黄璜等：大脑视知觉调控的神经机制 97 W iral M.,B ldow ski C..K ohler,A.,Singer&Muckli,L.2009).The tin ing Triantafy llou,C.,K anw isher,N.2008).Feedback of visual object of feedback to early visual cortex in the perception of lng-range apparent infomm ation to foweal retinotopic cortex.Nature Neuroscience,11 02),1439- motion.CerebralCortex,19(),1567-1582. 1445. W illiam s,M.A.,Baker,C.L,de Beeck,H.P.0.,Shim,W.M.,Dang,S., Neural Mechanism of Top-down Modulation in Visual Perception Huang Huang,Zhang Delong,Liang Bishan,Huang Ruiwang,Liu Ming (School of Psychology,Center for Studies of Psychological Application.South China Normal University,Guangzhou,510631) (Department of Radiology,Guangdong Province Hospital of Traditional Chinese Medicine,Guangzhou,510120) Abstract Human brain is not a purely receiving machine;its perception system is plastic and self-directed.Indeed,the visual areas in the brain are interconnected in a complex pattern of feed-forward,lateral,and feedback pathways.The top-down system can send feed-back information to primary visual cortex which affects what we perceive.For a long time,the magnitude of cortical influences on this processing in early sensory cortex is mostly underestimated. In this review,we first conceptualized the processing of the top-down modulation.Then we introduced the neural basics of the top-down modulation in visual perception.Perception process has been shown to work in a spatially distributed cortical network including the subcortical structures and primary visual cortex.Early visual areas do more than encoding raw sensory signals;they also participate in processing activities corresponding to a visual perception.Research indicates that neural activation of the top-down modulation is modulated by expertise,selective attention,mental imagery and even emotion.Methods that are usually used in past research are also included in this review.Both the figure-ground segregation paradigm and degraded paradigm are applied to realize the functional dissociation.And it is essential that the feed-forward and feedback modulation components are independently stimulated or inactivated. To provide more detailed insights,we highlighted the models that interpret the perception modulation function.The attention modulation model posits that feedback to primary visual cortex modulates,tunes,or anticipates the ottom-up response to visual stimuli through selective attention.The top-down attention modulation is crucial for elucidating th an filt ensory infor ation by paying attentions to the most behaviorally relevant events.The competition between learning new objects and recognizing old ones is conceptualized in the Adaptive Resonance Theory,in the case that the internal model well explains the sensory stimulation,the neuronal responses are enhanced and such recurrent enhancement is believed to lead to conscious recognition.A more complex account of the cortical feedback modulation is provided by the hierarchical predictive coding model.Perception processing has to do with the fact that predicted signals will depend on whether different sensory signals are determined. This model proposes a matching inhibition mechanism,correctly predicted that the bottom-up signals are cancelled from further processing,or attenuated.There are many instances where top-down projections might contribute to VI activation even in the absence of any stimulation.So here comes the baseline activity theory and the global neuronal workspace model,proposing that there are other computational spaces in the brain which could distinguish the top-down modulation from the local processors by their reciprocal long-range anatomical interconnection.Spontaneous baseline activity is another instance of stimulus-unrelated pro ssing in primary cortex which may be a form of the top-down modulation.Finally,we discussed the theoretical constraints and the future research orientations.Recurrent interactions between higher and lower visual areas allow high-level neurons in the present model to express different modes of information in their firing patters.A more elaborate paradigm and precise data analysis methods are promoted. Key words visual perception,top-down modulation,neural mechanism,perception modulation models ?1994-2015 China Academic Journal Electronic Publishing House.All rights reserved.http://www.cnki.net黄 璜等 : 大脑视知觉调控的神经机制 97 Wibral, M., Bledowski, C., Kohler, A., Singer, W., & Muckli, L. (2009). The timing of feedback to early visual cortex in the perception of long-range apparent motion. Cerebral Cortex, 19(7), 1567-1582. Williams, M. A., Baker, C. I., de Beeck, H. P. O., Shim, W. M., Dang, S., Triantafyllou, C., & Kanwisher, N. (2008). Feedback of visual object information to foveal retinotopic cortex. Nature Neuroscience, 11(12), 1439- 1445. Neural Mechanism of Top-down Modulation in Visual Perception Huang Huang1 , Zhang Delong2 , Liang Bishan1 , Huang Ruiwang1 , Liu Ming1 ( 1 School of Psychology, Center for Studies of Psychological Application, South China Normal University, Guangzhou, 510631) ( 2 Department of Radiology, Guangdong Province Hospital of Traditional Chinese Medicine, Guangzhou, 510120) Abstract Human brain is not a purely receiving machine; its perception system is plastic and self-directed. Indeed, the visual areas in the brain are interconnected in a complex pattern of feed-forward, lateral, and feedback pathways. The top-down system can send feed-back information to primary visual cortex which affects what we perceive. For a long time, the magnitude of cortical infl uences on this processing in early sensory cortex is mostly underestimated. In this review, we first conceptualized the processing of the top-down modulation. Then we introduced the neural basics of the top-down modulation in visual perception. Perception process has been shown to work in a spatially distributed cortical network including the subcortical structures and primary visual cortex. Early visual areas do more than encoding raw sensory signals; they also participate in processing activities corresponding to a visual perception. Research indicates that neural activation of the top-down modulation is modulated by expertise, selective attention, mental imagery and even emotion. Methods that are usually used in past research are also included in this review. Both the fi gure-ground segregation paradigm and degraded paradigm are applied to realize the functional dissociation. And it is essential that the feed-forward and feedback modulation components are independently stimulated or inactivated. To provide more detailed insights, we highlighted the models that interpret the perception modulation function. The attention modulation model posits that feedback to primary visual cortex modulates, tunes, or anticipates the bottom-up response to visual stimuli through selective attention. The top-down attention modulation is crucial for elucidating the mechanisms by which we can fi lter sensory information by paying attentions to the most behaviorally relevant events. The competition between learning new objects and recognizing old ones is conceptualized in the Adaptive Resonance Theory, in the case that the internal model well explains the sensory stimulation, the neuronal responses are enhanced and such recurrent enhancement is believed to lead to conscious recognition. A more complex account of the cortical feedback modulation is provided by the hierarchical predictive coding model. Perception processing has to do with the fact that predicted signals will depend on whether different sensory signals are determined. This model proposes a matching inhibition mechanism, correctly predicted that the bottom-up signals are cancelled from further processing, or attenuated. There are many instances where top-down projections might contribute to V1 activation even in the absence of any stimulation. So here comes the baseline activity theory and the global neuronal workspace model, proposing that there are other computational spaces in the brain which could distinguish the top-down modulation from the local processors by their reciprocal long-range anatomical interconnection. Spontaneous baseline activity is another instance of stimulus-unrelated processing in primary cortex which may be a form of the top-down modulation. Finally, we discussed the theoretical constraints and the future research orientations. Recurrent interactions between higher and lower visual areas allow high-level neurons in the present model to express different modes of information in their fi ring patterns. A more elaborate paradigm and precise data analysis methods are promoted. Key words visual perception, top-down modulation, neural mechanism, perception modulation models