Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Department of Otorhinolaryngology - Head & Neck Surgery, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Cereb Cortex. 2021 May 10;31(6):3136-3152. doi: 10.1093/cercor/bhab014.
A recent formulation of predictive coding theory proposes that a subset of neurons in each cortical area encodes sensory prediction errors, the difference between predictions relayed from higher cortex and the sensory input. Here, we test for evidence of prediction error responses in spiking responses and local field potentials (LFP) recorded in primary visual cortex and area V4 of macaque monkeys, and in complementary electroencephalographic (EEG) scalp recordings in human participants. We presented a fixed sequence of visual stimuli on most trials, and violated the expected ordering on a small subset of trials. Under predictive coding theory, pattern-violating stimuli should trigger robust prediction errors, but we found that spiking, LFP and EEG responses to expected and pattern-violating stimuli were nearly identical. Our results challenge the assertion that a fundamental computational motif in sensory cortex is to signal prediction errors, at least those based on predictions derived from temporal patterns of visual stimulation.
近期的预测编码理论提出，每个皮质区域的一部分神经元对感觉预测误差进行编码，即从更高层次的皮质传递的预测与感觉输入之间的差异。在这里，我们在恒河猴初级视觉皮层和 V4 区的尖峰和局部场电位（LFP）记录中，以及在人类参与者的互补脑电图（EEG）头皮记录中，测试了预测误差反应的证据。在大多数试验中，我们呈现了一个固定的视觉刺激序列，而在一小部分试验中则违反了预期的顺序。根据预测编码理论，模式破坏刺激应该会引发强烈的预测误差，但我们发现，对预期和模式破坏刺激的尖峰、LFP 和 EEG 反应几乎相同。我们的结果挑战了这样一种说法，即在感觉皮层中，一种基本的计算模式是发出预测误差信号，至少是那些基于视觉刺激的时间模式推导出来的预测误差信号。
