The unity and diversity of executive functions and their contributions to complex "Frontal Lobe" tasks: a latent variable analysis.

▪ Abstract The prefrontal cortex has long been suspected to play an important role in cognitive control, in the ability to orchestrate thought and action in accordance with internal goals. Its neural basis, however, has remained a mystery. Here, we propose that cognitive control stems from the active maintenance of patterns of activity in the prefrontal cortex that represent goals and the means to achieve them. They provide bias signals to other brain structures whose net effect is to guide the flow of activity along neural pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task. We review neurophysiological, neurobiological, neuroimaging, and computational studies that support this theory and discuss its implications as well as further issues to be addressed

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An integrative theory of prefrontal cortex function

Publisher Summary This chapter focuses on the modern notion of short-term memory, called working memory. Working memory refers to the temporary maintenance of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment. These internal representations are short-lived, but can be maintained for longer periods of time through active rehearsal strategies, and can be subjected to various operations that manipulate the information in such a way that makes it useful for goal-directed behavior. Working memory is a system that is critically important in cognition and seems necessary in the course of performing many other cognitive functions, such as reasoning, language comprehension, planning, and spatial processing. This chapter demonstrates the functional importance of dopamine to working memory function in several ways. Elucidation of the cognitive and neural mechanisms underlying human working memory is an important focus of cognitive neuroscience and neurology for much of the past decade. One conclusion that arises from research is that working memory, a faculty that enables temporary storage and manipulation of information in the service of behavioral goals, can be viewed as neither a unitary, nor a dedicated system. Data from numerous neuropsychological and neurophysiological studies in animals and humans demonstrates that a network of brain regions, including the prefrontal cortex, is critical for the active maintenance of internal representations.

Chapter 11 Working memory

Co-Planar Stereotaxic Atlas of the Human Brain—3-Dimensional Proportional System: An Approach to Cerebral Imaging, J. Talairach, P. Tournoux. Georg Thieme Verlag, New York (1988), 122 pp., 130 figs. DM 268

Attention and Effort

While the search for a theory of rehabilitation by Caramazza and Hillis is welcomed, the model they propose is criticised on the grounds that it offers little more than a recommendation that we should wait until rehabilitation has occurred, and then attempt to understand it. The theme of this comment is to propose that it is necessary not only to understand the systems being treated, but also to have a model of how they can be changed by experience. Examples are given of ways in which recent developments in the cognitive neuropsychology of learning and memory may contribute to improved rehabilitation methods. It is suggested that an adequate theory of rehabilitation must combine a knowledge of the systems undergoing treatment with an understanding of how the principles of learning may be applied to their modification.

A theory of rehabilitation without a model of learning is a vehicle without an engine: A comment on caramazza and hillis

Time-estimation at reduced body-temperature.

A broad theory of depression is proposed based on a blend of Hume's (D. Hume, 1978, A Treatise of Human Nature. Oxford, England: Oxford University Press. Original work published 1739) concept of a ...

Working Memory and Emotion: Ruminations on a Theory of Depression:

Three experiments studied the long-term retention of parking locations. In Experiment 1, members of the Applied Psychology Unit (MU) attempted to recall where they had parked during the morning and afternoon of each of the previous 12 working days. A marked recency effect was observed. In Experiment 2, members of the APU Subject Panel were invited for a single test session, and asked where they had parked after a delay of 2 hours, 1 week or 1 month. Recall was excellent and did not differ as a function of delay, allowing a simple trace decay interpretation to be ruled out. A third experiment invited subjects to attend on two occasions separated by a 2-week interval. The subjects were then required to recall their parking locations some 4 weeks after either their first visit or their second visit. Performance in both groups was inferior to that observed in Experiment 2, and declined over time. A temporal discrimination model, based on laboratory studies of both long-term and short-term recency in ...

/pdf/where-did-you-park-your-car-analysis-of-a-naturalistic-long-574eyz198d.pdf

Where did you park your car? Analysis of a naturalistic long-term recency effect

Eighteen divers were tested four times under water, twice at a depth of 5 ft and twice at 100 ft. They performed three tests—digit copying, a sentence comprehension test and a manual dexterity test. All three showed a significant drop in efficiency at depth. This was small for digit copying (7-9 per cent) and manual dexterity (3 5 per cent), and somewhat larger for sentence comprehension (15-3 per cent). In all three cases the drop in efficiency was approximately the same as found at the equivalent pressure in a dry pressure chamber. This contrasts with previous results where impairment in the open sea has been considerably greater than in a dry chamber. Possible reasons for this discrepancy are discussed and it is suggested that level of anxiety may be a crucial factor.

Alan D. Baddeley

Papers

A theory of rehabilitation without a model of learning is a vehicle without an engine: A comment on caramazza and hillis

Time-estimation at reduced body-temperature.

Working Memory and Emotion: Ruminations on a Theory of Depression:

Where did you park your car? Analysis of a naturalistic long-term recency effect

Nitrogen Narcosis and Performance Under Water