著者

Sawahata Hirohito Toda Haruo Suzuki Takafumi Hasegawa Isao

出版者

Niigata University School of Medicine

雑誌

Acta medica et biologica = Acta medica et biologica (ISSN:05677734)

巻号頁・発行日

vol.58, no.2, 2011-09

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The primary visual cortex (V1) of the rat consists of a monocular (contralateral-eye-dominant) region (V1M) and a binocular region (V1B) that receives anatomical and functional inputs converging from both eyes. However, V1B contains a heterogeneous mosaic of neurons stochastically discharging with various degrees of ocular dominance, and it has been difficult to 5 estimate the size and behavior of the neuronal populations recruited by stimulation to individual eyes. To functionally characterize the V1B, we explore the similarities and differences of activation patterns between the contralateral and ipsilateral visual stimulation conditions in V1. Using a high density electrode array, 32-channel electrocorticogram (ECoG) was recorded from the whole surface of V1 of anesthetized Long-Evans rats. Despite a similarity of the spatial 10 activation patterns in the early phase, contralateral eye stimulation evoked consistently stronger responses and higher signal coherency between the most responsive site and adjacent sites than ipsilateral stimulation. Time-frequency analyses confirmed that contralateral activations were more widely distributed from V1B to V1M in low frequency powers (2-30 Hz). On the other hand, high frequency powers (30-100 Hz) were localized in V1B. These findings revealed 15 time-frequency domain properties of V1B. We speculate that the sustained high frequency activity reflected visual information flow from V1B to higher cortical centers.

著者

HASEGAWA Ryohei P. NAKAMURA Yoshiko HASEGAWA Yukako T. SAWAHATA Hirohito

出版者

日本感性工学会

雑誌

International Symposium on Affective Science and Engineering

巻号頁・発行日

vol.2019, pp.1-4, 2019

被引用文献数

1

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<p>We have been developing an EEG-based cognitive brain-machine interface (BMI) system, Neurocommunicator® to support patients with severe motor deficits in communication. This system uses an event-related potential (ERP) to decode the message (pictogram) that users want to convey. In addition to the communication aid, it would be expected for the Neurocommunicator to improve the QOL of the users in a variety of daily-life situations. In this study, we focused on the brain activity that reflected the decision-making process of customers. We used the virtual shopping task as a model of daily shopping, in which a variety of product images were used as visual stimuli for the sequential delayed matching-to-sample paradigm. We recorded EEG data from 12 normal subjects and examined the ERPs in two conditions; the subject selected one (target) out of 8 products (nontargets) either "to BUY" (positive condition) or "NOT to BUY" (negative condition). We observed the strong ERPs not only to the target "to BUY" but also to the target "NOT to BUY" compared to the nontarget. The magnitude of the response and the decoding accuracy of the former were, however, greater than the latter. These results suggest that the ERP to a product is enhanced by the intention to buy it, and that the ERP- based Neurocommunicator has potential to become a "body-free" shopping tool for patients with severe motor deficits as well as a real-time neuromarketing/neuroconsulting tool for any person.</p>