Visual Processing Within and Across Hemispheres: A Systems Factorial Technology Analysis.

Researchers have identified a processing preference exhibited by the left versus right hemispheres when a stimulus pattern contains multiple scales of information. Specifically, in identification tasks, the left hemisphere processes relatively local details while the right hemisphere attends to the global information. Later, researchers became interested in how information separately handled by the hemispheres might be combined to determine an overall response when both hemispheres have access to the same information (metacontrol). Previous attempts to use RT were limited by the lack of theoretical development within the methods. Systems Factorial Technology (SFT) outlines a set of response time methods to identify characteristics of a processing system underlying a simple cognitive task. These characteristics include mental architecture (serial, parallel, or coactive), decisional stopping rule (self-terminating, exhaustive), independence of processing systems, and workload capacity (limited, unlimited, or supercapacity). Recently, this framework has been extended to a nested architecture motivated by these questions of how visual perception may differ across the cerebral hemispheres and how that information may be combined during detection and identification tasks. The current study applies these theoretical results to the perception of hierarchically defined patterns (Exp. 1) and compound Gabor patches (Exp. 2) in three visual field conditions: left only, right only, and bilateral. We present detailed results from six observers to identify both architecture and processing capacity within and across the visual fields. Supplementary Information: The online version contains supplementary material available at 10.1007/s42113-025-00249-5.