section 11.6

Question 1

Bilateral lesions of the hippocampus invariably disrupt the

Answer 1

performance of tasks that involve memory for spatial location.

Question 2

morris water maze

Answer 2

intact rats placed at various locations in a circular pool of murky water rapidly learn to swim to a stationary platform hidden just below the surface. Rats with hippocampal lesions learn this simple task with great difficulty.

Question 3

radial arm maze test

Answer 3

several arms radiate out from a central starting chamber, and the same few arms are baited with food each day. Intact rats readily learn to visit only those arms that contain food and do not visit the same arm more than once each day. The ability to visit only the baited arms of the radial arm maze is a measure of reference memory and the ability to refrain from visiting an arm more than once in a given day is a measure of working memory. Hippocampal lesions cause major deficits on both of these memories.

Question 4

reference memory

Answer 4

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

Question 5

working memory

Answer 5

temporary memory that is necessary for the successful performance of a task on which one is currently working.

Question 6

place cells

Answer 6

many hippocampal neurons; neurons that respond only when a subject is in specific locations (i.e., in the place fields of the neurons).

Question 7

Wilson and McNaughton

Answer 7

shown that the firing of a rat’s place cells indicates where the rat “thinks” it is in the test environment, not necessarily where it actually is.

Question 8

entorhinal cortex

Answer 8

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

Question 9

grid cells

Answer 9

are entorhinal neurons that each have an extensive array of evenly spaced place fields, producing a pattern reminiscent of graph paper. The distance between the evenly spaced place fields is flexible.

Question 10

The even spacing of the place fields in the grid cells could enable

Answer 10

spatial computations in hippocampal place cells.

Question 11

Two lines of evidence suggested that the responses of hippocampal place cells depend on input from entorhinal grid cells:

Answer 11

• There is a major pathway from the entorhinal cortex to the hippocampus.
• Entorhinal grid cells respond relatively reflexively to location, whereas hippocampal place cells respond to place in combination with other features of the test environment.

Question 12

However, the discovery that the properties of hippocampal place cells emerge in developing rat pups prior to emergence of stable entorhinal grid cell firing challenges

Answer 12

the idea that input from entorhinal grid cells is essential for hippocampal place cell function.

Question 13

Place cells and grid cells are less prevalent in primates than in rats

Answer 13

and place cells in primates tend to respond to where subjects are looking rather than where they are located (termed spatial view cells).

Question 14

The major structures of the medial temporal lobes are the

Answer 14

hippocampus, amygdala, and medial temporal cortex.

Question 15

The medial temporal cortex is composed of

Answer 15

entorhinal, periphinal, and parahippocampal cortices.

Question 16

Concept (Jennifer Aniston) neurons

Answer 16

highly selective, each neuron responds to only a small number of test objects or individuals – often only could be found. Responses are highly invariant: if a neuron responded to a particular object on test 1, it tended to respond to that object on all subsequent tests.

Question 17

concept cells of the hippocampus were more

Answer 17

selective and more invariant that those of all the medial temporal lobe structures.

Question 18

If concept cells have been found to respond to more than one concept, there is

Answer 18

usually an obvious relation between them.

Question 19

Suggested the images trigger activity in circuits of

Answer 19

concept cells in the medial temporal lobes. These circuits supposedly store episodic memories that comprise the semantic components represented by each cell. Particular cells that represent related concepts ma each contribute to multiple circuits.