Exam 1: Chapter 1-3

Question 1

What is learning? memory?

Answer 1

Learning is the process by which changes in behavior arise as the result of experience interesting with the world.

Memory is the record of our past experiences, which are acquired through learning

Question 2

Aristotle proposed 3 rules of associationism. Know and be able to apply them.

Answer 2

1. Contiguity – experiences near each other in time/space are joined together
2. Frequency – experiences often repeated are connected more strongly
3. Similarity – experiences similar to one another are connected

Question 3

What is meant by the nature vs. nurture debate? Who are nativists discussed in this lecture and what do they believe? Empiricists? Why are psychologists concerned with this? I.e., does it make a difference if a schoolteacher is a nativist or empiricist, etc.?

Answer 3

The nature vs Nurture debate describes whether or not you grow up with the innate ability to do something or is taught.

Nativist: humans are shaped primarily by their inherited nature.
- Plato & Descartes

Empiricist: humans are shaped primarily by their experience (nurture). Endless possibilities with the right experiences,
- Aristotle

Psychologists are concerned with this cause this impacts all of humankind, how do we know what is taught and what is just innate?

Question 4

William James postulated that experience links ideas in the mind. This is the foundational truth of which field of psychology? What is dualism? Who coined the term?

Answer 4

• James proposed that experience links ideas in the mind.
• Remembering one idea would spread along links, retrieving a complex episode.

It would be the foundational truth for the cognitive of psychology.

Dualism is immaterial soul + mechanical body

Descartes coined the term.

Question 5

What are the 3 main criterion of natural selection? What does the idea of natural selection bring to the nature vs. nurture debate?

Answer 5

1. Inheritable trait
2. Natural variability
3. Relevance to survival

Natural Selection: the notion that heritable traits that provide reproductive advantages become more common in a population, leading over time to changes in existing species and even the evolution of new species.

Question 6

Know the experimental psychology associated with Ebbinghaus, Pavlov, and Thorndike. Additionally, some terms to understand from their experiments: memory savings, forgetting curve, classical & operant conditioning and Law of Effect.

Answer 6

Ebbinghaus - used himself as a sole participant in experiment testing memory
- studied memory in a distinctly modern and scientific way

• memory saving: how long does one save memories
• forgetting curve/Exponential retention curve: rapid initial forgetting, but progressively less forgetting with time.

Pavlov - Pavlov Dog
- classical conditioning
- pairing a stimulus with a response, The major difference between classical and operant is that classical relies on reflexes

Thorndike - placed cats in puzzle boxes
- operant conditioning
- law of effect: behaviors with positiveeffects are repeated; behaviors with negative effects are not.

Question 7

Who were some of the major behaviorists, and their major contributions?

Answer 7

John Watson - focus on behaviors
B.F. Skinner - “Skinner Box”

Question 8

Hull, Estes, Miller, and Rumelhart were some of the early key cognitive figures. What were some of their major scientific contributions to the field of learning and memory?

Answer 8

Hull - Mathematical Models of Learning

Estes - “defied Skinner”,
Mathematical Psychology

Miller- Information Theory, Digit Span: 7+-2

Rumelhart - distributed representation: some ideas overlap

Question 9

What are the three functions of the nervous system? What is the simplest expression of these functions? How is a neuron similar? What are the corresponding pathways that accomplish these functions? (incoming, processing, outgoing…)

Answer 9

1. CNS processes informationand generates behavioral plan
2. PNS sensory neurons collect information
3. PNS motor neurons relay behavioralplan to muscles and organs

The nervous system has three functions:
1. Collect information
2. Process information
3. Generate behavior

A neuron is similar due to it needing to collect info. from the axons then process the info. deciding whether or not to pass it on then do action potential then to do generate the info through the dendrites of the other neuron.
- Incoming (Axons)
- Processing (Soma)
- Outgoing (Dendrites)

Question 10

CNS consists of what structures? What are the divisions of the PNS?

