PSYC 550 Biological Bases of Behavior Emotions and Learning.

PSYC 550Biological Bases of

BehaviorEmotions and Learning

Emotions as Response Pattern

• medial nucleus– A group of subuclei of the amygdala that receives sensory

input, including information about the presence of odors and pheromones, and relays it to the medial basal forebrain and hypothalamus.

• lateral nucleus (LA)– A nucleus of the amygdala that receives sensory information

from the neocortex, thalamus, and hippocampus and send projections to the basal, accessory basal, and central nucleus of the amygdala.

• central nucleus (CE)– The region of the amygdala that receives information from

the basal, lateral, and accessory basal nuclei and sends projections to a wide variety of regions in the brain; involved in emotional responses.


• conditioned emotional response– A classically conditioned response that occurs when a

neutral stimulus is followed by an aversive stimulus; usually includes autonomic, behavioral, and endocrine components such as changes in heart rate, freezing, and secretion of stress-related hormones.

• threat behavior– A stereotypical species-typical behavior that warns another

animal that it may be attacked if it does not flee or show a submissive behavior.

• defensive behavior– A species-typical behavior by which an animal defends

itself against the threat of another animal.


• submissive behavior– A stereotypical behavior show by an

animal in response to threat behavior by another animal; serves to prevent an attack.

• predation– Attack of one animal directed at an

individual of another species on which the attacking animal normally preys.


• orbitofrontal cortex– The region of the prefrontal cortex at the base

of the anterior frontal lobes, just above the orbits of the eyes.

• ventromedial prefrontal cortex– The region of the prefrontal cortex at the base

of the anterior frontal lobes, adjacent to the midline.

Communication of Emotions

• volitional facial paresis– Difficulty in moving the facial muscles voluntarily;

caused by damage to the face region of the primary motor cortex or its subcortical connections.

• emotional facial paresis– Lack of movement of facial muscles in response to

emotions in people who have no difficulty moving these muscles voluntarily; caused by damage to the insular prefrontal cortex, subcortical white matter of the frontal lobe, or parts of the thalamus.

Learning

The Nature of Learning

• perceptual learning– Learning to recognize a particular stimulus.

• stimulus-response learning– Learning to automatically make a particular

response in the presence of a particular stimulus; includes classical and instrumental conditioning.


• classical conditioning• Hebb rule

– The hypothesis proposed by Donald Hebb that the cellular basis of learning involves strengthening of a synapse that is repeatedly active when the postsynaptic neuron fires.


• instrumental conditioning– A learning procedure whereby the effects of a particular

behavior in a particular situation increase (reinforce) or decrease (punish) the probability of the behavior; also called operant conditioning.

• reinforcing stimulus– An appetitive stimulus that follows a particular behavior and

thus makes the behavior become more frequent.• punishing stimulus

– An aversive stimulus that follows a particular behavior and thus makes the behavior become less frequent.

• motor learning– Learning to make a new response.

Synaptic Plasticity: Long-Term

Potentiation and Long-Term Depression• long-term potentiation (LTP)

– A long-term increase in the excitability of a neuron to a particular synaptic input caused by repeated high-frequency activity.

• hippocampal formation– A forebrain structure of the temporal lobe, constituting

an important part of the limbic system; includes the hippocampus proper (Ammon’s horn), dentate gyrus, and subiculum.

• entorhinal cortex– A region of the limbic cortex that provides the major

source of input to the hippocampal formation.


Potentiation and Long-Term Depression• dentate gyrus

– Part of the hippocampal formation; receives inputs from the entorhinal cortex and projects to the filed CA3 of the hippocampus.

• perforant path– The system of axons that travel from cells in the entorhinal

cortex to the dentate gyrus of the hippocampal formation.• field CA3

– Part of the hippocampus; receives input from the dentate gyrus and projects to the field CA1.

• pyramidal cell– A category of large neurons with a pyramid shape; found in

the cerebral cortex and Ammon’s horn of the hippocampal formation.

Synaptic Plasticity: Long-Term Potentiation and Long-Term Depression

• field CA1– Part of the hippocampus; receives inputs from field CA3 and

projects out of the hippocampal formation via the subiculum.• population EPSP

– An evoked potential that represents the EPSPs of a population of neurons.

• associative long-term potentiation– A long-term potentiation in which concurrent stimulation of

weak and strong synapses to a given neuron strengthens the weak ones.

• NMDA receptor– A specialized ionotropic glutamate receptor that controls a

calcium channel that is normally blocked by Mg2+ ions; involved in long-term potentiation.


Potentiation and Long-Term Depression

• nitric oxide synthase– An enzyme responsible for the production

of nitric oxide.• long-term depression (LTD)

– A long-term decrease in the excitability of a neuron to a particular synaptic input caused by stimulation of the terminal button while the postsynaptic membrane is hyperpolarized of only slightly depolarized.

Perceptual Learning

• short-term memory– Memory for a stimulus or an event that

lasts for a short while.

• delayed matching-to-sample task– A task that requires the subject to indicate

which of several stimuli has just been perceived.

Instrumental Conditioning and Motor Learning

• medial forebrain bundle (MFB)– A fiber bundle that runs in a rostral-caudal direction

though the basal forebrain and lateral hypothalamus; electrical stimulation of these axons is reinforcing.

• ventral tegmental area (VTA)– A group of dopaminergic neurons in the ventral

midbrain whose axons form the mesolimbic and mesocortical systems; plays a role in reinforcement.

• nucleus accumbens– A nucleus of the basal forebrain near the septum;

receives dopamine-secreting terminal buttons from neurons of the ventral tegmental area and is thought to be involved in reinforcement and attention.

Relational Learning

• anterograde amnesia– Amnesia for events that occur after some disturbance to

the brain, such as head injury or certain degenerative brain diseases.

• retrograde amnesia– Amnesia for events that preceded some disturbance to the

brain, such as a head injury or electroconvulsive shock.• Korsakoff’s syndrome

– Permanent anterograde amnesia caused by brain damage resulting from chronic alcoholism or malnutrition.

• confabulation– The reporting of memories of events that did not take

place without the intention to deceive; seen in people with Korsakoff’s syndrome.

Relational Learning

• perirhinal cortex– A region of limbic cortex adjacent to the

hippocampal formation that, along with the parahippocampal cortex, relays information between the enthorhinal cortex and other regions of the brain.

• parahippocampal cortex– A region of limbic cortex adjacent to the

hippocampal formation that, along with the perirhinal cortex, relays information between the entorhinal cortex and other regions of the brain.

Relational Learning

• episodic memory– Memory of a collection of perceptions of

events organized in time and identified be a particular context.

• semantic memory– A memory of facts and general information.

• semantic dementia– Loss of semantic memories caused by

progressive degeneration of the neocortex of the lateral temporal lobes.

LTP seems to be dependent on the

presence of:

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Which part of the brain is best known for identifying social

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PSYC 550 Biological Bases of Behavior Emotions and Learning.

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