Task-induced deactivation and the "resting" state

Abstract

Task-induced decreases in blood flow and the widespread use of "resting" baselines produced unexpected and discrepant results in early cognitive imaging studies, especially in language comprehension experiments. Here I describe from a personal perspective some of the events and thought processes leading to the first hypothesis-driven fMRI study of the "resting" state.

Figure 1

Overlap of regions showing “task-induced deactivation” and regions involved in semantic knowledge retrieval. Top row: Higher levels of BOLD signal during a “resting” state compared to a perceptual tone discrimination task. Bottom row: Higher levels of BOLD signal during a semantic decision task compared to a phonological control task. Overlapping regions include the medial temporal lobe, posterior cingulate gyrus, angular gyrus, and dorsomedial prefrontal cortex. Adapted from Binder et al. (1999).

Figure 2

Overlap of left hemisphere regions identified in a large-scale meta-analysis of 120 semantic imaging experiments (top) and regions showing task-induced deactivation in a comparison of “resting” and a perceptual tone discrimination task (bottom). Similarity between the maps is striking given that they are derived using very different types of data and analysis methods. Reprinted from Binder et al. (2009).