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Abstract #0722

Hemodynamic Response Timing in Human Lateral Geniculate Nucleus & Visual Cortex

SUMMA25Kevin W.-K. Tsai1, Thomas Witzel2, Tommi Raij2, Jonathan Polimeni2, Jyrki Ahveninen2, Wen-Jui Kuo3, John Belliveau2, Fa-Hsuan Lin1

1National Taiwan University, Taipei, Taiwan, Taiwan; 2Massachusetts General Hospital, United States; 3National Yang Ming University, Taiwan

Using magnetic resonance inverse imaging (InI) with 100-ms temporal resolution, whole-brain coverage, and uniform spatial resolution achieved by multiple projections, we recorded BOLD-contrast fMRI responses to visual hemifield stimuli. The lateral geniculate nucleus (LGN) was activated approximately 500 ms before the primary visual cortex (V1). The fact that the LGN->V1 delay is longer in BOLD recordings than in evoked electrophysiological responses may reflect interregional vasculature or neurovascular coupling differences, or relative onsets of evoked/induced neuronal activity.