RSK2 signaling in brain habenula contributes to place aversion learning

RSK2 is a Ser/Thr kinase acting in the Ras/MAPK pathway. Rsk2 gene deficiency leads to the Coffin-Lowry Syndrome, notably characterized by cognitive deficits. We found that mrsk2 knockout mice are unable to associate an aversive stimulus with context in a lithium-induced conditioned place aversion task requiring both high-order cognition and emotional processing. Virally mediated shRNA-RSK2 knockdown in the habenula, whose involvement in cognition is receiving increasing attention, also ablated contextual conditioning. RSK2 signaling in the habenula, therefore, is essential for this task. Our study reveals a novel role for RSK2 in cognitive processes and uncovers the critical implication of an intriguing brain structure in place aversion learning.     

High-fat diets impair spatial learning in the radial-arm maze in mice

It has been suggested that hyperglycemia and insulin resistance triggered by energy-dense diets can account for hippocampal damage and deficits of cognitive behaviour. We wonder if the impairment of learning and memory processes detected in diet-induced obese (DIO) mice is linked to diet composition itself. With this purpose we have evaluated learning performance in mice undergoing a short-term high-fat (HF) treatment, which leads to a pre-obese state characterized by increased adiposity without significant changes of glucose and insulin plasma levels. C57BL/6J mice were fed either a HF (45 kcal% from fat) or control diet (10 kcal% from fat) during 8 weeks. Learning performance was evaluated by using the four-arm baited version of the eight-arm radial maze test (RAM). Mice were trained to learn the RAM protocol and then memory was tested at different time-points. Time spent to consume food placed in baited arms and errors committed to find them were measured in all sessions. DIO mice significantly spent more time in learning the task and made a greater number of errors than controls. Moreover, retention tests revealed that both working and total memory errors were also more numerous in DIO mice. The current results show that short-term DIO impairs spatial learning and suggest that impairment of hippocampal learning elicited by HF diets might be perceptible before metabolic alterations linked to obesity develop.     

Some considerations about the biological appearance of pacing stimuli in visuomotor finger-tapping tasks

Sensorimotor synchronization is a crucial function for human daily activities, which relies on the ability of predicting external events. Synchronization performance, as assessed in finger-tapping (FT) tasks, is characterized by an anticipation tendency, as the tap generally precedes the pacing event. This synchronization error (SE) depends on many factors, in particular on the features of the pacing stimulus. Interest is growing in the facilitation effect that action observation has on motor execution. So far, neuroimaging and neurophysiology studies of motor priming via action observation have mainly employed tasks requiring single action instances. The impact of action observation on motor synchronization to periodic stimuli has not yet been tested; to this aim, a synchronization FT task may be an eligible probing task. The purpose of this study was to characterize a biological pacer at the behavioral level and provide information for those interested in studying the brain processes of continuous observation/execution coupling in timed actions using FT tasks. We evaluated the influence of the biological appearance of a pacer (a tapping finger) on SE, when compared to an abstract, kinematically equivalent pacer (a tilting hinged bar) and a more standard stimulus (a pulsating dot). We showed that the continuous visual display of a biological pacer yields comparable results to the abstract pacer, and a more robust performance and larger anticipations than a traditional pulsating stimulus.     

The effect of fixation transitions on quiet eye duration and performance in the soccer penalty kick: instep versus inside kicks

Male goalkeepers of intermediate skill level attempted to stop penalty kicks executed with the instep and inside foot, in situ. A mobile eye tracker and an external camera were used to collect the gaze and motor behaviors of the goalkeepers, as well as the penalty takers’ motor behaviors and flight of the ball. Percent saves was greater during instep (28%) than inside foot kicks (12%), but we detected few differences in fixation frequency, location, duration, or transitions that could be attributed to the type of kick used. Fixation transitions (or the frequency of gaze shifts between locations) were significantly higher on goals than on saves. During the final phase of the kicking action, the quiet eye was located on the visual pivot and was longer during saves than goals. Furthermore, when the final fixation on the ball exceeded approximately 1,100 ms, then the likelihood of goals increased. The results are discussed in light of past studies in goaltending and the dual demands of motor tasks that require information be fixated both early and late at spatial locations that exceed the limits of focal vision.     

Predicting the Vote: Implicit Attitudes as Predictors of the Future Behavior of Decided and Undecided Voters

Two studies assessed the predictive validity of implicit political attitudes in relation to voting behavior. In Study 1 , we demonstrated the validity of the adopted measure (i.e., the IAT; Greenwald, McGhee, & Schwartz, 1998 ) with a sample of voters who clearly sided with one of the opposing parties. In Study 2 , implicit political preferences were measured in a sample of undecided voters one month before the election, and actual voting behavior was assessed immediately after the election. Results demonstrated that implicit political attitudes were good predictors of future voting behaviors. These findings support the hypothesis of the presence of embryonic attitudes even in the case of those voters who at the explicit and conscious level deny any preference for one of the two opposing candidates.     

