Journal Article

Decoding brain responses to pixelized images in the primary visual cortex： implications for visual cortical prostheses

Bing-bing Guo Xiao-lin Zheng Zhen-gang Lu Xing Wang Zheng-qin Yin Wen-sheng Hou Ming Meng

2015

Overview

Visual cortical prostheses have the potential to restore partial vision. Still limited by the low-resolution visual percepts provided by visual cortical prostheses, implant wearers can currently only ＂see＂ pixelized images, and how to obtain the specific brain responses to different pixelized images in the primary visual cortex（the implant area） is still unknown. We conducted a functional magnetic resonance imaging experiment on normal human participants to investigate the brain activation patterns in response to 18 different pixelized images. There were 100 voxels in the brain activation pattern that were selected from the primary visual cortex, and voxel size was 4 mm × 4 mm × 4 mm. Multi-voxel pattern analysis was used to test if these 18 different brain activation patterns were specific. We chose a Linear Support Vector Machine（LSVM） as the classifier in this study. The results showed that the classification accuracies of different brain activation patterns were significantly above chance level, which suggests that the classifier can successfully distinguish the brain activation patterns. Our results suggest that the specific brain activation patterns to different pixelized images can be obtained in the primary visual cortex using a 4 mm × 4 mm × 4 mm voxel size and a 100-voxel pattern.

• Publisher: Medknow Publications and Media Pvt. Ltd,Medknow Publications & Media Pvt. Ltd,Department of Biomedical Engineering,Chongqing University,Chongqing,China,Department of Psychological and Brain Sciences,Dartmouth College,Hanover,NH,USA%Department of Biomedical Engineering,Chongqing University,Chongqing,China%Department of Psychological and Brain Sciences,Dartmouth College,Hanover,NH,USA%Key Lab of Visual Damage and Regeneration & Restoration,Third Military Medical University,Chongqing,China,Medknow Publications & Media Pvt Ltd,Wolters Kluwer Medknow Publications
• Subject: Analysis / Datasets / Evaluation / Experiments / Magnetic resonance imaging / nerve regeneration; primary visual cortex; electrical stimulation; visual cortical prosthesis; low resolution vision; pixelized image; functional magnetic resonance imaging; voxel size; neural regeneration; brain activation pattern / Prostheses / Prostheses and implants / Studies / Visual cortex / 假体 / 像素尺寸 / 初级视觉皮层 / 反应 / 图像解码 / 大脑 / 支持向量机 / 视皮层