Expecting the initial glimpse: prior target knowledge activation or repeated search does not eliminate scene preview search benefits

ABSTRACT

A brief glimpse of a scene can guide eye movements but it remains unclear how prior target knowledge influences early scene processing. Using the ‘flash-preview moving window’ (FPMW) paradigm to restrict peripheral vision during search, we manipulated whether target identity was presented before or after previews. Windowed search was more efficient following 250 ms scene previews, and knowing target identity beforehand further improved how search was initiated and executed. However, in Experiment 2 when targets were removed from scene previews, only the initiation of search continued to be modulated by prior activation of target knowledge. Experiment 3 showed that search benefits from scene previews are maintained even when repeatedly searching through the same type of scene for the same type of target. Experiment 4 replicated Experiment 3 whilst also controlling for differences in integration times. We discuss the flexibility of the FPMW paradigm to measure how the first glimpse affects search.

KEYWORDS:

• Flash-preview moving window
• eye movements
• scene perception
• expectation
• visual search

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Damien Litchfield http://orcid.org/0000-0003-3993-8699

Tim Donovan http://orcid.org/0000-0001-8520-3365

Notes

1 In <1% of trials participants did not fixate the central fixation cross following a preview but instead were already fixating the target location (only found in target-scene and scene-target conditions). Since this would effectively negate many eye movement metrics, these trials were excluded from analysis. It should be noted therefore that some of the most powerful effects of target/scene guidance were not included in the analysis.