Brain and Behaviour - Chapter 12: Learning, Memory, and Intelligence

Vocabulary practice flashcards covering localized memory representations, types of memory, amnesia, hippocampal mechanisms, cellular plasticity (LTP/LTD), and the neurobiology of intelligence from Chapter 12 of Biological Psychology by James W. Kalat.

Classical conditioning

A form of associative learning pioneered by Ivan Pavlov in which pairing an unconditioned stimulus with a conditioned stimulus changes the response to the conditioned stimulus.

Conditioned stimulus (CS)

A stimulus that initially evokes no specific response of interest, but comes to elicit a conditioned response after pairing with an unconditioned stimulus

e.g. A sound

Unconditioned stimulus (UCS)

A stimulus that automatically, naturally, and reliably elicits an unconditioned response without any prior training.

e.g. Meat powder

Unconditioned response (UCR)

An automatic, unlearned physiological or behavioral reaction elicited directly by an unconditioned stimulus.

e.g. Salivation from a dog

Conditioned response (CR)

A learned response elicited by a conditioned stimulus after repeated pairings with an unconditioned stimulus.

e.g. A dog salivating at a sound

Instrumental conditioning/ operant conditioning

A learning process in which an individual's voluntary behaviour controls the presentation of a reinforcer or a punishment.

Reinforcer

Any event or stimulus following an operant response that increases the future probability that the response will occur again.

e.g. When a rat enters a maze and finds Froot Loops cereal, its probability of entering that arm at future opportunities increases

Punishment

Any event or stimulus following an operant response that decreases the future probability that the response will occur again.

e.g. When a rat enters a maze and gets shocked its probability of entering that arm at future opportunities increases

The difference between classical and instrumental conditioning

• In instrumental conditioning, the individual’s response determines the outcome (reinforcer or punishment)

• In classical conditioning, the CS and UCS occur at certain times regardless of the individual’s behaviour

Engram

The physical or biochemical representation of what’s been learned in the nervous system,

e.g. A localized neural connection between two brain regions.

Equipotentiality

Karl Lashley's principle stating that all regions of the cerebral cortex contribute equally to complex functioning behaviors, such as learning.

Mass action

Karl Lashley's principle stating that the cortex works as a whole

i.e. Having more preserved cortex yields better complex functioning and learning.

The unnecessary assumptions of Lashley’s conclusions

The cerebral cortex is the best or only place to search for an engram

The unnecessary assumptions of Lashley’s conclusions (con’t)

Studying one example of learning is just as good as studying any other.

Lateral interpositus nucleus (LIP)

A specific cerebellar nucleus identified by Richard F. Thompson and colleagues as the primary site essential for learning conditioned responses

e.g. The eyeblink reflex in rabbits.

Red nucleus

A midbrain motor structure receiving input from the cerebellum where temporary inactivation suppresses the execution of conditioned motor responses, and vice versa

Red nucleus (con’t)

It doesn’t prevent learning from occurring in the cerebellum

Short-term memory

Memory for events that have just occurred, characterized by limited storage capacity and rapid decay without active rehearsal.

Long-term memory

Memory for events from times further back, featuring a virtually unlimited storage capacity, long persistence without continuous rehearsal, and retrievability via cues or hints.

Memory consolidation

The biological process whereby short-term memory traces are stabilized, strengthened, and stored into permanent long-term memory representations.

Flashbulb memories

Accurate, vivid memories of the circumstances surrounding hearing about shocking, highly charged events.

e.g. For the COVID-19 pandemic, it would be a memory of where a person was and what they were doing on the day they found out about the onset of the pandemic, when that day would’ve been unremarkable otherwise

How are flashbulb memories formed

Highly emotional experiences arouse the locus coeruleus, which increases norepinephrine release throughout the cortex and dopamine release in the hippocampus

How are flashbulb memories formed (con’t)

Emotional experiences also increase the secretion of epinephrine and cortisol that activate the amygdala and hippocampus

Synaptic tag-and-capture

A mechanism underlying flashbulb memories where a mild, non-dramatic event that would normally fade is captured and consolidated alongside an emotionally stimulating or dramatic event occurring shortly thereafter.

e.g. One would quickly forget a minor scare like driving on snow and you skidding on a slippery patch; but skidding on a second slippery patch and wrecking the car would form a long-term memory of not only the accident but also the earlier slip.

Working memory

An active system proposed by Baddeley and Hitch emphasizing the temporary storage and simultaneous manipulation of information while working on a cognitive task.

Delayed response task

A standard experimental test of working memory requiring a subject to retain and respond to a brief stimulus presentation after a prescribed delay period.

Why would we have evolved genes to increase forgetting?

One likely hypothesis is that we need to forget outdated information to replace it with new information

Amnesia

A significant loss of memory resulting from brain damage, disease, or psychological trauma.

