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

/pdf/an-integrative-theory-of-prefrontal-cortex-function-2j9unprn5f.pdf

An integrative theory of prefrontal cortex function

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

A neglected question regarding cognitive control is how control processes might detect situations calling for their involvement. The authors propose here that the demand for control may be evaluated in part by monitoring for conflicts in information processing. This hypothesis is supported by data concerning the anterior cingulate cortex, a brain area involved in cognitive control, which also appears to respond to the occurrence of conflict. The present article reports two computational modeling studies, serving to articulate the conflict monitoring hypothesis and examine its implications. The first study tests the sufficiency of the hypothesis to account for brain activation data, applying a measure of conflict to existing models of tasks shown to engage the anterior cingulate. The second study implements a feedback loop connecting conflict monitoring to cognitive control, using this to simulate a number of important behavioral phenomena.

Conflict monitoring and cognitive control.

Part I. Experimental Studies: 2. Experiment in psychology 3. Experiments on perceiving III Experiments on imaging 4-8. Experiments on remembering: (a) The method of description (b) The method of repeated reproduction (c) The method of picture writing (d) The method of serial reproduction (e) The method of serial reproduction picture material 9. Perceiving, recognizing, remembering 10. A theory of remembering 11. Images and their functions 12. Meaning Part II. Remembering as a Study in Social Psychology: 13. Social psychology 14. Social psychology and the matter of recall 15. Social psychology and the manner of recall 16. Conventionalism 17. The notion of a collective unconscious 18. The basis of social recall 19. A summary and some conclusions.

Remembering. A Study in Experimental and Social Psychology, Cambridge (University Press) 1964.

: A growing body of evidence suggests that traditional views of automaticity are in need of revision. For example, automaticity has often been treated as an all-or-none phenomenon, and traditional theories have held that automatic processes are independent of attention. Yet recent empirial data suggests that automatic processes are continuous, and furthermore are subject to attentional control. In this paper we present a model of attention which addresses these issues. Using a parallel distributed processing framework we propose that the attributes of automaticity depend upon the strength of a process and that strength increases with training. Using the Stroop effect as an example, we show how automatic processes are continuous and emerge gradually with practice. Specifically, we present a computational model of the Stroop task which simulates the time course of processing as well as the effects of learning.

/pdf/on-the-control-of-automatic-processes-a-parallel-distributed-2h69lq40qv.pdf

On the control of automatic processes: A parallel distributed processing account of the stroop effect

http://cs.northwestern.edu/~paritosh/papers/sketch-to-models/klahr-dunbar-dual-space-search-cogsci-1988.pdf

Dual space search during scientific reasoning

In 1965 Jacques Monod and François Jacob were awarded the Nobel prize for discovering that there are regulator genes that control the activity of other genes. They discovered this by investigating the utilization of energy sources, such as glucose, in E. coli. E. coli need glucose to live and their most common source of glucose is lactose. When lactose is present, E. coli secrete betagalactosidase enzymes that break down lactose into glucose. Betagalactosidase is secreted only when lactose is present. Jacob and Monod discovered that a set of regulator genes inhibit the genes that produce betagalactosidase until betagalactosidase is needed. They proposed that there are two genes I and O that regulate the activity of the betagalactosidase producing genes and that the production of beta-gal is controlled by an inhibitory regulation mechanism. As can be seen from Figure 1, when no lactose is present the I gene produces an inhibitor that binds to the O gene, and this prevents the betagalactosidase genes from producing betagalactosidase. When Lactose is present, the inhibitor secreted by the I gene binds to the lactose, rather than the O gene. When this happens, the betagalactosidase genes are no longer inhibited and, consequently, they produce betagalactosidase. When all the lactose is used, the inhibitor again binds to the O gene and production of betagalactosidase stops. Monod and Jacob made this discovery using various mutations where the I, O, and betagalactosidase genes were mutated. Crucially, they initially thought that genetic control was due to genes switching on, or activating, other genes. It was only after a large amount of research that they discovered that the mechanism of control was inhibition. Not only was this discovery relevant to production of betagalactosidase, but it was a general model of genetic control that transformed biological research.

How scientists really reason: scientific reasoning in real-world laboratories

This chapter reports an investigation of "On-line Creativity." I present a new account of the cognitive and social mechanisms underlying complex thinking of creative scientists as they work on significant problems in contemporary science. I lay out an innovative methodology that I have developed for investigating creative and complex thinking in a realworld context. Using this method, I have discovered that there are a number of strategies that are used in contemporary science that increase scientists' likelihood of making discoveries. The findings reported in this chapter provide new insights into complex scientific thinking and will dispel many of the myths surrounding the generation of new concepts and scientific discoveries.

Kevin Dunbar

Papers

On the control of automatic processes: A parallel distributed processing account of the stroop effect

Dual space search during scientific reasoning

How scientists really reason: scientific reasoning in real-world laboratories

How scientists think: On-line creativity and conceptual change in science.

Heuristics for scientific experimentation: a developmental study.