Onset and Offset as Determinants of the Simon Effect

We investigated the presence and the characteristics of the Simon effect for onset and offset targets when these stimuli are randomly intermixed. In Experiment 1, two possible target locations were occupied by an occluder. On onset trials, a target appeared above an occluder, while on offset trials one of the occluders disappeared, revealing the target underneath. In Experiment 2, four stimuli appeared randomly in six possible locations. On onset trials, a new stimulus appeared in an empty location while on offset trials, one of the initial stimuli disappeared. In both experiments, the Simon effect for onset and offset targets was characterized by similar size, time course and sequential modulation, suggesting similar sensorimotor interactions between target and response locations. However, the Simon effect in the current trials was more evident when the same type of target (onset or offset) was repeated on successive trials demonstrating the role of stimulus category in its modulation

Social and non-social categorisation in investment decisions and learning

Funding: This research was supported by the Spanish Ministry of Education, Culture and Sports, with pre-doctoral FPU fellowship FPU14/07106 to MT, and the Spanish Ministry of Economy and Competitiveness, with research projects PSI2014-52764-P and PSI2017-84926-P to JL. Participation of JAA was funded by the Action 7 of the Research Support Plan of the University of Jaén.Categorical processes allow us to make sense of the environment effortlessly by grouping stimuli sharing relevant features. Although these processes occur in both social and non-social contexts, motivational, affective and epistemic factors specific to the social world may motivate individuation over categorisation of social compared to non-social stimuli. In one experiment, we tested this hypothesis by analysing the reliance on categorical versus individuating information when making investment decisions about social and non-social targets. In an adaptation of the iterative trust game, participants from three experimental groups had to predict the economic outcomes associated with either humans (i.e., social stimuli), artificial races (i.e., social-like stimuli), or artworks (i.e., non-social stimuli) to earn economic rewards. We observed that investment decisions with humans were initially biased by categorical information in the form of gender stereotypes, but later improved through an individuating learning approach. In contrast, decisions made with non-social stimuli were initially unbiased by categorical information, but the category-outcomes associations learned through repeated interactions were quickly used to categorise new targets. These results are discussed along with motivational and perceptual mechanisms involved in investment decisions and learning about social and non-social agents.Publisher PDFPeer reviewe

Spatial Stroop and spatial orienting: the role of onset versus offset cues

The present study investigated whether offset cues have the same attentional consequences in the spatial Stroop effect as onset cues. Experiments 1 and 2 compared the attentional effects of onset-offset cues versus offset cues on the spatial Stroop effect, whereas Experiment 3 compared the attentional effects of onset versus offset cues. Across these experiments, independent of cue type (onset-offset or onset vs. offset) and even at long stimulus-onset asynchrony, attentional cueing did not revert into inhibition of return and was modulated by spatial Stroop with greater cueing effects for incongruent arrow&#39;s direction and position. In addition, onset-offset or onset and offset cues produced comparable cueing effects in the location-direction congruent condition, and onset-offset or onset cues produced greater facilitation than offset cues in the incongruent condition. From a different perspective, peripheral cueing modulated the spatial Stroop effect in the same direction for onset-offset or onset and offset cues, although the reduction in spatial Stroop at cued locations was smaller with offset than with onset-offset or onset cues.</p

Modulation of spatial Stroop by object-based attention but not by space-based attention

Earlier studies have shown that the spatial Stroop effect systematically decreases when a peripheral precue is presented at the same location as the target, compared to an uncued location condition. In this study, two experiments were conducted to explore whether the cueing modulation of spatial Stroop is object based and/or space based. In Experiment 1, we found evidence favouring the view that the cueing modulation of the spatial Stroop effect is entirely object based, as no differences were found in conflict reduction for the same-location and same-object conditions. In Experiment 2, the cue was predictive, and a similar object-based modulation of spatial Stroop was still observed. However, the direction of such modulation was affected by the rectangles' orientation. Overall, the pattern of results obtained favours the object-integration (Lupianez Milliken, 1999; Lupianez, Milliken, Solano, Weaver, Tipper, 2001) and referential-coding accounts (Danziger, Kingstone, Ward, 2001) and seems to provide evidence against the attention-shift account (Rubichi, Nicoletti, Iani, Umilta, 1997; Stoffer, 1991)

Alerting, orienting and executive control: the effects of sleep deprivation on attentional networks

Sleep deprivation alters attentional functions like vigilance or tonic alerting (i.e., sustaining an alert state over a period of time). However, the effects of sleep loss on both orienting and executive control are still not clear, and no study has assessed whether sleep deprivation might affect the relationships among these three attentional systems. In order to investigate the efficiency of the three attentional networks-alerting, orienting and executive control-within a single task, we used the Attention Network Test (ANT). Eighteen right-handed male participants took part in the experiment, which took place on two consecutive days. On the first day, each participant performed a 20 min training session of the ANT. On the second day, participants remained awake for 24 h during which time the ANT was performed once at 5:00 p.m. and once at 4:00 a.m. Results showed an overall slowing of reaction times in the nocturnal session, indicating a strong decrease in vigilance. Furthermore, sleep deprivation did affect attentional orienting and executive control. Results are consistent with the hypothesis that the tonic component of alerting interacts with both attentional orienting and executive functions

