关键词: 视觉表征, 联想性编码, 顶-底信息加工, 颞下回皮层和前额叶皮层

Abstract: Bottom-up processing and feature detecting theory based on strong electrophysiological evidences has played a dominant role in the visual research for long time. People know top-down processing just by common sense. Knowledge or experience are recalled from memory by reactivation of their neural representations and affected visual processes. However recently, researches from human and monkey provide experimental evidences for top-down processing. First, mnemonic representation of visual objects and faces, located in the ventral processing stream of visual perception in monkey, provide the best evidences of how neuronal codes are created by neurons that have the special ability to link the representations of temporally associated stimuli; second, experiments suggest that not only bottom-up signals from the retina but also top-down signals from the prefrontal cortex can trigger the retrieval of associative codes, which may serve as a neural basis both for the conscious recall and for the visual processes affected by top-down processing Further studies will improve people's understanding of the causal relation of activation and behavior by use of combined fMRI and electrophysiology or lesion studies.

Key words: visual representation, associative code, top-down information processing, inferior temporal lobe and prefrontal lobe