Answer 10

CNS is the spinal cord and the brain.
PNS is everything else:
1. Sensory Organs
2. Muscles
3. Body Organs

Question 11

Know the following brain structures and their important functions: brainstem, reticular formation, cerebellum, thalamus, basal ganglia, hippocampus, amygdala, corpus callosum, cerebral cortex (including the four lobes)

Answer 11

• brainstem: connects the brain and spinal cord and completes many basic physiological functions, such as breathing and digestion.
• reticular formation: plays an important role in attention.
• cerebellum (little brain): important for motor control and coordination.
• thalamus (the egg): is responsible for relaying and filtering sensory information on its way to the cortex.
• Basal ganglia: movement, cognition, emotion (CPGP- caudate, putamen, globus pallidus)
• Hippocampus (the seahorse): remembering/retrieving autobiographical memories
• Amygdala (the almond): emotion and emotional memories
• Corpus callosum: connects cortex of the two hemispheres
• Cerebral cortex (bark): Six (6) thin layers of cells on the outer surface of the brain
  • Frontal lobes – planning and performing complex actions
  • Parietal lobes – touch, feeling, sense of space
  • Occipital lobes – vision
  • Temporal lobes – hearing and remembering

Question 12

What can we learn by comparing neuroanatomy across species?

Answer 12

• First lesson: bigger isn’t necessarily better.
• Brains vary not just in overall size, but in relative proportions.
• These differences seem to reflect different specializations for each species niche.
• Relative to other animals, humans have a disproportionately large cerebral cortex.
• Enhanced cortical proportions are shared by other animals we consider clever, such as dolphins and chimps.

Question 13

What are the special morphological aspects of neurons? Shape=function. Understand how the special shapes of the structures help the neuron communicate with other neurons, muscles, glands, and organs.

Answer 13

Neurons have a wide variety of shapes and sizes for different processing tasks: SHAPE = FUNCTION.

• more dendrites, more axon collateral sprouts
• a single axon for a motor neuron talk to 100 muscle cells

Question 14

What are glial cells? Which glial cells provide myelination in the CNS? In the PNS?

Answer 14

Glia provide support, structure, and nourishment for neurons, and outnumber neurons by about 9:1.

• Oligodendrocytes do myelination in CNS
• Schwann cells do myelination in PNS

Question 15

Know the best neuroimaging techniques for evaluating structure. And for evaluating function? How can these techniques help us understand the brain regions involved in and the effects of learning?

Answer 15

Techniques for Evaluating Structure:

• CT or (CAT scan)
• Magnetic Resonance Imaging (MRI):
  
  • Approach: Detection of water density
  • Results: Extremely detailed 3-d model of the living brain
• Diffusion Tensor Imaging (DTI):
  
  • Approach: Uses MRI to measure white matter tractsof nerves (brain wiring) –> water diffusion
  • Results: It is possible to reconstruct the connectionsin the brain, including the strength of theseconnections.

Techniques for Evalutating Function:

• PET (positron emission tomography) – injects a radioactive tracer to the blood
• PET measures regional cerebral blood flow (rCBF), but indicates activity.
• fMRI (functional MRI) – same as anatomical MRI, but signal detected relates to blood oxygenation

Advantages:
- High spatial resolution: 1 mm or more with stronger magnet
- Temporal resolution: ~1-4 s before blood level change is sufficient to measure
- No radiation

Disadvantages:
- blood flow slow not precise
- ongoing brain activity
- brain differences

Both PET and fMRI suffer from a major drawback: ongoing brain activity

EEG measures electrical activity non-invasively, through electrodes placed on the scalp.
- Pros - Fast, non-invasive measure of overall brain activity (sleep, wake, coma)

• Cons – Weak, noisy signal reflecting large portions of the brain all at once; so far, can only read general brain states.

Question 16

Know the process of neuronal communication (slide 30) both pre- and post-synaptically and major neurotransmitters (slide 34). How can a modulatory neurotransmitter be able to excite some neurons but inhibit others? What is the refractory period?

Answer 16

Hebbian Learning:
- Circles here are cortical neurons, and the lines are connections between them.
- Stimulus inputs activate a subset of the neurons (solid circles)
- Connections between coactive neurons are strengthened (heavy lines)
- After connections between coactive neurons have been established, an incomplete version of a familiar stimulus may activate just some of the neurons (solid circles) in the subset that represents the stimulus

• Common pathway for each sense:
  
  • sensory organs -> thalamus -> primary sensory cortex
• Each primary sensory cortex is specialized for initial processing, then relays on to other cortical areas.
• The neurotransmitter can either help (excite) or hinder (inhibit) neuron B from firing its own action potential (***)
• Modulate – alters the neurons in a more lasting way
• Refractory Period - during which that neuron can’t fire another action potential

-modulatory neurotransmitter (serotonin or dopamine):
- modulating behaviors through entire brain regions
- what type of receptor it lands at makes it act either excitatory or inhibitory

Major NTs:
- Glutamate: Most prevalent excitatory NT
- GABA: Main inhibitory NT
- Acetylcholine: connects motor neurons and muscles, regulates memory and attention
- Dopamine: associated with voluntary movement, regulates reward-seeking behavior
- Norepinephrine: Increases arousal, contributes to long-lasting memories
- Epinephrine: increase attention and concentration
- Serotonin: regulates sleep, mood, appetite, and aggression
- Histamine: regulates sleep and arousal
- Glycine: Decreases neural activity

Question 17

What is neurophysiology? What do single cell recordings allow researchers to investigate? What is neuropsychology? What can we learn from studying patients with brain injuries?

