Introspection in dual-tasks: Conditions and sources of the PRP neglect
Final Report Abstract
When participants perform two tasks in close succession, responses to the second task are usually prolonged in comparison to when the two task are performed without temporal overlap (the PRP effect). Strikingly, it has been found that the PRP effect is not reflected in introspective reports of reaction times (‘introspective blind spot’), suggesting that people are unaware of their dual-task costs. In this project, we have replicated the basic finding of an unawareness of dual-task costs using several reporting methods, such as the standard visual analog scale, temporal reproduction, temporal comparison and trial reconstruction. The initially proposed explanation of this phenomenon, namely a conscious perception bottleneck (a serial processing bottleneck that encompasses response selection as well as conscious perception), was tested in several experiments and received little support. Instead, we have identified sources of information that seem to bias introspective reports, such as experienced difficulty, the inter-response interval, and other intervals present in the trial. Based on the results of this project, we propose an alternative explanation for the introspective blind spot – that resource competition leads to a failure to transfer information from the object-level (the task itself) to the meta-level (the representation of the task and one’s performance). More specifically, the working memory demands and the pace of events in a dual task may leave insufficient cognitive and temporal resources for the system to build up an appropriate representation of task performance. Consequently, participants use a variety of valid or invalid cues to provide an estimate of their reaction times. Overall, the project has considerably improved our understanding of introspection in attentionally demanding tasks and provided a model that can be further specified and applied to related tasks in future research. Another important and more general question for future research concerns the potential role of introspection in the control of one’s own behavior and performance.
Publications
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(2014). Distorted subjective reports of stimulus onsets under dual-task conditions: Delayed conscious perception or estimation bias? Consciousness and Cognition, 30, 36-47
Bratzke, D., Bryce, D., & Seifried-Dübon, T.
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(2014). Introspective reports of reaction times in dual-tasks reflect experienced difficulty rather than timing of cognitive processes. Consciousness and Cognition, 27, 254 – 267
Bryce, D., & Bratzke, D.
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(2015). Are introspective reaction times affected by the method of time estimation? A comparison of visual analogue scales and reproduction. Attention, Perception & Psychophysics, 77, 978- 984
Bryce, D., & Bratzke, D.
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(2016). Multiple timing of nested intervals: Further evidence for a weighted sum of segments account. Psychonomic Bulletin & Review, 23, 317-323
Bryce, D., & Bratzke, D.
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(2016). Temporal discrimination of one’s own reaction times in dual-task performance: Context effects and methodological constraints. Attention, Perception, & Psychophysics, 78, 1806-1816
Bratzke, D., & Bryce, D.
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(2017). Are participants' reports of their own reaction times reliable? Reexamining introspective limitations in active and passive dual-task paradigms. Acta Psychologica, 172, 1-9
Bryce, D., & Bratzke, D.
