The functional role of high beta oscillations (20–35 Hz) during feedback processing has been suggested to reflect unexpected gains. Using a novel gambling task that separates gains and losses across blocks and directly compares reception of monetary rewards to a ‘no-reward/punishment’ condition with equal probability we aimed to further investigate the role of beta oscillations. When contrasting different feedback conditions across rewards, we found that a late low beta component (12–20 Hz) had increased in power during the omission of rewards relative to the reception of rewards, while no differences were observed during the loss domain. These findings may indicate that late low beta oscillations in the context of feedback processing may respond to omission of gains relative to other potential outcomes. We speculate that late low beta oscillations may operate as a learning mechanism that signals the brain to make future adequate decisions. Overall, our study provides new insights for the role of late low beta oscillations in reward processing.

In this study, we investigated the effect of transcranial alternating current stimulation (tACS) on voluntary risky decision making and executive control in humans. Stimulation was delivered online at 5 Hz (θ), 10 Hz (α), 20 Hz (β), and 40 Hz (γ) on the left and right frontal area while participants performed a modified risky decision-making task. This task allowed participants to voluntarily select between risky and certain decisions associated with potential gains or losses, while simultaneously measuring the cognitive control component (voluntary switching) of decision making. The purpose of this experimental design was to test whether voluntary risky decision making and executive control can be modulated with tACS in a frequency-specific manner. Our results revealed a robust effect of a 20-Hz stimulation over the left prefrontal area that significantly increased voluntary risky decision making, which may suggest a possible link between risky decision making and reward processing, underlined by β-oscillatory activity.

The epistemological chasm between how we (implicitly and subjectively) perceive or imagine the actual world and how we (explicitly and “objectively”) think of its underlying entities has motivated perhaps the most disconcerting impasse in human thought: the explanatory gap between the phenomenal and physical properties of the world. Here, I advocate a combination of philosophical skepticism and simplicity as an informed approach to arbitrate among theories of consciousness. I argue that the explanatory gap is rightly a gap in our understanding, but one that is not surprising; and we being observers biased by our first-person perspective and our existence may both hinder and (the realization we have them) assist our reasoning. Further, I unfold the concept of observer into two distinct notions based on its functional and phenomenal aspects, and exploit this device to elucidate the subject-observer relationship. Then, I proceed to analyze the philosophical zombie dilemma. Lastly, I contend that from a skeptical viewpoint, panpsychism (or neutral monism) is the most parsimonious doctrine accounting for the explanatory gap, and suggest that it would be possible to make headway in the hard problem of consciousness by uncovering non-trivial causal relationships between qualia states and functional states, if routine and controlled manipulation of neural circuits were easily available.

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