TY - JOUR
T1 - Spatial and temporal separation fails to counteract the effects of low prevalence in visual search
AU - Kunar, Melina A.
AU - Rich, Anina N.
AU - Wolfe, Jeremy M.
PY - 2010/6
Y1 - 2010/6
N2 - Recent research has shown that, in visual search, participants can miss 30-40% of targets when they only appear rarely (i.e., on 1-2% of trials). Low target prevalence alters the behaviour of the searcher. It can lead participants to quit their search prematurely (Wolfe, Horowitz, & Kenner, 2005), to shift their decision criteria (Wolfe et al., 2007), and/or to make motor or response errors (Fleck & Mitroff, 2007). In this paper we examine whether the low prevalence (LP) effect can be ameliorated if we split the search set in two, spreading the task out over space and/or time. Observers searched for the letter "T" among "L"s. In Experiment 1, the left or right half of the display was presented to the participants before the second half. In Experiment 2, items were spatially intermixed but half of the items were presented first, followed by the second half. Experiment 3 followed the methods of Experiment 2 but allowed observers to correct perceived errors. All three experiments produced robust LP effects with higher errors at 2% prevalence than at 50% prevalence. Dividing up the display had no beneficial effect on errors. The opportunity to correct errors reduced but did not eliminate the LP effect. Low prevalence continues to elevate errors even when observers are forced to slow down and permitted to correct errors.
AB - Recent research has shown that, in visual search, participants can miss 30-40% of targets when they only appear rarely (i.e., on 1-2% of trials). Low target prevalence alters the behaviour of the searcher. It can lead participants to quit their search prematurely (Wolfe, Horowitz, & Kenner, 2005), to shift their decision criteria (Wolfe et al., 2007), and/or to make motor or response errors (Fleck & Mitroff, 2007). In this paper we examine whether the low prevalence (LP) effect can be ameliorated if we split the search set in two, spreading the task out over space and/or time. Observers searched for the letter "T" among "L"s. In Experiment 1, the left or right half of the display was presented to the participants before the second half. In Experiment 2, items were spatially intermixed but half of the items were presented first, followed by the second half. Experiment 3 followed the methods of Experiment 2 but allowed observers to correct perceived errors. All three experiments produced robust LP effects with higher errors at 2% prevalence than at 50% prevalence. Dividing up the display had no beneficial effect on errors. The opportunity to correct errors reduced but did not eliminate the LP effect. Low prevalence continues to elevate errors even when observers are forced to slow down and permitted to correct errors.
UR - http://www.scopus.com/inward/record.url?scp=77953484515&partnerID=8YFLogxK
U2 - 10.1080/13506280903361988
DO - 10.1080/13506280903361988
M3 - Article
C2 - 21442052
AN - SCOPUS:77953484515
SN - 1350-6285
VL - 18
SP - 881
EP - 897
JO - Visual Cognition
JF - Visual Cognition
IS - 6
ER -