Assessment 1 Study Guide

Question 1

What determines the function of a neurotransmitter?

Answer 1

1) type of receptor it binds to (most important)
2) chemical structure of the receptor
3) location in the nervous system where it is released

Question 2

How does the nervous system encode for stimulus intensity (how is the action potential affected)?

Answer 2

through the frequency of the action potentials, but it doesn’t change the size of the action potential (which remains the same)

Question 3

What are some experimental methods to determine the function of a brain area?

Answer 3

1) Lesion studies (damaging brain regions and seeing how it affects function/behavior)
2) brain stimulation - using electrical stimulation to see how it affects function/behavior
3) brain imaging techniques - fMRI and PET to visualize activity in response to various stimuli

Question 4

What is the scientific process? What are the different steps and how are they
important?

Answer 4

1) observation
2) question
3) hypothesis
4) experiment
5) analysis
6) conclusion
7) reporting
8) replication

Question 5

In general, how are sensory stimuli relayed to the brain (What are the 3 relay stations of the CNS)?

Answer 5

1) receptor
2) spinal cord + brainstem (RS = relay station)
3) thalamus (RS)
4) cerebral cortex (RS)

Question 6

How does the CNS encode stimulus quantity?

Answer 6

1) rate coding -frequency of action potentials
2) population encoding - pattern and number of neurons activated

Question 7

How does the CNS encode stimulus quality?

Answer 7

1) labeled line coding
2) pattern coding

???’s on this one

Question 8

What is convergence and how does it contribute to our ability to encode sensory information?

Answer 8

convergence = multiple neurons synapse onto a single neuron but it can also refer to how multiple senses converge into the relay nuclei

Question 9

What are the inputs and outputs to the neocortex?

Answer 9

INPUTS:
1) sensory inputs - which come from the thalamus, save for olfactory
2) association areas - areas receiving multiple sensory inputs, involved in planning, attention, decision making
3) subcortical inputs - receives inputs from hippocampus, amygdala and other modulatory systems

OUTPUTS:
1) motor outputs - to spinal cord and brainstem (autonomic system)
2) subcortical outputs - basal ganglia, thalamus, limbic system to affect behavior
3) feedback loops - into prior input areas to create more processed/dynamic info
4) other cortical outputs - for more integration

Question 10

What is the overall function of association cortices?

Answer 10

Integrating and processing of various sensory info to affect behavior/cognition/decision making

thus, attention, memory, spatial navigation, sensory info integration, and decision making

Question 11

What are the inputs to the association cortices? What inputs to the association cortices are unique?

Answer 11

Association cortices receive inputs from multiple primary sensory areas of the brain, and other sensory areas to form a more complex perception of the environment.

Unique inputs are the higher-level processed info (i.e. already processed) that comes from primary processing areas, along with input from the limbic system and areas involved with memory

Question 12

What are basic features of cortical regions (i.e., what is specific about each of the cortical layers, I, II, III, IV, and V)?

Answer 12

Layer 1 (molecular layer) - horizontal communication, has dendrites from neurons in other layers
Layer 2 (external granular layer) - intracortical communication, has granule and pyramidal neurons
Layer 3 (external pyramidal layer) - interconnecting cortical areas in same hemisphere with medium sized pyramidal neurons
Layer 4 (internal granular layer) - main input layer for sensory info, receives input from thalamus having stellate and pyramidal neurons (internal pyramidal layer) - main output layer with long pyramidal neurons to for spinal cord, brainstem and motor output

Question 13

What is the overall function of the temporal association cortex? What evidence (both in humans and in animals) supports this?

Answer 13

-auditory, language comprehension and memory integration with sensory input

-evidence is via imaging and lesion studies which showed these behaviors/functions affected

Question 13

What is hemispheric bias and why does it occur? How does this apply to the parietal association cortex? How does this apply to the temporal association cortex?

Answer 13

1) hemispheric bias = tendency of one hemisphere to be more involved in a specific function than that other, creating some lateralization of brain function

2) in the parietal association cortex - specifically with the right hemisphere affecting spatial processing and the left affecting language tasks

3) for the temporal association cortex - this involves language processing in the left hemisphere, and non-verbal spatial processing in the right

Question 14

What is an agnosia? What is prosopagnosia?

Answer 14

1) agnosia - inability to recognize objects/people, sounds, etc

2) prosopagnosia - inability to recognize faces

Question 15

What are the subregions of the frontal association cortex and what are their
corresponding functions? What does this indicate about the frontal association cortex?

Answer 15

1) frontal association cortex sub-regions:
-PFC - decision making, planning, impulse control
-orbitofrontal cortex - emotion and reward processing
-broca’s area - speech and language processing

2) indicates - its importance in higher cognitive functions in behavior, attention, etc allowing adaptive/nuanced responses

Question 16

What is the frontoparietal attention network? What brain regions are involved in this?

Answer 16

FPA network = involved in attention, managing executive function, and prioritization of sensory info to facilitate cognitive/decision making

Key Regions:
1) dlPFC - executive functions, working memory
2) vlPFC - reward processing
3) lateral PFC - top-down attention/modulatory output to LIP
4) posterior parietal cortex - LIP, spatial attention

PFC lesions affect performance in Wisconsin Sorting Task (color, shape, etc)

Question 16

What is attention? & how do researchers characterize attention?

