Abstract
The visual search paradigm has had an enormous impact in many fields. A theme running through this literature has been the distinction between preattentive and attentive processing, which I refer to as the two-stage assumption. Under this assumption, slopes of set-size and response time are used to determine whether attention is needed for a given task or not. Even though a lot of findings question this two-stage assumption, it still has enormous influence, determining decisions on whether papers are published or research funded. The results described here show that the two-stage assumption leads to very different conclusions about the operation of attention for identical search tasks based only on changes in response (presence/absence versus Go/No-go responses). Slopes are therefore an ambiguous measure of attentional involvement. Overall, the results suggest that the two-stage model cannot explain all findings on visual search, and they highlight how slopes of response time and set-size should only be used with caution.
Highlights
The well-known visual search paradigm has had an enormous impact on many aspects of science
When the target is present, the slopes are negative in the GNG task but positive for the present or absent (PA) task
The fact that the slopes are very small in the PA multiconjunction search is troubling for the two-stage assumption on its own since the results suggest that the search is ‘‘preattentive.’’ But the results from the GNG task are even harder to account for under the two-stage assumption
Summary
The well-known visual search paradigm has had an enormous impact on many aspects of science. The paradigm was designed to assess the function of visual attention (Neisser, 1963; Treisman & Gelade, 1980; Wolfe, 1998) and the operation of early visual cortical areas (Julesz, 1981; Nakayama & Martini, 2011). In the vast majority of visual search studies, performance is assessed with response times. Search slopes that measure how response times change as more distractors are added to the display are presumed to assess the speed of the search and whether attention is involved. If the slopes are around zero, the common assumption is that the target can be detected preattentively, while if search times increase with set-size, this is considered to reflect that attention moves around the search array, seeking the target.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
