86,548 research outputs found
Determining priority between attentional and referential-coding sources of the Simon effect through optokinetic stimulation
No full textThe “Simon effect” is the performance advantage for spatially corresponding target–response ensemblesthat is observed when coding of target position is irrelevant for the selection of motor responses. The“attentional-shift” account of the Simon effect holds that it arises from the congruency between responselocation and the direction of the last shift of attention toward the target. The “referential-coding” accounttraces the origin of the Simon effect back to the congruency between the response location and theposition of the target with respect to a spatial reference frame. We were able to contrast these twohypotheses using full-field horizontal optokinetic stimulation (OKS). It was shown that OKS moving inone horizontal direction drives covert orienting of attention toward the side of arrival of OKS, i.e. the “Incoming”side, which is opposed to the direction of OKS motion toward the “Out-going” side (Teramoto etal., 2004; Watanabe, 2001). We therefore asked healthy participants to discriminate between slow andfast velocities of leftward or rightward OKS. “Fast” and “slow” responses were associated to responsebuttons positioned in the left or right side of space. The “attentional-shift” account of the Simon effectpredicts that response compatibility should be related to the direction of the attentional shift induced byOKS, i.e. in the direction opposite to OKS motion. By contrast, the “referential-coding” hypothesis predictsthat response compatibility should be related to the direction of OKS displacement with respect to itsstarting position.Weobserved faster RTs when the response button was on the “In-coming” side of space,opposite to the direction ofOKSmotion. This result supports priority of attentional over referential-codingfactors in the genesis of the Simon effect
Attention control and susceptibility to hypnosis
No full textThe present work aimed at assessing whether the interference exerted by task-irrelevant spatial information is comparable in high- and low-susceptible individuals and whether it may be eliminated by means of a specific posthypnotic suggestion. To this purpose high- and low-susceptible participants were tested using a Simon-like interference task after the administration of a suggestion aimed at preventing the processing of the irrelevant spatial information conveyed by the stimuli. The suggestion could be administered either in the absence or following a standard hypnotic induction. We showed that, outside from the hypnotic context, the Simon effect was similar in high and low-susceptible participants and it was significantly reduced following the posthypnotic suggestion in high-susceptible participants only. These results show that a specific posthypnotic suggestion can alter information processing in high-susceptible individuals and reduce the interfering effect exerted by arrow stimuli
Searching for a tactile target: the impact of set-size on the N140cc
No full textThe time needed to find a visual target amongst distractors (search task) can increase as a function of the distractors’ number (set-size) in the search-array (inefficient search). While the allocation of attention in search tasks has been extensively investigated and debated in the visual domain, little is known about these mechanisms in touch. Initial behavioral evidence shows inefficient search behavior when participants have to distinguish between target and distractors defined by their vibro-tactile frequencies. In the present study, to investigate the allocation of attention to items of the search-array we measured the N140cc during a tactile task in which the set-size was manipulated. The N140cc is a lateralized component of event-related brain potentials recently described as a psychophysiological marker of attentional allocation in tactile search tasks. Participants localized the target, a singleton frequency, while ignoring one, three or five homogeneous distractors. Results showed that error rates linearly increased as a function of set-size, while response times were not affected. Reliable N140cc components were observed for all set-sizes. Crucially, the N140cc amplitude decreased as the number of distractors increased. We argue that the presence of additional distractors hindered the preattentive analysis of the search array resulting in increased uncertainty about the target location (inefficient preattentive stage). This, in turn, increased the variability of the deployment of attention to the target, resulting in reduced N140cc amplitudes. Consistent with existing behavioral evidence, these findings highlight systematic differences between the visual and the tactile attentional systems
L’influenza dell’interdipendenza sulla costruzione di rappresentazioni condivise
No full textIl presente lavoro ha voluto indagare se l’emergere di rappresentazioni condivise, ritenute essere alla base dell’azione condivisa, possa essere influenzato da fattori sociali, quali l’appartenenza di gruppo ed il rapporto di interdipendenza che lega due co-agenti. Tenendo in considerazione alcuni costrutti derivanti dalla psicologia sociale, in due esperimenti è stato chiesto ai partecipanti di svolgere insieme un compito Simon, manipolando la percezione di appartenenza allo stesso gruppo in base ad una categorizzazione sperimentale creata ad-hoc (Esperimento 1: coppie appartenenti vs. coppie non appartenenti alla stessa categoria) e il tipo di relazione di interdipendenza (Esperimento 2: situazione cooperativa vs. competitiva). I risultati dimostrano come l’effetto Simon sociale non sia modulato da una semplice categorizzazione in gruppi, ma sia significativamente influenzato dal tipo di interdipendenza percepita. L’effetto Simon risulta infatti assente solo nella situazione competitiva. Questi dati suggerirebbero che in condizioni di interazione, di norma, gli individui tendono a costruire rappresentazioni condivise che presuppongono la cooperazione tra individui. Mentre l’appartenenza a gruppi diversi non compromette la costruzione di rappresentazioni condivise, l’interazione competitiva tra gli individui della stessa coppia la influenza negativamente
Hypnotic suggestion modulates cognitive conflict: The case of the flanker compatibility effect
