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Shared population-level dynamics in monkey premotor cortex during solo action, joint action and action observation.
Studies of neural population dynamics of cell activity from monkey motor areas during reaching show that it mostly represents the generation and timing of motor behavior. We compared neural dynamics in dorsal premotor cortex (PMd) during the performance of a visuomotor task executed individually or cooperatively and during an observation task. In the visuomotor conditions, monkeys applied isometric forces on a joystick to guide a visual cursor in different directions, either alone or jointly with a conspecific. In the observation condition, they observed the cursor's motion guided by the partner. We found that in PMd neural dynamics were widely shared across action execution and observation, with cursor motion directions more accurately discriminated than task types. This suggests that PMd encodes spatial aspects irrespective of specific behavioral demands. Furthermore, our results suggest that largest components of premotor population dynamics, which have previously been suggested to reflect a transformation from planning to movement execution, may rather reflect higher cognitive-motor processes, such as the covert representation of actions and goals shared across tasks that require movement and those that do not.
Probability Distortion Depends on Choice Sequence in Rhesus Monkeys.
Humans and other primates share many decision biases, among them our subjective distortion of objective probabilities. When making choices between uncertain rewards we typically treat probabilities nonlinearly: overvaluing low probabilities of reward and undervaluing high ones. A growing body of evidence, however, points to a more flexible pattern of distortion than the classical inverse-S one, highlighting the effect of experimental conditions in shifting the weight assigned to probabilities, such as task feedback, learning, and attention. Here we investigated the role of sequence structure (the order in which gambles are presented in a choice task) in shaping the probability distortion patterns of rhesus macaques: we presented 2 male monkeys with binary choice sequences of MIXED or REPEATED gambles against safe rewards. Parametric modeling revealed that choices in each sequence type were guided by significantly different patterns of probability distortion: whereas we elicited the classical inverse-S-shaped probability distortion in pseudorandomly MIXED trial sequences of gamble-safe choices, we found the opposite pattern consisting of S-shaped distortion, with REPEATED sequences. We extended these results to binary choices between two gambles, without a safe option, and confirmed the unique influence of the sequence structure in which the animals make choices. Finally, we showed that the value of gambles experienced in the past had a significant impact on the subjective value of future ones, shaping probability distortion on a trial-by-trial basis. Together, our results suggest that differences in choice sequence are sufficient to reverse the direction of probability distortion.SIGNIFICANCE STATEMENT Our lives are peppered with uncertain, probabilistic choices. Recent studies showed how such probabilities are subjectively distorted. In the present study, we show that probability distortions in macaque monkeys differ significantly between sequences in which single gambles are repeated (S-shaped distortion), as opposed to being pseudorandomly intermixed with other gambles (inverse-S-shaped distortion). Our findings challenge the idea of fixed probability distortions resulting from inflexible computations, and points to a more instantaneous evaluation of probabilistic information. Past trial outcomes appeared to drive the "gap" between probability distortions in different conditions. Our data suggest that, as in most adaptive systems, probability values are slowly but constantly updated from prior experience, driving measures of probability distortion to either side of the S/inverse-S debate.
Cinnamon: The historic spice, medicinal uses, and flavour chemistry
Cinnamon has long been a popular culinary (and medicinal) spice. Nowadays, in the West, it is predominantly found in sweet foods (e.g., desserts, traditional, and/or seasonal baked foods, such as cinnamon rolls, plum pudding, mince pies, and mulled wine), as well as in many cola beverages, perhaps explaining why it is widely considered to be a ‘sweet’ spice, despite having a slightly bitter taste. Historically, it was commonly used in savoury dishes as well. In the Middle East and India, the spice retains its association with savoury cuisine (e.g., in dishes such as curry and pilau, as well as meat tagines in Morocco). The four major commercially-viable species of cinnamon (Cinnamomum verum, C. cassia, C. burmannii, and C. loureiroi) have distinct flavour profiles, meaning that care should be taken when using this spice in the kitchen, especially given the naming confusion that exists between cinnamon and cassia. Although essential oil is extracted from many parts of the cinnamon tree, only the bark from the lateral shoots tends to be used in cuisine nowadays. Cinnamon is used as the quills (whole or broken parts), as the dried ground powder or, in the food industry, as the essential oil (i.e., as a flavouring agent). The scent of cinnamon also appears in various perfumes/fragrances as well as being a popular element in festive potpourri. There is currently growing interest in cinnamon's potential neutraceutical, neuroprotective, and prebiotic properties.
Cognitive behavioural therapy for social anxiety disorder in people with bipolar disorder: a case series.
BACKGROUND: Social anxiety disorder increases the likelihood of unfavourable outcomes in people with bipolar disorder. Cognitive behavioural therapy (CBT) is the first-line treatment for social anxiety disorder. However, people with bipolar disorder have been excluded from the studies that this recommendation is based on. METHOD: We completed a case series to obtain initial data on whether CBT is an acceptable, safe, and effective treatment for social anxiety disorder in people with bipolar disorder. RESULTS: Eleven euthymic participants with bipolar disorder attended up to sixteen treatment and three follow-up sessions of CBT for social anxiety disorder. Participants attended on average 95% of the offered CBT sessions. No adverse events were reported. Participants' mean score on the Social Phobia Inventory decreased from 46.5 (SD 6.6) before the treatment to 19.8 (SD 11.9) at the end of the sixteen-session intervention and further to 15.8 (SD 10.3) by the end of the 3-month follow-up. This degree of improvement is equivalent to the effect observed in studies of CBT for social anxiety disorder in people without severe mental illness. CONCLUSIONS: This case series provides preliminary evidence that CBT is acceptable, safe, and effective for treating social anxiety disorder in people with bipolar disorder during euthymia. A randomized controlled trial is needed to confirm these findings, and to establish whether treatment for social anxiety disorder improves the course of bipolar disorder.