Lecture 9: Learning and Memory 1 Flashcards
Who was patient H.M., and why did he undergo brain surgery?
H.M. (Henry Molaison) was a patient with severe epilepsy who underwent a bilateral medial temporal lobotomy to treat his condition.
What was the purpose of the medial temporal lobotomy in H.M.’s case?
The surgery aimed to alleviate his epilepsy, but it was an invasive and imprecise procedure.
What cognitive impairment did H.M. experience after his surgery?
He developed anterograde amnesia, meaning he was unable to form new memories after the surgery.
Who was the main researcher studying H.M.s condition?
Brenda Milner, a British-Canadian neuropsychologist, was the first to document the cognitive damage from the surgery.
How many other patients underwent similar surgeries to H.M.?
Eight other patients also had the surgery
Why is H.M.’s case considered ethically questionable?
The surgery was performed with limited knowledge of its risks and benefits, making its ethical acceptability debatable.
What was William Beecher Scoville’s attitude toward the surgery?
Scoville, the surgeon, prioritized action over thought and may have been motivated by career advancement rather than just therapeutic outcomes.
How did H.M.’s case impact medical practices regarding epilepsy surgery?
It highlighted the severe cognitive consequences of such surgeries, leading to a shift toward less invasive and more precise methods.
What brain structures were affected by H.M.’s surgery?
The surgery damaged the hippocampus (the intended target), amygdala, entorhinal cortex, and fully removed the parahippocampal cortex.
Why is it difficult to attribute H.M.’s memory impairments to a single brain region?
Multiple brain structures were damaged, making it impossible to determine which specific area was responsible for the memory deficits.
What was the broader impact of H.M.’s case on neuroscience?
It was a crucial starting point for human cognitive neuroscience, helping researchers link brain damage to cognitive functions.
What is the mirror tracing task, and why is it difficult?
The mirror tracing task requires tracing an image while viewing it in a mirror, making movements reversed and contradicting previous hand-eye coordination learning.
What type of learning does the mirror tracing task measure?
It measures motor skill learning but also requires unlearning previous motor habits, making it not “process pure.”
How is learning measured in the mirror tracing task?
Learning is measured by counting the number of tracing errors, which decrease over multiple training days.
What does the error rate on day 3 of the mirror tracing task indicate?
It reflects the cumulative learning from day 1 and day 2, showing that learning is retained over multiple days.
How did H.M. perform on the mirror tracing task?
He showed a normal motor learning curve, meaning he improved with practice despite his brain lesions.
Why was H.M.’s ability to learn the mirror tracing task surprising?
His brain lesions suggested that learning should be impaired, but his ability to improve indicated that motor learning occurs outside the damaged regions.
Could H.M. consciously remember doing the mirror tracing task before?
No, if asked, he would say he had never done the task before, despite showing improvement.
What type of memory was impaired in H.M.?
His declarative memory (which stores names, dates, facts, and events) was impaired.
What is a single dissociation in cognitive neuroscience?
It occurs when a person can do one cognitive task but not another, like H.M. who could learn a motor task but not remember doing it.
What is a double dissociation?
It occurs when another person with different brain damage shows the opposite pattern—struggling with motor learning but retaining declarative memory.
What conclusion was initially drawn about the hippocampus from H.M.’s case?
Researchers claimed that the hippocampus was crucial for declarative memory but not skill learning.
Why was the claim about the hippocampus overstated?
H.M.’s lesions were extensive, making it unclear whether declarative memory relies solely on the hippocampus or a broader network of brain regions.
What did later research reveal about learning and brain areas?
Learning requires a wide network of brain regions, rather than being confined to the hippocampus alone.
What was Karl Lashley trying to discover in his experiments?
He aimed to find the cortical engram—the specific brain location for learning and memory, particularly in maze navigation.
What were Lashley’s key findings about memory storage?
Learning was not stored in one specific location; instead, impairments increased as more cortex was removed, supporting the principle of mass action.
What is the principle of equipotentiality?
It suggests that if one part of the cortex is damaged, other areas can take over its function.
