L14- interaction btw perception and action Flashcards
re-excitation AKA reactivation
encoding required = first excitation
retrieval required second excitation.
reactivation -
- give cue
auditory recalls better with sound cue than visual
fusiform face area recalls better with pic than with sound.
- more recall - area of brain relating to that mode of perception needed.
common area for encoding and retrieval
though hippocampus - but maybe not.
seems as tho perceptual areas invovled with encoding and retrieval
nyberg - explicit memory of actions
motor cortex reactivated when recalling memory/action.
geng - saccades to remember location
fixate, target in spot. when disappears move eyes to it.
- reactive retinotopic visual cortex.
skinner -FFA
FFA reactivation during recall of faces
patient DF - what happened?
- cortical damage?
symptoms?
hypoxia from CO poisoning
- large lesions in ventrolateral occipital region, sparing v1.
- lesions: r/l lateral occipital cortex = LOC, ventral. left anterior parietal lobe.
visual form agnosia = problem recognizing object form. missing wholistic form.can draw from memory. orientations of hand - vision for action is intact.
optic ataxia patient RV
- dorsal stream, posterior parietal lesion.
poor visual motor transformation. good at perception of target & object.
– better at copying, but motor planning absent. cant estimate finger grasp.
RV vs DF
- ID objects as same/diff
- interact w object
- RV»_space; DF for naming.
- DF»_space;> RV for gripping. RV does random, incorrect.
perception ? Action?
- vvisual form agnosia
- optic ataxia
vfa; no perception, yes action = ventral damage
oa: yes perception, no action = dorsal stream
ventral stream damage
visual form agnosia
dorsal damage
optic ataxia
effects on delay on grip scaling
actions that require memory.
- need to use memory to remember object. slow arm movement, open hand wide, earlier. but still difference in grip between two object.
area used for object grasping?
AIP =dorsal.
area used for recognition
LOC = ventral
brain areas - activity for grasping/reaching and intact/scrambled
AIP - more active for grasping than reaching.
AIP - no difference in perception of intact vs scrambled.
LOC - same activtiy for reaching/grasping.
LOC - more activtiy for recognizing intact object than scrambled.
DF - delayed grasping
- immediately - quite accurate at grasping
- delay, can no longer grasp properly because image not on retina. - memory system needs to be activated.
DF doesnt have LOC, cant remember - so does LOC store info?
AIP store info? brain activity during action task
- see image, delay in dark, reach in dark.
see image = brain peaks
delay - moderately active brain. peaks again when touch.
grasping/reaching in fMRI
audio - told action. 18 sec delay. told - go/ignore. 18 sec
why 18 sec delay?
because of slow hemodynamic delay of BOLD signal
2 tasks done to ID 2 areas of interest
- grabbing vs reaching
- object vs scrambled
- frontal area & more posterior to visualize LOC
Left and right AIP showed what?
more grasp than reach response.
activation stays high during delay - same level during delay for both conditions.
more selectivity/activtiy for grasping than reaching.
left LOC - what is shown?
no activation over delay
- but can “see” thing in the dark. brain is coding for that spot in visual space even during the dark.
conjunction test in brain areas activated for both tasks
- doesnt care about memory delay. cares about what task - more activation for richer object recognition.
