Lecture 7 - Sensory Modularity

Question 1

Modularity

Answer 1

is the idea that specific areas (modules) of the brain are
specialized to process certain types of information or perform
certain functions.

Question 2

Sensory Modularity

implies that sensory info should be….

implies that we should be able to find ____ neural circuits that…..

Answer 2

suggests that specific brain regions are responsible for processing certain types of sensory information (audition, taste, touch, smell)

• The sensory information should be (initially) processed
independently from other senses (no mixing).

• We should be able to find specific neural circuits that carry this information (info about taste, visual events, etc…).

Question 3

Johannes Müller

Answer 3

in 1842, proposed that perception is based on the “nerve energies” received in the brain.

“what you’re experiencing has less to do with the distal stimulus and more to do with which neurons are being activated - some intrinsic property to these neurons (nerve energy) and if you activate them you will send that energy to the brain)

Question 4

Doctrine of specific nerve energies

Answer 4

This suggested that specific perceptions and their
qualities/features depended on which neurons were stimulated.

• So, it wasn’t the (distal) stimulus per se, but rather the activation of 
the neuron (by any means necessary) that was responsible for the sensation. 

This was one of the earliest examples of separating brain
responses by discrete neural function.

Question 5

proximal stimulus

Answer 5

the interaction at the level of the receptor that seems to be responsible for our perceptions

Question 6

one of the earliest examples of separating brain

responses by discrete neural function.

Answer 6

Doctrine of specific nerve energies

Question 7

Doctrine of specific nerve energies later becomes more generalized..

Answer 7

….the activation of the
target area in cortex was the critical element of the sensory
experience instead of the receptor-level

downstream from wherever that receptor was going to target in the brain, part of the brain was actually activated

Question 8

if you activate the cortex in just the right way, without the receptors

Answer 8

you can still get the same kind of associated perceptual experience

Question 9

TMS

Answer 9

Transcranial Magnetic Stimulation

you use a magnetic coil to create a magnetic field and it’s going to induce electrical impulse through the skull into the brain

can try to induce a particular area

Question 10

phosphenes

Answer 10

TMS done over the occipital cortex perceived as flashes of light that appear in space

Question 11

Occipital lobe

Answer 11

vision

Question 12

temporal lobe

Answer 12

audition

Question 13

parietal lobe

Answer 13

touch

Question 14

piriform cortex

Answer 14

cortex

Question 15

insula and operculum

Answer 15

taste

Question 16

neuron doctrine

Answer 16

the neuron is the basic

cellular unit for processing information

Question 17

Neuronal activity can be causally triggered by three sources:

Answer 17

1. Chemical signals (e.g. neurotransmitters)
2. Electrical signals (e.g. action potentials, gap junctions)
3. Environmental signals

cortex doesn’t care which one it is, as long as it gets to the right sensory cortex, that’s what’s received

Question 18

receptors

Answer 18

are specialized neurons that respond to specific kinds of environmental energy.