Rigidity in social and emotional memory in the R6/2 mouse model of Huntington's disease

Four experiments were conducted to examine social and emotional memory in the R6/2 transgenic mouse model of Huntington’s disease. First, R6/2 mice were tested in a social transmission of food preference task where they had to acquire a preference for a flavoured food (acquisition) and subsequently to learn a preference for a different flavour (shifted reinforcement). R6/2 mice performed well in the acquisition trial. However, they were impaired in the shifted reinforcement trial and perseverated on the first preference learned. Second, mice were trained in an inhibitory avoidance paradigm, with either one or two footshocks delivered during the training. WT mice given one footshock showed retention levels lower than those of mice trained with two footshocks. By contrast, there was no difference in retention levels of R6/2 mice given either one or two footshocks. Third, mice were tested in an active avoidance task that paired a mild footshock with a warning light. R6/2 mice had a strong age-dependent deficit in this task. Finally, mice were tested in a conditioned taste aversion task that paired a saccharine solution with a nausea-inducing agent (LiCl). R6/2 mice displayed normal aversion, however this was not extinguished following repeated exposure to saccharine solution alone. Our data show that while R6/2 mice have functional hippocampus-based memory, they have deficits in striatum-based memory skills. Further, social and emotional memories appear to be encoded in a rigid way that is not influenced by subsequent learning or by arousal levels.     

Expert-novice differences in cognitive and execution skills during tennis competition

This study deals with decision and execution behavior of tennis players during competition. The study is based on the expert-novice paradigm and aims to identify differences between both groups in the decision-making and execution variables in serve and shot actions in tennis. Six expert players (elite Spanish tennis players) and six novice players (grade school tennis players) took part in this study. To carry out this study, the observation protocol defined by McPherson and Thomas in 1989, in which control, decision-making and execution variables were included, was used, where it was applied to the performance of the tennis player in a real match situation. In the analysis, significant differences between experts and novices in decision-making and execution variables are found wherein it can be observed that experts display a greater ability to make the appropriate decisions, selecting the most tactical responses to put pressure on the opponent. Expert tennis players were also able to carry out forceful executions to their opponent with greater efficiency, making the opponent's response to a large extent more difficult. These findings are in accordance with those of McPherson and colleagues.     

QUANTUM REALITY AND ETHOS: A THOUGHT EXPERIMENT REGARDING THE FOUNDATION OF ETHICS IN COSMIC ORDER

The authors undertake a thought experiment the purpose of which is to explore possibilities for understanding moral principles in analogy with cosmic order. The experiment is based on three proposals, which are described in detail: an ontological, a neurological, and a moral proposal. The ontological proposal accepts from the phenomena of quantum physics that there is a nonempirical domain of physical reality that consists not of material things but of what is philosophically conceptualized as a realm of nonmaterial forms. This realm of forms is the realm of potentiality in physical reality that quantum physics posits as an indivisible Wholeness—the One. It is the ultimate reality because everything empirical is the actualization of its forms. The neurological proposal is the hypothesis that the brain is sensitive to the potentiality waves in the cosmic field, as ordinary measuring instruments in physics are sensitive to potentiality waves at the quantum level, so that the cosmic field can communicate with the human brain. The third proposal assumes that the communication with the cosmic field can translate into moral ideas and actions. Even though the three proposals underlying the thought experiment are highly speculative, they lead to definite implications that make sense in their own right and can be applied in a useful way. From the order of reality some simple rules of conduct follow that are identical with traditional moral rules but have the character of rules of well‐ness, leading to new aspects of Aristotle's concept of eudaimonia and Kant's concept of the highest good. In analogy with the structure of physical reality, where all empirical phenomena are actualizations of nonempirical forms, it is suggested that the structure of morality, too, is that of a tacit, nonempirical form that actualizes in explicit principles and moral acts through our consciousness. The tacit form is thought to exist in the realm of cosmic potentiality, together with all the other forms that the empirical world actualizes. It can appear spontaneously in our consciousness when needed, offering its guidance to our judgment and free will. Because it does not appear in the form of commandments accompanied by threats, the actions of the tacit moral form define a higher level of morality, similar to that offered by some aspects of the Christian teaching, where one acts not out of fear but on the desire to do things right.