I before U: Temporal order judgements reveal bias for self-owned objects

Abstract

A multitude of studies demonstrate that self-relevant stimuli influence attention. Self-owned objects are a special class of self-relevant stimuli. If a self-owned object can indeed be characterised as a self-relevant stimulus then, consistent with theoretical predictions, a behavioural effect of ownership on attention should be present. To test this prediction, a task was selected that is known to be particularly sensitive measure of the prioritisation of visual information: the temporal order judgement. Participants completed temporal order judgements with pictures of "own" and "experimenter" owned objects (mugs) presented on either side of a central fixation cross. There was a variable onset delay between each picture, ranging between 0 ms and 105 ms, and participants were asked to indicate which mug appeared first. The results indicated a reliable change in the point of subjective simultaneity (PSS) in favour of their own mug. Such a change in the PSS was not observed for two groups of participants who were exposed to a mug but did not keep the mug. A further experiment indicated that the source of the bias in PSS was more consistent with a criterion shift or top-down attentional prioritisation rather than a perceptual bias. These findings suggest that ownership, beyond mere-touch, mere-choice, or familiarity, leads to prioritised processing and responses, but the mechanism underlying the effect is not likely to be perceptual in nature.

Self-prioritization during stimulus processing is not obligatory

“…This difference in the manner in which stimuli acquire self-relevance (i.e., self-surrogate vs. self-associate) may have important implications for the course and products of self-referential processing, hence the automaticity of selfprioritization (Humphreys & Sui, 2016;Sui & Humphreys, 2017). Accordingly, extending previous research (Constable et al, 2019;Falbén et al, 2019), here we considered whether task sets moderate self-prioritization when participants evaluate stimuli (i.e., geometric shapes) that denote the self and a friend (Sui et al, 2012).…”

“…When emphasis switched instead to a perceptual appraisal of the stimuli (i.e., reporting the orientation of pencils/pens), self-prioritization failed to emerge. Likewise, when required to report which of two objects initially appeared on the computer screen (i.e., temporal order judgment task)-a mug owned-by-self or a mug owned-by-the-experimenter- Constable, Welsh, Huffman, and Pratt (2019) revealed that participants were biased toward reporting that self-owned (vs. experimenter-owned) items were presented first. This effect was abolished, however, when the requested judgment was orthogonal to the dimension of interest (i.e., ownership), such that participants were asked to report whether a mug appeared to the left or right of fixation.…”

“…Of course, ownership paradigms differ in several important respects from the shape-label matching tasks that have dominated work on this topic (Humphreys & Sui, 2016;Sui & Gu, 2017;, but perhaps most significantly in terms of the status of the stimuli on which judgments are rendered (Constable et al, 2019;Falbén et al, 2019;Golubickis, Falbén, Cunningham, & Macrae, 2018;Sui et al, 2012Sui et al, , 2013Sui et al, , 2014Truong, Roberts, & Todd, 2017). Whereas in perceptual-matching tasks geometric shapes serve as proxies for various social targets (e.g., self is a triangle, friend is a square); in ownership tasks, in contrast, everyday objects are linked with the self and others through association (e.g., self owns pens, friend owns pencils).…”

“…That is, like other seemingly automatic processes, selfprioritization is dependent on higher-order factors-including intentions, goals, and task sets-that shape stimulus processing and response generation (Kiefer, 2007;Memelink & Hommel, 2013;Moors & De Houwer, 2006;Naccache, Blandin, & Dehaene, 2002). In particular, whereas self-relevance should facilitate performance when task sets yield access to shape-target associations in memory (Janczyk et al, 2019;Sui et al, 2012Sui et al, , 2013Sui et al, , 2014; absent these specific processing conditions, self-prioritization is unlikely to emerge (Constable et al, 2019;Dalmaso et al, in press;Falbén et al, 2019;Siebold et al, 2015;Stein et al, 2016). Functioning in this way, self-prioritization is consistent with Hommel's (1998Hommel's ( , 2004Hommel's ( , 2018 Theory of Event Coding (TEC).…”

“…In a shape-classification task, here we considered how task sets impact self-prioritization (Constable et al, 2019;Falbén et al, 2019). Participants first associated geometric shapes (e.g., square, triangle) with either the self or a best friend (Sui et al, 2012).…”