No full textThe present work was aimed at investigating whether the flanker compatibility effect can be eliminated by means of a posthypnotic suggestion influencing attentional focusing. In Experiment 1, participants who scored high and low on hypnotic susceptibility performed the flanker compatibility task when naturally awake and when under a posthypnotic suggestion aimed at increasing the target's discriminability from the flankers. Results showed that the posthypnotic suggestion effectively eliminated the flanker compatibility effect in highly susceptible participants, whereas low-susceptibility participants did not show any reduction in the effect. In Experiment 2, highly susceptible participants performed the task after receiving a suggestion but without the induction of hypnosis. Results showed that the suggestion alone was not sufficient to reduce the flanker compatibility effect. These results support the view that in highly susceptible participants, hypnotic suggestion can influence the ability to focus on relevant information
A study on the intertwined effect of cognitive impairment and depression on disability
No full textA study on the intertwined effect of cognitive impairment and depression on disability. In NEUROBIOLOGY OF AGING - ISSN:0197-4580 vol. 2
Hypnotic suggestion modulates cognitive conflict - The case of the flanker compatibility effect
No full textThe present work was aimed at investigating whether the flanker compatibility effect can be eliminated by means of a posthypnotic suggestion influencing attentional focusing. In Experiment 1, participants who scored high and low on hypnotic susceptibility performed the flanker compatibility task when naturally awake and when under a posthypnotic suggestion aimed at increasing the target's discriminability from the flankers. Results showed that the posthypnotic suggestion effectively eliminated the flanker compatibility effect in highly susceptible participants, whereas low-susceptibility participants did not show any reduction in the effect. In Experiment 2, highly susceptible participants performed the task after receiving a suggestion but without the induction of hypnosis. Results showed that the suggestion alone was not sufficient to reduce the flanker compatibility effect. These results support the view that in highly susceptible participants, hypnotic suggestion can influence the ability to focus on relevant information
Cognitive impairment and postural control in elderly
No full textBackground: a correct postural control stems by central nervous system-cortical and subcortical- and the peripheral one. With aging, the highprevalence of polimorbidity undermines these mechanisms determining agrowth of risk to falls. Some evidence has showed that an interpolatedcognitive task increases, even in healthy subjects, postural imbalance.At the moment, just a little has known about the relationship betweenmild-moderate dementia and postural control. Objective: to investigate1. possible differences in postural sways between controls and dementedsubjects at quiet standing and with an interpolated cognitive task; 2. die roteof frontal functions in the integration of postural and cognitive performance,requiring spatial or verbal skills. Materials and methods: we have chosen34 subjects: M = 14 and F = 20, aged between 65 and 85, 10 controls and24 demented patients with MMSE score ranging from 21 to 26. Ancillarytests were applied to exclude visual, hearing, vestibular and proprioceptivedisabling deficits, muscle strength deficits, high level of co-morbidity.Tinetti's scale was applied to check balance and gait, while three indices ofthe CAMDEX (CAMCOG, Depress and Organicity) were used to evaluatethe cognitive level, depressive symptoms and functional abilities. Both DualTask test and verbal fluency were used to assess frontal functions. Twocomputerized indices of postural control were obtained by a static forceplatform (Kistler type 9284) allowing to measure the postural sway, in arepeated 20" trials protocol, in two different experimental conditions: 1. atquiet standing condition, with subsequently open and closed eyes sessions2. at interference condition, with the performance of an interpolated verbal(counting back) or spatial (a plane rotation pictures paradigm) cognitivetask, administrated to each subject in a random sequence. Conclusions:the results show that any significant difference could be detected betweengroups at basal evaluation, while sways significantly increase in dementiapatients at interference trials, namely during verbal cognitive task. Moreovera significant relationship could be detected between the increase of posturalsways during verbal task and frontal impaired performance in dementedsubjects
The role of attention in the occurrence of the affordance effect
No full textIt has been demonstrated that visual objects activate responses spatially corresponding to the orientation (left or right) of their graspable parts. To investigate the role of attention orienting in the generation of this effect, which we will refer to as affordance effect, we ran three experiments in which the target stimulus could either correspond or not with a dynamic event capturing attention. Participants were required to press a left or right key according to the vertical orientation (upward or inverted) of objects presented with their handles oriented to the right or to the left. In Experiments 1 and 2, the objects were located above or below fixation, while in Experiment 3, to assess the contemporary presence of the affordance and Simon effects, the objects were located to the left or right of fixation. The results showed that while the affordance effect, when evident, was always relative to the target object, irrespective of its attentional capturing properties, the Simon effect occurred relative to the event capturing attention. These findings suggest that automatic and controlled processes of visual attention may play a differential role in the occurrence of the two effects
Attention control and susceptibility to hypnosis
No full textThe present work aimed at assessing whether the interference exerted by task-irrelevant spatial information is comparable in high- and low-susceptible individuals and whether it may be eliminated by means of a specific posthypnotic suggestion. To this purpose high and low-susceptible participants were tested using a Simon-like interference task after the administration of a suggestion aimed at preventing the processing of the irrelevant spatial information conveyed by the stimuli. The suggestion could be administered either in the absence or following a standard hypnotic induction. We showed that, outside from the hypnotic context, the Simon effect was similar in high and low-susceptible participants and it was significantly reduced following the posthypnotic suggestion in high-susceptible participants only. These results show that a specific posthypnotic suggestion can alter information processing in high-susceptible individuals and reduce the interfering effect exerted by arrow stimuli
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