Visual search is slowed when visuospatial working memory is occupied

Woodman, Geoffrey F.; Luck, Steven J. · 2004 · OpenAlex-citations

DOI: 10.3758/bf03196569

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study investigates whether maintaining spatial information in visual working memory impairs the efficiency of concurrent visual search, addressing a gap left by previous research. Earlier work by Woodman, Vogel, and Luck (2001) demonstrated that filling visual working memory with object features (such as color or shape) did not reduce search efficiency, suggesting that visual search relies on a spatial subsystem rather than an object subsystem. The current experiment tests this hypothesis by examining interference between visual search and the maintenance of spatial locations. The authors employed a dual-task paradigm with twelve participants. In the memory task, subjects viewed two white dots presented sequentially to encode their spatial locations, followed by a 5-second retention interval, and then a test array to detect if a location had changed. In the search task, subjects identified the orientation of a gap in one of several squares (set sizes of 4, 8, or 12). The critical condition required subjects to perform the search task during the retention interval of the memory task. To prevent verbal recoding of spatial information, participants performed articulatory suppression throughout trials. Performance in the dual-task condition was compared to baseline performance when each task was performed in isolation. The results revealed significant mutual interference between the two tasks. Visual search efficiency, measured by the slope of the reaction time function relative to set size, was significantly greater in the dual-task condition (74.4 msec/item) than in the search-alone condition (52.9 msec/item). This indicates that search became less efficient as the number of items increased when spatial working memory was occupied. Additionally, spatial memory accuracy declined significantly in the dual-task condition (82% correct) compared to the memory-alone condition (95% correct). Crucially, this memory impairment increased as the set size of the concurrent search task increased, demonstrating a set-size-dependent interference effect. Search accuracy remained high and unaffected by the dual-task load. These findings indicate that visual search and spatial working memory share common limited-capacity processing resources, whereas object working memory does not. The authors propose that this shared resource likely involves visuospatial attention or a common system for representing spatial locations. The results support the theoretical distinction between separate spatial and object working memory subsystems, aligning with neuroanatomical evidence for distinct dorsal (where) and ventral (what) pathways. This study clarifies that while object memory does not hinder search, the cognitive load of maintaining spatial locations directly competes with the attentional mechanisms required for efficient visual search.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-prismaquant on 2026-06-25; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• visual search