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

The use of novel measures to detect Accelerated Long-term forgetting in people with epilepsy: The Crimes Test and Four Doors Test.

Working memory in perspective: Foreword

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How does processing affect storage in working memory tasks

What can symmetry tell us about working memory

Several attempts to test the Gestalt hypothesis of autonomous change in the memory trace have shown trends which, though mutually consistent, do not fit the Gestalt hypothesis. Expt I aimed to reproduce these effects. Two figures were used (circles with gaps of 15° or 60°), one retention interval (15 sec) and two methods of testing: reproduction, in which the subject first copies the figure and then draws it from memory; and recognition, using the method of identical stimuli. In the recognition test, subjects tended to judge an identical 60° gap as ‘larger’ after 15 sec, implying closure of the gap in the memory trace, but the 15° gap showed no effect. No reliable changes in gap size occurred using the method of reproduction. Expt II tried to increase the sensitivity of this method by stressing the importance of reproducing the gap accurately. Again results were negative. Expt III tested the hypothesis that the recognition effect found was due to guessing habits. The initial stimulus was presented as before, but the recognition stimulus was replaced by the momentary illumination of a blank card purporting to be a brief presentation of the recognition figure. Subjects were thus forced to guess. The pattern of responses was almost identical with that found in the previous recognition study. Conclusions are: (1) the consistent trends previously found using the method of identical stimuli are probably due to guessing habits; (2) there is no evidence for autonomous change in the short-term retention of form.

Alan D. Baddeley

Papers

The use of novel measures to detect Accelerated Long-term forgetting in people with epilepsy: The Crimes Test and Four Doors Test.

Working memory in perspective: Foreword

How does processing affect storage in working memory tasks

What can symmetry tell us about working memory

Closure and response bias in short-term memory for form.