Correlation between temporal response of fMRI and fast reaction time in a language task

Correlation between behavioral parameters and fMRI responses can provide an advanced understanding of the neuronal processes. A lexical decision task was employed to examine the correlation between the reaction time (RT) and the temporal parameters in event-related BOLD responses. Word frequency was manipulated in the experiment. RTs for high-frequency, low-frequency and pseudowords were measured during fMRI (417 +/- 9 ms, 631 +/- 22 ms and 658 +/- 15 ms, respectively). For high-frequency words, RTs were significantly shorter than that for low-frequency and pseudowords (p < 0.0005). In the left inferior frontal region, the FWHM of the fMRI responses was significantly correlated with RT (p < 0.001), which may correspond to areas with sustained activation during the whole processing.