Brain fog

Long-term cognitive blunting and memory loss commonly reported following recovery from COVID-19 or cancer therapies

Brain fog (con’t)

It’s linked to immune overactivity, impaired cerebral blood flow, cortical gray matter shrinkage, and reduced myelin.

Brain fog’s symptoms

It’s marked by periods of forgetfulness, confusion, slow thinking, and impaired concentration

Brain fog’s possible causes

One hypothesis for brain fog is that the COVID virus causes a powerful reaction by the immune system that produces enough inflammatory cytokines to damage the blood-brain barrier and activate microglia cells that damage neurons and axons

Brain fog’s possible causes (con’t)

The reaction to the virus impairs the blood flow to the brain

Alzheimer's disease

A progressive neurodegenerative disorder associated with severe gradual memory loss, cortical atrophy, amyloid plaques, and neurofibrillary tangles

Alzheimer's disease (con’t)

It gradually progresses to confusion, depression, apathy, hallucinations, delusions, sleeplessness, and loss of appetite

Alzheimer's disease statistics

It affects approximately $50\%$ of individuals over age 85.

Alzheimer's disease and procedural skills

Patients with Alzheimer’s learn procedural skills better than facts.

Alzheimer’s and Down syndrome

Most people with Down syndrome get Alzheimer’s disease if they survive into middle age

Alzheimer’s causes

• Genetics

• Sleep deprivation

• Excessive salt intake

• Lack of exercise

• Type 2 diabetes as insulin activity in the brain is important for storing memories

Plaques and tangles

Histopathological hallmarks of Alzheimer's disease consisting of extracellular deposits of $b\text{-amyloid}$ protein and intracellular accumulations of abnormal tau protein.

The APOE gene

A gene that comes in several forms that makes a protein that contributes to many functions, including lipid metabolism and control of the blood-brain barrier

The APOE gene and down syndrome

People with one copy of the type 4 gene (APOE4) have four times the normal risk of Alzheimer’s, and people with two copies have 15 times the normal risk.

The APOE4 gene and Alzheimer’s disease

The APOE4 gene and at least two other genes are linked to many cases of early-onset Alzheimer’s disease

Tau protein

A part of the intracellular support structure of axons

Amyloid-beta, tau proteins, and Alzheimer’s disease

Alzheimer’s disease is linked to an increase in Amyloid-beta and tau proteins

Amyloid-beta, tau proteins, and Alzheimer’s disease (con’t)

As the chemicals accumulate in neurons, they spread within and among cells, disrupting neurotransmission, damaging axons, dendrites, mitochondria, and triggering waves of microglia that kill neurons

Infant amnesia

The universal tendency in which older children and adults have little to no conscious recollection of events from the first few years of life

Infant amnesia (con’t)

It’s largely attributed to ongoing hippocampal neurogenesis replacing early synaptic traces and underdeveloped encoding skills

Infant amnesia causes

The development of language, or a sense of self, or complex reasoning abilities as children grow older

Anterograde amnesia

The inability to encode and form new lasting memories for events occurring after the onset of brain injury.

Retrograde amnesia

The loss of memories for events, people, or facts acquired prior to the occurrence of brain damage.

Semantic memory

A subtype of explicit declarative memory representing generalized factual knowledge and concepts without reference to personal experience.

e.g. State capitals

Episodic memory

A subtype of explicit declarative memory dedicated to personally experienced events tied to a specific spatial and temporal context

e.g. What you did on April 23rd, 2025

Explicit memory/ declarative memory

Deliberate, conscious retrieval of past information that an individual recognizes and declares as a memory

Implicit memory

An influence of prior experience on current behaviour, choices, or performance without conscious or deliberate awareness of the original memory.

e.g. H. M. became comfortable and familiar with certain people, such as the psychologists who worked with him over the years, although he didn’t remember their names or where he had met them

Procedural memory

A category of implicit memory governing the learning and execution of motor skills, actions, and automatic behavioural habits.

e.g. Riding a bike

Delayed matching-to-sample task

A behavioral task assessing declarative memory in which an animal inspects a sample object and, following a delay, must choose the test stimulus that matches the initial sample.

Delayed nonmatching-to-sample task

A behavioral task evaluating declarative memory where an animal sees a sample object and, after a delay, is rewarded for choosing the unfamiliar object that differs from the original sample.

Sharp-wave ripples

High-frequency synchronous oscillations ($70\text{--}180\,\text{Hz}$) generated in the hippocampus that transmit coordinated information to the cerebral cortex to access and consolidate memories.

Radial maze

An experimental apparatus containing eight or more arms (some having food at the end) extending from a central hub, utilized to test spatial working memory by seeing if an animal avoids revisiting previously cleared arms.