Dissociating inhibition of return from endogenous orienting of spatial attention: Evidence from detection and discrimination tasks

In the present series of experiments, peripheral informative cues were used in order to dissociate endogenous and exogenous orienting of spatial attention using the same set of stimuli. For each block of trials, the cue predicted either the same or the opposite location of target appearance. Crucially, using this manipulation, both expected and unexpected locations could be either cued or uncued. If one accepts the hypothesis that inhibition of return (IOR) is an attentional effect that inhibits the returning of attention to a previously attended location (Posner & Cohen, 1984), one would not predict an IOR effect at the expected location, since attention should not disengage from the location predicted by the cue. Detection and discrimination tasks were used to examine any potential difference in the mechanism responsible for IOR as a function of the task at hand. Two major results emerged: First, IOR was consistently observed at the expected location, where, according to the traditional "reorienting" hypothesis, IOR is not supposed to occur. Second, a different time course of cueing effects was found in detection versus discrimination tasks, even after controlling for the orienting of attention. We conclude that IOR cannot be accounted for solely by the "reorienting of attention" hypothesis. Moreover, we argue that the observed time course differences in cueing effects between detection and discrimination tasks cannot be explained by attention disengaging from cues later in discrimination than in detection tasks, as proposed by Klein (2000). The described endogenous-exogenous dissociation is consistent with models postulating that endogenous and exogenous attentional processes rely on different neural mechanisms

Investigating hemispheric lateralization of reflexive attention to gaze and arrow cues

Recent studies have demonstrated that central cues, such as eyes and arrows, reflexively trigger attentional shifts. However, it is not clear whether the attentional mechanisms induced by these two cues are similar or rather differ in some important way. We investigated hemispheric lateralization of the orienting effects induced by the two cue types in a group of 48 healthy participants comparing arrows and eye gaze as central non-predictive cues in a discrimination task, in which a target stimulus was briefly presented in one of two peripheral positions (left or right of fixation). As predicted by neuropsychological data, reflexive orienting to gaze cues was only observed when the target was presented in the left visual field, whereas reflexive orienting to arrow cues occurred for targets presented in both left and right visual fields. (C) 2012 Elsevier Inc. All rights reserved

Object-based attentional effects in response to eye-gaze and arrow cues

Recent studies have demonstrated that central cues, such as eyes and arrows, reflexively trigger attentional shifts. However, it is not clear whether the attention induced by these two cues can be attached to objects within the visual scene. In the current study, subjects' attention was directed to one of two objects (square outlines) via the observation of uninformative directional arrows or eye gaze. Then, the objects rotated 90 degrees clockwise or counter-clockwise to a new location and the target stimulus was presented within one of these two objects. Results showed that independent of the cue type participants responded faster to targets in the cued object than to those in the uncued object. This suggests that in dynamic displays, both gaze and arrow cues are able to trigger reflexive shifts of attention to objects moving within the visual scene. (C) 2013 Published by Elsevier B.V

Eye Gaze Versus Arrows as Spatial Cues: Two Qualitatively Different Modes of Attentional Selection

This study aimed to evaluate the type of attentional selection (location- and/or object-based) triggered by two different types of central noninformative cues: eye gaze and arrows. Two rectangular objects were presented in the visual field, and subjects' attention was directed to the end of a rectangle via the observation of noninformative directional arrows or eye gaze. Similar experiments with peripheral cues have shown an object-based effect: faster target identification when the target is presented on the cued object as compared to the uncued object, even when the distance between target and cue was the same. The three reported experiments aimed to compare the location- and object-based attentional orienting observed with arrows and eye gaze, in order to dissociate the orienting mechanisms underlying the two types of orienting cues. Results showed similar cueing effects on the cued versus oppositely cued locations for the two cue types, replicating several studies with nonpredictive gaze and arrow cues. However, a pure object-based effect occurred only when an arrow cue was presented, whereas a pure location-based effect was only found for eye-gaze cues. It is suggested that attention is nonspecifically directed to nearby objects when a noninformative arrow is used as cue, whereas it is selectively directed to a specific cued location when noninformative eye gaze is used. This may be mediated by theory of mind mechanisms

Social and non-social categorisation in investment decisions and learning

Categorical processes allow us to make sense of the environment effortlessly by grouping stimuli sharing relevant features. Although these processes occur in both social and non-social contexts, motivational, affective and epistemic factors specific to the social world may motivate individuation over categorisation of social compared to non-social stimuli. In one experiment, we tested this hypothesis by analysing the reliance on categorical versus individuating information when making investment decisions about social and non-social targets. In an adaptation of the iterative trust game, participants from three experimental groups had to predict the economic outcomes associated with either humans (i.e., social stimuli), artificial races (i.e., social-like stimuli), or artworks (i.e., non-social stimuli) to earn economic rewards. We observed that investment decisions with humans were initially biased by categorical information in the form of gender stereotypes, but later improved through an individuating learning approach. In contrast, decisions made with non-social stimuli were initially unbiased by categorical information, but the category-outcomes associations learned through repeated interactions were quickly used to categorise new targets. These results are discussed along with motivational and perceptual mechanisms involved in investment decisions and learning about social and non-social agents