Chapter 12: Learning, Memory, and Intelligence

Question 1

Thompson found a localized engram, whereas Lashley did not. What key differences in procedures or assumptions were probably responsible for their different results?

Answer 1

Thompson studied a different, simpler type of learning. Also, he looked in the cerebellum instead of the cerebral cortex.

Question 2

What evidence indicates that the red nucleus is necessary for performance of a conditioned response but not for learning the response?

Answer 2

If the red nucleus is inactivated during training, the animal makes no conditioned responses during the training, so the red nucleus is necessary for the response. However, as soon as the red nucleus recovers, the animal can show conditioned responses at once, without any further training, so learning occurred while the red nucleus was inactivated.

Question 3

Why should we conclude that consolidation depends on more than just holding a short-term memory long enough for protein synthesis?

Answer 3

People can store some memories for hours or days without forming a permanent memory, whereas they form emotionally important memories quickly.

Question 4

What mechanism causes flashbulb memories?

Answer 4

Emotionally exciting memories stimulate the locus coeruleus, which increases norepinephrine throughout the cortex and dopamine to the hippocampus. Emotional excitement also increases epinephrine and cortisol, which activate the amygdala and hippocampus.

Question 5

How does the cortex store a working memory during a delay?

Answer 5

Occasional bursts of gamma oscillations (45 to 100 Hz) occur in cells that responded to a stimulus, but the bursts alternate among cells instead of persisting throughout the delay in any one cell.

Question 6

On what kind of question is someone with Korsakoff’s syndrome most likely to confabulate?

Answer 6

Patients with Korsakoff’s syndrome most often confabulate on questions about themselves. Many confabulations are statements that were true at one time.

Question 7

Why did researchers look for a gene on chromosome 21 as a probable cause of early-onset Alzheimer’s disease?

Answer 7

People with Down syndrome, caused by an extra copy of chromosome 21, almost always develop Alzheimer’s disease in middle age.

Question 8

Dr. Lahey proposed that the cortex works as a whole, and that the more cortex you have, the better. He called this _____.
a. cortical importance
b. mass action
c. equipotentiality
d. the law of engram

Answer 8

mass action

Correct. Lahey proposed the idea of mass action—that the cortex works as one unit and the more cortex the better. However, he based his work on a faulty assumption—that the cerebral cortex was the best and only place to search for an engram. Investigators who discarded his assumptions reached different conclusions.

Question 9

Most scientists have replaced the idea of short-term memory with _____.
a. periodic memory
b. episodic memory
c. amnesia
d. working memory

Answer 9

working memory

Correct. Baddeley and Hitch (1994) introduced the term working memory to refer to the way we store information while we are working with it. A common test of working memory is the delayed response task.

Question 10

Gena has been diagnosed with Korsakoff’s syndrome. As a result of being deficient in ______, she has been experiencing memory loss.
a. vitamin B2
b. vitamin C
c. vitamin B1
d. vitamin D

Answer 10

vitamin B1

Correct. Gena’s damage from Korsakoff’s syndrome is brain damage caused by prolonged thiamine deficiency (vitamin B1). Prolonged thiamine deficiency leads to a loss or shrinkage of neurons throughout the brain, especially in the dorsomedial thalamus, the main source of input to the prefrontal cortex. The symptoms of Korsakoff’s syndrome are similar to those of people with damage to the prefrontal cortex, including apathy, confusion, and memory loss.

Question 11

Which types of memory were most impaired in H. M. and people with similar amnesia?

Answer 11

H. M. had severe anterograde amnesia (difficulty forming new long-term memories) and a severe loss of episodic memories.

Question 12

Which types of memory were least impaired in H. M. and people with similar amnesia?

Answer 12

H. M. had nearly intact working memory, implicit memory, and procedural memory.

Question 13

According to the context hypothesis, why does hippocampal damage impair recent memories more than distant memories?

