Reward expectation yields distinct effects on sensory processing and decision making in the human brain
Fig 3
Space-specific, but not choice-specific, reward expectation modulates attention-related ERPs.
A. (Top) ERP waveform from posterior electrodes (see bottom panel) in the space-specific reward expectation session (data averaged across n = 24 participants and both “gain” and “loss” blocks). x-axis: time relative to stimulus onset. Shaded regions: time epochs for quantifying contralateral N2pc (grey shading) and contralateral P300 (purple shading). (Bottom) Scalp topography of (left) N2pc and (right) P300 amplitudes for each electrode. Convention: FX and VR sides are on the left and right visual hemifields, respectively. White circles: occipitoparietal electrodes for ERP quantification. B. ERP waveform modulation induced by reward contingency change (ΔERP = ERPVR > FX – ERPVR < FX) in the space-specific reward expectation session for the FX (solid line) and VR (dashed line) sides. Waveforms were measured from electrodes contralateral to the respective side. Shading on traces (orange and gray): s.e.m. for ΔERP traces (FX and VR sides, respectively). Light gray overlaid trace and colored overbars: ERP waveform (not to scale) and time epochs, respectively, for reference, from panel A. C. (Left) Contralateral N2pc component modulation induced by reward contingency change (ΔN2pc = N2pcVR > FX – N2pcVR < FX) for the FX (filled symbols) and VR (open symbols) sides in the space-specific reward expectation session. (Right) Same as in the left panel, but for contralateral P300 component modulation (ΔP300 = P300VR > FX – P300VR < FX). y-axis in both panels is plotted in symmetric logarithmic scale. 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 B, but showing ERP waveform modulation induced by reward contingency change (ΔERP = ERPLib. – ERPCons.) in the choice-specific reward expectation session. Other conventions are the same as in panel B. E. Same as in panel C, but showing contralateral N2pc component (ΔN2pc = N2pcLib. – N2pcCons.; left) and contralateral P300 component (ΔP300 = P300Lib. – P300Cons.; right) modulation in the choice-specific reward expectation session. Other conventions are the same as in panel C. Data are available at https://doi.org/10.6084/m9.figshare.25966015 [34].