Brain and Behavior Discovery Institute, Graduate Program in Neuroscience, Georgia Health Sciences University, Augusta, Georgia, USA.
J Neurophysiol. 2013 Feb;109(4):1036-44. doi: 10.1152/jn.00385.2012. Epub 2012 Nov 28.
Selective attention experimental designs have shown that neural responses to stimuli in primary somatosensory cortex are stronger when the sensory stimuli are task relevant. Other studies have used animals under no task demands for data collection. The relationship between neural responses in the brain during behavior, and while an animal has no task demands, remains underexplored. We trained two animals to perform somatosensory detection for several weeks, followed by somatosensory discrimination for several weeks. Data in response to physically identical stimuli were collected from cortical implants while the animal was under no task demands before each behavioral session and also during that behavioral session. The Fourier spectra of the field potentials during detection or discrimination compared with the no task condition demonstrated suppression of the somatosensory μ-rhythm that is associated with readiness and anticipation of cognitive use of somatosensory and motor inputs. Responses to the task target were stronger during detection and discrimination than in the no task condition. The amplitude normalized time course of the target evoked response was similar in both cases. Evoked responses to the task distractor were not significantly stronger during behavior than in recordings under no task demands. The normalized time course of the distractor responses showed a suppression that peaks 30-35 ms after the onset of the response. The selectivity of this within trial suppression is the same as the selectivity of enduring suppression evident in studies of sensory cortical plasticity, which suggests the same neural process may be responsible for both.
选择性注意实验设计表明，当感觉刺激与任务相关时，初级体感皮层对刺激的神经反应更强。其他研究则在动物没有任务要求的情况下收集数据。在行为过程中大脑的神经反应与动物没有任务要求时的神经反应之间的关系仍未得到充分探索。我们训练了两只动物进行数周的体感检测，然后进行数周的体感辨别。在每次行为之前，当动物没有任务要求时，从皮质植入物中收集对物理上相同刺激的反应数据，以及在该行为期间收集数据。与无任务条件相比，检测或辨别过程中的场电位的傅里叶频谱显示出对体感 μ 节律的抑制，该节律与认知使用体感和运动输入的准备和预期有关。在检测和辨别任务中，对任务目标的反应比无任务条件更强。在两种情况下，目标诱发反应的幅度归一化时间过程相似。在行为期间，任务干扰物的诱发反应并不比无任务需求记录时明显更强。干扰物反应的归一化时间过程显示出抑制，在反应开始后 30-35 毫秒达到峰值。这种试验内抑制的选择性与在感觉皮层可塑性研究中明显的持续抑制的选择性相同，这表明可能有相同的神经过程负责这两者。
