1．题目：“生命之述”系列讲座2019-26 Selective impairment of causal inference across sensory modalities in autism spectrum disorder
报告人：Dora Angelaki 教授
In recent years statistical inference has been proposed to be abnormal in autism spectrum disorder (ASD). Here we used multiplse sensory modalities to test causal inference in ASD. First, we used audio-visual localization: the auditory and visual stimuli were presented at congruent and incongurent locations and at different levels of relative cue reliability and conflict (i.e., spatial disparity between visual and auditory stimuli) to test three predictions of statistical inference: improved reliability of multisensory spatial localization, down-weighting less reliable cues and decreasing frequency of common source perception at large spatial disaprity and poor cue reliability. Second, we used self-motion in the presence of independently moving objects to test similar properties. Across sensory modalities, we found a striking dichotomy in the pattern of ASD behavior. In the absence of conflict or at small conflicts below perceptual awareness, spatial localization in ASD participants was similar to controls and consistent with the predictions of optimal cue integration. However, at large conflicts, ASD participants reported a common source less frequenty than control participants. In contrast, they continued to integrate the cues despite the large conflict. These results suggest that instead of a generalized deficit in multisensory integration, tasks that require causal inference can differentially modulate ASD behavior even with identical stimuli.
Dora Angelaki教授,美国科学院院士,美国人文与科学院院士。美国纽约大学神经科学中心教授。曾任美国贝勒医学院神经科学系主任,Journal of neuroscience 主编。主要从事认知及系统神经生物学方面的研究，在Nature，Natature Neuroscience,neuron等杂志发表论文200余篇。
2. 题目：“生命之述”系列讲座 2019-27 Neural mechanisms for perceiving object motion during self-motion
报告人：Gregory DeAngelis 教授
Many organisms have highly evolved neural circuits for processing visual motion cues. However, most laboratory studies of visual motion perception are performed under highly simplified conditions in which there is no self-motion such that object motion in the world directly maps onto retinal image motion. Under many natural conditions, however, we must judge object motion during self-motion, which greatly complicates the problem. Thus, the brain needs to parse the complex pattern of retinal image motion into components that correspond to object motion and self-motion. In addition, to compute object motion in world coordinates, the brain must estimate self-motion and factor it into computations of object motion. I will describe two studies that make important progress into understanding the visual and multi-sensory mechanisms by which the brain computes object motion during self-motion. I will show that neural activity in macaque area MT reflects the operation of a “flow parsing” mechanism (which has been previously established in human psychophysics) that discounts global optic flow resulting from self-motion. I will also show that neural activity in area VIP reflects flexible computation of object motion in either world- or head-centered coordinates. Together, these studies begin to reveal critical neural processes that are involved in perceiving object motion under more natural conditions in which self-motion also occurs.
Gregory DeAngelis教授,美国罗切斯特大学,脑与认知科学系系主任。Journal of Neuroscience杂志资深编辑。主要从事视觉神经生物学方面的研究，在Nature,Science,Natature Neuroscience，neuron，PNAS等杂志发表论文110余篇。