PFC

Question 1

Functional imaging data show

Answer 1

some specific associations between particular cognitive functions and local prefrontal activations (Luria, 1966)

Question 2

However, there is also strong evidence for

Answer 2

common regions of recruitment in response to a wide range of different cognitive demands (Drewe, 1975)

Question 3

These regions include the cortex in and around the

Answer 3

posterior part of the inferior frontal sulcus, the frontal operculum/anterior insula and the dorsal part of the anterior cingulate

Question 4

Converging data comes from electrophysiology in the monkey who?

Answer 4

Asaad et al., 1998

Question 5

What did the cells in the monkeys encode?

Answer 5

code many aspects of task events, including information relevant to stimuli, responses, working memory delays, response rules and reward states.

Question 6

How are cells in the PFC organized and what do they respond to?

Answer 6

Cells of many different types are found closely intermingled and widely distributed across the lateral surface with individual cells showing evidence for adaptability of function, coding different information in different task contexts

Question 7

What may underlie the adaptability of neurons in PFC?

Answer 7

perhaps through the dense interconnections that exist within the prefrontal cortex (Pandya, 1996)

Question 8

What can the PFC be considered as and why?

Answer 8

In a particular task context, many cells become tuned to code information that is specifically relevant to this task. In this sense, the prefrontal cortex acts as a global workspace or working memory (Dehaene, 1998) onto which can be written those facts that are needed in a current mental program.

Question 9

What does adaptability imply?

Answer 9

Such adaptability in itself implies selective attention, or a selective emphasis on relevant inputs and the filtering out of irrelevant inputs.

Question 10

If a given neuron can code different information in different task contexts, it follows that

Answer 10

in any particular context, there is a selective removal of inputs that might drive the cell, but are currently unnecessary

Question 11

What evidence do we have for selective removal of inputs?

Answer 11

the loss of currently irrelevant stimulus distinctions is seen directly in the single-unit data (Rao, 1997)

Question 12

To achieve processing coherence, multiple brain systems

Answer 12

share a strong tendency to converge to represent similar or related information (Duncan, 1996; 1997)

Question 13

What are the implications of brain regions converging?

Answer 13

Because of this, a highly selective focus on task-relevant information in the prefrontal cortex supports the processing of related information in other systems, including those concerned with the description of sensory inputs, the generation of motor commands, the representation of long-term or semantic knowledge, and the assessment of motivational significance