Event-related functional MRI: Implications for cognitive psychology

Functional magnetic resonance imaging (fMRI) has rapidly emerged as a power ful technique in cognitive neuroscience. We describe and critique a new cla ss of imaging experimental designs called event-related fMRI that exploit t he temporal resolution of fMRI by modeling fMRI signal changes associated w ith behavioral trials as opposed to blocks of behavioral trials. Advantages of this method over block designs include the ability to (a) randomize tri al presentations, (b) test for functional correlates of behavioral measures with greater power, (c) directly examine the neural correlates of temporal ly dissociable components of behavioral trials (e.g., the delay period of a working memory task), and (d) test for differences in the onset time of ne ural activity evoked by different trial types. Consequently, event-related fMRI has the potential to address a number of cognitive psychology question s with a degree of inferential and statistical power not previously availab le.