NeuroPhysiology Terms

Question 1

Trigger Feature

Answer 1

pattern of stimuli that will maximally activate a particular neuron

eg. centre-surround receptive field (on centre/off suround) maximally activated by a light just on centre

Question 2

M-Pathway

Answer 2

photoreceptors (rods/cones) -> diffuse bipolar cells -> parasol ganglion cells (M-Cells).

Question 3

P-Pathway

Answer 3

photoreceptors (cones) -> midget bipolar cells -> midget ganglion cells (P-Cells)

Question 4

M-Cells

Answer 4

large cell body,
very few (10%),
sparse/long branching,
input from periphery,
rapid conduction speed, transient response type,
large receptive field,
high sensitivity to contrast,
black and white wavelengths

Question 5

P-Cells

Answer 5

small cell body,
many (80%),
dense/short branching,
input from fovea,
low conduction speed,
sustained response type,
small receptive field,
low sensitivity,
wavelength sensitive (color)

Question 6

Bistratified Type Cells

Answer 6

(10%) carry signals from short wavelength cones
project to koniocellular layer

Question 7

Lateral Geniculate Nucleus

Answer 7

where most ganglion cells project too,
has two major subdivisions: magnocellular, parvocellular, also koniocellular
in thalamus

Question 8

Magnocellular Layer

Answer 8

2 ventral (bottom) large cell layers,
input comes from large M-cells, found in all Mammals,
good for motion detection, temporal analysis, depth perception
more primitive

Question 9

Parvocellular Layer

Answer 9

4 dorsal (upper) small cell layers,
input comes from small P-Cells,
found in Primates,
form analysis, spatial analysis, colour vision,
recently evolved

Question 10

Koniocellular

Answer 10

smallest LGN cells located between (and ventral to) parvo and magno layers, input from bistratified RGCs, only in primates

Question 11

Equiluminant Stimuli

Answer 11

same intensity of light (amount of light), different wavelengths, can impair motion perception

Question 12

Blobs

Answer 12

pillar-like cortical sections,
found in V1 layers 2/3,
revealed by cytochrome oxidase staining of mitochondria,
input from parvo and konio,
no orientation selectivity, monocular sensitivity, wavelength/brightness selective,
most doubly colour opponent

Question 13

Interblobs

Answer 13

areas between blobs in V1 layers 2 and 3,
input from parvo,
cells are orientation selective, small receptive field, binocular sensitivity, not wavelength selective, not sensitive to direction of movement

Question 14

Simple Cell

Answer 14

(V1, layer 4) responds best to bar/line/edge of light, in particular location on retina, having specific orientation, constructed by converging centre-surround cells

Question 15

Complex Cell

Answer 15

(V1; layers 2, 3, 4, 6, V2) responds best to: bar/line/edge of light, in particular location on retina, having specific orientation and moving in certain direction

Question 16

Hypercomplex/End-stopped Cell

Answer 16

(V2, V3) responds best to: bar/corner/angle having certain lenght/width, in particular location on retina, having specific orientation, moving in certain direction

Question 17

Location Column

Answer 17

cells respond to stimuli from same retinal location

Question 18

Occular Dominance Column

Answer 18

cells respond to stimuli presented to one eye only

Question 19

Orientation Column

Answer 19

Cells respond to stimuli of same orientation; adjacent orientation columns differ in orientation selectivity by 10 degrees

Question 20

Packing Problem

Answer 20

how are three parameters of information (3D), mapped onto a 2-D representational space, solving this problem produces singularities

Question 21

Cerebral Achromatopsia

Answer 21

deficit in colour vision without loss of object perception

eg. implicated with V4
Ventral Path

Question 22

Prospagnosia

Answer 22

loss of ability to recognize faces with otherwise normal vision

implicated with IT

Ventral Path

Question 23

Akinetopsia

Answer 23

inability to perceive motion of objects

implicated with MST

Dorsal / Parietal Path

Question 24

Balient’s Syndrome

Answer 24

has optic ataxia (cant reach/grasp objects),
optic apraxia (inability to guide eye movements and change visual fixation),
simultagnosia (inability to perceive more than aspect of a visual stimulus and integrate into a whole.
Intact what system but damaged where

Question 25

Visual Form Agnosia

Answer 25

inability to extract global structure, despite intact low-level sensory processing (acuity, colour, brightness discrimination intact), can’t recognize/discriminate like shapes,
intact where system but damaged what system

Question 26

Double Dissociation

Answer 26

When function in 1 aspect is impaired but another aspect is intact and vice versa. shows two functions are independent of each other

eg. Dorsal / Ventral stream through visual form agnosia and Balient’s Syndrome