Depressive traits are associated with a reduced effect of choice on implicit sense of agency

Our everyday actions and their subsequent outcomes are accompanied by a feeling of control or agency. This sense of agency (SoA) is dependent on the contribution of both prospective factors (e.g., action choice), and retrospective factors (e.g., outcome valence) with considerable variation in the population. We manipulated freedom of choice and valence of outcome to assess the relationship between implicit SoA and subclinical depressive and psychosis-like traits in a cohort of healthy young adults. Participants (N=150) completed a Libet Clock task, in which they had either a free or forced choice of which of two buttons to press, and received either a positive or negative outcome (cash register or klaxon). Participants were required to judge the time on the clock the tone sounded. We measured outcome binding, the shift in the perceived time of the outcome back in time towards the moment of the action. Participants also completed questionnaires on both depressive and psychosis-like traits. Positive outcomes strongly increased intentional binding. The evidence favoured no effect of freedom of choice on average, but this was influenced by inter-individual differences. Individuals reporting more depressive traits had less of a difference in intentional binding between free and forced choice conditions. The findings show that implicit SoA is sensitive to outcome valence and differs across the subclinical depression continuum.

Motor planning under uncertainty

Actions often require the selection of a specific goal amongst a range of possibilities, like when a softball player must precisely position her glove to field a fast-approaching ground ball. Previous studies have suggested that during goal uncertainty the brain prepares for all potential goals in parallel and averages the corresponding motor plans to command an intermediate movement that is progressively refined as additional information becomes available. Although intermediate movements are widely observed, they could instead reflect a neural decision about the single best action choice given the uncertainty present. Here we systematically dissociate these possibilities using novel experimental manipulations and find that when confronted with uncertainty, humans generate a motor plan that optimizes task performance rather than averaging potential motor plans. In addition to accurate predictions of population-averaged changes in motor output, a novel computational model based on this performance-optimization theory accounted for a majority of the variance in individual differences between participants. Our findings resolve a long-standing question about how the brain selects an action to execute during goal uncertainty, providing fundamental insight into motor planning in the nervous system.

Routine and sentinel surveillance methods

Surveillance, whether active or passive, is a dynamic process. It is fundamental to public health decision-making and subsequent action. Choice of diseases for surveillance, development of methods, ongoing systematic evaluation and dissemination to those who need to know, are each components which require expert, knowledgeable attention. The communication age will greatly redefine approaches to surveillance, both for data acquisition and dissemination. Especially in the dissemination area, the public health community needs to strengthen its capacity

Dichotomous dopaminergic and noradrenergic neural states mediate distinct aspects of exploitative behavioral states

The balance between exploiting known actions and exploring alternatives is critical for survival and hypothesized to rely on shifts in neuromodulation. We developed a behavioral paradigm to capture exploitative and exploratory states and imaged calcium dynamics in genetically identified dopaminergic and noradrenergic neurons. During exploitative states, characterized by motivated repetition of the same action choice, dopamine neurons in SNc encoding movement vigor showed sustained elevation of basal activity that lasted many seconds. This sustained activity emerged from longer positive responses, which accumulated during exploitative action-reward bouts, and hysteretic dynamics. Conversely, noradrenergic neurons in LC showed sustained inhibition of basal activity due to the accumulation of longer negative responses in LC. Chemogenetic manipulation of these sustained dynamics revealed that dopaminergic activity mediates action drive, whereas noradrenergic activity modulates choice diversity. These data uncover the emergence of sustained neural states in dopaminergic and noradrenergic networks that mediate dissociable aspects of exploitative bouts.

Integration of off-line & on-line: the Concept and Action Choice of Online Teaching of Vocational Education in Post-epidemic Era

During the epidemic period, vocational colleges made a preliminary exploration of online teaching in response to the national call of "suspending classes without stopping learning",Due to lack of experience, many problems and deficiencies were exposed. This paper systematically analyzes and summarizes the crux of online teaching in vocational colleges during the epidemic period, and then combs out the reform ideas of online teaching,which provides certain guidance and action path for the normal operation of online teaching mechanism in the post-epidemic era—integration of off-line & on-line, and concretely expounds the specific path of integration of off-line & on-line towards normalization of from three levels: home-school integration, virtual-real integration and production-education integration.

Motor planning under uncertainty

ABSTRACTActions often require the selection of a specific goal amongst a range of possibilities, like when a softball player must precisely position her glove to field a fast-approaching ground ball. Previous studies have suggested that during goal uncertainty, the brain prepares for all potential goals in parallel and averages the corresponding motor plans to command an intermediate movement that is progressively refined as additional information becomes available. Although intermediate movements are widely observed, they could instead reflect a neural decision about the single best action choice at each point in time given the remaining uncertainty. Here we systematically dissociate these possibilities using novel experimental manipulations, and find that when confronted with uncertainty, humans generate a single motor plan that optimizes task performance, rather than averaging potential motor plans. In addition to accurate predictions of population-averaged changes in motor output, a novel computational model based on this performance-optimization theory accounted for a remarkable 80-90% of the variance for individual differences between participants. Our findings resolve a long-standing question about how the brain selects an action to execute during goal uncertainty, providing fundamental insight into motor planning in the nervous system.

SUSTAINED DOPAMINERGIC PLATEAUS AND NORADRENERGIC DEPRESSIONS MEDIATE DISSOCIABLE ASPECTS OF EXPLOITATIVE STATES

ABSTRACTWe are constantly faced with the trade-off between exploiting actions with known outcomes and exploring alternative actions whose outcomes may be better. This balance has been hypothesized to rely on dopaminergic neurons of the substantia nigra pars compacta (SNc)1 and noradrenergic neurons of the locus coeruleus (LC)2–3. We developed a behavioral paradigm to capture exploitative and exploratory states, and imaged calcium dynamics in genetically-identified dopaminergic SNc neurons and noradrenergic LC neurons during state transitions. During exploitative states, characterized by motivated repetition of the same action choice, we found dichotomous changes in baseline activity in SNc and LC, with SNc showing higher and LC showing lower sustained activity. These sustained neural states emerged from the accumulation of lengthened positive responses and hysteretic dynamics in SNc networks, and lengthened negative responses in LC. Sustained activity could not be explained by classical reinforcement learning parameters, and in SNc but not LC, emerged in subpopulations coding for response vigor. Manipulating the sustained activity of SNc and LC revealed that dopaminergic activity primarily mediates engagement and motivation, whereas noradrenergic activity modulates action selection. These data uncover the emergence of sustained neural states in dopaminergic and noradrenergic networks that mediate dissociable aspects of exploitative bouts.