How did different types of cortical cuts affect learning performance?
Perpendicular cuts had little effect, while undercutting slabs of cortex caused significant impairment, suggesting brain circuits run vertically.
How did Lashley’s research change our understanding of memory in the brain?
It showed that memory is widely distributed across the cortex rather than being localized to a single brain area.
Why is it problematic to claim that a specific brain system directly causes a psychological process?
True causality requires direct manipulation of the brain system and observing reliable changes in the psychological process, which is ethically impossible in humans.
Why do lesion studies in humans provide limited causal evidence?
Brain damage from surgery or accidents is often widespread, affecting multiple systems, and psychological changes may result from other factors like trauma or inflammation.
What is a major limitation of brain imaging techniques like MRI and CT scans?
They provide only correlational data with low resolution, meaning they show activity levels but cannot determine what function an area performs.
How can animal studies help establish causal links between brain areas and behaviour?
Researchers can precisely manipulate brain function in animals, allowing for controlled experiments on behaviour, though generalising findings to humans is limited.
What is triangulation, and how does it strengthen neuropsychological research?
Triangulation combines evidence from human scans, lesion studies, and animal experiments to make stronger inferences about brain-behaviour relationships.
How is the hippocampus removed in monkeys compared to rats?
In monkeys, suction is applied from below, whereas in rats, access is gained from the top.
What is a major confound in hippocampal lesion studies across species?
The method of removal unintentionally damages different cortical areas—rhinal cortex in monkeys and parietal cortex in rats—potentially influencing results.
Why is it important to acknowledge confounds in lesion studies?
Unintended cortical damage may alter results, making it harder to isolate the role of the hippocampus in psychological functions.
What are some more precise techniques for studying brain function?
Pharmacological agents (often reversible) allow temporary manipulation, and electrophysiology uses electrodes to stimulate or record neuron activity during tasks.
What is the ultimate goal of these experimental techniques?
To enable more accurate causal claims about how specific brain systems contribute to psychological processes.
How is the hippocampus removed in monkeys compared to rats?
In monkeys, suction is applied from below, whereas in rats, access is gained from the top.
What is a major confound in hippocampal lesion studies across species?
The method of removal unintentionally damages different cortical areas—rhinal cortex in monkeys and parietal cortex in rats—potentially influencing results.
Why is it important to acknowledge confounds in lesion studies?
Unintended cortical damage may alter results, making it harder to isolate the role of the hippocampus in psychological functions.
What are some more precise techniques for studying brain function?
Pharmacological agents (often reversible) allow temporary manipulation, and electrophysiology uses electrodes to stimulate or record neuron activity during tasks.
What is the ultimate goal of these experimental techniques?
To enable more accurate causal claims about how specific brain systems contribute to psychological processes.
How is long-term memory (LTM) categorized?
LTM is divided into declarative memory (episodic and semantic) and non-declarative memory (skills and emotional conditioning).
What did HM’s case reveal about different types of memory?
He had intact procedural skill learning (e.g., mirror tracing) but impaired declarative memory, meaning he could not recall past experiences.
Why was HM’s case insufficient to isolate the role of the hippocampus?
His lesions were too extensive, affecting multiple brain regions, making it unclear whether the hippocampus alone caused his memory impairment.
What is the delayed non-matching to sample task, and why is it used?
A primate learns that a previously rewarded object (e.g., a key) will not be rewarded next time, encouraging a win-shift strategy. It helps test episodic memory and hippocampal function.
What is the key question researchers aim to answer using this task?
Whether hippocampal lesions impair episodic learning in a similar way to HM’s memory deficits.
How did selective hippocampal lesions affect memory performance in monkeys?
Monkeys with only hippocampal lesions had a small reduction in performance, while larger lesions involving additional cortical areas led to greater deficits.
What pattern of impairment was observed with increasing lesion size?
The more brain regions were damaged (hippocampus → parahippocampus → perirhinal + entorhinal cortex), the worse the memory impairment became.
How does this study relate to Lashley’s principle of mass action?