Answer 17

• Neurophysiology is the study of the activity and function of neurons.
• Direct implantation of wires into the brain allows both recording and stimulation of single neurons –> Although invasive, recordings can provide a direct readout of neural communication, making it possible for scientists to “decode” the information being processed in the brain.
• neuropsychology - studies of human patients with specific brain lesions
  • Determine area of brain region (e.g. with MRI).
  • Do tests to determine what behavioral abilities are impaired.
  • Tentatively conclude that the damaged brain region is responsible for the impaired behaviors.

Question 18

Lashley’s search for the engram didn’t pan out. Why? What is the Theory of Equipotentiality?

Answer 18

it didn’t pan out due to:
- Only lesioned cortex! Failed to test other brain areas.
- Also, test wasn’t sensitive: rats could learn to run it by sight, smell, and even touch so small memory problems weren’t being detected.

• Theory of Equipotentiality (proposed by Flourens, 1824): which states that memories are stored globally, by the brain as a whole, rather than in one particular brain region.

Question 19

What does it mean to say that neurons are “dynamic”? How does neural plasticity lead to Hebbian learning?

Answer 19

• Neurons are extremely dynamic—the brain is constantly re-wiring itself based on experience.
• The general term for this dynamic rewiring is neural plasticity.
• Hebbian Learning is the principle that learning involves strengthening the connections of coactive neurons; often stated as:
  “neurons that fire together wire together”

Question 20

Define and understand the concepts of long-term potentiation and long-term depression. What kinds of changes do each make in the physical restructuring of neurons?

Answer 20

LTP – long-term potentiation: when two neurons fire at same time repeatedly, synapses between them get stronger (fire together, wire together)

LTD – long-term depression: when two neurons fire out of sync, synapses between them get weaker (out of sync, lose link)

LTP – sprouting of new synaptic contacts between co-activated neurons
LTD – retraction/dismantling of synaptic contacts between non-cooperating neurons

Question 21

What is habituation? Sensitization? For what types of situations might these learning behaviors be important/ubiquitous? Be able to explain the behavioral phenomenon associated with each.

Answer 21

Habituation: decreased response to a innocuous stimulus over time.

Sensitization: increased response to a noxious stimulus over time.

Remember: weaker, innocuous stimulus = quickest habituation. Stronger, noxious stimulus = quickest sensitization.

Question 22

Understand dishabituation, spontaneous recovery, and stimulus specificity.

Answer 22

Dis-habituation:
- A novel/arousing stimulus can temporarily recover responses to the habituating stimulus.
- This fades quickly, though.

Spontaneous Recovery:
- When repeated stimulus stops, behavior gradually returns to normal.
- Time for recovery depends on several factors …

Stimulus Specificity (how you discriminate):
- Generally, responses only decrease to the habituating stimulus.
- For very similar stimuli, however, there can be some generalization.

Question 23

How can you create a more long-term habituation to a stimulus?

Answer 23

Short vs. Long-Term:
- More repetitions of the stimulus, longer-lasting habituation; with many repetitions, effects can become relatively permanent.
- Pattern of experience matters, though …

Massed vs. Spaced:
- Taking breaks between sessions of repeated stimuli makes habituation develop more slowly but last much longer (works better for studying, too).

Question 24

The “state system” is an important component of the Dual-Process Theory. Why?

Answer 24

Groves & Thompson (1970) proposed that habituation and sensitization reflect differential activation of two different systems:
- A low-threshold Stimulus- Motor Response (S-R) pathway that weakens with repeated use
- A high-threshold “state system” that, when activated, increases responses globally

state system: identify if this stimulus is innocuous or nocuous, the information that you get through this world at the moment, ex. have an awful day and you catch your clothing on a door

Question 25

Tolman proposed the idea of latent learning. What is that?

