You detect while I search: examining visual search efficiency in a joint search task

ABSTRACT

Numerous factors impact attentional allocation, with behaviour being strongly influenced by the interaction between individual intent and our visual environment. Traditionally, visual search efficiency has been studied under solo search conditions. Here, we propose a novel joint search paradigm where one individual controls the visual input available to another individual via a gaze contingent window (e.g., Participant 1 controls the window with their eye movements and Participant 2 – in an adjoining room – sees only stimuli that Participant 1 is fixating and responds to the target accordingly). Pairs of participants completed three blocks of a detection task that required them to: (1) search and detect the target individually, (2) search the display while their partner performed the detection task, or (3) detect while their partner searched. Search was most accurate when the person detecting was doing so for the second time while the person controlling the visual input was doing so for the first time, even when compared to participants with advanced solo or joint task experience (Experiments 2 and 3). Through surrendering control of one’s search strategy, we posit that there is a benefit of a reduced working memory load for the detector resulting in more accurate search. This paradigm creates a counterintuitive speed/accuracy trade-off which combines the heightened ability that comes from task experience (discrimination task) with the slower performance times associated with a novel task (the initial search) to create a potentially more efficient method of visual search.

KEYWORDS:

• Visual attention
• visual search
• working memory

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 We examined whether fixation duration (the length of time spent fixating a certain aspect of the visual scene) or saccade amplitude (the length of the eye movement) differed across conditions to determine if search became more efficient with experience. We also examined whether fixations durations were longer and if saccade amplitudes were shorter in the joint versus solo conditions. This eye movement pattern, signifying a slower search strategy, may be expected in a joint condition where one individual is responsible for the visual input of their counterpart. We had anticipated that this increase in accountability would lead the individual controlling the visual input to be more thorough and perhaps less efficient in joint search relative to when completing the task individually. However, there were no informative differences in the eye movement kinematics when comparing joint search versus when individuals searched for themselves. As a slower search strategy was not observed in the joint condition, our performance data cannot be attributed to a simple speed versus accuracy trade-off. Instead, the superior accuracy performance seen in Session E seems to occur due to a reduced working memory load of the target detector. This individual was not required to remember previously fixated locations as their counterpart was controlling the visual window and, as such, mental resources could be directed entirely towards detecting and responding to the target. Given that we did not observe any meaningful differences in fixation duration and saccade amplitude in Experiment 1, we focused only on RT and accuracy in the subsequent experiments.