Like Lashley’s findings in maze learning, this study showed that memory is not localized to a single site, but rather, larger lesions cause greater deficits.
What does this study suggest about brain organization for memory?
It discourages the idea that single brain regions control specific psychological functions, supporting the view that memory relies on large, interconnected networks.
How do these findings challenge simple brain-behaviour claims?
They show that psychological functions are not confined to single brain areas but depend on integrated systems that extend across multiple regions.
Which brain region is responsible for procedural skill learning, such as in the mirror tracing task?
The basal ganglia and striatal region support procedural skill learning.
What brain area is critical for emotional conditioning, such as fear conditioning?
The amygdala plays a key role in emotional conditioning.
Which neural structures support low-level motor conditioning and simple reflexes?
Eyeblink conditioning relies on the cerebellum, while simple reflexes are controlled by the brainstem, which is closely linked to the cerebellum.
How does priming relate to Lashley’s maze learning experiments?
Priming—where prior exposure to a stimulus improves response—may have helped rats navigate mazes by sequentially activating memory for the next turn. Cortical lesions likely impaired this process.
Why is it misleading to say “Brain area X plays a role in psychological function Y”?
Most tasks are not process pure—they require multiple forms of memory. It’s more accurate to say “Brain area X is required for performance of task Y” rather than assuming it only supports a single psychological function.
What is Aplysia, and why is it used in learning studies?
Aplysia is a sea mollusc used to study cellular learning processes due to its simple nervous system and its gill withdrawal reflex, which responds to threats.
How does Aplysia’s gill withdrawal reflex help in studying learning?
Researchers tap Aplysia’s siphon, mimicking a potential threat, and measure the extent of gill withdrawal to study learning and memory processes.
What is habituation, and how is it demonstrated in Aplysia?
Habituation occurs when repeated siphon taps lead to less gill withdrawal, as Aplysia learns the tap is non-threatening.
What type of learning is habituation?
Habituation is non-associative learning—Aplysia learns that the siphon tap predicts nothing harmful rather than associating two stimuli.
Why is the Aplysia model useful for studying neural learning mechanisms?
Its simple nervous system allows researchers to track cellular changes during learning, providing insight into basic neural mechanisms.
How is the duration of habituation memory measured in Aplysia?
By tracking the duration of gill withdrawal in response to siphon taps over multiple testing sessions (T1–T4) and recall tests (R1–R3).
What do the recall tests (R1, R2, R3) show about memory retention?
R1 (1 day later) and R2 (1 week later) show good retention, but R3 (3 weeks later) shows partial memory decay.
Why were two experiments conducted on habituation memory?
To ensure the results were reproducible and not just due to chance.
What does this study suggest about the stability of habituation memory?
Habituation memory is long-lasting but gradually decays over weeks.
Why is Aplysia an important model for studying learning?
It allows researchers to test cellular mechanisms of learning in a simple and controlled system.
What is classical conditioning?
It is learning an association between two or more things that are statistically related in the environment.
Why has classical conditioning evolved?
To help organisms encode statistical regularities in their surroundings for adaptive behavior.
What types of organisms have been used to study classical conditioning at the cellular level?
Aplysia, fruit flies, honeybees, flatworms, pond snails, anemones, and nematode worms.
How does classical conditioning differ from habituation?
Classical conditioning involves associating stimuli, while habituation involves ignoring a repeated, irrelevant stimulus.
What is an example of classical conditioning in animals?
A dog learning to salivate at the sound of a bell after repeated pairings with food (Pavlovian conditioning).
What was Pavlov originally studying in dogs?
How saliva promotes digestion, collecting saliva to analyze its role.
What unexpected observation led Pavlov to study conditioning?
Dogs began salivating before food appeared, just upon seeing Pavlov enter the room.
How did Pavlov systematically test this phenomenon?
He paired a metronome sound (conditioned stimulus) with food (unconditioned stimulus) to create a learned salivary response.
What did Pavlov’s experiment demonstrate?
Animals can learn associations between neutral stimuli (metronome) and biologically relevant stimuli (food).
