Tremblay Sébastien, Doucet Guillaume, Pieper Florian, Sachs Adam, Martinez-Trujillo Julio
Cognitive Neurophysiology Laboratory, Department of Physiology, McGill University, Montreal, Quebec, QC H3G 1Y6, Canada, Integrated Program in Neuroscience, Montreal Neurological Institute, McGill University, Montreal, Quebec, QC H3A 2B4, Canada.
Cognitive Neurophysiology Laboratory, Department of Physiology, McGill University, Montreal, Quebec, QC H3G 1Y6, Canada.
J Neurosci. 2015 Jun 17;35(24):9038-49. doi: 10.1523/JNEUROSCI.1041-15.2015.
Local field potentials (LFPs) are fluctuations of extracellular voltage that may reflect the physiological phenomena occurring within a volume of neural tissue. It is known that the allocation of spatial attention modulates the amplitude of LFPs in visual areas of primates. An issue that remains poorly investigated is whether and how attention modulates LFPs in executive brain areas, such as the lateral prefrontal cortex (LPFC), thought to be involved in the origins of attention. We addressed this issue by recording LFPs from multielectrode arrays implanted in the LPFC of two macaques. We found that the allocation of attention can be reliably decoded on a single-trial basis from ensembles of LFPs with frequencies >60 Hz. Using LFP frequencies <60 Hz, we could not decode the allocation of attention, but we could decode the location of a visual stimulus as well as the endpoint of saccades toward that stimulus. The information contained in the high-frequency LFPs was fully redundant with the information contained in the spiking activity of single neurons recorded from the same electrodes. Moreover, the decoding of attention using γ frequency LFPs was less accurate than using spikes, but it was twice more stable across time. Finally, decorrelating the LFP signals from the different electrodes increased decoding performance in the high frequencies by up to ∼14%. Our findings suggest that LFPs recorded from chronically implanted multielectrode arrays in the LPFC contain information about sensory, cognitive, and motor components of a task in a frequency-dependent manner.
局部场电位（LFPs）是细胞外电压的波动，可能反映神经组织体积内发生的生理现象。已知空间注意力的分配会调节灵长类动物视觉区域中局部场电位的幅度。一个尚未得到充分研究的问题是，注意力是否以及如何调节执行脑区（如外侧前额叶皮层（LPFC））中的局部场电位，而该脑区被认为与注意力的起源有关。我们通过记录植入两只猕猴LPFC中的多电极阵列的局部场电位来解决这个问题。我们发现，注意力的分配可以在单次试验的基础上，从频率>60Hz的局部场电位集合中可靠地解码出来。使用频率<60Hz的局部场电位，我们无法解码注意力的分配，但我们可以解码视觉刺激的位置以及朝向该刺激的扫视终点。高频局部场电位中包含的信息与从同一电极记录的单个神经元的尖峰活动中包含的信息完全冗余。此外，使用γ频率局部场电位解码注意力的准确性低于使用尖峰，但在时间上的稳定性是后者的两倍。最后，使来自不同电极的局部场电位信号去相关，可使高频解码性能提高约14%。我们的研究结果表明，从长期植入LPFC的多电极阵列记录的局部场电位以频率依赖的方式包含有关任务的感觉、认知和运动成分的信息。