Answer 13

Recent memories include details of context, and the hippocampus is essential for memory of context. Most old memories include only the gist of the event, and the hippocampus is less important for memories of that type.

Question 14

In addition to an animal’s location, what else do many place cells monitor?

Answer 14

Some also respond to time or the direction the animal is heading

Question 15

What is the evidence that rats can imagine the future?

Answer 15

When a rat pauses at a choice point in a maze, place cells respond in sequence as if the animal were traveling down one arm or another of the maze

Question 16

How do grid cells at ventral levels of the entorhinal cortex differ from those at dorsal levels?

Answer 16

Moving dorsal to ventral, the grid cells respond to larger areas.

Question 17

Which type of memory would be easier to describe in words, memory based on the hippocampus or the striatum?

Answer 17

Hippocampal-based memory, being explicit, is generally easier to describe in words. The habits based on the striatum are sometimes harder to describe.

Question 18

During hospitalization for a severe concussion, Mose got nervous because he didn’t remember anything from the day he got hurt. He is suffering from _____.
a. Korsakoff’s syndrome
b. Broca’s syndrome
c. retrograde amnesia
d. anterograde amnesia

Answer 18

retrograde amnesia

Correct. Mose appears to have retrograde amnesia, which is the loss of memory for events that occurred before the brain damage.

Question 19

Dr. Ankney is using a radial arm maze to demonstrate the importance of the ______ for _____ memory.
a. hippocampus; spatial
b. hippocampus; semantic
c. cerebellum; short-term
d. cerebellum; spatial

Answer 19

hippocampus; spatial

Correct. Several types of evidence demonstrate the importance of the hippocampus and nearby areas for spatial memory. Dr. Ankney finds that rats with damage to the hippocampus can learn to avoid the never-correct arms, but even after much training they often enter a correct arm twice. That is, they forget which arms they have already tried.

Question 20

Dr. Tempel is working with a patient who previously knew what a zebra was. Now, the patient calls a picture of a zebra a “horse” and keeps asking why someone painted the horse a strange pattern. Dr. Tempel’s patient likely has _____.
a. semantic dementia
b. short-term memory loss
c. Korsakoff’s syndrome
d. Alzheimer’s disease

Answer 20

semantic dementia

Correct. People with damage in the anterior temporal cortex suffer semantic dementia, a loss of semantic memory. Dr. Tempel’s patient seems to have lost the memory of a zebra entirely.

Question 21

How can a Hebbian synapse account for the basic phenomena of classical conditioning?

Answer 21

In a Hebbian synapse, pairing the activity of a weaker (CS) axon with a stronger (UCS) axon produces an action potential, and in the process strengthens the response of the cell to the CS axon. On later trials, it will produce a bigger depolarization of the postsynaptic cell, which we can regard as a conditioned response.

Question 22

When serotonin blocks potassium channels on the presynaptic terminal, what is the effect on transmission?

Answer 22

Blocking potassium channels prolongs the action potential and therefore prolongs the release of neurotransmitters, producing an increased response.

Question 23

Before LTP: In the normal state, what is the effect of glutamate at the AMPA receptors? At the NMDA receptors?

Answer 23

Before LTP, glutamate stimulates AMPA receptors but usually has little effect at the NMDA receptors because magnesium blocks them.

Question 24

During the formation of LTP, when a burst of intense stimulation releases much more glutamate than usual at two or more incoming axons, what is the effect of the glutamate at the AMPA receptors? At the NMDA receptors?

Answer 24

During the formation of LTP, the massive glutamate input strongly stimulates the AMPA receptors, thus depolarizing the dendrite. This depolarization enables glutamate to excite the NMDA receptors also

Question 25

After the neuron has gone through LTP, what is now the effect of glutamate at the AMPA receptors? At the NMDA receptors?

Answer 25

After the neuron has gone through LTP, what is now the effect of glutamate at the AMPA receptors? At the NMDA receptors?

Question 26

Why are both brain size and brain-to-body ratio unsatisfactory ways of estimating animal intelligence?

