Human V5/MT+: comparison of functional and cytoarchitectonic data.

Area of Science:

• Neuroscience
• Human visual cortex research
• Functional neuroimaging

Background:

• Current methods for identifying the human visual motion area (V5/MT+) are based on paradigms developed for monkeys.
• A precise anatomical correlate for the human V5/MT+ has been lacking.

Purpose of the Study:

• To identify the putative human area V5/MT+ using functional magnetic resonance imaging (fMRI).
• To compare the location of the functionally identified V5/MT+ with the cytoarchitectonic area hOc5 derived from post-mortem brains.
• To establish the correspondence between functional activation and anatomical location in the human visual cortex.

Main Methods:

• fMRI was used to model Blood-Oxygen-Level-Dependent (BOLD) responses to moving versus stationary dot patterns.
• Functional activations were compared with cytoarchitectonic probability maps of area hOc5 from ten post-mortem human brains.
• Analyses included single-subject and group random-effects analyses, as well as functional probability maps (fPM).

Main Results:

• Bilateral visual cortex activations corresponding to motion perception were observed.
• A significant overlap was found between the functionally defined V5/MT+ and the cytoarchitectonically defined area hOc5.
• Specific percentages of overlap were reported for right and left hemispheres, indicating substantial correspondence.

Conclusions:

• This study provides the first direct evidence linking the functionally identified human V5/MT+ with the cytoarchitectonically defined area hOc5.
• The findings help to refine the anatomical localization of the human visual motion area.
• The combination of fMRI and cytoarchitectonic mapping offers a robust approach for delineating visual areas.