Andrea Marotta

Inhibition of Return in Response to Eye Gaze and Peripheral Cues in Young People with Asperger's Syndrome.

Inhibition of return (IOR) reflects slower reaction times to stimuli presented in previously attended locations. In this study, we examined this inhibitory after-effect using two different cue types, eye-gaze and standard peripheral cues, in individuals with Asperger’s syndrome and typically developing individuals. Typically developing participants showed evidence of IOR for both eye-gaze and peripheral cues. In contrast, the Asperger group showed evidence of IOR to previously peripherally cued locations but failed to show IOR for eye-gaze cues. This absence of IOR for eye-gaze cues observed in the participants with Asperger may reflect an attentional impairment in responding to socially relevant information.

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.

Attention network test — The impact of social information on executive control, alerting and orienting

According to the attention network approach, attention is best understood in terms of three functionally and neuroanatomically distinct networks - alerting, orienting, and executive attention. An important question is whether social information influences the efficiency of these networks. Using the same structure as the Attentional Network Test (ANT), we developed a variant of this test to examine attentional effects in response to stimuli with and without social-cognitive content. Fish, drawings or photographs of faces looking to the left or right were used as target stimuli. Results collected from twenty-four university students showed that photographs of faces positively affected attentional orienting and executive control, whereas reduced the efficiency of alerting, as compared to both face drawings and fish. These results support the status of human faces as a special class of visual stimuli for the human attentional systems.

Impaired reflexive orienting to social cues in attention deficit hyperactivity disorder

The present study investigated whether another person’s social attention, specifically the direction of their eye gaze, and non-social directional cues triggered reflexive orienting in individuals with Attention Deficit Hyperactivity Disorder (ADHD) and age-matched controls. A choice reaction time and a detection tasks were used in which eye gaze, arrow and peripheral cues correctly (congruent) or incorrectly (incongruent) signalled target location. Independently of the type of the task, differences between groups were specific to the cue condition. Typically developing individuals shifted attention to the location cued by both social and non-social cues, whereas ADHD group showed evidence of reflexive orienting only to locations previously cued by non-social stimuli (arrow and peripheral cues) but failed to show such orienting effect in response to social eye gaze cues. The absence of reflexive orienting effect for eye gaze cues observed in the participants with ADHD may reflect an attentional impairment in responding to socially relevant information.

Efficiency and interactions of alerting, orienting and executive networks: The impact of imperative stimulus type

The Attention Network Test (ANT) generates measures of three attention networks: alerting, orienting and executive control. Arrows have been generally used as imperative stimuli in the different versions of this paradigm. However, it is unknown whether the directional nature of these stimuli can modulate the efficiency of the executive control and its interaction with alerting and orienting. We developed three ANT variants to examine attentional effects in response to directional and non-directional stimuli. Arrows (ANTI-A), colored fruits (ANTI-F) and black geometrical-shape (ANTI-G) were used as imperative stimuli (i.e., flanker stimuli). Data collected from fifty-two university students, in two experiments, showed that arrows stimuli produced a greater interference effect and a greater orienting effect as compared to the other stimuli. Moreover, only arrows modulated the interaction between executive control and orienting: a reduced flanker effect in spatially cued trials was only observed in ANTI-A. These results suggest that the directional value of the stimuli increases the conflict and modulates the efficiency of executive control and its interaction with orienting network.

Hemispheric modulations of the attentional networks

Although several recent studies investigated the hemispheric contributions to the attentional networks using the Attention Network Test (ANT), the role of the cerebral hemispheres in modulating the interaction among them remains unclear. In this study, two lateralized versions of this test (LANT) were used to investigate theal effects on the attentional networks under different conflict conditions. One version, the LANTI-A, presented arrows as target and flankers, while the other version, the LANTI-F, had fruits as target and flankers. Data collected from forty-seven participants confirmed well-known results on the efficiency and interactions among the attentional networks. Further, a left visual field advantage was found when a target occurred in an unattended location (e.g. invalid trials), only with the LANTI-F, but not with LANTI-A. The present study adds more evidence to the hemispheric asymmetry of the orienting of attention, and further reveals patterns of interactions between the attentional networks and the visual fields across different conflicting conditions, underlying the dynamic control of attention in complex environments.

Visual Search and Emotion: How Children with Autism Spectrum Disorders Scan Emotional Scenes

This study assessed visual search abilities, tested through the flicker task, in children diagnosed with autism spectrum disorders (ASDs). Twenty-two children diagnosed with ASD and 22 matched typically developing (TD) children were told to detect changes in objects of central interest or objects of marginal interest (MI) embedded in either emotion-laden (positive or negative) or neutral real-world pictures. The results showed that emotion-laden pictures equally interfered with performance of both ASD and TD children, slowing down reaction times compared with neutral pictures. Children with ASD were faster than TD children, particularly in detecting changes in MI objects, the most difficult condition. However, their performance was less accurate than performance of TD children just when the pictures were negative. These findings suggest that children with ASD have better visual search abilities than TD children only when the search is particularly difficult and requires strong serial search strategies. The emotional–social impairment that is usually considered as a typical feature of ASD seems to be limited to processing of negative emotional information.

Controlling attention to gaze and arrows in attention deficit hyperactivity disorder

The aim of this research was to assess implicit processing of social and non-social distracting cues in children with ADHD. Young people with ADHD and matched controls were asked to classify target words (LEFT/RIGHT) which were accompanied by a distracter eye-gaze or arrow. Typically developing participants showed evidence of interference effects from both eye-gaze and arrow distracters. In contrast, the ADHD group showed evidence of interference effects from arrow but failed to show interference from eye-gaze. This absence of interference effects from eye-gaze observed in the participants with ADHD may reflect an attentional impairment in attending to socially relevant information.

Investigating gaze processing in euthymic bipolar disorder: Impaired ability to infer mental state and intention, but preservation of social attentional orienting

Euthymic bipolar disorder (BD) has been associated with subtle impairment in face processing. However, it is not known whether their difficulties extend to the processing of gaze. In the present study, two tasks, both of which rely on the ability to make use of the eye region of a pictured face, were used: the Reading the Mind in the Eyes test and the Eye-gaze cueing task. Compared to healthy controls, BD patients were impaired at judging mental state from images of the face but showed normal susceptibility to the direction of gaze as an attentional cue. These findings suggest that BD patients present selective gaze processing impairment, limited to the sensitivity to intention and emotion. This impairment could account at least partially for the higher levels of interpersonal problems generally observed in BD.

Arrows don’t look at you: Qualitatively different attentional mechanisms triggered by gaze and arrows

Eye gaze conveys rich information concerning the states of mind of others, playing a critical role in social interactions, signaling internal states, and guiding others’ attention. On the basis of its social significance, some researchers have proposed that eye gaze may represent a unique attentional stimulus. However, contrary to this notion, the majority of the literature has shown indistinguishable attentional effects when eye gaze and arrows have been used as cues. Taking a different approach, in this study we aimed at finding qualitative attentional differences between gazes and arrows when they were used as targets instead of as cues. We used a spatial Stroop task, in which participants were required to identify the direction of eyes or arrows presented to the left or the right of a fixation point. The results showed that the two types of stimuli led to opposite spatial interference effects, with arrows producing faster reaction times when the stimulus direction was congruent with the stimulus position (a typical spatial Stroop effect), and eye gaze producing faster reaction times when it was incongruent (a “reversed” spatial Stroop effect). This reversed Stroop is interpreted as an eye-contact effect, therefore revealing the unique nature of eyes as special social-attention stimuli.