Answer 16

Attention = concentrating on one aspect while ignoring others

Characterized by its types, including:
-sustained
-selective
-divided
-shifting

Question 17

What are the caveats to interpreting results on which brain regions are involved with attention?

Answer 17

-interconnectivity/complex reactions - very few brain regions only do one thing. They are connected and interconnected to many regions, which means that the same function/behavior could be modulated/affected by several systems

-method limitations - while imaging the brain can provide us with information, there are certain regions which are hard to record from or fully study/analyze

Question 18

What is learning? & What is memory?

Answer 18

Learning = process by which new info is acquired, leading to a change in behavior, knowledge or skills via adapting to new info, or updating old info

Memory = the function that enables the storage, retention and retrieval of information to influence current/future behavior

Question 18

What is the contribution of Dr. Brenda Milner and Patient HM to the field of learning and memory?

Answer 18

Dr. Milner’ work with patient HM led to the discovery of the hippocampus’s role in memory, and helping us understand how specific structures impacted memory performance, while demonstrating specific aspects of memory (short-term, long term, procedural, declarative, etc)

Question 19

What type of memory was disrupted in Patient HM?

Answer 19

Mostly long-term memory for facts, places, events and experiences. This is why he couldn’t remember why he was being tested, even though he could follow the instructions for the test (i.e. mirror tracing task)

Question 19

What is the delayed non-matching to sample task? What does it measure? What brain region is involved?

Answer 19

Delayed non-matching to sample task = a cognitive test in which an individual must select an object that is different from a previously presented sample after a delay.

It measures the ability to recognize familiar and novel objects.

The brain region involved is the MTL, particularly the hippocampus.

Question 20

What is the delayed-response task? What brain region is involved? What evidence supports this?

Answer 20

Delayed-response task = a cognitive test where subjects must remember the location of a stimulus over a delay period before responding, measuring working memory and attention.

The brain region involved is primarily the PFC.

Evidence supporting this includes neuroimaging studies and observations of impaired performance in individuals with damage to the prefrontal cortex, demonstrating its crucial role in maintaining information over short periods of time.

Question 20

How would you measure declarative memory in animals?

Answer 20

You could do the Morris water maze or the radial arm maze to test their ability to remember the location of the platform (water maze) or the food (radial arm), thus testing/measuring their ability to remember the place/location where the goal was.

Question 21

What is Pavlovian (or classical) conditioning? What is the unconditioned stimulus, the unconditioned response, the conditioned stimulus, the conditioned response?

Answer 21

Pavlovian conditioning is whereby you pair an unconditioned response (salivating to the bell, not the food itself) to a conditioned stimulus (food, which causes salivation).

The UC is the bell

The UR is the salivating to the bell

The CS is the food

The CR is the salivating to the food

Question 22

Can we observe learning and memory?

Answer 22

It is difficult to observe a memory itself, but we can infer it by the changes to responses over time or the retrieval of info/experiences/events/faces presented many days, weeks, months or years ago

Question 23

What is involved in memory acquisition?
& What is involved in memory consolidation?

Answer 23

Memory acquisition involves the initial encoding of information into a form that can be stored in the brain.

Memory consolidation is the process by which initial, unstable short-term memories are gradually stabilized into long-term memory, involving synaptic changes and neural reorganization, particularly within the hippocampus and associated cortical areas.

Question 23

What are the different stages of learning and memory?

Answer 23

Learning and memory involve three main stages:

1) encoding - the process of taking in new information and converting it into a construct that can be stored within the brain.
2) consolidation - Consolidation refers to the stabilization of a memory trace after the initial acquisition, transforming short-term memories into long-term ones
3) retrieval - retrieval is the process of accessing and bringing into consciousness the information stored in long-term memory.

Question 24

Where in the brain are memories stored?

Answer 24

At the synaptic level across regions and networks specific for the processing of info/stimuli associated (no pun intended) with that region

Question 25

What is an engram? How does the engram relate to learning and memory?

Answer 25

Engrams are the locations of memories or memory traces across a set of neurons which are connected in a network. This model is often used for developing AI and AI related learning models. They can be widely distributed in the brain.

The cell assembly is what creates the engram.

Retrieval of a memory requires the activation of that specific engram, which can also reconsolidate the engram, or also make it available for disruption.

Question 26

What is a cell assembly? How does a cell assembly relate to learning and memory?

Answer 26

Cell assemblies are the connections that link a network of cells critical for making engrams. So you can have a behavioral experience which activates specific neurons, which said neurons communicate with each other, which then strengthens the synaptic connections between them

Question 27

What is meant by, “cells that fire together wire together”?

Answer 27

This is related to Donald Hebb, me thinks in the book ‘Organization of Behavior’ whereby he noted that specific cells (pre and post synaptic) would fire together, and that process of firing together would strengthen their connections, thus making them easier to activate, or ‘wire together’ into a network. This became a crucial model for understanding plasticity.