Chapter 11: Learning, Memory, and Amnesia

Amnesia

loss of memory

anterograde amnesia

an inability to form new memories

basal forebrain

A midline area of the forebrain, which is located just in front of and above the hypothalamus and is the brain's main source of acetylcholine

bilateral medial temporal lobectomy

The removal of the medial portions of both temporal lobes, including the hippocampus, the amygdala and the adjacent cortex

CA1 subfield

The region of the hippocampus that is commonly damaged by cerebral ischemia

concept cells

Cells, such as those found in the medial temporal lobe, that respond to ideas or concepts rather than to particulars. Also known as Jennifer Aniston neurons

delayed nonmatching-to-sample test

a test in which the subject is presented with an unfamiliar sample object and then, after a delay, is presented with a choice between the sample object and an unfamiliar object, where the correct choice is the unfamiliar object

dual-trace theory

The theory that memories are temporarily stored in the hippocampus until they can be transferred to a more stable cortical storage system. Also known as standard consolidation theory.

electroconvulsive shock

a brief pulse of electricity that is passed through the brain and can severely disrupt newly formed memories; electroconvulsive therapy is sometimes used to alleviate severe depression

Engram

a change in the brain that stores a memory

Engram cells

neurons that maintain an engram

entorhinal cortex

an area of the medial temporal cortex that is a major source of neural signals to the hippocampus

episodic memories

Explicit memories for the particular events and experiences of one's life

explicit memories

conscious memories

global amnesia

amnesia for information presented in all sensory modalities

global cerebral ischemia

an interruption of blood supply to the entire brain

grid cells

entorhinal neurons that each have an extensive array of evenly spaced place fields, producing a pattern reminiscent of graph paper

implicit memories

Memories that are expressed by improved performance without conscious recall or recognition

incomplete-pictures test

A test of memory measuring the improved ability to identify fragmented figures that have been previously observed

infantile amnesia

the normal inability to recall events from early childhood

Jennifer Aniston neurons

Neurons, such as those found in the medial temporal lobe, that respond to ideas or concepts rather than to particulars. Also known as concept cells.

learning

the brain's ability to change in response to experience

lobectomy

an operation in which a lobe, or a major part of one, is removed from the brain

lobotomy

An operation in which a lobe, or a major part of one, is separated from the rest of the brain by a large cut but is not removed

long-term depression

the long-lasting decrease in the strength of synaptic transmission

long-term memory

memory for experiences that endures after the experiences are no longer the focus of attention

long-term potentiation

the enduring facilitation of synaptic transmission that occurs following activation of synapses by high-intensity, high frequency stimulation of presynaptic neurons

medial diencephalic amnesia

Amnesia that is associated with damage to the medial diencephalon (e.g., Korsakoff's amnesia)

medial temporal cortex

cortex in the medial temporal lobe that lies adjacent to the hippocampus and amygdala

medial temporal lobe amnesia

Amnesia associated with bilateral damage to the medial temporal lobes; its major feature is anterograde amnesia for explicit memories in combination with preserved intellectual functioning

mediodorsal nuclei

a pair of thalamic nuclei, damage to which is thought to be responsible for many of the memory deficits associated with Korsakoff's syndrome

memory

the brain's ability to store and access the learned effects of experiences

memory consolidation

The transfer of short-term memories to long-term storage

metaplasticity

the modulation of long term potentiation (LTP) and/or long-term depression (LTD) induction by prior synaptic activity

morris water maze test

a widely used test of spatial memory in which rats must learn to swim directly to a platform hidden just beneath the surface of a circular pool of murky water

mumby box

An apparatus that is used in a rat version of the delayed nonmatching-to-sample test

Nootropics

a class of drugs that enhance cognitive function

place cells

Neurons that respond when an animal is in a particular location in allocentric space (normally found in the hippocampus)

posttraumatic amnesia

amnesia following a nonpenetrating blow to the head

prefrontal cortex

area in the frontal lobe responsible for higher-level cognitive functioning

pyramidal cell layer

one of the major layers of cell bodies in the hippocampus

radial arm maze test

A widely used test of rats' spatial ability in which the same arms are baited on each trial, and the rats must learn to visit only the baited arms only one time on each trial

reconsolidation

the theory that each time a memory is retrieved from long term storage, it is temporary held in labile short term memory, where it is once again susceptible to disruption before it is reconsolidated

reference memory

memory for the general principles and skills that are required to perform a task

remote memory

memory for experiences in the distant past

retrograde amnesia

an inability to retrieve information from one's past

semantic memories

Memories of general knowledge, including facts, rules, concepts, and propositions.

short-term memory

activated memory that holds a few items briefly, such as the seven digits of a phone number while dialing, before the information is stored or forgotten

standard consolidation theory

Theory that memories are temporarily stored in the hippocampus until they can be transferred to a more stable cortical storage system

transcription factors

Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.

transient global amnesia

Sudden onset of compete anterograde amnesia and learning abilities, pronounced retrograde amnesia, preservation of memory for personal identity, anxious awareness of memory loss with repeated and often perseverative questioning, overall normal behavior

working memory

a newer understanding of short-term memory that focuses on conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory