Ezequiel Morsella

Department of Psychology, San Francisco State University

and

Department of Neurology, University of California, San Francisco

Homing in on the neural correlates and basic cognitive mechanisms associated with conscious states: Implications for self-regulation.

There is a consensus that conscious states are associated with only a subset of all brain regions/processes and that they permit the integration of information/processes that would otherwise be independent. Recent developments reveal that it is easier to home in on the basic, component processes associated with consciousness than on the neural correlates of consciousness. In particular, the study of conscious conflict (e.g., when one holds one’s breath) has revealed much about the nature of these states. Conscious conflict is just one of many kinds of interactions in the nervous system. Other kinds of interactions/crosstalk, such as afference binding (e.g., intra- or inter-sensory interactions [e.g., the McGurk effect]) or interactions involving non-skeletal muscle effectors (e.g., integrations involving the pupillary reflex), can occur unconsciously. Similarly, motor control and basic stimulus-response associations (efference binding), such as pressing a button in response to a subliminal stimulus or inhaling reflexively, can occur unconsciously. Research reveals that conscious conflicts are special in that they involve the simultaneous activation of two conflicting streams of efference binding toward the skeletal muscle output system (e.g., signaling inhale and do not inhale). Such efference-efference binding results in integrated actions such as holding one’s breath, breathing faster for a reward, carrying a hot dish of food, performing the Stroop task, or suppressing socially-inappropriate behavior. Conscious states are not necessary for smooth muscle actions or skeletomotor actions that are unintegrated, such as those driven by a single stimulus-response (SàR) stream (e.g., withdrawing one’s hand from a hot stove). From this standpoint (Supramodular Interaction Theory; Morsella, 2005), conscious states function above the level of the traditional Fodorian module to permit crosstalk among specialized, and often multi-modal, skeletomotor-related systems, as captured by the principle of parallel responses into skeletal muscle (PRISM). For example, regarding a process such as digestion, one is conscious only of those phases of the process requiring coordination with skeletal muscle plans (e.g., chewing). The PRISM acronym is conceptually related to the principle, for just as a prism can combine different colors to yield a single hue, conscious states cull simultaneously activated response tendencies to yield a single, adaptive skeletomotor action (e.g., holding one’s breath). Thus, consciousness permits a form of crosstalk in the brain that is essential for integrated action-goal selection. I will review evidence for this new framework proposing that conscious states are required for integration, but for only certain kinds of integration in the nervous system.