58 research outputs found

    Effects of guanidine on synaptic transmission in the spinal cord of the frog

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    The effects of guanidine on motoneurons of the isolated frog spinal cord were studied by adding the drug to the solution bathing the cord during intracellular recording. Guanidine (5·10–4 M) did not alter the membrane potential of motoneurons. The main effect was a marked increase of the amplitudes and frequencies of small spontaneously occurring inhibitory postsynaptic potentials. The hyperpolarizing component of postsynaptic potentials evoked by stimulation of dorsal roots was also enhanced by guanidine. Higher concentrations of guanidine (5·10–3 M) resulted in a very large and irreversible increase of the small spontaneously occurring inhibitory potentials, which now appeared in a regular, rhythmic pattern. The effects of guanidine could easily be blocked by increasing the magnesium ions (15 mM) in the bath solution. These results indicate that guanidine facilitates the release of an inhibitory transmitter in afferent terminals of the frog spinal cord either by a direct action on these terminals or indirectly by an action on nerve endings impinging on inhibitory interneurons

    Performance blocks in sport : recommendations for treatment and implications for sport psychology practitioners

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    Sport psychologists are increasingly confronted with performance difficulties where athletes mysteriously lose the ability to execute automatic movements. Traditionally referred to as the yips or lost move syndrome, the generic term performance blocks has recently been put forward to encompass these types of problems that manifest in locked, stuck, and frozen movements, loss of fine and/or gross motor control, and debilitating anxiety. Two recent investigations examined the effectiveness of eye movement desensitization and reprocessing with graded exposure to treat two performance block-affected individuals. Evaluation of the interventions showed improved performance of the affected skills and reduced anxiety in both cases. Interview data collected on completion of each intervention confirmed that associated symptoms were also alleviated. The success of these two interventions offers considerable value to sport psychologists, the implications of which the current article hopes to address. Specifically, the manuscript provides an overview of current research pertaining to performance blocks, followed by recommendations for treatment and implications for sport psychologists. The importance of involving clinical psychology support in formulation and treatment processes of performance blocks is highlighted, and a call for further research investigating treatment is put forwar

    Unconscious bias in the suppressive policing of Black and Latino men and boys: neuroscience, Borderlands theory, and the policymaking quest for just policing

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    his article applies neuroscience and Borderlands theory to reveal how unconscious bias currently stabilizes suppressive policing practices in America despite new efforts at reform. Illustrative cases are offered from Oakland and Santa Barbara, California, with a focus on civil gang injunctions (CGIs) and youth gang suppression. Theoretical analysis of these cases reveals how the unconscious biases of validity illusions and framing effects operate despite the best intentions of law enforcement personnel. Such unconscious or implicit biases create contradictions between the stated beliefs and actions of law enforcement. In turn, these unintended self-contradictions then work to the detriment of Latino and Black boys. The analysis here also extends to how unconscious biases and unintended self-contradictions can influence municipal policymaking in favor of suppressive police tactics such as CGIs, thereby displacing evidence-based policies that are proven to be far more effective. The article concludes with brief discussion of some of the means by which the unconscious biases – effects to which everyone is involuntarily prone – can be disrupted
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