Reward expectation yields distinct effects on sensory processing and decision making in the human brain
Fig 4
Space-specific, but not choice-specific, reward expectation produces lateralized alpha power suppression.
A. Time–frequency spectrogram showing the difference in the reward-induced modulation of contralateral alpha power (Δα = αVR > FX – αVR < FX) between the FX and VR sides (ΔαFX – ΔαVR) in the space-specific reward expectation session (data averaged across all n = 24 participants). x-axis: Time relative to stimulus onset (vertical dashed line); y-axis: frequency relative to the individual alpha frequency (IAF) of each participant (horizontal dashed lines: IAF ± 0.5 Hz). Inset: Alpha-band power spectrum and IAF peak for a representative participant, measured in a 500 ms pre-stimulus time window from occipitoparietal electrodes (see panel B). Gray shading: IAF ± 0.5 Hz. B. Scalp topography of Δα (defined in panel A) for each electrode in the space-specific reward expectation session. White circles: occipitoparietal electrodes used for quantifying contralateral IAF alpha power in panel A, and for subsequent analyses. Other conventions are the same as bottom panel in Fig 3A. C. Reward-induced modulation of contralateral alpha power (Δα, at IAF ± 0.5 Hz) for the FX (filled) and VR (open) sides in the space-specific reward expectation session. Other conventions are the same as in Fig 2A. Asterisks: statistical significance levels assessed with a Wilcoxon signed rank test (***p < 0.001, **p < 0.01, *p < 0.05, n.s.: not significant). D. Same as in panel A, but showing the difference in the reward-induced modulation of contralateral alpha power (Δα = αLib. – αCons.) between the FX and VR sides in the choice-specific reward expectation session. Other conventions are the same as in panel A. E. Same as in panel B, but showing the scalp topography of Δα for the choice-specific reward expectation session. Other conventions are the same as in panel B. F. Same as in panel C, but showing reward-induced modulation of contralateral alpha power for the choice-specific reward expectation sessions. Other conventions are the same as in panel C. Data are available at https://doi.org/10.6084/m9.figshare.25966015 [34].