02231nas a2200205   4500008004100000245007600041210006900117260001200186520158000198653001401778653000801792653001001800653002201810653003101832100001601863700002501879700002501904700001901929856007701948       2015                        eng d00aCortical alpha activity predicts the confidence in an impending action.0 aCortical alpha activity predicts the confidence in an impending   c07/20153 aWhen we make a decision, we experience a degree of confidence that our choice may lead to a desirable outcome. Recent studies in animals have probed the subjective aspects of the choice confidence using confidence-reporting tasks. These studies showed that estimates of the choice confidence substantially modulate neural activity in multiple regions of the brain. Building on these findings, we investigated the neural representation of the confidence in a choice in humans who explicitly reported the confidence in their choice. Subjects performed a perceptual decision task in which they decided between choosing a button press or a saccade while we recorded EEG activity. Following each choice, subjects indicated whether they were sure or unsure about the choice. We found that alpha activity strongly encodes a subject's confidence level in a forthcoming button press choice. The neural effect of the subjects' confidence was independent of the reaction time and independent of the sensory input modeled as a decision variable. Furthermore, the effect is not due to a general cognitive state, such as reward expectation, because the effect was specifically observed during button press choices and not during saccade choices. The neural effect of the confidence in the ensuing button press choice was strong enough that we could predict, from independent single trial neural signals, whether a subject was going to be sure or unsure of an ensuing button press choice. In sum, alpha activity in human cortex provides a window into the commitment to make a hand movement.10acertainty10aEEG10ahuman10aneural correlates10aperceptual decision-making1 aKubánek, J1 aHill, Jeremy, Jeremy1 aSnyder, Lawrence, H.1 aSchalk, Gerwin  uhttp://journal.frontiersin.org/article/10.3389/fnins.2015.00243/abstract02782nas a2200193   4500008004100000022001400041245009600055210006900151260001200220300001400232490000700246520218000253100001702433700002502450700002402475700002202499700001902521856004802540       2013                        eng d  a1095-957200aA low-frequency oscillatory neural signal in humans encodes a developing decision variable.0 alowfrequency oscillatory neural signal in humans encodes a devel  c12/2013  a795–8080 v833 aWe often make decisions based on sensory evidence that is accumulated over a period of time. How the evidence for such decisions is represented in the brain and how such a neural representation is used to guide a subsequent action are questions of considerable interest to decision sciences. The neural correlates of developing perceptual decisions have been thoroughly investigated in the oculomotor system of macaques who communicated their decisions using an eye movement. It has been found that the evidence informing a decision to make an eye movement is in part accumulated within the same oculomotor circuits that signal the upcoming eye movement. Recent evidence suggests that the somatomotor system may exhibit an analogous property for choices made using a hand movement. To investigate this possibility, we engaged humans in a decision task in which they integrated discrete quanta of sensory information over a period of time and signaled their decision using a hand movement or an eye movement. The discrete form of the sensory evidence allowed us to infer the decision variable on which subjects base their decision on each trial and to assess the neural processes related to each quantum of the incoming decision evidence. We found that a low-frequency electrophysiological signal recorded over centroparietal regions strongly encodes the decision variable inferred in this task, and that it does so specifically for hand movement choices. The signal ramps up with a rate that is proportional to the decision variable, remains graded by the decision variable throughout the delay period, reaches a common peak shortly before a hand movement, and falls off shortly after the hand movement. Furthermore, the signal encodes the polarity of each evidence quantum, with a short latency, and retains the response level over time. Thus, this neural signal shows properties of evidence accumulation. These findings suggest that the decision-related effects observed in the oculomotor system of the monkey during eye movement choices may share the same basic properties with the decision-related effects in the somatomotor system of humans during hand movement choices.1 aKubanek, Jan1 aSnyder, Lawrence, H.1 aBrunton, Bingni, W.1 aBrody, Carlos, D.1 aSchalk, Gerwin  uhttp://www.ncbi.nlm.nih.gov/pubmed/23872495