Allocation of attention in the visual field.

TLDR

Attentional resources can be distributed across the visual field with low resolution or focused narrowly with higher processing power. The study examined whether attention can be simultaneously allocated to multiple locations, whether processing mode can switch within a trial, and the costs of concentrating on an invalid location. Participants identified a target letter among eight in circular displays, with precues indicating primary and secondary locations 150 ms before onset or no cue in control trials, and a second experiment tested assumptions, leading to a zoom‑lens model of attentional resources.

Abstract

This research investigated whether attentional resources can be simultaneously allocated to several locations in a visual display, whether the mode of processing (serial or parallel) can be switched within a trial, and the nature of the costs when attentional resources are concentrated on an invalid location. Subjects were required to determine which of two target letters was present in eight-letter circular displays. In precue conditions, a primary and a secondary target location were designated 150 ms before target onset by an indicator that varied in validity. In the control conditions no cue was provided. A second experiment verified several assumptions that had been made in interpreting the data of Experiment 1. Modifications in Jonides' (1983) two-process model were suggested in terms of a zoom lens model of attentional resources. Instead of two alternative processing modes, attentional resources are conceived as capable of distribution over the visual field, but with low resolving power, or as continuously constricting to small portions of the visual field with a concomitant increase in processing power.