Learning and Memory 2: Beyond Hippocampus

Question 1

describe the temporal categories of memory (3)

Answer 1

1) Short-term memory _ aka working and immediate memory
- ability to hold information across an undistracted delay
2) Long-term memory (new memories) _ memory of thing not lost by distraction
3) Remote memory _ memory of events many months to years ago

Question 2

what are four kinds of nondeclarative memory?

Answer 2

Nonassociative learning
Classical/Operant/Emotional Conditioning
Procedural learning
Priming

Question 3

what is working memory and how much can it hold?

Answer 3

Mental manipulation and online holding of information over relatively short periods of time.
7 +/- 2 pieces of information, although chunking is possible

Question 4

what are the two divions of working memory and where do lesions affect them?

Answer 4

1) phonologic information (e.g., the ability to keep a phone number in your head)
- lesions in left hemisphere
2) spatial information (e.g., the ability to mentally follow a route that is described to you)
-lesions in right hemisphere

Question 5

what parts of the brain does working memory use?

Answer 5

dorsolateral prefrontal cortex (DLPFC) is implicated in almost all WM tasks
also subcortical and posterior cortical areas

the idea that working memory relies primarily on DLPFC with input from subcortical and posterior cortical regions was on the summary slide of the lecture so might be important

Question 6

what are characteristics of working memory impairment?

Answer 6

Difficulty following multistep commands
Trouble multitasking
Easy loss of task set (forgetting the rules)
Inefficient learning
Reduced contextual memory
Impaired verbal fluency
Impaired comprehension of complex sentences

Question 7

what are conditions that lead to working memory impairment?

Answer 7

Conditions that affect the frontal lobes or their relevant connections:
Examples:
Focal: Infarcts, tumors
Multifocal: e.g., multiple sclerosis
Neurodegenerative: AD, PD, HD, LBD, etc.
Psychiatric: ADHD, OCD, schizophrenia, depression

Question 8

what is consolidation?

Answer 8

the process by which memories are solidified into long-term stores
Consolidation involves gradual transfer of information from hippocampal circuits to neocortical ones

Question 9

what is some evidence that supports that long term storage of memories does not require the hippocampus?

Answer 9

patients who have undergone electroconvulsive therapy (ECT) to treat psychiatric disorders develop a temporally graded retrograde amnesia associated with therapy, such that events leading up to their ECT session are recalled poorly compared to more remote past events. This implies that some process occurs that differentiates remote memories from recently formed ones in a way that makes them more resistant to disruption, and that this process of transferring memories to long-term storage is gradual.

Also Patient H.M. had very clear recall of remote experiences prior to his life-altering surgery and graded memory deficits for the events leading up to the surgery.

Question 10

What might consolidation and long-term storage entail at the neural level?

Answer 10

One well-supported theory is that consolidation strengthens associations between multiple stimulus inputs and activations of previously stores information. The hippocampus is thought to coordinate this strengthening of associations, but the effects are believed to take place in the neocortex.

Question 11

what is interesting about the anatomical representation of long-term memories in the neocortex?

Answer 11

often related to the modality of information being stored.

Calling up representations of visual stimuli activates visual cortical areas, calling up memories of a familiar song activates neuronal assemblies in the auditory cortex, and so forth

Question 12

what is nonassociative learning? Two kinds?

Answer 12

Nonassociative learning results when an animal or person is exposed once or repeatedly to a single type of stimulus

1) Habituation: decrease in response to a benign stimulus when that stimulus is presented repeatedly
2) Sensitization: increased response to various stimuli after a noxious stimulus

Question 13

what is the habituation example with the aplysia?

Answer 13

Habituation of the gill siphon reflex occurs when repeated stimulation of the siphon results in a diminished gill withdrawal reflex.

In a series of investigations it has been shown that the siphon-gill reflex is mediated by a monosynaptic connection between a sensory neuron and a motor effector.

Question 14

what is the sensitization example with the aplysia? What is the underlying mechanism? (more detail next lecture!)

Answer 14

the tail of the animal is stimulated just before the siphon is, then the withdrawal of the gill is quicker and more forceful.

The underlying mechanism appears to involve serotonergic, axoaxonal synapses.

Question 15

in mammals where does nonassociative learning take place?

Answer 15

spinal reflexes

Question 16

does nonassociative learning require conscious awareness?

Answer 16

no

Question 17

what are the three forms of conditioning and how are they different?

Answer 17

classical, operant, and emotional conditioning

Classical conditioning entails learning a relationship between two stimuli.
Operant conditioning involves learning a relationship between an organism_s behavior and the consequences of that behavior.
Emotional conditioning involves the learned association between a stimulus and an emotional response.

Question 18

who introduced classical conditioning?

Answer 18

Pavlov and the dogs!

Question 19

what is an area of the brain implicated in classical conditioning?

Answer 19

cerebellelum
studied with eyeblink reflexes in rabbits

The importance of the cerebellum in classical conditioning is indicated more directly by the fact that electrical stimulation of the two major inputs to the cerebellum can substitute for the conditioned stimulus and unconditioned stimulus

Question 20

how are emotional responses to stimuli developed?

Answer 20

largely implicit

Question 21

what part of the brain plays a large role in emotional conditioning?

Answer 21

amygdala

amygdala is connected to areas of the nervous system that mediate physiologic effects of fear and other emotional states

Question 22

what can lesions of the amygdala result in ?

Answer 22

Klu_ver-Bucy syndrome
Blunted emotionality
Lack of fear response
Altered sexual behavior
Hyperorality
Visual agnosia

Question 23

describe Operant conditioning

Answer 23

Formation of predictive relationships between actions and consequences
- Law of effect –>behaviors that produce favorable changes in the environment are repeated, while behaviors that are followed by aversive consequences are avoided.
- A critical component of decision-making and planning

Question 24

what parts of the brain are involved in operant conditioning?

Answer 24

Dorsomedial frontal cortex implicated in reward-related behavior

Dopaminergic projections from the ventral tegmental area are involved in reward learning

Nucleus Accumbens

Question 25

what is Procedural learning?

Answer 25

Includes many skills –> Description is typically inadequate to transfer ability

Question 26

can H.M do procedural learning?

Answer 26

yes! Writing in mirror

Procedural learning is unconscious

Question 27

what parts of the brain are involved in procedural learning?

Answer 27

Supplementary motor area
Basal ganglia
Cerebellum

Question 28

what causes procedural learning deficits?

Answer 28

Parkinson_s disease
Other movement disorders
Focal lesions - Tumors or Strokes
Depression

Question 29

what is priming?

Answer 29

A benefit in the ability to detect or identify words or objects after recent experience with them

Ability to be primed to stimuli is unrelated to explicit recall of stimuli.
Occurs robustly in patients with anterograde amnesia.
Many kinds of stimuli can be primed, including concepts –> nurse example in slides

Question 30

what does priming improve?

Answer 30

Improves perception for specific stimuli
Affects information available to explicit memory systems
it is modality-specific