¹ Department of Psychiatry and Behavioural Sciences, The University of Western Australia, Australia
² School of Psychology, The University of Queensland, Australia
³ The University of Sydney, Australia
⁴ Department of Psychology, The University of Western Australia, Australia
⁵ Department of Pharmacology, The University of Western Australia, Australia

Correspondence to: David Neumann (D.Neumann@ccrn.uwa.edu.au)

Abstract

A dissociation between two putative measures of resource allocation, electrodermal orienting and secondary task reaction time (RT), has been observed during a discrimination and counting task. The anomalous finding of this dissociation effect, secondary task RT, was investigated by varying the nature of the counting task. Participants (N = 24) were presented with circle and ellipse shapes. Group Count was asked to count how many times one shape was presented (task-relevant) and ignore all presentations of another shape (task-irrelevant). Group Longer was asked to count the number of longer-than-usual presentations of the task-relevant shape and ignore the task-irrelevant shape. Concurrent with the counting task, each group performed a RT task to an auditory probe. Secondary RT at probe positions of 50, 150, and 250 ms following shape onset was slower during task-irrelevant shapes than during task-relevant shapes. Secondary RT also showed at downward parallel trend across probe positions for each shape. These results did not differ between groups. The RT data are interpreted as reflecting a serial processing mechanism, not a resource limited mechanism, thus providing an explanation of the dissociation effect. The implications for resource allocation models or orienting and research on human workload interactions are discussed.

Poster Number: PAneumann0645
Keywords: orienting, electrodermal, secondary RT, resources, dissociation,