Unconsciously perceived arrows yield an endogenous, automatic orienting of attention

Unconsciously perceived arrows yield an endogenous, automatic orienting of attention Stefania Mereu (smereu@uiuc.edu) Department of Psychology, 603 East Daniel St, Champaign, IL 61820 USA Maria Casagrande (maria.casagrande@uniroma1.it) Dipartimento di Psicologia, via dei Marsi 78 Roma, 00185 Italy Abstract Symbolic cues have always been thought to elicit voluntary orienting of attention. Arrows, as well as other centrally presented cues, could lead to reflexive shifts of attention, without showing, however, the biphasic pattern (initial facilitation / later inhibition) typical of peripheral automatic orienting. This study evaluated the role of awareness in endogenous orienting of attention, in order to understand whether it is necessary for either automatic or voluntary orienting, or both. Results showed a facilitation at brief cue- target intervals in both the aware and unaware conditions; a tendency to inhibition at longer intervals for non-predictive arrows, but only in the aware condition; a facilitation with no inhibition for predictive arrows, in both the aware and unaware conditions. Our results suggest that arrows can cause automatic shifts of endogenous attention, which can be triggered by unconsciously perceived cues, implying that awareness is not necessary for automatic attention to occur. Keywords: spatial orienting; attention; arrows; symbolic cues; automatic; unconscious perception. Introduction Since Posner (1980) suggested the dissociation between endogenous and exogenous orienting of attention, it has been assumed that symbolic, centrally presented cues, yield to voluntary shifts of attention, while peripheral abrupt onset cues elicit automatic shifts of attention. It is possible to observe the automatic orienting in a peripheral cueing task, even though cues are not consciously perceived (McCormick, 1997; Ivanoff & Klein, 2003; Lambert et al., 1999). McCormick (1997) instructed participants to reorient their attention toward the opposite location of a non-perceived peripheral cue. Results showed faster RT (facilitation) for target appearing at the cued location with brief stimulus onset asynchronies (SOA) and slower RT (inhibition of return, IOR) with longer SOA. Neither reorientation following predictive cues McCormick (1997), nor IOR in a non-predictive paradigm (Ivanoff & Klein, 2003; Lambert et al., 1999) has been found, with not- consciously perceived cues. However, Casagrande, Mereu, Martella and Marotta (2006), showed facilitation at the location indicated by a centrally presented and predictive arrow, which was invisible due to visual masking suggesting that even voluntary orienting could be elicited unconsciously. However, it has been suggested that arrows (Tipples, 2002), as well as other types of central cues like eye gaze (Friesen and Kingstone, 1998), may trigger a reflexive orienting of attention because they can elicit shifts of attention even though they are not predictive of the target onset location. So, the shifting of attention found in Casagrande et al., (2006) studies can be ascribed to automatic instead of voluntary orienting. The aim of this study is to evaluate the role of awareness in endogenous orienting of attention, in order to understand whether it is necessary for either automatic or voluntary orienting, or both. Experiment 1 The results found in Casagrande et al., (2006) seem to suggest what was proposed earlier (e.g. Warner et al., 1990), that both a voluntary and an automatic component coexist in the endogenous orienting of attention. Otherwise, one should accept the idea that either voluntary orienting could be elicited by not consciously perceived cues or that the endogenous orienting of attention is not voluntary at all. This last case would bring into question almost 30 years of modeling of attention, which claims that endogenous is voluntary. It is possible that if the orienting of attention found in Casagrande et al. (2006) study using a centrally presented cue is the product of an automatic orienting mechanism, the same results could be observed in a non informative paradigm where the cue is not a reliable predictor of the target onset location. In order to verify this hypothesis, we conducted an experiment in which the cues (arrows) were non-predictive of the target location and we gave no instruction about the cue to naive observers who never participated in a cueing task before. Showing an effect on non predictive, central, masked cues would confirm that the endogenous orienting has an automatic component, which could occur in the absence of awareness, in line with studies that showed a reflexive orienting after non-consciously perceived peripheral cues (McCormick, 1997; Ivanoff and Klein, 2003; Lambert et al., 1999). Method Participants Sixteen right handed students with normal or corrected-to-normal vision (age 25.7; ± DS: 2.56) participated in the experiment after signing a consent form.