Implicit Detection Observation in Different Features, Exposure Duration, and Delay During Change Blindness

Wang Xiang

doi:10.3389/fpsyg.2020.607863

Abstract

To investigate whether implicit detection occurs uniformly during change blindness with single or combination feature stimuli, and whether implicit detection is affected by exposure duration and delay, two one-shot change detection experiments are designed. The implicit detection effect is measured by comparing the reaction times (RTs) of baseline trials, in which stimulus exhibits no change and participants report “same,” and change blindness trials, in which the stimulus exhibits a change but participants report “same.” If the RTs of blindness trials are longer than those of baseline trials, implicit detection has occurred. The strength of the implicit detection effect was measured by the difference in RTs between the baseline and change blindness trials, where the larger the difference, the stronger the implicit detection effect. In both Experiments 1 and 2, the results showed that the RTs of change blindness trials were significantly longer than those of baseline trials. Whether under set size 4, 6, or 8, the RTs of the change blindness trials were significantly longer than those in the baseline trials. In Experiment 1, the difference between the baseline trials’ RTs and change blindness trials’ RTs of the single features was significantly larger than that of the combination features. However, in Experiment 2, the difference between the baseline trials’ RTs and the change blindness trials’ RTs of single features was significantly smaller than that of the combination features. In Experiment 1a, when the exposure duration was shorter, the difference between the baseline and change blindness trials’ RTs was smaller. In Experiment 2, when the delay was longer, the difference between the two trials’ RTs was larger. These results suggest that regardless of whether the change occurs in a single or a combination of features and whether there is a long exposure duration or delay, implicit detection occurs uniformly during the change blindness period. Moreover, longer exposure durations and delays strengthen the implicit detection effect. Set sizes had no significant impact on implicit detection.

Highlights

Change blindness refers to an inability of an observer to detect a change in a visual scene even if they have good eyesight and know that a change is imminent (Simons and Rensink, 2005; Rensink, 2018)
The purpose of the current study was to explore (1) whether implicit detection can occur with a single feature or a combination of features, (2) whether the implicit detection effect is stronger with longer exposure duration, and (3) whether the implicit detection effect is weaker with longer delays
Set sizes had no significant impact on implicit detection because the capacity of pre-attention is infinite

Summary

Introduction

Change blindness refers to an inability of an observer to detect a change in a visual scene even if they have good eyesight and know that a change is imminent (Simons and Rensink, 2005; Rensink, 2018). Studies using eye-tracking showed that the gaze duration at the change location was significantly longer than at other locations (Hollingworth et al, 2001; Delvenne et al, 2007). These results indicate that, to a certain extent, the change has been registered and located (Reynolds and Withers, 2015). Electrophysiological results (Busch, 2013; Lyyra et al, 2014; Ball et al, 2015; Hadid and Lepore, 2017; Scrivener et al, 2019), brain imaging (Kiat et al, 2018), and brain stimulation (Morgan et al, 2013; Hsu et al, 2014; Lyyra, 2014) support implicit detection consistently. The existence of implicit detection has been verified, little is known about the influencing factors, which necessitates further investigation

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