Laboratory for Integrative Neural Systems

When we perceive the visual image of an object in the external world, the brain constructs a representation which mediates recognition. The ultimate goal of our research is to understand the framework of such representations, the neural mechanisms by which they are constructed, and the processes which accomplish recognition on the basis of those representations. In order to reach this goal we investigate the structure and function of the primate visual association cortices. In particular, we focus on the inferotemporal area TE. This area is the final, purely visual stage of the occipitotemporal pathway, thought to be essential for the recognition of objects by means of their visual images. In addition, this area has strong connections with the medial temporal structures essential for the formation of recognition memory. Individual neurons in area TE respond optimally to moderately complex visual features. Since none of the visual features are specific enough, it takes the combined activation of multiple feature neurons to represent a particular object in area TE. Thus, because it is essential to investigate the spatial as well as temporal patterns of neural activity, we use intrinsic signal imaging and multicellular recording techniques. We also work on developing imaging techniques with improved spatial and temporal resolutions.

Research Subjects

• Development of multiple electrode array techniques for online imaging of neuronal activity
• Development of functional imaging techniques with high spatial and temporal resolutions
• Interpretation of object representation in visual recognition task
• Internal representation of objects in visual association cortices

Publications

1. Miyakawa N, Katsumata N, Blake D, Merzenich M, and Tanifuji M.:
   "High-density multielectrode array with independently maneuverable electrodes and silicone oil fluid isolation system for chronic recording from macaque monkey"
   Journal of Neuroscience Methods 211: 114-124 (2012)
2. Hayashi R, and Tanifuji M.:
   "Which image is in awareness during binocular rivalry? Reading perceptual status from eye movements"
   Journal of Vision 12: 1-11(2012)
3. Sato, T., Uchida, G., and Tanifuji, M.:
   "Cortical columnar organization is reconsidered in inferior temporal cortex"
   Cerebral Cortex 19: 1870-1888 (2009)
4. Rajagopalan, U.M. and Tanifuji, M.:
   "Functional optical coherence tomography reveals localized layer-specific activations in cat primary visual cortex in vivo"
   Optics Letters 32: 2614-2616 (2007)
5. Yamane, Y., Tsunoda, K., Matsumoto, M., Phillips, N. A., and Tanifuji, M.:
   "Representation of the spatial relationship among object parts by neurons in macaque inferotemporal cortex"
   J. Neurophysiol 96, 3147-3156 (2006)
6. Maheswari, R.U., Takaoka, H., Kadono, H., Homma, R., and Tanifuji, M.:
   "Novel functional imaging technique from brain surface with optical coherence tomography enabling visualization of depth resolved functional structure in vivo"
   J. Neurosci. Methods. 124, 83-92 (2003)
7. Maheswari R.U., Takaoka, H., Homma, R., Kadono, H. and Tanifuji, M.:
   "Implementation of optical coherence tomography (OCT) in visualization of functional structures of cat visual cortex"
   Opt. Comm. 202: 47-54 (2002)
8. Tsunoda, K., Yamane, Y., Nishizaki, M., and Tanifuji, M.:
   "Complex objects are represented in macaque inferotemporal cortex by the combination of feature columns"
   Nature Neurosci. 4, 832-838 (2001)
9. Wang, G., Tanifuji, M., and Tanaka, K.:
   "Functional architecture in monkey inferotemporal cortex revealed by in vivo optical imaging"
   Neurosci. Res. 32: 33-46 (1998)
10. Wang, G., Tanaka, K., and Tanifuji, M.:
    "Optical Imaging of functional organization in the monkey inferotemporal cortex"
    Science 272: 1665-1668 (1996)