3.2 memory, attention, motion pocessing, visual agnosias

what is hippocampus responsible for

remembering objects and activation of hippocampus depends on subject’s past experience

what is hippocampus not responsible for

recognizing objects

which area does not need visual info to elicit a response

neurons in hippocampus

what actually allows us to perceive the form of an object and form of a face

total number of receptive fields and their geometry

define Binocular rivalry

perception alternates between two completely different images presented to each eye separately, rather than blending them into one

what concept allows us to Process perceives retinal image of right or left eye SEPARATELY

binocular rivalry

for binocular rivalry, neurons respond according to the image that the subject attends to in superimposed images. what area is activated if we pay attention to face

FFA

for binocular rivalry, neurons respond according to the image that the subject attends to in superimposed images. what area is activated if we pay attention to house

PPA

whatdid Sheinberg and Logothetis do

they produce binocular rivalry on trained monkeys

Convert attention

paying attention to an object somewhere in your visual field without fixating directly on

if we decide where to pay attention then brain activity is influenced by the attended stimulus. what concept is this

Top-down processing

top down processing

perceptual process where brain uses pre-existing knowledge to interpret new sensory info

which area of the brain respond to motion

Middle temporal area (MT) or V5 area in ocipito-temporal area of the brain

what did Hubel and Wiesel do

they showed that complex cells in V1 were responding to bars moving to certain directions

what was used to study neurons in MT or V5

random dots kinematograms

what is coherence threshold

critical number of dots necessary so that the subjects perceive coherent motion in a random dot kinematogram

if <10% of dots moving in motion processing, how do we perceive the dots

moving in random directions

As coherence percentage increased, how do we respond to the dots moving

subjects responded more accurately to direction of motion and more neurons on MT/V5 are firing

what is Medial-superior temporal area (MST

it is part of dorsal stream plays a role in detecting optic flow

which area shows increased neuronal activity when observers were looking at point-light walkers (dots in motion)

Superior-temporal sulcus (STS) in temporal lobe

which area is a multi sensory area that process biological motion and speech, integrates visual and auditory info and plays role in emotions and imitation

Superior-temporal sulcus (STS) in temporal lobe

aside from STS, what area is activated when looking at point-light walkers

fusiform face area (FFA)

Object agnosia

inability to recognize objects

Visual Agnosia

General term for the inability to recognize objects or sensory data despite functional eyes and intact elementary vision

Prosopagnosia

inability to recognize faces (face blindness) caused by lesions in the FFA, OFA, STS, or occipito-temporal cortex

Colour agnosia

inability to associate colours with particular objects

Colour anomia

inability to name colours

Cerebral achromatopsia

inability to discriminate colours due to cerebral damage and not due to abnormal retinal photoreceptors (world perceived in shades of grey and is caused by extrastriate cortical damage (V4/IT)

Visual space agnosia

inability to spatial orientation within visual environment

Akinetopsia

inability to perceive motion

Visual space agnosia

inability to spatial orientation within visual environment