Beta oscillations have been predominantly observed in sensorimotor cortices and basal ganglia structures and they are thought to be involved in somatosensory processing and motor control. Although beta activity is a distinct feature of healthy and pathological sensorimotor processing, the role of this rhythm is still under debate. Here we review recent findings about the role of beta oscillations during experimental manipulations (i.e., drugs and brain stimulation) and their alteration in aging and pathology. We show how beta changes when learning new motor skills and its potential to integrate sensory input with prior contextual knowledge. We conclude by discussing a novel methodological approach analyzing beta oscillations as a series of transient bursting events.

Choosing between equally valued options is a common conundrum, for which classical decision theories predicted a prolonged response time (RT). This contrasts with the notion that an optimal decision maker in a stable environment should make fast and random choices, as the outcomes are indifferent. Here, we characterize the neurocognitive processes underlying such voluntary decisions by integrating cognitive modelling of behavioral responses and EEG recordings in a probabilistic reward task. Human participants performed binary choices between pairs of unambiguous cues associated with identical reward probabilities at different levels. Higher reward probability accelerated RT, and participants chose one cue faster and more frequent over the other at each probability level. The behavioral effects on RT persisted in simple reactions to single cues. By using hierarchical Bayesian parameter estimation for an accumulator model, we showed that the probability and preference effects were independently associated with changes in the speed of evidence accumulation, but not with visual encoding or motor execution latencies. Time-resolved MVPA of EEG-evoked responses identified significant representations of reward certainty and preference as early as 120 ms after stimulus onset, with spatial relevance patterns maximal in middle central and parietal electrodes. Furthermore, EEG-informed computational modelling showed that the rate of change between N100 and P300 event-related potentials modulated accumulation rates on a trial-by-trial basis. Our findings suggest that reward probability and spontaneous preference collectively shape voluntary decisions between equal options, providing a mechanism to prevent indecision or random behavior.

19Choosing between equally valued options can be a conundrum, for which classical decision 20 theories predicted a prolonged response time (RT). Paradoxically, a rational decision-maker 21 would need no deliberative thinking in this scenario, as outcomes of alternatives are indifferent. 22How individuals choose between equal options remain unclear. Here, we characterized the 23 neurocognitive processes underlying such voluntary decisions, by integrating advanced cognitive 24 modelling and EEG recording in a probabilistic reward task, in which human participants chose 25 between pairs of cues associated with identical reward probabilities at different levels. We 26 showed that higher reward certainty accelerated RT. At each certainty level, participants 27 preferred to choose one cue faster and more frequently over the other. The behavioral effects on 28 RT persisted in simple reactions to reward cues. By using hierarchical Bayesian parameter 29 estimation for an accumulator model, we showed that the certainty and preference effects were 30 independently associated with the rate of evidence accumulation during decisions, but not with 31 visual encoding or motor execution latencies. Time-resolved multivariate pattern classification of 32 EEG evoked response identified significant representations of reward certainty and preference 33 choices as early as 120 ms after stimulus onset, with spatial relevance patterns maximal in 34 middle central and parietal electrodes. Furthermore, EEG-informed computational modelling 35 showed that the rate of change between N100 and P300 event-related potentials reflected 36 changes in the model-derived rate of evidence accumulation on a trial-by-trial basis. Our findings 37 suggested that reward certainty and preference collectively shaped voluntary decisions between 38 equal options, providing a mechanism to prevent indecision or random behavior. 39Keywords: decision making, reward certainty, preference bias, EEG, cognitive modelling 40 suggesting a possible bias between equal options, rendering some options more preferred than 63 others. 64Previous research on equal choices raises three further unresolved issues. First, it is unclear how 65 reward certainty and preference bias impact on different sub-components of the decision-making 66 process. Second, functional imaging studies have localized the mesocorticolimbic dopaminergic 67 network to be involved in both reward certainty and preference processing (Tobler et al., 2007; 68 Abler et al., 2009). Less is known about how macroscopic brain activities relating to these effects 69 unfold in time. Third, conventional equal-choice paradigms commonly use subjective ratings to 70 quantify and equate values of options. This design has been shown to be vulnerable to value 71 fluctuations (Chen and Risen, 2010; Izuma and Murayama, 2013) that originate from voluntary 72 choices themselves (Festinger, 1957;Bem, 1967). 73Here, we addressed these questions by combining advanced computational modelling and EEG 74 in a probabilistic reward t...

Background: Copy number variation (CNV) is an important cause for human disease. Due to relatively high selection pressure operating against pathogenic CNVs, their rate is maintained in the population by de novo formation. The rates of de novo CNVs are increased in neurodevelopmental disorders. However only a few studies have been performed on relatively healthy individuals, making it problematic to calculate the magnitude of this increased rate. Methods:The UK Biobank recruited about half a million randomly selected middle-aged members of the general population of the UK. We re-constructed family relationships from the genotypic data and identified 923 parent-offspring trios that passed out quality control filters. Potential de novo CNVs of >100 kb in size were identified and the log R ratios (LRR) and B allele frequency (BAF) traces of the trio members were visually inspected for those regions. We had no opportunity to validate CNVs with a laboratory method, but the traces appeared conclusive. Results and Discussion:We identified 10 CNVs >100kb in size, a rate of 1.1%. These rates are very similar to those in previous large studies. Using previous large studies, we provide overall rates among 4844 trios for different size ranges that are expected in relatively healthy populations. These rates can be used for comparison in studies on disease populations.