Answer 26

If we consider ourselves to be the most intelligent species, we are confronted with the fact that we have neither the largest brains nor the highest brain-to-body ratios. Total neuron number is a more promising correlate of intelligence.

Question 27

Why do recent studies show a stronger relationship between brain size and IQ than older studies did?

Answer 27

The use of MRI greatly improves the measurement of brain size, in comparison to measurements based on the skull.

Question 28

How do researchers explain why males and females are equal in intelligence despite differences in brain size?

Answer 28

Women’s brains, having deeper sulci, include approximately the same number of neurons as men’s brains. Also, women’s brains have different patterns of connections.

Question 29

The conclusion that genetic variation contributes to variations in human intelligence comes mainly from what type of evidence?

Answer 29

It is based largely on comparisons of monozygotic and dizygotic twins. Also, certain genetic mutations are known to produce intellectual disabilities, and many genetic variations are correlated with small variations of intelligence within the normal population.

Question 30

Why were our ancient ancestors able to evolve larger numbers of neurons than other species?

Answer 30

Because of cooking, cooperative breeding, and upright locomotion, they were able to decrease the energy necessary for other organs and functions.

Question 31

Dr. Pavlov is using classical conditioning to train his dogs. Based on what we know about the pairing of the unconditioned stimulus with the conditioned stimulus and the effect each has on responses, we assume that Dr. Pavlov is relying, at least in part, on _____ synapses.
a. unconditioned
b. Pavlovian
c. Hebbian
d. reconditioned

Answer 31

Hebbian

Correct. A Hebbian synapse is one that can increase its effectiveness as a result of simultaneous activity in the presynaptic and postsynaptic neurons. Such synapses are essential for many kinds of associative learning. Dr. Pavlov would have relied on these synapses to train his dogs.

Question 32

Which of the following is NOT a property of long-term potentiation (LTP)?
a. Specificity
b. Reflexivity
c. Associativity
d. Cooperativity

Answer 32

Reflexivity

Correct. LTP shows three properties that make it an attractive candidate for a cellular basis of learning and memory: specificity (strengthening of active synapses), cooperativity (simultaneous stimulation by two or more axons produces LTP more strongly than does repeated stimulation by just one axon), and associativity (pairing a weak input with a strong input enhances later response to the weak input).

Question 33

Dr. Hewett is trying to come up with a method to improve memory in her patients. What will likely produce the best results?
a. Adapting the neurophysiological methods
b. Developing new chemical methods
c. Utilizing behavioral methods
d. Developing new neuroimmunological methods

Answer 33

Utilizing behavioural methods

Correct. Dr. Hewett knows that behavioral methods to improve memory are her best bet. She should tell her patients that if they want to remember something later, study it well now, rehearse it later, and periodically test themselves. Consistent physical exercise also improves memory, as do good nutrition, adequate sleep, and stress management.

Question 34

Humans and primates have a large _____ mass in proportion to _____ mass.
a. brain; body
b. cerebrum; cerebellum
c. body; brain
d. neuron; glial

Answer 34

brain; body

Correct. In general, log of body mass is a good predictor of log of brain mass. Primates in general and humans in particular have a large brain mass in proportion to body mass.

Question 35

Intelligence has been shown to be affected by ______.
a. both genetics and the environment
b. genetics only
c. the environment only
d. prenatal exposure to hormones

Answer 35

both genetics and the environment

Correct. As with almost any important psychological variable, variations in intelligence reflect contributions from both genetic and environmental influences. This has been demonstrated in studies of twins as well as studies of children who grow up in impoverished conditions.

Question 36

The human brain constitutes ____ percent of the body’s mass, but consumes ____ percent of its fuel.
a. 2; 20
b. 20; 2
c. 2; 50
d. 10; 20

Answer 36

2: 20
Correct. The brain is a metabolically expensive organ. The human brain constitutes 2 percent of the body’s mass, but consumes 20 percent of its fuel.