Chapter 12 book notes Flashcards
Thompson found a localized engram, whereas Lashley did not. What key differences in procedures or assumptions were probably responsible for their different results?
Thompson studied a different type of learning. Also, he looked at the cerebellum instead of the cerebral cortex
What evidence indicated that the red nucleus is necessary for performing the conditioned eyelid response but not for learning it?
When the red nucleus was inactivated during training, the animal made no conditioned responses, so the red nucleus is necessary for the response. However, as soon as the red nucleus recovered, the animal exhibited conditioned responses, so learning occurred while the red nucleus was inactivated.
Why should we conclude that consolidation depends on more than just holding a short-term memory long enough for protein synthesis?
People can store some memories for hours or days without forming a permanent memory, whereas they form emotionally important memories quickly.
What mechanism causes flashbulb memories?
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.
How does the cortex store a working memory during a delay?
Activity reverberates among cortical cells and between the thalamus, maintaining a simplified code of just the info needed for a response.
Why did researchers look for a gene on chromosome 21 as a probable cause for early-onset Alzheimer’s disease?
Most people with Down syndrome, caused by an extra copy of chromosome 21, develop Alzheimer’s disease in middle age.
Which gene, and what chemicals, are most strongly linked to Alzheimer’s disease?
The APOE4 gene increases the risk of Alzheimer’s disease. Two chemicals accumulate in this disease: (Beta)-amyloid and tau protein
What are the consequences of the rapid formation of new neurons in an infant hippocampus?
Rapid formation of new neurons in the infant hippocampus facilitates new learning, but at the cost of also increasing forgetting
Keyword: classical conditioning
Pairing two stimuli together and changing the response to one of them
Keyword: conditioned stimulus (CS)
A stimulus that elicits no response
Keyword: unconditioned stimulus (UCS)
A stimulus that elicits an unconditioned response
Keyword: unconditioned response (UCR)
An automatic response to the unconditioned stimulus
Keyword: conditioned response (CR)
A new response to the conditioned stimulus, made after pairing the unconditioned stimulus with the conditioned stimulus
Keyword: instrumental learning
AKA Operant learning; a response leads to a reinforcer or punishment
Keyword: reinforcer
Increases the future probability of a response
Keyword: punishment
Suppresses the frequency of a response
Keyword: engram
The physical representation of what has been learned
Keyword: equipotentiality
All parts of the cortex contribute equally to complex behaviors such as learning
Keyword: mass action
More cortex is better
Keyword: short-term memory
Memories of events that have just occurred
Keyword: long-term memory
Memories of events from further back
Keyword: consolidate
Strengthen
Keyword: working memory
Refers to the way we store information while we work on it
Keyword: delayed response task
A task in which one responds to something they saw or heard a short while ago
Keyword: amnesia
Memory loss
Keyword: Alzheimer’s disease
Most common form of severe memory loss
Keyword: APOE
This gene makes a protein that contributes to many functions, including lipid metabolism and control of the blood-brain barrier
Keyword: (Beta)-amyloid
One of two major chemicals that contribute to Alzheimer’s disease
Keyword: tau protein
One of two major chemicals that contribute to Alzheimer’s disease
Keyword: infant amnesia
Universal experience that older children and adults remember very little of what happened in their first few years
What evidence led Lashley to draw his conclusions of equipotentiality and mass action?
Impairment of learning depended on the amount of damage rather than the location
Which of Lashley’s assumptions did researchers later reject?
Any convenient example of learning reveals the mechanisms for all learning
Why did Thompson conclude that eye-blinking conditioning did not depend on the red nucleus?
Rabbits learned from training while the red nucleus was suppressed
Why did Hebb infer a difference between short-term and long-term memory?
Some memories form quickly and some are permanent
How does emotional arousal facilitate consolidation?
Increased release of norepinephrine, epinephrine, and cortisol
How does the cortex store a working memory?
Reverberating activity between the thalamus and the cortex
People with which condition are more likely to develop Alzheimer’s disease in middle age?
