This research implements a random dot kinematogram(RDK)using virtual reality(VR)and analyzes the results based on normal subjects.Visual motion perception is one of visual functions localized to a specific cortical ar...This research implements a random dot kinematogram(RDK)using virtual reality(VR)and analyzes the results based on normal subjects.Visual motion perception is one of visual functions localized to a specific cortical area,the human motion perception area(human analogue for the middle temporal/middle superior temporal area)located in the parieto–occipito–temporal junction of the human brain.The RDK measures visual motion perception capabilities.The stimuli in conventional RDK methods are presented using a monitor screen,so these devices require a spacious dark room for installation and use.Recently,VR technology has been implemented in different medical domains.The test method proposed in this study include a VR-based RDK that can independently measure human motion perception abilities without any spatial constraints via a VR head-mounted display.Subsequently,the VR-based RDK was implemented,and the visual perception abilities of the normal subjects were measured based on varying coherences.In both screen-and VR-based RDK tests,the easier the stimulus is,the higher the correct answer rate and the shorter the reaction time.No significant differences in coherence thresholds were observed between the two test methods.The VRbased RDK proposed in this study can be used as a diagnosis tool for visual motion perception and neurodegenerative disorders affecting the posterior region of the brain.展开更多
Apparent motion stimulus induces visual perception of smooth motion even though there is no speed information. We examined whether human brain response as measured by magnetoencephalography carries direction informati...Apparent motion stimulus induces visual perception of smooth motion even though there is no speed information. We examined whether human brain response as measured by magnetoencephalography carries direction information in the visually presented apparent motion of a randomdot pattern in a similar manner as continuous motions that have speed and direction information. Although there was no significant effect of motion direction on the peak response latency and amplitude, mutual information entropy (IE) significantly increased after the motion onset at approximately 36 ms after the response latency in 41% of the evaluations. Detailed analysis of the data from five subjects who participated in both the present apparent motion and our previous coherent motion studies revealed that the maximum IE latency (delay) for apparent motion was significantly longer than that for coherent motion, although the mean maximum IE was the same. The results indicate that direction is represented in the response waveform evoked by apparent motion but the manner is different from that for coherent motion probably due to the distinct neural processes engaged only for the apparent motion perception. We consider that direction and speed can be processed separately in the human brain because direction information was generated without speed information for the perception of apparent motion.展开更多
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.2019R1F1A1062752 and 2019R1C1C1006539)and was supported by the Soonchunhyang University Research Fund.
文摘This research implements a random dot kinematogram(RDK)using virtual reality(VR)and analyzes the results based on normal subjects.Visual motion perception is one of visual functions localized to a specific cortical area,the human motion perception area(human analogue for the middle temporal/middle superior temporal area)located in the parieto–occipito–temporal junction of the human brain.The RDK measures visual motion perception capabilities.The stimuli in conventional RDK methods are presented using a monitor screen,so these devices require a spacious dark room for installation and use.Recently,VR technology has been implemented in different medical domains.The test method proposed in this study include a VR-based RDK that can independently measure human motion perception abilities without any spatial constraints via a VR head-mounted display.Subsequently,the VR-based RDK was implemented,and the visual perception abilities of the normal subjects were measured based on varying coherences.In both screen-and VR-based RDK tests,the easier the stimulus is,the higher the correct answer rate and the shorter the reaction time.No significant differences in coherence thresholds were observed between the two test methods.The VRbased RDK proposed in this study can be used as a diagnosis tool for visual motion perception and neurodegenerative disorders affecting the posterior region of the brain.
文摘Apparent motion stimulus induces visual perception of smooth motion even though there is no speed information. We examined whether human brain response as measured by magnetoencephalography carries direction information in the visually presented apparent motion of a randomdot pattern in a similar manner as continuous motions that have speed and direction information. Although there was no significant effect of motion direction on the peak response latency and amplitude, mutual information entropy (IE) significantly increased after the motion onset at approximately 36 ms after the response latency in 41% of the evaluations. Detailed analysis of the data from five subjects who participated in both the present apparent motion and our previous coherent motion studies revealed that the maximum IE latency (delay) for apparent motion was significantly longer than that for coherent motion, although the mean maximum IE was the same. The results indicate that direction is represented in the response waveform evoked by apparent motion but the manner is different from that for coherent motion probably due to the distinct neural processes engaged only for the apparent motion perception. We consider that direction and speed can be processed separately in the human brain because direction information was generated without speed information for the perception of apparent motion.
