Differential time course of implicit and explicit cueing by colour and orientation in visual search

Abstract

Using a cued conjunction search task, Anderson, Heinke, and Humphreys (2010) demonstrated larger effects from cueing target colour than from cueing target orientation. In this study, we separated the implicit (nonexpectation-dependent) and explicit (expectation-dependent) effects of orientation and colour visual cues. In Experiment 1, we replicated the original findings for short cue durations (100–200 ms), demonstrating that cues matching the physical property of the target on 80% of trials exert a rapid effect on search. These early cueing effects on reaction times were supported by evidence of guidance from cues on early eye movements. Experiment 2 introduced a feature to the cue that randomly matched the colour or orientation of the target. When cue orientation was predictive, there were strong implicit effects based on whether the colour of the cue and target matched. When cue colour was predictive, there were only weak effects from the cue's orientation. Implicit effects from cue colour remained when orientation-predictive cues were used and colour was unlikely to predict the target (Experiment 3). The data suggest that strong effects of colour cueing result from a combination of implicit and explicit processes, whereas effects from orientation cues are largely limited to the explicit guidance of visual search.

Keywords:

• Colour
• Cueing
• Explicit
• Implicit
• Search

Acknowledgements

This work was supported by grants from the ESRC, BBSRC, EPSRC, and MRC (UK). The work was completed in partial fulfilment of a PhD by GMA.

Notes

¹We differentiate between cue validity, where there is a predictive link between cue feature and the target, and whether the cue matches or differs to the target where any link was nonpredictive.