Chen Yao, Martinez-Conde Susana, Macknik Stephen L, Bereshpolova Yulia, Swadlow Harvey A, Alonso Jose-Manuel
Department of Biological Sciences, State University of New York, 33 West 42nd Street, New York, New York 10036, USA.
Nat Neurosci. 2008 Aug;11(8):974-82. doi: 10.1038/nn.2147. Epub 2008 Jul 6.
Spatial attention enhances our ability to detect stimuli at restricted regions of the visual field. This enhancement is thought to depend on the difficulty of the task being performed, but the underlying neuronal mechanisms for this dependency remain largely unknown. We found that task difficulty modulates neuronal firing rate at the earliest stages of cortical visual processing (area V1) in monkey (Macaca mulatta). These modulations were spatially specific: increasing task difficulty enhanced V1 neuronal firing rate at the focus of attention and suppressed it in regions surrounding the focus. Moreover, we found that response enhancement and suppression are mediated by distinct populations of neurons that differ in direction selectivity, spike width, interspike-interval distribution and contrast sensitivity. Our results provide strong support for center-surround models of spatial attention and suggest that task difficulty modulates the activity of specific populations of neurons in the primary visual cortex.
空间注意力增强了我们在视野受限区域检测刺激的能力。这种增强被认为取决于所执行任务的难度，但这种依赖性背后的神经元机制在很大程度上仍不为人知。我们发现，任务难度在猴子（猕猴）皮层视觉处理的最早阶段（V1区）调节神经元的放电率。这些调节在空间上具有特异性：增加任务难度会提高注意力焦点处的V1神经元放电率，并抑制焦点周围区域的放电率。此外，我们发现反应增强和抑制是由方向选择性、脉冲宽度、脉冲间隔分布和对比度敏感度不同的不同神经元群体介导的。我们的结果为空间注意力的中心-外周模型提供了有力支持，并表明任务难度调节初级视觉皮层中特定神经元群体的活动。
