together in a presentation of the entire target object

– perception can be said to be assembled together using our attention processes.

Task: present oriented bars on both sides of the display

Cue attention to be remembered side — vary numbers of items in display

Basic electrical signal should be balanced on both side but you are paying attention on the cued side

anoxic brain injury mri

Delay around 900ms;

Maintain the orientation on the cued side– change detection

Sustained activity during delay period

Greater negativity over posterior contralateral channels

Calculate difference between is and contralateral channels; contralateral delay activity (CDA)

CDA increases with number of items held in WM; plateaus at capacity, typically around 3-4 items (NOT 7)

Follow up experiment:

Split group based on capacity limit

Task: remember orientation of red bars

Results: at a set size of 2 items, there does not seem to be a huge difference between low capacity participants and high capacity participants

Another follow up experiment:

Split group based on capacity limit

Task: remember orientation of red bars, ignore BLUE

anoxic brain injury mri

Results: low capacity participants show greater ERP response, they store distractors. High capacity individuals can effectively ignore distractors, their ERP response shows very little modulation

Conclusion:

ERP responses are pointing to posterior brain areas for capacity limit; fmri studies confirmed parietal lobe

There groups of participants:

– 8 amnesia patents with korsakoff’s syndrome, two patients with another form of amnesia

– alcoholic patients without amnesia undergoing treatment ALC

– patients without amnesia, no history of alcoholism

Method:

First phase of experiment: implicit

– present list of words; task was to rate the words in terms off how much they liked each word; fattens focused on rating rather than committing the words to memory.Anoxic brain injury mri

Second phase

– free recall: recall as meany words as possible from the original list; test of explicit memory

Word completion test: patients present with three letter fragments and told that each was the beginning of an english word and were asked to write a a few letters to make each into a word. You can write any english word but please write the first word that comes to mind – implicit memory test

Ie: par — party, parrot, parent

Results:

Free recall (explicit memory test);

Patients with amnesia cannot recall words from earlier phase, reveals the nature of the deficit.

World completion: amnesia patents performed as well as other groups on implicit test of memory (word completion). Priming can occur in the absence of explicit memory.Anoxic brain injury mri

Conclusion:

Different types in memory within the LTM