Answer 25

• All of this points to latent learning, or learning that takes place even when there is no specific motivation to obtain or avoid a specific consequence (food, shock …)

Question 26

Stimulus “familiarity” manifests in several ways. How are novel object recognition, priming, perceptual learning and spatial learning manifestations of familiarity? Know each concept.

Answer 26

• Novel object recognition/familiarity: altered response to stimuli that have been previously encountered.
• Priming: when exposure to a stimulus biases future behavior, often without conscious processing of the stimulus.
• Perceptual learning: repeated experiences with a set of stimuli improve ability to distinguish those stimuli. Can occur with directed training (discrimination training) or by mere exposure.
• Spatial learning: the acquisition of information about one’s surroundings

Question 27

How is perceptual learning different than habituation?

Answer 27

• Perceptual learning: Simply encountering a stimulus makes it increasingly easier to tell it apart from other stimuli.
• Habituation: getting used to a stimulus with repeated exposure

Question 28

What is an invertebrate model system often used to study the neural mechanisms of learning and memory?

Answer 28

• Aplysia californica, the “sea hare”, has only 20,000 neurons in its CNS; the neurons are also very large.
• popular for neural mechanisms of learning and memory

Question 29

What is the gill-withdrawal reflex of the Aplysia? Understand how this reflex is a simple expression of the 3 main functions of a nervous system.

Answer 29

Gill-withdrawal reflex:
- Touch the tail, siphon, or gill. (Collect information & Process information)
- The gill contracts within the mantle. (Generate behavior)
- Time to relaxation is measured.

Question 30

What can we learn about the neural mechanisms of habituation and sensitization from this model? I.e., what happens to synapses in habituation? Sensitization? How can certain neurotransmitters be modulatory?

Answer 30

Habituation:
- Repeated touch depletes sensory neuron of transmitter: synaptic depression
- Some synapses pruned.

Sensitization
- Tail-shock activates interneurons that releases serotonin.
- The serotonin modulates sensory neurons to release more transmitter on next activation.
- In-long term sensitization, new sensory-motor synapses are added.

Lessons learned from Aplysia:
- Habituation and sensitization cause opposing changes in synapse function (depression vs. facilitation), causing weakening vs. strengthening of reflex circuits.
- Learning can involve both direct changes in synapse function and modulation.
- With repeated training, there is re-wiring (adding/subtracting synapses) to support long-term memory storage.

Question 31

Know what it means when we say that cortical plasticity associated with perceptual learning is clearly evidenced by observing brain structural changes before, during, and after learning.

Answer 31

• Cortical plasticity: refinement in the receptive fields of neurons of the sensory cortex due to development or experience.
• Studies with opossums have also revealed that the development of cortical structure and function depends on repeated experiences.

Task: 2-point discrimination
- Touch finger tips with 1 or 2 tiny pins
- Participant reports if he or she feels 1 or 2 pins (with eyes closed)
- Sensitivity: smallest distance where participant is reliably correct
Experiment
- Baseline measurement of sensitivity + fMRI scan
- 2 hours of training to right hand only (repeated trials with feedback)
- Post-test for sensitivity + fMRI scan
Results
- Much better sensitivity in trained hand
- Increased area of activation in right finger area of somatosensory cortex!!

Question 32

What is meant by “receptive field”? How is the cortex organized to account for the differences of receptive fields on our body? How does Hebbian plasticity change the organization of the cortex with experiences (i.e., learning)?

Answer 32

Each neuron within sensory cortex has a distinct receptive field—part of the world it responds to (e.g., touch to the lip).

• This suggests a kind experience-based “natural selection” for the most useful synaptic connections.
• Repeated experience with a stimulus may help neurons tuned to that stimulus “win” and expand their synaptic connections.

Question 33

What role does the hippocampus play in mere exposure learning and how?

Answer 33

• The hippocampus is one of the most extensively studied brain regions in the field of learning and memory.
• The hippocampus has “place cells”: cells whose receptive field seems to be a particular location or place that is familiar.

Question 34

Clinically, why would it be important to use implants, etc. to stimulate, and activate sensory receptors as soon as possible if there is a deficit for some reason?

Answer 34

• In constraint-induced movement therapy the “good” limb is restrained, forcing use of the desensitized limb.
• This gives a chance for use of the damaged limb and can improve behavioral performance and expands cortical representations for the limb.
• due to learned non-use we need to activate sensory receptors asap if there is a deficit, also need training to understand and learn how to use them again