LECTURE 3

Question 1

MRI (MAGNETIC RESONANCE IMAGING)

Answer 1

Uses powerful magnetic field to align atoms that form neural tissues. Composed of three parts: magnetic field (always on), radio-frequency (alternate on and off) and gradient imaging (Provides 3D images).

Question 2

fMRI

Answer 2

Focused on BOLD - Blood Oxygen Level Dependent signals. Increased neural activity in one part of the brain shows increase of oxygen there, which changes

Question 3

ERP

Answer 3

Calculated from EEG
recordings
* Signal is time-locked to a
specific event & averaged
over multiple instances of
that event type

Question 4

Primary Motor Cortex
(M1)

Answer 4

• Somatotopic representation
• Coarse-grained
• Corresponds to muscle groups or
  possible actions (not continuous
  surface of the skin)
• Called the motor homunculus

Question 5

Retina

Answer 5

Contains photoreceptor cells turning wavelengths of light into electrical signals

Question 6

Foveal

Answer 6

Where most our vision of the outside world comes from.

Question 7

Optic Nerves

Answer 7

Retinal ganglion cells converge here to leave the eye and go to the LGN

Question 8

Rods

Answer 8

Colorless, low threshold so can easily differentiate between light and dark bands, found at the peripheries, slow to detect changes in light.

Question 9

Cones

Answer 9

RGB wavelength of color detectors, fast to detect changes in light and found at the foveal, high threshold so only useful in broad or well-lit conditions

Question 10

Relationship between photoreceptors. bipolar cells and retinal ganglion cells

Answer 10

Photoreceptors -> converge activity and form bipolar cells -> Converge and form retinal ganglion cells

Question 11

2 pathways from vision to brain

Answer 11

Tectopulvinar
retino genicultae striate pathway

Question 12

Tectopulvinar

Answer 12

10% of optic fibres use this
Fast acting

Question 13

Lateral geniculate nucleus

Answer 13

Part of the thalamus. Projects to the V1 from here.

Question 14

Cells of striate cortex

Answer 14

• Simple cells
• Respond to bars of different orientations
• Complex cells
• Also respond to bars of different orientations, but less particular about
  location of line
• Hyper-complex cells
• Respond maximally to lines of certain lengths

Question 15

Binocular disparity

Answer 15

the
image that falls on each
retina is different as the
eyes are positioned in
different locations.
* The brain uses this
information to determine
depth

Question 16

Cortical blindness

Answer 16

blindness of
cortical origin rather than
problem in eye or optic nerve

Question 17

Blindsight

Answer 17

condition in which
people have no conscious
experience of “seeing,” because
of extensive damage to striate
cortex, yet can make rudimentary
visual discriminations