Biomedical subjects

Sandro Rubichi

Publications and source records attributed to Sandro Rubichi.

7 recordsLinked to original sources

PubMed2006

Are visual stimuli sufficient to evoke motor information? Studies with hand primes.

In two experiments we assessed whether seeing objects automatically activates information regarding how to manipulate them. In Experiment 1 participants categorized photographs of objects that could be manipulated either with a power or a precision grip into artefacts or natural kinds. Target-objects were preceded by primes consisting of photographs of hands in grasping postures (precision or power grip). Experiment 2 involved a preliminary motor training phase in which each visual prime was associated with the actual motor action. In both experiments, natural kinds graspable with a power grip produced the fastest responses. In Experiment 2 we also found a congruency effect between the prime and the kind of grip required by the object (precision, power). Results suggest that visual stimuli automatically activate motor information. Specific motor programs are, however, activated only if motor training is performed before the categorization task. Implications of the results for the understanding of the organization of conceptual and motor information in the brain are discussed.

Adolescent↗

PubMed2006

Hypnotic suggestion modulates cognitive conflict: the case of the flanker compatibility effect.

The 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.

Adult↗

PubMed2006

Spatial coding in two dimensions.

There has been growing interest in exploring human performance for situations in which stimuli and/or responses vary along both horizontal and vertical dimensions. Earlier studies indicated that there is a prevalence of the horizontal dimension over the vertical dimension in the spatial codes that are used for response selection. We review evidence about spatial coding for 2-D stimulus-response sets and accounts that have been proposed for explaining how it takes place. Particular attention is devoted to the relative salience account, which provides the most comprehensive explanation of 2-D spatial coding. We also evaluate the influence of speed of spatial code formation, number of reference frames, and learning on subjects' performance in 2-D tasks.

Conditioning, Classical↗

PubMed2005

Hypnotic susceptibility, baseline attentional functioning, and the Stroop task.

According to the theoretical framework relating hypnosis to attention, baseline attentional functioning in highly hypnotizable individuals should be more efficient than in low hypnotizable individuals. However, previous studies did not find differences in Stroop-like tasks in which the measure indicative of the Stroop interference effect was based on response latencies. This study was designed to determine whether subjects with different levels of hypnotic susceptibility show differences in baseline attentional functioning. To assess this hypothesis, high, medium, and low hypnotizable subjects performed a Stroop task designed to evaluate accuracy performance, before being subjected to hypnotic induction. Results showed that the Stroop interference effect was smaller in high hypnotizable subjects than in low hypnotizable subjects, whereas it was not different between high, and medium hypnotizable subjects. This outcome supports the notion that baseline attentional functioning is related to hypnotic susceptibility.

Attention↗

PubMed2004

Long-term effects of vaccination on attentional performance.

To investigate the possible influence of stimulation of the immune system on cognitive tasks, healthy volunteers were vaccinated against hepatitis B and tested over a 6 month-period in a simple reaction times and the Stroop task. In general, the "Stroop effect" demonstrates that both the name and meaning of a word are automatically processed even when voluntary attention is trying hard not to process them. Unlike placebo group, vaccinated subjects showed a persistent lack of the classical Stroop effect. These findings may be explained by a constraint satisfaction model of the Stroop task, assuming a selective weakening of the connection matrix, and suggest that immune-cognitive effects may occur, besides the well known immune-cognitive influences like those elicited by emotional stress.

Adult↗

PubMed2004

Right-left prevalence with task-irrelevant spatial codes.

The present work investigated the right-left prevalence effect caused by the automatic activation of horizontal and vertical spatial codes in a task (Simon task) in which spatial information is task-irrelevant. Experiment 1 showed a horizontal Simon effect and a vertical Simon effect with a two-dimensional stimulus-response set. In Experiments 2 and 3, the right-left prevalence was obtained in two-dimensional Simon tasks with two contralateral effectors and four effectors respectively. Experiment 4 showed that horizontal coding is based on multiple spatial codes, whereas only one spatial code was formed for vertical coding. On the whole, these results support the notion that the right-left prevalence effect is a general phenomenon affecting spatial coding, and suggest that the horizontal dimension is prevalent because it is based on multiple spatial codes.

Analysis of Variance↗

PubMed2004

Right-left prevalence effect with horizontal and vertical effectors.

We investigated the right-left prevalence effect in spatial compatibility tasks by assessing subjects' performance on a two-dimensional task in which both the horizontal and vertical spatial dimensions were task relevant. Two experiments were performed, in which stimulus-response mappings were one-dimensional (Experiment 1) and two-dimensional (Experiment 2). The subjects responded by using either horizontal or vertical effectors to stimuli appearing in four possible locations. With the one-dimensional mapping, the spatial compatibility effect was present only in the dimension relevant to the mapping. With the two-dimensional mapping, the horizontal compatibility effect was always present, whereas the vertical compatibility effect was present only when vertical effectors were used. This pattern of results indicates that horizontal coding takes place with either horizontal or vertical effectors, whereas vertical coding takes place only when vertical effectors are used.

Humans↗