Perceptual processing along the ventral visual pathway to the hippocampus is hypothesized to be substantiated by signal transformation from retinotopic space to relational space, which represents interrelations among constituent visual elements regardless of their absolute retinotopic positions. However, our visual perception necessarily reflects the first person’s perspective based on the retinotopic space. Naya group discovered that neurons in the macaque temporal lobe areas represent the first person’s perspective as a combination of two distinct visual signals on relational space for a recognition of an item and on retinotopic space for locating the item in an environment, which was published online on July 8th in 2020 at Cerebral Cortex (Chen & Naya, “Automatic Encoding of a View-Centered Background Image in the Macaque Temporal Lobe.” https://doi.org/10.1093/cercor/bhaa183)
Figure 1. Encoding of item and location in two view conditions and two encoding states. Subjects were required to remember the item and location of the sample stimuli in the Active encoding (AE) condition, which were tested in the response phase. While in the Passive encoding (PE) condition, only passive viewing was required. Fixation requirement was indicated by the while dot.
Not only the identity information, current results from Naya group suggest that the location information of an object, which was presumably provided by the large background view, may still exist in the inferior temporal lobe of the ventral path. Interestingly, the above identity and location information are of a very different nature. In the F-V condition of the active-encoding (AE) task, the inferior temporal lobe has significant cells encoded identify and location information, while in passive-encoding (PE) task, only significant location information was detected. These results may suggest that the visual information from the retina, has at least two different processing channels along the ventral path: active coding channel which is responsible for processing identity information on the relational space, and passive coding channel that retain the large-scale background image on the retinotopic space which can provide a specific location information.
The study was conducted by He Chen and Yuji Naya. He Chen, a postdoctoral fellow at School of Psychological and Cognitive Sciences at Peking University, is the first author. Yuji Naya, a researcher at School of Psychological and Cognitive Sciences at Peking University, is the corresponding author.
Funding: National Natural Science Foundation of China, Center for Life Sciences in China, National Center for Protein Sciences at Peking University, School of Psychological and Cognitive Sciences at Peking University. Special thanks to Alex, Donald and Frank.
Paper link: https://doi.org/10.1093/cercor/bhaa183