Radial maze (con’t)

In a variation of the task, a rat might learn that the arms with a rough floor never have food or that the arms pointing toward the window never have food

Radial maze and hippocampal damage

Rats with damage to the hippocampus can learn to avoid the incorrect arms, but even after much training, they often enter a correct arm twice due to forgetting which arms they already tried

Morris water maze task

A spatial navigation test where a rodent swims in murky circular pool to locate a hidden rest platform positioned slightly beneath the water surface.

Morris water maze task and hippocampal damage

A rat with hippocampal damage slowly learns to find the platform if it always starts from the same place and can always turn the same direction to find the rest platform

Place cells

Hippocampal pyramidal neurons that fire selectively when an individual occupies a particular physical location within a known environment and faces in a specific direction.

Place cells (con’t)

They modify their responses depending on the environment

Time cells

Hippocampal neurons that respond most strongly at a particular point within a sequence of times

e.g. A rat that has to run on a treadmill for 20 seconds to receive reward

Grid cells

Neurons in the entorhinal cortex that discharge at multiple evenly spaced locations, and are arranged in a regular hexagonal lattice as an animal navigates an environment.

The thing about the place cells and time cells of the hippocampus

They relate to the previous discussion of episodic memory

Striatum

A forebrain basal ganglia structure that mediates slow, probabilistic learning and habit formation relative to one's own body

Striatum (con’t)

It controls aspects of memory different from those of the hippocampus

Striatum’s components

It comprises:

• Caudate nucleus

• The putamen

Why don’t we forget habits?

We continue practicing those skills and habits, plus the habits and skills depend on the striatum, not the hippocampus

Probabilistic learning (statistical learning)

Learning what’ll probably happen under certain circumstances, or what to expect when the outcome isn’t entirely predictable

Semantic dementia

A gradual loss of semantic memory and conceptual knowledge resulting from progressive atrophy of the anterior temporal cortex.

e.g. When one saw a picture of a zebra, they called it a horse but then pointed at the stripes and asked what “those funny things” were; they’d lost the concept of a zebra

Hebbian synapse

A synapse that increases in transmission efficiency due to simultaneous, concurrent electrical activation in both the presynaptic and postsynaptic neurons.

Aplysia

A marine mollusk frequently chosen for neurophysiological investigations of learning and memory because of its relatively small nervous system containing unusually large, easily identifiable neurons.

Habituation

A progressive decrease in behavioral responsiveness to a repetitive, harmless stimulus, caused in Aplysia by a reduction in neurotransmitter release from the sensory neuron onto the motor neuron.

Sensitization

An enhancement in behavioral response to mild environmental stimulation following exposure to an intense noxious stimulus, mediated by serotonin-induced closure of presynaptic potassium channels.

Long-term potentiation (LTP)

A long-lasting increase in synaptic efficacy occurring when one or more presynaptic axons stimulate a postsynaptic dendrite with a rapid, repetitive burst of impulses.

Specificity

A foundational property of long-term potentiation stating that only the specific synapses onto a target dendrite that have been vigorously stimulated become strengthened.

Cooperativity

A property of long-term potentiation where simultaneous stimulation by two or more distinct input axons produces a substantially stronger potentiated response than repeated stimulation of a single axon.

Associativity

A property of long-term potentiation whereby pairing a weak input with a concurrently active strong input enhances subsequent synaptic responsiveness to the weak input.

Long-term depression (LTD)

A sustained decrease in synaptic efficacy that develops when presynaptic axons fire at low rates or remain inactive relative to other afferent inputs.

AMPA receptor

An ionotropic glutamate receptor whose channel opens upon glutamate binding to permit the influx of sodium ($\text{Na}^+$) ions into the postsynaptic neuron, producing membrane depolarization.

NMDA receptor

An ionotropic glutamate receptor channel that is normally obstructed by a magnesium ($\text{Mg}^{2+}$) ion, requiring postsynaptic membrane depolarization before glutamate can open it to allow sodium ($\text{Na}^+$) and calcium ($\text{Ca}^{2+}$) entry.

Retrograde transmitter

A signaling molecule synthesized and emitted by an intensely depolarized postsynaptic dendrite that travels upstream across the synaptic cleft to modify neurotransmitter release from the presynaptic axon terminal.

Intelligence

A concept that includes learning, memory, reasoning, and problem-solving

General intelligence (g)

A theoretical cognitive construct introduced by Charles Spearman reflecting how most people who are above average on any cognitive skill are above average on most of the others also

Genetics and intelligence

Variations in intelligence reflect contributions from both genetic and environmental influences

e.g. Comparisons of monozygotic and dizygotic twins where monozygotic twins resemble each other even if they are reared separately

Why are humans more intelligent than any other life form

Their brains have a significantly higher number of neurons with greater functionality

Why have humans evolved have larger brains compared to other life forms?

Humans refined their hunting, sustenance, and survival skills over time, thus decreasing the amount of energy they need to use