biopsych chapter 13

learning

the process of acquiring new & relatively enduring information, behavior patterns, or abilities, characterized by modifications of behavior as a result of practice, study, or experience

memory

the ability to learn & neurally encode information, consolidate the information for longer-term storage, & retrieve or reactivate the consolidated information at a later time; the specific information that is stored in the brain

amnesia

severe impairment of memory

retrograde amnesia

difficulty in retrieving memories formed before the onset of amnesia

patient H.M. (the late Henry Molaison)

a man who was unable to encode new declarative memories because of surgical removal of medial temporal lobe structures

anterograde amnesia

difficulty in forming new memories beginning with the onset of a disorder

hippocampus

a medial temporal lobe structure that is important for spatial cognition, learning, & memory

declarative memory

a memory that can be stated or described

nondeclarative memory

a memory that is shown by performance rather than by conscious recollection

delayed non-matching-to-sample task

a test in which the individual must respond to the unfamiliar stimulus in a pair of stimuli

patient N.A.

a still-living man who is unable to encode new declarative memories, because of damage to the dorsomedial thalamus & the mammillary bodies

dorsomedial thalamus

a limbic system structure that is connected to the hippocampus

mammillary bodies

one of a pair of limbic system structures that are connected to the hippocampus

korsakoff’s syndrome

a memory disorder, caused by thiamine deficiency, that is generally associated with chronic alcoholism

confabulate

to fill in a gap in memory with a falsification, often seen in korsakoff’s syndrome

patient K.C. (the late Kent Cochrane)

a man who sustained damage to the cortex that rendered him unable to form & retrieve episodic memories

episodic memory

memory of a particular incident or a particular time & place

semantic memory

generalized declarative memory, such as knowing the meaning of a word

skill learning

the process of learning to perform a challenging task simply by repeating it over & over

basal ganglia

a group of forebrain nuclei, including the caudate nucleus, globus pallidus, & putamen, found deep within the cerebral hemispheres; they are crucial for skill learning

priming

the phenomenon by which exposure to a stimulus facilitates subsequent responses to the same or a similar stimulus

associative learning

a type of learning in which an association is formed between two stimuli or between a stimulus & a response; it includes both classical & instrumental conditioning

classical conditioning

a type of associative learning in which an originally neutral stimulus acquires the power to elicit a conditioned response when presented alone

cerebellum

a structure located at the back of the brain, dorsal to the pons, that is involved in the central regulation of movement & in some forms of learning

instrumental conditioning

a form of associative learning in which the likelihood that an act (instrumental response) will be performed depends on the consequences (reinforcing stimuli) that follow it

cognitive map

a mental representation of the relative spatial organization of objects & information

place cells

a neuron in the hippocampus that selectively fires when the animal is in a particular location

sensory buffers

a very brief type of memory that stores the sensory impression of a scene; in vision, it is sometimes called iconic memory

short-term memories (STMs)

a form of memory that usually lasts only seconds, or as long as rehearsal continues; working memory can be considered a portion of this where information can be manipulated

long-term memories (LTMs)

an enduring form of memory that lasts days, weeks, months, or years; this has a very large capacity

encoding

the first process in the memory system, in which the information entering sensory channels is passed into short-term memory

consolidation

the second process in the memory system, in which information in short-term memory is transferred to long-term memory

retrieval

the third process of the memory system, in which a stored memory is used by an organism

post-traumatic stress disorder (PTSD)

a disorder in which memories of an unpleasant episode repeatedly plague the person

memory trace

a persistent change in the brain that reflects the storage of memory

reconsolidation

the return of a memory trace to stable long-term storage after it has been temporarily made changeable during the process of recall

neuroplasticity

the ability of the nervous system to change in response to experience or the environment

impoverished condition (IC)

an environment for laboratory rodents in which each animal is housed singly in a small cage without complex stimuli

standard condition (SC)

the usual environment for laboratory rodents, with a few animals in a cage & adequate food & water, but no complex stimulation

enriched condition (EC)

an environment for laboratory rodents in which animals are group-housed with a wide variety of stimulus objects

habituation

a form of nonassociative learning in which an organism becomes less responsive following repeated presentations of a stimulus

hebbian synapses

a synapse that is strengthened when it successfully drives the postsynaptic cell

tetanus

an intense volley of action potentials

long-term potentiation (LTP)

a stable & enduring increase in the effectiveness of synapses following repeated strong stimulation

dentate gyrus

a strip of gray matter in the hippocampal formation

glutamate

an amino acid transmitter; the most common excitatory transmitter

NMDA receptors

a glutamate receptor that also binds the glutamate agonist NMDA (N-methyl-D-aspartate) & that is both ligand-gated & voltage-sensitive

AMPA receptors

a fast-acting ionotropic glutamate receptor that also binds the glutamate agonist AMPA

retrograde transmitter

a neurotransmitter that is released by the postsynaptic neuron, diffuses back across the synapse, & alters the functioning of the presynaptic neuron