視覚4
Vision 4
O2-7-4-1
他者認知のためのミラーシステムを含んだ側頭葉―前頭葉ネットワーク
Mirror system in frontal-temporal cortical circuit for action observation in non-human primate

○鈴木航1, 坂野拓1, 宮川尚久1, 一戸紀孝1
○Wataru Suzuki1, Taku Banno1, Naohisa Miyakawa1, Noritaka Ichinohe1
国立精神・神経医療研究センター 神経研究所 微細構造研究部1
Dept Ultrastructural res, National Inst of Neurosci, NCNP, Tokyo, Japan1

Common marmoset (Callithrix jacchus) is an attractive primate model for studying social communication due to its cooperative breeding behavior, imitative behavior, and so on. However, it is difficult to determine systematically the access location, e.g., electrode penetration site, in frontal cortex (FC) that contain areas relevant to social information processing, because there is no landmark on the cortical surface. In last meeting, we have reported areas in the superior temporal sulcus (STS) of marmoset in which cells strongly respond to other's grasping action. In this study, we conducted simultaneous unit recording, one from STS responsive to other's action and the other from FC that was anatomically connected, using in vivo surface connection imaging (Ichinohe et al., 2012). An experiment consisted of four steps. (1): cells responsive to other's action were identified in STS under anesthetized condition. (2): a florescent tracer was injected into the identified area. (3): Multi-electrodes were implanted in the injection site in STS and in the labeled patches of projection cells in FC. (4): single- or multi-unit recordings were conducted during the animal was observing grasping action of a food performed by an experimenter. Cells in STS and FC strongly responded when the food was presented just before the experimenter reached it or was touched. Response magnitude depended on reaching direction of hand and decreased for grasping action without food. The responses decreased when the it was grasped by forceps and this modulation was observed more in FC than in STS. Some cells in FC, not in STS, also responded when the animal executed grasping action, indicating that mirror neurons (MN) existed in marmoset. The results indicate that temporal-frontal cortical circuit including MN encodes other's action with surrounding context, suggesting useful model for investigating neural substrate for understanding of other's action and disorder with social impairment like ASD.
O2-7-4-2
成体内神経結合可視化法を用いて証明したサル後部下側頭葉のFeedforwar neuronとintrinsic neuronが別の種類の細胞であり、それぞれ速い認知と正確な認知を司っていること
Distinct Feedforward and Intrinsic Neurons in Posterior Inferotemporal Cortex Revealed by in Vivo Connection Imaging

○一戸紀孝1,2
○Noritaka Ichinohe1,2, Elena Borra2, Kathleen S. Rockland2
国立精神・神経医療研究センター 神経研究所 微細構造研究部1, 理研、BSI, 皮質機能構造研究チーム2
NCNP, NIN, Dept. Ultrastructural Res.1, RIKEN, BSI, Lab. for Cortical Oranization and Systematics2

We investigated circuits for object recognition in macaque anterior (TE) and posterior inferotemporal cortex (TEO), using a two-step method for in vivo anatomical imaging. In step 1, red fluorescent tracer was injected into TE to reveal and Pre-target patches of feedforward neurons in TEO. In step 2, these were visualized on the cortical surface in vivo, and injected with green fluorescent tracer. Histological processing revealed that patches >500μm from the injection site in TEO consisted of intermingled green TEO-TE intrinsically projecting neurons and red TEO-to-TE neurons, with only few double-labeled neurons. In contrast, patches near the injection site in TEO contained many double-labeled neurons. Two parallel, spatially intermingled circuits are suggested: (1) TEO neurons having very local intrinsic collaterals and projection to TE (2) TEO neurons projecting more widely in the intrinsic network, but not to TE. These parallel systems might be specialized for, respectively, fast vs. highly processed signals.
O2-7-4-3
下側頭葉視覚連合野の顔細胞が符号化している図形特徴に対する乳児の選択的注視
Preferential looking of human infants to image fragments encoded by face neurons in monkey inferior temporal cortex

○谷藤学1, 市川寛子2, 山下和香代2, 小林恵2, 金沢創3, 山口真美2, 大脇崇史4
○Manabu Tanifuji1, Hiroko ichikawa2, Wakayo Yamashita2, Megumi Kobayashi2, So Kanazawa3, Masami Yamaguchi2, Takashi Owaki4
理化学研究所1, 中央大・文・心理2, 日本女子大・心理3, 豊田中央研究所4
RIKEN Brain Science Institute, Saitama, Japan1, Department of Psychology, Chuo University, Tokyo, Japan2, Department of Psychology, Japan Women's University, Kanagawa, Japan3, Toyota Central R&D Labs., Aichi, Japan4

Face cells in monkey inferior temporal (IT) cortex are known to respond faces better than non-face objects. However, the responses are not equal across faces. Some cells prefer monkey faces than human face, and vice versa. Thus, these neurons should capture some aspect of faces, but features captured by face cells are still not well understood. As previously reported (Owaki, et al., Soc. for Neurosci. Abstr., 465.03, 2012), we have developed a computational method to extract visual features that explain neural responses to objects including monkey and human faces, and non-face objects. In this approach, we hypothesized that we can find the features somewhere in natural scenes since IT cortex works for natural object vision. Among 560,000 image fragments of natural scenes, we successfully identified fragments that explain responses of face neurons (on average, identified fragments explain 46 % of variance in object responses). Interestingly, these fragments were not necessarily facial parts. Many of them are cut out from non-face images, suggesting (1) that face cells represent generic visual features and (2) that specific representation of faces are achieved by combinations of features. In this study, we addressed a question whether these features are really the component features for humans to identify faces. To address this question, we conducted preferential look tasks with human infants, and investigated whether infants preferred the fragments encoded by face neurons to the other fragments as infants prefer faces than non-face objects. We found that the infants indeed prefer the fragments identified for face cells. Interestingly, this was not the case for face cells responding monkey faces better than human faces. These results provide further evidence that our search strategy captures features encoded by face cells, and suggested that the analysis of responses of face cells can be a useful tool to address facial features preferred by human infants.
O2-7-4-4
Neuronal responses to face-like stimuli in the monkey superior colliculus
○Nui Nguyen1, Etsuro Hori1, Jumpei Matsumoto1, Anh Hai Tran1, Taketoshi Ono1, Hisao Nishijo1
System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama1

The superficial layers of the superior colliculus (sSC) appear to function as a subcortical visual pathway that bypasses the striate cortex for the rapid processing of coarse facial information. Responses of neurons in the monkey sSC were recorded during a delayed non-matching-to-sample (DNMS) task in which monkeys were required to discriminate among 5 categories of visual stimuli (photos of faces with different gaze directions, cartoon faces, face-like patterns [3 dark blobs on a bright oval], eye-like patterns, and simple geometric patterns). Of the 605 sSC neurons that were recorded, 216 neurons responded to the visual stimuli. Among the stimuli, face-like patterns elicited responses with the shortest latencies. Low-pass filtering of the images did not influence the responses. However, scrambling of the images increased the responses in the late phase, and this was consistent with a feedback influence from upstream areas. A multidimensional scaling analysis indicated that the sSC neurons could specifically encode face-like patterns during the first 25-ms period after stimulus onset, and stimulus categorization developed in the next three 25-ms periods. The amounts of stimulus information that was conveyed by the sSC neurons and the number of stimulus-differentiating neurons were consistently higher during the 2nd to 4th 25-ms periods than during the first 25-ms period. These results provide the electrophysiological bases that the sSC neurons preferentially filtered face-like patterns with short latencies to allow for the rapid processing of coarse facial information and developed categorization of the stimuli in later phases through feedback from upstream areas.
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