Models & Metrics of Human Executive Control - Progress (03/99)

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1) MILESTONES:

Associated milestones will be indicated by letters:

 

A. Effects of practice and switching on concurrent task performance (FY99)

B. Identify multiple loci information bottlenecks by recording brain activity (FY99)

2) RESEARCH OBJECTIVE:

Extend and validate the APEX model of executive control by specifying the role of executive control in cognitive processing and how control failure leads to human error in complex task environments.

3) SIGNIFICANT PROGRESS AND PUBLICATIONS:

A. Practice and Task Switching.

Ruthruff, E. Johnston, J.C. & Van Selst, M. Why practice reduces dual-task interference. Accepted for publication in Journal of Experimental Psychology: Human Perception & Performance.

IMPACT: Explores the causes for our previous finding that extended practice reduces interference in the Psychological Refractory Period Paradigm. Found evidence for a primary cause—the shortening of processing stages that create

a central single-channel bottleneck—and a secondary cause—an increase in the ability to perform secondary task central stages during the bottleneck.

B. Multiple Bottlenecks.

McCann, R.S. Remington, R.W & Van Selst, M. (1998). Automaticity in visual word processing: A dual-task investigation

IMPACT: Demonstrated that a dual-task bottleneck prevents the process of word identification, even though previous evidence indicates that single letter identification is not prevented.

4) SIGNIFICANT EXTERNAL LIAISONS:

A. Our collaboration with John Gabrielli at Stanford University collected our first fMRI scans of a human subject while 1) performing a spatial attention task and 2) perfforming in a dual-task paradigm. Both common activity and activity specific to the separate paradigms was found.

5) ISSUES:

None.