Dorsal = __ (___ processing)

(also: ___)

Ventral = __ (__ processing)

Dorsal = where (spatial processing)

(also: how)

Ventral = what (object processing)

What are the 2 brain regions that information from the primary visual cortex travels to for dorsal/where and ventral/what processing?

dorsal/where:  Posterior Parietal Cortex

ventral/what:  Inferotemporal Cortex

What 4 types of studies have provided evidence that there are distince 'what' and 'where' systems?

Lesion studies

Electrophysiological studies

Neurophysiological studies

Brain imaging studies

In monkey lesion studies, monkeys were trained to

perform __ of __ tasks.  The tasks were:

a) ?

b) ?

In monkey lesion studies, monkeys were trained to

perform 1 of 2 tasks.  The tasks were:

a)  Landmark discrimination

In monkey lesion studies, for both the landmark and object discrimination tasks, to what level were the monkeys trained?

What step was next after the monkeys were trained?

In monkey lesion studies, for both the landmark and object discrimination tasks, to what level were the monkeys trained?

they were trained 'to criterion'

What step was next after the monkeys were trained?

the rule was reversed

 Identify the 2 illustrations

[image]

 Identify the 2 illustrations

[image]

both are from

monkey lesion studies:

top is the

Landmark Discrimination Task

bottom is the

Object Discrimination Task

In the monkey lesion studies,

for the Landmark Task results:

__ lobe lesion monkeys showed __ impairment

while

__ lobe lesion monkeys showed __ impairment

In the monkey lesion studies,

for the Landmark Task results:

temporal lobe lesion monkeys showed minimal impairment

while

parietal lobe lesion monkeys showed significant impairment

In the monkey lesion studies,

for the Object Task results:

__ lobe lesion monkeys showed __ impairment

while

__ lobe lesion monkeys showed __ impairment

In the monkey lesion studies,

for the Object Task results:

temporal lobe lesion monkeys showed much impairment

while

What and where processing differ in their dependence on

inter-hemispheric processing.

The 'what' pathway goes from the primary visual cortex to the temporal cortex.  This pathway exists separately in each hemisphere. It makes sense that disrupting the visual cortex for either hemisphere then the temporal cortex for the opp. hemisph. should disrupt vision.

Why is this NOT what happens in this situation?

What single factor can be added that makes it so this IS what happens?

The 'what' pathway goes from the primary visual cortex to the temporal cortex.  This pathway exists separately in each hemisphere. It makes sense that disrupting the visual cortex for either hemisphere then the temporal cortex for the opp. hemisph. should disrupt vision.

Why is this NOT what happens in this situation?

'what' processing can be accomplished with interhemispheric cnxns;

ie, use RH visual crtx. and LH temporal crtx.

What single factor can be added that makes it so this IS what happens?  -  cutting the corpus callosum

The lack of impariment seen in the 'what' pathway lesion experiment disappears for the 'where' pathway; big impairment occurs on the Landmark task. Why?

'where' processing is largely dependent

on intrahemispheric connections