Chapter 4

Question 1

spatial organization

Answer 1

the way stimuli at specific locations in environment are represented at specific locations in the nervous system

Question 2

electronic maps

Answer 2

translation of image on retina into electrical signals higher up

Question 3

retinotopic map

Answer 3

electronic map of retina on cortex where location on visual cortex correspond to locations on the retina (2 pts cloase together on an object and on retina are close on visual cortex) - distorted, not equivalent to size of receptor area

Question 4

fovea

Answer 4

accounts for 0.01% of retinal area but 8-10 % of retinotopic map on cortex - studied with brain imaging, a dot presented on fovea and in periphery, more excitation in cortex when spot is on fovea

Question 5

PET

Answer 5

brain imaging, low does tracer injected that indicates volume of blood flow which indicates increased activity

Question 6

fMRI

Answer 6

magnetic field presented, iron in blood is magnetically charged, more iron = more blood = more activity as blood loses oxygen; very precise

Question 7

Localization columns

Answer 7

organization of occipital cortex - perpendicular to surface - all neurons in a localization solumn have their receptive fields at the same location on the retina

Question 8

orientation columns

Answer 8

all neurons along perpendicular fire more to specific locations; when electrode is moved obliquely across columns, preferred orientation of neurons changes in an orderly fashion (all represented within 1mm, called a hyper column)

Question 9

ocular dominance

Answer 9

most neurons respond better to one eye than the other

Question 10

ocular dominance column

Answer 10

neurons with same dominance organized into columns in cortex (1L and 1R in each hypercolumn)

Question 11

tiling

Answer 11

columns working together to cover whole visual field

Question 12

streams and pathways

Answer 12

studied by Ungerlieder and Mishkin, used ablation to measure- monkeys taught to carry out particular tasks, area ablated and retaught, if they could no longer do task researchers could extrapolate that the area removed was in charge of that task

Question 13

object discrimination problem

Answer 13

shown one object then presented with 2 choice task, if correct object was pushed over they received a food reward

Question 14

landmard discrimination problem

Answer 14

push over/remove cover of shape closest to a tall cylinder

Question 15

ventral pathway

Answer 15

“what” pathway; after ablation of temporal lobe, object discrimination was very difficult; indicates that this is the pathway responsible for determining an objects identity

Question 16

dorsal pathway

Answer 16

“where, how/action” pathway; ablation of parietal lobe made landmark discrimination difficult; indicates that this is the pathway responsible for determining location

Question 17

double dissociations

Answer 17

helps in understanding effects of brain damage - study of 2 people; in one funciton A absent and B is present, and opposite in the other

Question 18

pathway study in “normal” functioning patients

Answer 18

Ganel; illusion of two lines - length estimation task (spread thumb and index to indicate how long), grasping task (reach toward line and grasp by ends, sensors on fingers measure length); illusion worked for perception but not action

Question 19

module

Answer 19

structure that is specialized to process information about a particular type of stimuli

Question 20

Fusiform face area (FFA)

Answer 20

in fusiform gyrus on underside of brain below IT cortex (roughly equiv. to face area in monkeys)

Question 21

Parahippocampal face area (PFA)

Answer 21

activated by images depicting indoor and outdoor scenes, spatial layout (same response to furnished and unfurnished rooms)

Question 22

Estrastriate body area (EBA)

Answer 22

activated by pictures of bodies/parts of bodies (not faces)

Question 23

spatial organization of visual system

Answer 23

spatial map is retinotopic (pts on LGN and cortex correspond to particular points on retina), weaker as messages reach higer areas

Question 24

functional organization of visual system

Answer 24

what, where, how? cortical areas rich in neurone that respond to specific stimulation

Question 25

experience dependent plasticity

Answer 25

supports that experience perceiving plays a role in perceptual development

Question 26

expertise hypothesis

Answer 26

proficiency in perceiving certain things can be explained by changes in the brain caused by long exposure, practice or training i.e. Greebles, FFA response to faces may be because we are “face experts”