Neural Bases of Cognition

Question 1

Neuron

Answer 1

Cell body
Contains mechanisms to keep cell alive

Axon
Tube filled with fluid that transmits electrical

Dendrites
Multiple branches reaching from the cell body, which receives information from other neurons
Dendrites: multiple branches reaching from the cell body, which
receives information from other neurons

Sensory receptors
Specialized to respond to information received from the senses

Synapse
• electrical to chemical
• 100 billion cells
• 100–500 trillion synapses
Synapse: space between axon of one
neuron and dendrite of another
• When the action potential reaches the
end of the axon, synaptic vesicles open
and release chemical
neurotransmitters
• Neurotransmitters cross the synapse
and bind with the receiving dendrites

How Neurons Communicate
• Neurotransmitters: chemicals that affect the electrical signal of the
receiving neuron
• Excitatory:
increases chance neuron will fire
•Inhibitory:
decreases chance neuron will fire

How Neurons Process Information
• Not all signals received lead to action potential
• The cell membrane processes the number of impulses received
• An action potential results only if the threshold level is reached
•Interaction of excitation and inhibition

Question 2

Amygdala

Answer 2

• The brain damage associated with Capgras syndrome
involves the amygdala, an almond-shaped structure
that is important for emotional processing.

Question 3

Localization of Function

Answer 3

Localization of Function: Limbic System
• Hippocampus: forming memories
• Amygdala: emotions and emotional memories

• Specific functions are served by specific areas of the brain
• Cognitive functioning breaks down in specific ways when areas of
the brain are damaged
• Cerebral cortex (3-mm thick layer that covers the brain) contains
mechanisms responsible for most of our cognitive functions

Question 4

Hippocampus

Answer 4

Critical for memory formation
• Explicit
• Personal events
• Spatial cognition
• Memory
• Navigation

Question 5

Frontal, parietal, temporal, and occipital lobes

Answer 5

• Each cerebral
hemisphere can
be divided into
four lobes:
• Frontal lobes
• Parietal lobes
• Temporal lobes
• Occipital lobes

Frontal
• Reasoning and planning
• Language, thought, memory, motor functioning

• Parietal
• Touch, temperature, pain, and pressure
• Temporal
• Auditory and perceptual processing
• Language, hearing, memory, perceiving forms
• Occipital
• Visual processing
• Primary receiving areas for the senses
• Occipital lobe: vision
• Parietal lobe: touch, temperature, pain
• Temporal lobe: hearing, taste, smell
• Coordination of information received from all senses
• Frontal lobe

Question 6

Agnosia

Answer 6

problems identifying familiar objects

Question 7

Aphasia

Answer 7

problems with language

Question 8

Sensory Coding

Answer 8

Sensory code: the information contained in the firing of neurons that
represent what we perceive
• Two proposals
• Specificity coding: The representation of specific stimuli are signaled by
activity in specific neurons
• Distributed coding: The representation of specific stimuli by the pattern of
firing of many neurons

Question 9

Specificity Coding

Answer 9

Grandmother cells
• The visual system
represents more
complex aspects of the
scene at higher levels
• At the highest levels,
single cells code for
particular objects
• These cells are only
excited when an object
with the proper
combination of features
is in view

Requires a different cell
for every object we can
recognize
• Spontaneous activity
would make a single cell
error prone and its loss
would cause the
representation to be lost
• These concerns have led
most researchers to
embrace ensemble
coding in which a
number of feature
detectors signal the
presence of objects

Question 10

Distributed Coding (population)

Answer 10

Specific stimuli are represented by the pattern of firing of many
neurons
• A limited number of neurons could represent a nearly unlimited
number of specific stimuli