PSYC 550 Biological Bases of Behavior Emotions 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. Emotions as Response Pattern • 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. Emotions as Response Pattern • 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. Emotions as Response Pattern • 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. Copyright © Allyn & Bacon 2007 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. The Nature of Learning • 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. The Nature of Learning • 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: LongTerm 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. Synaptic Plasticity: Long-Term 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. Synaptic Plasticity: Long-Term 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: cortisol dopamine glutamate vasopressin 10 si n pr es so va gl ut a m at e m in e pa do rt is ol 25% 25% 25% 25% co 1. 2. 3. 4. pu s x 10 am oc ip p H da rb ito fr on ta m yg O A lc or te la 25% 25% 25% 25% O TEO Amygdala Orbitofrontal cortex Hippocampus TE 1. 2. 3. 4. Which part of the brain is best known for identifying social emotions?