Work

What are the shapes of response time distributions in visual search?

Year: 2010

Type: article

Abstract: Many visual search experiments measure response time (RT) as their primary dependent variable. Analyses typically focus on mean (or median) RT. However, given enough data, the RT distribution can be a rich source of information. For this paper, we collected about 500 trials per cell per observer for both target-present and target-absent displays in each of three classic search tasks: feature search, with the target defined by color; conjunction search, with the target defined by both color and orientation; and spatial configuration search for a 2 among distractor 5s. This large data set allows us to characterize the RT distributions in detail. We present the raw RT distributions and fit several psychologically motivated functions (ex-Gaussian, ex-Wald, Gamma, and Weibull) to the data. We analyze and interpret parameter trends from these four functions within the context of theories of visual search.

Source: Journal of Experimental Psychology Human Perception & Performance

DOI: 10.1037/a0020747

Authors: Evan M. Palmer, Todd S. Horowitz, Antonio Torralba, Jeremy M. Wolfe

Institutions: Brigham and Women's Hospital, Harvard University, Massachusetts Institute of Technology

Language: English

Topic: Visual perception and processing mechanisms

Subfield: Cognitive Neuroscience

Field: Neuroscience

Domain: Life Sciences

Open Access status: green

Funders: National Eye Institute, Air Force Office of Scientific Research

Awards: PSYCHOPHYSICAL STRUCTURE OF HUMAN VISION, Time Course of Guidance in Visual Search, G8729578689, Prevalence effects in visual search: Theoretical and practical implications