How did the dogs’ response change after repeated pairings of the metronome and food?
They salivated at the metronome alone, expecting food—showing classical conditioning.
What is temporal contiguity in classical conditioning?
The conditioned stimulus (CS) must occur before the unconditioned stimulus (US) to be effective—acting as a predictive warning signal.
What is the blocking effect in conditioning?
If an existing CS already fully predicts the US, a new CS won’t be learned—learning only occurs if the new CS improves prediction.
Why does blocking demonstrate that conditioning is selective?
It shows that the brain optimizes learning by only acquiring useful, non-redundant information about the environment.
How does classical conditioning shape daily life?
It helps us form expectations—whenever we anticipate something based on past experiences, classical conditioning is at work.
How does classical conditioning ensure adaptive behavior?
It allows organisms to predict important events, preparing them to respond appropriately to their environment.
Why is eye blink conditioning more convenient than Pavlov’s model?
It only requires observing an eye blink, rather than collecting saliva, making it easier to measure.
What is the reflex pathway in eye blink conditioning?
An air puff to the eye naturally triggers a blink via the cranial nerves.
How does conditioning occur in eye blink experiments?
A sound (CS) is paired with an air puff (US) until the sound alone elicits a blink (CR).
What does cerebellar damage reveal about learning?
It impairs eye blink conditioning, showing that the cerebellum is crucial for learning conditioned reflexes.
How does eye blink conditioning help in neuroscience?
It allows researchers to deduce neural circuits involved in simple conditioned reflexes.
What is the key difference between classical conditioning and operant learning?
Classical conditioning involves learning associations between stimuli, while operant learning involves learning the relationship between one’s own actions and their consequences.
How did Thorndike study operant learning?
He placed cats in a box, where they learned to press a lever to escape.
What did Thorndike observe about the learning curve?
Learning was gradual, not sudden insight, as cats became incrementally faster rather than showing an immediate breakthrough.
What is Thorndike’s Law of Effect?
Behaviours followed by positive outcomes (e.g., escape) become stronger, reinforcing the association between the situation and response.
How does the Law of Effect explain learning?
It suggests that pleasure strengthens stimulus-response associations, leading to habit formation over time.
What is spatial learning, and why is it important?
Spatial learning involves understanding where things are in space to aid navigation, such as in maze learning or finding a home location.
How did Charles Turner study spatial learning in ants?
He observed ants using landmarks like leaves to navigate back to their nest. When he moved the landmarks, the ants searched in the wrong place, showing they relied on landmarks.
What did Nico Tinbergen discover about digger wasps?
Digger wasps used landmarks to locate their nests. When Tinbergen moved the landmarks, the wasps searched in the wrong location, proving they depended on these cues.
What is the Morris water maze, and what does it test?
The Morris water maze is an experiment where rats swim to a hidden platform using landmarks outside the bath, testing their spatial learning and memory.
How is the hippocampus related to spatial learning?
The hippocampus plays a key role in processing spatial memory, and its cellular mechanisms have been studied extensively in the Morris water maze.
What are the different types of memory storage?
Memory is divided into:
- Sensory buffer (temporary storage for stimuli, e.g., between visual saccades).
- Working memory (short-term holding of information, e.g., remembering a number before writing it down).
- Intermediate memory (requires repeated learning before becoming long-term through consolidation).
What are the possible outcomes for information in short-term memory (STM)?
Information in STM can either:
- Be used and forgotten or
- Be consolidated into long-term memory (LTM) for later retrieval.
How does fear conditioning in rats demonstrate memory consolidation?
Rats learn to freeze in a context that signals shock. Memory is tested months later to see if they still recall the association.
How does hippocampal damage affect fear memory over time?
Lesions to the hippocampus impair memory if done 1 day after learning but not 28 days later, suggesting memory transfers away from the hippocampus over time.
What brain region stores fear memory after consolidation?
The cortex stores fear memory by day 28, as shown by the fact that cortical lesions impair memory at this stage, but not at day 1.