Down syndrome
What is known about the heritability of Alzheimer’s disease?
Early-onset Alzheimer’s disease has a higher heritability than later-onset Alzheimer’s disease
Currently, what seems to be the most promising explanation for infant amnesia?
Forming many new memories in infants replaces old ones
What general point do the studies of H.M. and similar patients tell us about the nature of memory?
Episodic memory differs from semantic memory, explicit memory differs from implicit memory, and declarative memory differs from procedural memory. In each case, brain damage can impair one without the other
What brain activity occurs when you recall an episodic memory?
The hippocampus retrieves information from cortical areas in the proper sequence
Why does recent episodic memory include more detail than older memories?
The hippocampus stores detailed episodic memories, and the cortex stores semantic memories and general relationships. As time passes, the hippocampal representation fades.
What evidence indicates that hippocampal ripples represent efforts to remember something?
The ripples last longer when people recall an autobiographical event, and especially when they have to struggle to recall it
In addition to an animal’s location, what else do many place cells monitor?
Some also respond to time or the direction the animal is heading
What is the evidence that rats can imagine the future?
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
How do place cells and time cells relate to episodic memory?
Episodic memories almost always include the location of the remembered event, and often the approximate time as well
Would Parkinson’s disease patients be more impaired at learning new facts or at acquiring new habits?
Parkinson’s disease patients are more impaired at acquiring new habits. Habit learning depends on the striatum more than the hippocampus, and the striatum is damaged in Parkinson’s disease
In probabilistic learning situations, how does initial learning differ from later learning?
At first, responding depends on declarative memory controlled by the hippocampus. After extensive practice, the striatum develops habits of responding that weigh many types of information to produce the most accurate responding
Key term: anterograde amnesia
Inability to form memories for events after brain damage
Key term: retrograde amnesia
Loss of memories for events prior to brain damage
Key term: semantic memories
Memories of factual information
Key term: episodic memory
Memory of personal events
Key term: explicit memory
Deliberate recall of information that one recognizes as a memory, AKA declarative memory
Key term: declarative memory
Deliberate recall of information that one recognizes as a memory, AKA explicit memory
Key term: implicit memory
Influence of experience on behavior, even if one is unaware of it
Key term: delayed matching-to-sample task
An animal sees an object and, after a delay, gets to choose between two objects, from which it must choose the previously displayed one
Key term: delayed nonmatching-to-sample task
Similar to the delayed matching-to-sample task except the object is different from the sample
Key term: sharp-wave ripples
Messages bounced back and forth between the hippocampus and cerebral cortex to reactivate a memory
Key term: radial maze
Key term: Morris water maze
Key term: place cells
Key term: time cells
Key term: grid cells
Key term: striatum
Part of the basal ganglia consisting of the caudate nucleus and the putamen
Key term: probabilistic learning
Statistical learning—learning what will probably happen under certain circumstances, or what to expect when the outcome is not entirely predictable
Key term: semantic dementia
A loss of semantic memory
What is antegrade amnesia?
Inability to form new memories
What is most impaired in patients with hippocampal damage?
Ability to imagine the future
What was most severely impaired in patient H.M.?
Episodic memory
What type of memory does the delayed match to sample task measure?
Declarative memory
How does memory storage in the hippocampus relate to memory storage in the cortex?
They develop in parallel from the start
What do sharp wave ripples in the hippocampus apparently indicate?
Effort to recall a memory
What type of memory do the radial maze and Morris water maze test?
Spatial memory
Evidence that rats can imagine the future came from recordings from what type of cell?
Place cells
Why are certain cells in the entorhinal cortex called grid cells?
They respond to locations distributed in a hexagonal grid
The striatum is primarily responsible for which type of learning?
Gradual learning habits
Which brain area is most important for gradual probabilistic learning?
Striatum
If someone can answer questions about personal experiences, but never volunteers much about them, and describes them as if they happened to someone else, where is the probable damage?
