Motor imagery and ‘placebo-racket effects’ in tennis serve performance

ObjectivesThis study aimed at confirming whether Motor Imagery (MI) enhances tennis serve performance, and determining whether a placebo condition could affect the beneficial effects of MI.DesignThis study used a 3 × 2 factorial design. Three groups of tennis players were compared in service performance outcomes before and after a training session.MethodsTwenty-two tennis players were assigned into three groups: a control (C) and two experimental groups subjected to a similar MI intervention, one group using their regular own racket (MI group) while the other used a placebo racket (P group).ResultsAnalyses of Covariance revealed no significant group difference when comparing serve velocity after training session, but MI training improved serve accuracy and regularity. Combining placebo racket with MI further resulted in greater serve accuracy score as compared to MI alone. Players' perception of their serve quality improved after MI, and this effect was reinforced in the P group.ConclusionThese findings revealed that MI may be useful to achieve peak performance, and that the implement placebo effect might be a factor in sport performance, hence promoting the beneficial effects of alternative methods to improve tennis serve performance.     

Mother–Calf vocal communication in Atlantic walrus: a first field experimental study

In all colonial pinnipeds studied, mother–young vocal recognition exists and allows rapid and reliable meetings in spite of the confusing environment of the breeding colony. The efficiency of this recognition process guarantees pup survival, especially in species where females alternate foraging sea trips and lactation periods on land. The Atlantic Walrus (Odobenus rosmarus rosmarus) is a highly gregarious pinniped with females attending their calves for an extended period of time (2–3 years). Although we expect mother–calf vocal recognition to occur in this species due to the high density of individuals packed in herds, it has never been experimentally demonstrated. Here, we assessed the individual stereotypy of both mother and calf barks recorded in the wild by measuring frequency and temporal acoustic parameters. Both discriminant function and artificial neural network analyses resulted in high correct classification rates, underlying a well-defined individual stereotypy in parameters related to frequency modulation and frequency values. Playback experiments showed that mothers were more responsive to the barks of their own calf than to those of unrelated young. Finally, propagation experiments revealed that barks propagate at greater distances over water surface than over ice, acoustic features such as frequency modulation and frequency spectrum being highly resistant to degradation during propagation. Thus, acoustic analysis and propagation experiments suggest that these frequency parameters might be the key acoustic features involved in the individual identification process. This experimental study clearly demonstrates that Atlantic walrus has developed a highly reliable mother–calf vocal communication allowing such strong social bond.     

Attentional modulation of visual-evoked potentials by threat: investigating the effect of evolutionary relevance

In dot-probe tasks, threatening cues facilitate attention to targets and enhance the amplitude of the target P1 peak of the visual-evoked potential. While theories have suggested that evolutionarily relevant threats should obtain preferential neural processing, this has not been examined empirically. In this study we examined the effects of evolutionarily relevant (e.g. spiders and snakes) and irrelevant (e.g. knifes and syringes) threatening cues. Non-predictive threatening cues (in left or right visual field) were paired with non-threatening cues and were followed by neutral targets in the same or opposite location. The amplitude of the target P1 was increased in contralateral electrodes when the target followed in the same location as the threatening cues. This effect did not interact with evolutionary relevance. Both evolutionary relevant and evolutionary irrelevant threats led to increased P1 amplitude, although the effect was stronger for modern threats. We conclude that the threat-superiority effect is robust and largely independent of the type of threatening stimulus.     

Toward an Anthropology of Exchange in Tamil Nadu

This article is an attempt to present the cultural conceptions of exchange that appear in studies of medieval South Indian redistributive processes and the anthropology of Tamil caste, kinship, and marital transactions. As such it does not engage theological understandings of gifts to and from South Indian deities. The approach is sociological, and the argument is that whether the mode is redistributive or donative, Tamil exchanges create social relationships that are embedded in meanings of distinction and precedence. What is handed out is a position in a social order that is first and foremost hierarchical, a rank in a social sequence, so that not merely things and services but social distinctions move through the social landscape.     

