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スケジュール

講演者

fMRI registration based on diffusion tensor imaging for reducing the cost of experiments

Functional magnetic resonance imaging (fMRI) acquisitions include a great deal of individual variability. This individual difference often generates obstacles to the efficient use of databanks from multiple subjects. Although recent studies have suggested that inter-regional connectivity reflects individuality, conventional three-dimensional (3D) registration methods that calibrate inter-subject variability are based on anatomical information about the gray matter shape (e.g., T1-weighted). Here, we present a new registration method focusing more on the white matter structure, which directly related to the connectivity in the brain. Our registration method, based on diffusion tensor imaging (DTI), transferred functional maps of individuals to a common anatomical space. The DTI-based registration allowed a more precise transformation of gray matter boundaries than a well-established T1-based method.

In this talk, we would like to discuss how to absorb structural differences and fucus on functional differences incorporating open data.

The relationship between digit representation and myelin distribution in human S1.

Similar to better-known cytoarchitecture, myelo-architecture also reflects the functional segregation of cerebral cortex. Recently, noninvasive MRI could estimate both functional representations and myeloarchitecture in human cerebral cortex. However, it is unclear the extent to which in vivo myeloarchitecture reflects the finer-scale functional organization in humans. It is well known that primary somatosensory cortex (S1) holds precise body-part representations. Thus, we investigated the relationship between the relative myelin content and the individual digit areas in human primary somatosensory cortex (S1). By combining the high-resolution functional MR images measured in 7T with the multi-modal image registration method, we illustrated the fine-grained digit representations in individual’s S1. We also found a clear boundary of myelin distribution within S1. Interestingly, these digit representations (D2-D5) did not cross the myelin boundary. These findings suggest that myeloarchitecture reflects fine-scale functional subdivision at least in human S1.

Is it time to put rest to rest?

The phenomenon of spontaneous, or “resting state”, activity in the human brain has revolutionized how we acquire and analyze neuroimaging data. But what has resting-state data taught us about cognition? I argue that while human neuroscientists have gleaned valuable insights from the foray into resting state, we are now at a point where accelerating our understanding of the basic principles of brain function will require a move back toward task-based acquisitions. Compared to resting state, task-based fMRI data are higher quality, more reliable, and more sensitive to meaningful individual differences. Specifically, naturalistic paradigms (e.g., movie watching) yield data that are flexibly analyzed to study multiple functional systems in a single acquisition, and enhance functional connectivity-based prediction of behavioral traits.