A new methodology providing evidence of two distinct processes in the production of hand/foot simultaneous responses

To get simultaneous responses of the hand and the foot, it is mandatory to compensate for the longer peripheral motor conduction delay of the foot. According to the reactive-projective model [Paillard, J. (1948). Quelques données psychophysiologiques relatives au déclenchement de la commande motrice (Some psychophysiological data in relation to the releasing of the motor commands). Année Psychologique, 28-47; Paillard, J. (1990). Réactif et prédictif: deux modes de gestion du geste de la motricité. In V. Nougier, & J. Blanchi (Eds.), Pratiques sportives et modélisation du geste (Sport activity and gesture modeling) (pp. 13-56). Grenoble: Université Joseph-Fourier.] no compensation occurs in a reaction time situation; the hand responds before the foot, which indicates a single motor command released for both effectors. However, in a self-initiated condition, the foot tends to precede the hand suggesting that two distinct motor commands are issued, with the foot command first. Fully self-initiated movements are not usual. It is more usual to prepare a response in anticipation of the time occurrence of a stimulus (e.g., a musician following a conductor, synchronized swimmers emerging together with the music). Therefore, we developed a methodology to test whether the model holds in an anticipation coincidence task. In Experiment 1, the participants were asked to initiate a synchronized hand/foot response when the continuous visual stimulus (constant speed) reaches a target. The results fitted the model. In Experiment 2, anticipation coincidence tasks were performed in three conditions: using the foot (1) or the hand (2) alone, and using the hand and the foot simultaneously (3). Following a constant stimulus protocol, short tones were randomly produced, prior the stimulus, to indicate the participants to inhibit their response. As expected, the frequencies of correct inhibition in each preset period followed a sigmoid curve. The command release is assumed to occur at the biserial point (50% of inhibition). The results confirmed that the motor command of the foot is released sooner than the command of the hand. The hand/foot delay is lower in the simultaneous condition, because the command of the hand is released 40 ms earlier; while the foot command is 10 ms earlier. These data confirm and extend the projective-reactive model to a new category of coordination behavior.     

Biphasic ERK1/2 activation in both the hippocampus and amygdala may reveal a system consolidation of contextual fear memory

There is accumulating evidences to suggest that memory consolidation in some conditions involves two waves of neuronal plastic change. Using two fear conditioning procedures in male C57BL/6J mice, we have recently shown that consolidation of the foreground contextual fear memory required two waves of ERK1/2 activation in hippocampal CA1, while consolidation of cue conditioning was only associated with the early phase of activation. The present experiment further showed that this bi-phasic pattern of ERK1/2 activation was not restricted to hippocampal CA1, but could also be observed in other fear memory-related brain areas. The unpaired conditioning procedure (context in foreground) induced two waves of ERK1/2 activation in hippocampal CA1 and CA3, as well as in the LA and BLA nuclei of the amygdala. In contrast, the paired conditioning procedure (context in background) led to a transient early phase only in hippocampal CA1 and LA. In addition, ERK1/2 phosphorylation in the hippocampus was found to correlate with that in the amygdala nuclei specifically after the unpaired procedure. Taken together, our data suggest that the observed biphasic pattern of neuronal plastic events may reflect the interplay between hippocampal and amygdala activity-dependent plasticity critical for the system consolidation of contextual fear memory.     

Functional neuroimaging of autobiographical memory

Functional neuroimaging studies of autobiographical memory have grown dramatically in recent years. These studies are important because they can investigate the neural correlates of processes that are difficult to study using laboratory stimuli, including: (i) complex constructive processes, (ii) recollective qualities of emotion and vividness, and (iii) remote memory retrieval. Constructing autobiographical memories involves search, monitoring and self-referential processes that are associated with activity in separable prefrontal regions. The contributions of emotion and vividness have been linked to the amygdala and visual cortex respectively. Finally, there is evidence that recent and remote autobiographical memories might activate the hippocampus equally, which has implications for memory-consolidation theories. The rapid development of innovative methods for eliciting personal memories in the scanner provides the opportunity to delve into the functional neuroanatomy of our personal past.     

The explanatory potential of artificial societies

It is often claimed that artificial society simulations contribute to the explanation of social phenomena. At the hand of a particular example, this paper argues that artificial societies often cannot provide full explanations, because their models are not or cannot be validated. Despite that, many feel that such simulations somehow contribute to our understanding. This paper tries to clarify this intuition by investigating whether artificial societies provide potential explanations. It is shown that these potential explanations, if they contribute to our understanding, considerably differ from potential causal explanations. Instead of possible causal histories, simulations offer possible functional analyses of the explanandum. The paper discusses how these two kinds explanatory strategies differ, and how potential functional explanations can be appraised.     

Passion for Driving and Aggressive Driving Behavior: A Look at Their Relationship

The purpose of the present research was to investigate the relationship between passion for driving and aggressive driving behavior in 3 studies. Study 1 examined the association between passion and aggressive driving behavior in a sample of undergraduate students. Results showed that an obsessive passion for driving was associated with aggressive driving behavior, while harmonious passion was not. Study 2 replicated these results with an ecologically valid sample of community‐dwelling drivers. Finally, Study 3 replicated the results obtained in Studies 1 and 2 in a laboratory setting using a driving simulator under controlled frustrating driving situations with judges' assessment of aggressive driving behavior. Study 3 also showed that the emotion of anger mediated the obsessive‐passion/aggressive‐driving‐behavior relationship.     

Learning from Minimal Economic Models

It is argued that one can learn from minimal economic models. Minimal models are models that are not similar to the real world, do not resemble some of its features, and do not adhere to accepted regularities. One learns from a model if constructing and analysing the model affects one’s confidence in hypotheses about the world. Economic models, I argue, are often assessed for their credibility. If a model is judged credible, it is considered to be a relevant possibility. Considering such relevant possibilities may affect one’s confidence in necessity or impossibility hypotheses. Thus, one can learn from minimal economic models.

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Induced Reminiscence of Love and Chivalrous Helping

This study tested the effect of semantically-induced thoughts of love on chivalrous helping. A field setting of four hundred and one participants was divided into two groups. One group was interviewed and asked to retrieve the memory of a love episode, and the second group, the control group, was asked to retrieve a piece of music that they love. The two groups encountered another confederate, who inadvertently lost a stack of compact discs when they neared each other. The results demonstrated that participants were more helpful when they were male, when the person in need of help was female, and when they were induced to retrieve the memory of a love episode.