Reward expectation differentially modulates attentional behavior and activity in visual area V4
Reward expectation differentially modulates attentional behavior and activity in visual area V4
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DOI：
10.1038/nn.4141
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发表时间：
2015-11-01
影响因子：
25
通讯作者：
Salzman, C. Daniel
中科院分区：
文献类型：
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作者：
Baruni, Jalal K.;Lau, Brian;Salzman, C. Daniel
当注意力集中到神经元感受野时，视觉区 V4 的神经活动就会增强。然而，这种增强的来源尚不清楚，因为大多数生理研究都是通过改变与特定位置相关的绝对奖励及其相对于其他位置的价值来操纵注意力。我们训练猴子辨别不同半视野中同时出现的两种刺激的方向，同时我们独立地改变与每个位置的正确辨别相关的奖励幅度。注意力的行为测量由每个位置的相对值控制。相比之下，V4 中的神经元始终受到绝对奖励值的调节，只要感受野位置与大奖励相关，就会表现出活动增加、伽玛带功率增加和试验间变异性降低。这些数据挑战了空间注意力的感知益处依赖于 V4 中信噪比增加的观念。相反，这些好处可能来自下游选择机制。
Neural activity in visual area V4 is enhanced when attention is directed into neuronal receptive fields. However, the source of this enhancement is unclear, as most physiological studies have manipulated attention by changing the absolute reward associated with a particular location as well as its value relative to other locations. We trained monkeys to discriminate the orientation of two stimuli presented simultaneously in different hemifields while we independently varied the reward magnitude associated with correct discrimination at each location. Behavioral measures of attention were controlled by the relative value of each location. By contrast, neurons in V4 were consistently modulated by absolute reward value, exhibiting increased activity, increased gamma-band power and decreased trial-to-trial variability whenever receptive field locations were associated with large rewards. These data challenge the notion that the perceptual benefits of spatial attention rely on increased signal-to-noise in V4. Instead, these benefits likely derive from downstream selection mechanisms.