The rubber hand illusion: sensitivity and reference frame for body ownership

When subjects view stimulation of a rubber hand while feeling congruent stimulation of their own hand, they may come to feel that the rubber hand is part of their own body. This illusion of body ownership is termed 'Rubber Hand Illusion' (RHI). We investigated sensitivity of RHI to spatial mismatches between visual and somatic experience. We compared the effects of spatial mismatch between the stimulation of the two hands, and equivalent mismatches between the postures of the two hands. We created the mismatch either by adjusting stimulation or posture of the subject's hand, or, in a separate group of subjects, by adjusting stimulation or posture of the rubber hand. The matching processes underlying body ownership were asymmetrical. The illusion survived small changes in the subject's hand posture, but disappeared when the same posture transformations were applied to the rubber hand. Mismatch between the stimulation delivered to the subject's hand and the rubber hand abolished the illusion. The combination of these two situations is of particular interest. When the subject's hand posture was slightly different from the rubber hand posture, the RHI remained as long as stimulation of the two hands was congruent in a hand-centred spatial reference frame, even though the altered posture of the subject's hand meant that stimulation was incongruent in external space. Conversely, the RHI was reduced when the stimulation was incongruent in hand-centred space but congruent in external space. We conclude that the visual-tactile correlation that causes the RHI is computed within a hand-centred frame of reference, which is updated with changes in body posture. Current sensory evidence about what is 'me' is interpreted with respect to a prior mental body representation.     

Preemptive War, Americanism, and Anti-Americanism

Abstract: The war against Iraq unleashed in March 2003 spawned an attempt to silence the protest movement by accusing it of anti‐Americanism. This essay argues that the theory according to which right‐wing anti‐Americanism and left‐wing anti‐Americanism coincide is a myth. A new issue appears now, a paradox that characterizes the United States, where democracy developed within the white community concomitantly with the enslavement of blacks and the deportation of American Indians. In the American “Herrenvolk democracy,” a line of demarcation between whites and people of color fosters the development of relations based on equality within the white community. Furthermore, U.S. history is marked by the fundamentalist tendency to transform the Judeo‐Christian tradition into a sort of national religion that consecrates the exceptionalism of the American people and the sacred mission with which they are entrusted (“Manifest Destiny”). Europe is unable thoroughly to comprehend the American mixture of religious and moral fervor, on the one hand, and overt pursuit of political, economic, and military world domination, on the other. But it is this mixture, or rather this explosive combination, this peculiar fundamentalism, that constitutes the greatest threat to world peace today.     

Processing Italian Relative Clauses: Working Memory Span and Word Order Effects on RTs

In this study, the authors aim to clarify whether the subject–object asymmetry in relative clause comprehension is due to the use of parsing strategies (Active Filler Theory) or to a greater memory load generated by object sentences. Two experiments investigate how individual differences in working memory span may influence the reading times of relative sentences in Italian, a language characterized by a flexible structure. The results of Experiment 1 indicate that object extraction is more complex than subject extraction when sentences have a canonical structure. Furthermore, low-span participants have particular difficulties with object relative sentence comprehension. The results of Experiment 2 show that subject-relative clauses with uncanonical structures are more complex to understand than object-relative clauses, and low-span participants have more difficulties than high-span participants in elaborating both subject and object relative clauses. These data seem to be coherent with the Active Filler Theory.     

Cognitive and neural determinants of response strategy in the dual-solution plus-maze task

Response strategy in the dual-solution plus maze is regarded as a form of stimulus-response learning. In this study, by using an outcome devaluation procedure, we show that it can be based on both action-outcome and stimulus-response habit learning, depending on the amount of training that the animals receive. Furthermore, we show that deactivation of the dorso-medial and the dorso-lateral striatum with Botulinum neurotoxin A, mimicked or abolished, respectively, the effects of practice on the sensitivity of the response strategy to outcome devaluation. These findings have relevant implications for the understanding of the learning mechanisms underlying different overt behaviors in this widely used maze task.     

Out of your hand's reach, out of my eyes' reach

When witnessing another's action, people recruit the same motor resources that enable them to efficiently perform that action, thus gazing at its target well before the agent's hand. But just to what extent does this recruitment help people in grabbing another's action target? If the latter seems to be out of the agent's reach, will this impact on people's gaze behaviour? We recorded proactive eye movements while participants witnessed someone else trying to reach for and grasp objects located either within or outside his reach. Proactivity of gaze was impaired when the targets were just out of the agent's reach. This effect is likely to be due to an interpersonal bodily space representation that allows one to map another's reaching space, thus prompting proactive eye movements towards the target just in case the agent is in the position to act upon it.     

Running with emotion: When affective content hampers working memory performance

This study tested the hypothesis that affective content may undermine rather than facilitate working memory (WM) performance. To this end, participants performed a running WM task with positive, negative and neutral words. In typical running memory tasks, participants are presented with lists of unpredictable length and are asked to recall the last three or four items. We found that accuracy with affective words decreased as lists lengthened, whereas list length did not influence recall of neutral words. We interpreted this pattern of results in terms of a limited resource model of WM in which valence represents additional information that needs to be manipulated, especially in the context of difficult trials.     

The effectiveness of reward and punishment contingencies on response inhibition

The relative effectiveness of reward and punishment on the development of response inhibition was evaluated developmentally. Forty kindergarten and forty second-graders received response inhibition training with half of each group rewarded for inhibiting and half punished for not inhibiting. Reward involved the presentation of positive reinforcers, whereas punishment involved their removal. Punishment produced more inhibition at both age levels than did reward. Transfer of inhibition training was evaluated in two tasks. Transfer effects were observed only on one of the two tasks. Reinforcement contingencies and age did not differentially influence the magnitude of transfer.