A growing body of evidence demonstrates a rhythmic characteristic of spatial attention, with the corresponding behavioral performance fluctuating periodically. Here, we investigate whether and how the rhythmic characteristic of spatial attention is affected by reward—an important factor in attentional selection. We adopted the classic spatial cueing paradigm with a time-resolved stimulus-onset-asynchrony (SOA) between the spatial cue and the target such that responses to the target in different phases could be examined. The color of the spatial cue was associated with either a high or low level of reward. Results showed that in the low-frequency band (<2 Hz) where classic exogenous spatial attention effects (i.e., facilitation and inhibition of return; IOR) appeared, reward enhanced the late IOR effect through facilitating behavioral responses to the target at the uncued location. Recurring lower alpha power (alpha inhibition) which fluctuated in a low-theta frequency (2–3 Hz) was observed at the cued location relative to the uncued location, irrespective of the reward level of the cue. Importantly, the recurring alpha inhibition emerged earlier (~120 ms) in the high-reward condition relative to the low-reward condition. We propose that the recurring alpha inhibition at the cued location implies a recurring attention sampling at the cued location and the expectation of a high reward makes the periodic attention sampling emerge earlier.

越来越多的证据显示出空间注意的节奏特征，相应的行为表现周期性地波动。在这里，我们研究空间注意力的节奏特征是否以及如何受到奖励的影响，奖励是注意力选择的重要因素。我们采用经典的空间提示范例，在空间提示和目标之间采用时间分辨的刺激发作-异步（SOA），以便可以检查对目标在不同阶段的响应。空间提示的颜色与奖励的高低有关。结果表明，在低频频带（<2 Hz）中出现了经典的外源性空间注意力效应（即促进和抑制返回； IOR），奖励通过促进对未提示位置处目标的行为响应而增强了后期IOR效果。无论提示的奖励级别如何，在提示位置相对于非提示位置，都观察到以低theta频率（2-3 Hz）波动的反复出现的较低α功率（alpha抑制）。重要的是，相对于低奖励条件，在高奖励条件下较早（〜120 ms）出现了反复出现的α抑制。我们建议在提示位置重复出现alpha抑制意味着在提示位置重复出现注意力采样，而对高回报的期望会使定期注意采样出现得更早。无论提示的奖励级别如何，在提示位置相对于非提示位置，都观察到以低theta频率（2-3 Hz）波动的反复出现的较低α功率（alpha抑制）。重要的是，相对于低奖励条件，在高奖励条件下较早（〜120 ms）出现了反复出现的α抑制。我们建议在提示位置重复出现alpha抑制意味着在提示位置重复出现注意力采样，而对高回报的期望会使定期注意采样出现得更早。无论提示的奖励级别如何，在提示位置相对于非提示位置，都观察到以低theta频率（2-3 Hz）波动的反复出现的较低α功率（alpha抑制）。重要的是，相对于低奖励条件，在高奖励条件下较早（〜120 ms）出现了反复出现的α抑制。我们建议在提示位置重复出现alpha抑制意味着在提示位置重复出现注意力采样，并且对高回报的期望使得定期注意采样出现得较早。