Locus coeruleus
How can the Hebbian synapse account for the basic phenomenon of classical conditioning?
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 the conditioned response
When sodium blocks potassium channels on the presynaptic terminal, what is the effect on transmission?
Blocking potassium channels prolongs the action potential and therefore prolongs the release of neurotransmitters, producing an increased response
Before LTP, what is the effect of glutamate at the AMPA receptors? at the NMDA receptors?
Before LTP, glutamate stimulates AMPA receptors but usually not the NMDA receptors, because magnesium blocks them
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?
The massive glutamate input stimulates the AMPA receptors enough to depolarize the dendrite and enable glutamate to excite the NMDA receptors
After the neuron has gone through LTP, what is now the effect of the glutamate at the AMPA receptors? At the NMDA receptors?
After LTP has been established, glutamate stimulates the AMPA receptors more than before, mainly because of an increased number of AMPA receptors. At the NMDA receptors, it is again usually ineffective.
Why should you be unimpressed with the statement that a supplement has been “clinically tested”? Why should you be unimpressed by a testimonial that a “product works for me”?
Being clinically tested says nothing about the results of the test. A testimonial is no substitute for a double-blind, placebo-controlled experiment.
Key term: Hebbian synapse
Key term: habituation
Key term: sensitization
Key term: long-term potentiation (LTP)
Key term: specificity
If some of the synapses on a cell have been highly active and others have not, only the active ones become strengthened
Key term: cooperativity
Nearly simultaneous stimulation by two or more axons produces LTP more strongly than does repeated stimulation by just one axon
Key term: associativity
Paring a weak input with a strong input enhances later responses to the weaker input
Key term: long-term depression (LTD)
A prolonged decrease in response at a synapse, occurs for axons that have been less active than others
Key term: AMPA receptor
Key term: NMDA receptor
Key term: BDNF
Brain-derived neurotrophic factor
Key term: retrograde transmitter
What is true about the Hebbian synapse?
It strengthens as a result of experience
Cells that fire together wire together, but only under what condition?
The cells are close together
Why is Aplysia an appealing animal for studies of the physiology of learning?
The neurons are the same from one individual to another
What causes habituation in Aplysia?
A change at a synapse
What is meant by the “associativity” of LTP?
Pairing two stimuli increases responsiveness to the weak one
How do AMPA and NMDA synapses differ?
They respond differently to different drugs
Why are NMDA receptors usually unresponsive?
Magnesium ions block their channel
Which ion enters through an NMDA channel when the synapse is stimulated?
Calcium
In the United States, is it possible to market a supplement that produces only placebo effects?
Yes, if the advertisements do not make unverified claims
What evidence supports the conclusion that genetic variation contributes to variations in human intelligence?
The evidence is based largely on comparisons of monozygotic and dizygotic twins. Also, genetic mutations can produce intellectual disabilities.
Why are brain size and brain-to-body ratio unsatisfactory ways of estimating animal intelligence?
If we consider ourselves to be the most intelligent species, we are confronted with the fact we have neither the largest brains nor the highest brain-to-body ratios. Total neuron number is a more promising correlate of intelligence.
Why do recent studies show a higher relationship between brain size and IQ than older studies did?
The use of MRI greatly improves the measurement of brain size in comparison to measurements based on the skull
Why were our ancient ancestors able to evolve a larger number of neurons than other species?
Because of cooking, cooperative breeding, and upright locomotion, they were able to decrease the energy necessary for other organs and functions
What is meant by the g factor of intelligence?
General
The evidence for a genetic factor of intelligence comes mainly from what type of research?
Comparison of twins
Human brains exceed those of all other species in what regard?
Number of neurons
Why would it be a mistake to measure people’s intelligence by measuring their brains?
The correlation between brain size and intelligence is low
When researchers selectively bred guppies for large brains, what occurred?
The guppies decreased their reproduction
Theorists believe that early humans were able to evolve greater intelligence because of an improvement in what?
Nutrition
