Cognitive Neuroscience

Question 1

Define ‘cognitive neuroscience’

Answer 1

Studies the neural basis of cognition

Question 2

How can we study the physiology of cognition using levels of analysis?

Answer 2

We can study the brain at levels ranging from the whole brain, to structures within the brain, to chemicals that create electrical signals within these structures.

Question 3

Neuron

Answer 3

Cell that is specialized to receive and transmit information in the nervous system

Question 4

Nerve net

Answer 4

A network of continuously interconnected nerve fibers. Acts like a highway without any interruptions.

Different from neural networks where fibers are connected by synapses

Question 5

Cajal’s discovery about neurons

Answer 5

Individual units (neurons) are the basic building blocks of the brain.

Neuron doctrine: individual neurons transmit signals. They are connected but not continuous as proposed by the nerve net

Question 6

Resting potential

Answer 6

Difference in charge between the inside and outside of a nerve fiber when it is at rest (no other electrical signals are present)

Question 7

Nerve impulse

Answer 7

AKA action potential. Electrical response transmitted down the axon (nerve fiber). Responsible for transmitting neural information and communication between neurons.

Question 8

Neurotransmitter

Answer 8

A chemical released at the synapse when action potential signal reaches the synapse. It transmits the signal across the gap

Question 9

What is the connection between nerve firing and sensory experience? Provide an example.

Answer 9

Shape and height remains the same as pressure/ intensity increases, however, the rate of neural firing increases.

Ex; shining a bright light into eyes will cause the nerve impules to crowd close together because the sensation is intense. Shining a dim light will cause nerve impulses to be separated by long intervals because the sensation is weak.

Question 10

How do neurons represent information?

Answer 10

Stimuli cause neural firing that is transmitted across many interconnected areas in the brain.

Question 11

Feature detectors

Answer 11

Neurons that respond to specific visual features or the more complex features that make up environmental stimuli

Question 12

Experience-dependent plasticity

Answer 12

Structure of the brain is changed by experience. Neurons develop so they respond best to the type of stimulation that they are exposed to.

Question 13

Hierarchical processing

Answer 13

Processing that occurs in a progression from lower to higher areas of the brain.

Neurons in one area (such as the visual cortex) respond to simple stimuli send their axons to higher levels of the visual system which respond to more complex stimuli, and then send signals to even higher areas combining and interacting further and creating neurons that respond to even more complex stimuli such as faces

Question 14

What are the three types of coding?

Answer 14

1. Specificity coding
2. Population coding
3. Sparse coding

Question 15

Specificity coding

Answer 15

The idea that an object can be represented by the firing of a specialized neuron that responds only to that specific object.

Question 16

Population coding

Answer 16

The representation of a particular object by the pattern of firing of a large number of neurons.

Question 17

Sparse coding

Answer 17

Occurs when a particular object is represented by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent

Question 18

Localization of function

Answer 18

One of the basic principles of brain organization. Location of specific functions in specific areas of the brain

Question 19

Principle of double dissociations

Answer 19

When two related mental processes are shown to function independently of each other.

Ex; a group of patients who have damage to Broca’s area can comprehend language but not speak fluently and a group of patients who have damage to Wernicke’s area can speak fluently but not comprehend language.

Question 20

Functional Magnetic Resonance Imaging (fMRI)

Answer 20

Measures how blood flow changes in response to cognitive activity. Increases or decreases in brain activity are indicated by colours - specific colours determine the amount of activation.

Question 21

Distributed representations

Answer 21

Occurs when a specific cognition activates many areas of the brain.

Question 22

Neural networks

Answer 22

Groups of neurons that are connected together. A logical extension of the idea of distributed processing.

Question 23

Four principles of neural networks

Answer 23

1. Complex structural pathways called networks that form the brain’s information highway
2. Within these structural pathways there are functional pathways that serve different functions
3. These networks operate dynamically
4. There is a resting state of brain activity, so parts of the brain are active all the time even when there is no cognitive activity

Question 24

Default Mode Network (DMN)

Answer 24

Network of structures that are active when a person is not involved in specific tasks.

One of the brains largest networks

When the DMN is active people’s minds tend to wander