Localized attentional inhibition within and between objects

J. Mounts, J. McCarley, B. Gavett, M. Buffan

Research output: Contribution to journalArticle

Abstract

Localized attentional inhibition has been observed in tasks involving perceptual discriminations near attentionally salient distractors (Caputo & Guerra, 1998; Mounts, 2000) and in tasks involving the identification of two targets (Bahcall & Kowler, 1999 . In some work, inhibition has been observed to increase monotonically as the separation between relevant items decreased. However, in other work nonmonotonicities have been observed - specifically, inhibition was diminished at the smallest separations (e.g., Bahcall & Kowler, 1999 . This series of experiments explored the contribution of grouping mechanisms to these nonmonotonicities by assessing target identification as a function of target-distractor separation within- and between-objects. Stimuli comprised nodes each consisting of a cross inscribed within a circle. Objects were created by uniform connectedness of multiple nodes. Each trial, the cross within one node rotated 90 degrees to create an attentionally salient distractor. After a short delay, a segment was removed from one cross to create a T-shaped target pointing left or right. The observers' task was to discriminate the orientation of this target. RT and accuracy were measured as a function of distractor-target separation, both when targets and distractors were and were not connected to form a single object. Consistent with previous work, inhibition decreased with the separation between the target and salient distractor. However, the magnitude of inhibition was mediated by whether the target and distractor are parts of the same or different objects; inhibition at a given spatial separation was smaller when the target and distractor were grouped to form a single object. Results suggest that performance sparing at locations nearest a salient distractor may be the result of perceptual grouping of target and distractor.

Original languageEnglish
JournalJournal of Vision
Volume1
Issue number3
DOIs
Publication statusPublished - 1 Dec 2001
Externally publishedYes

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