Trust in organismic development, autonomy support, and adaptation among mothers and their children

The current studies examined relations between mothers’ trust in organismic development, autonomy supportive parenting, and adaptation among mothers and their young children. Study 1 showed that trust in organismic development was distinct from optimism, neuroticism, and social desirability whereas it correlated with having relaxed expectations for developmental milestones and making fewer social comparisons about one’s child. Study 2 used observational methods to demonstrate a significant link between trust in organismic development and mothers behaving in an autonomy-supportive rather than controlling manner toward their 1-year-old child during puzzle solving activities. Study 3 used a 1 year prospective design to show that trust in first time mothers was associated with better maternal and child adaptation over time, controlling for initial levels of adaptation and child temperament. Study 4 explored possible social/political antecedents of trust in organismic development by comparing the beliefs of first time mothers from Canada and Norway. The four studies suggest that trust in organismic development fosters autonomy supportive parenting practices and positive maternal and child adaptation. These findings are discussed from the perspective of self-determination theory.

The effects of the contingence during the visual habituation task in 3 and 6 months old infants]

Thirty-six 3-month old infants and the same number of 6-month old infants underwent three visual habituation procedures differentiated by degree of behavioural contingency. Results showed significant differences between conditions only for the six-month olds: the lower the contingency, the higher the visual fixation scores. Results support some of the propositions that Gergely and Watson (1996, 1999) have put forth regarding the developmental model for detecting contingencies. The results also challenge the traditional model for visual habituation which suggests that varied durations of visual fixation should basically be determined by the visual characteristics of the stimulus.     

Legal aspects of the risks raised by nanotechnologies in the field of medicine

The major breakthroughs achieved in nanotechnologies open new avenues in the field of healthcare--aid to diagnosis, upgrading medical treatment efficacy, development of regenerative medicine--but they are also associated with risks, hence the increasing need of legislation. So far very little research work has been conducted on this technology whose applications are still limited and whose potential hazards are not yet clearly apprehended. The more and more frequent uses of nanoparticles in medical imaging and in current research projects dealing with tissue engineering or RFID raises the following question: is the current legislative framework relevant in light of the specificities of nano-objects? The challenge is twofold: the legal approach must encompass the nanometric element itself as a "legal object" but it must include the use of nanotechnologies and their final aims. There is still some degree of uncertainty concerning the innocuity of nanoparticles so that the use of nanoelements in aid to medical diagnosis and in clinical trials must take into account and anticipate the potential harmful effects on patients and on biomedical research teams. But due to the fact that a clear understanding of nanoparticles as specific objects with new features is still missing, the existing regulations on chemical substances, medicinal products, medical devices or cosmetics do not seem to be appropriate. So considering nanoparticles as "singular" legal objects is a prerequisite requiring an approach based on the precautionary principle. Misusing nanotechnologies in the medical field is also a cause for great concern. Threats on individual freedom and on private life as well as on human identity are real and they raise recurring questions. The possible deviations in the use of these techniques, the temptations to "trespass the limits" are also common to info technologies and to biotechnologies but the threats triggered by the nanotechnologies are enhanced by the possibilities offered by the nanometric size and the expected convergence of these different technologies. One should refer to leading guiding principles in order to solve the future conflicts between the different sets of values, especially in the medical field by always remembering the Hippocratic oath "primum non nocere, deinde curare"     

Making up for lost opportunities: the protective role of downward social comparisons for coping with regrets across adulthood

Two longitudinal studies showed that if adults confront low opportunities to overcome regrets, downward social comparisons can exert self-protective functions across the adult life span, irrespective of age (Study 1 N = 104 young and older adults, Study 2 N = 51 older adults). Both studies found that downward relative to upward social comparisons were associated with improvements in participants' positive (but not negative) affect, if they perceived low as opposed to high opportunities to overcome regrets. Moreover, Study 2 showed that this beneficial effect on change in positive affect mediated the experience of fewer cold symptoms over time. Supplemental analyses further indicated that the mechanism linking social comparison processes and opportunities with positive (but not negative) affect was associated with the capacity for goal reengagement. In addition, these analyses showed that the obtained effects were largely unrelated to the severity of regret-related consequences and thus ruled out an alternative explanation of the findings.