Cognitive Mode Detectable with Task-Based fMRI: Multiple Demand (MD)

In the context of task-based functional magnetic resonance imaging (fMRI), cognitive modes can be defined as task-general cognitive/sensory/motor processes which reliably elicit specific blood-oxygen-level-dependent (BOLD) signal pattern configurations. A number of cognitive modes are detectable with task-based fMRI, and here we focus on multiple demand (MD), a mid-trial peaking cognitive mode, already well known in the task-based fMRI literature. The BOLD signal configurations associated with MD are modulated by a range of tasks, and here we present five. For each task, we report: (1) specific pattern-based (as opposed to coordinate-based) anatomical details essential for distinguishing MD from other BOLD-based cognitive modes, and (2) task-induced BOLD signal changes associated with MD over a range of task conditions. In order to facilitate recognition, we nick-named the anatomical patterns specific to MD as follows: (1) Jumping Jack Flash, (2) Ape Nostrils, (3) Flexing Hands, and (4) Wipe Your Mouth Bear Triple Jam. Evidence for MD was derived from the timing and magnitude of task-induced BOLD signal changes induced by the following tasks: autobiographical event simulation, evidence integration, probabilistic reasoning, Raven’s standard progressive matrices, and social cognition. Based on observation of task-induced BOLD signal changes across these tasks, MD function could fit the original definition of attentional resources to individual parts of a complex task, but it was also noted that many other cognitive modes were general to many tasks, MD was not present in all tasks and in fact was not as commonly observed as other modes, and MD could even show deactivation under task conditions requiring for internal attention.