The basic nuts and bolts underlying human action remain mysterious from a mechanistic point of view. Everyday actions such as naming an object, suppressing the urge to say something, grabbing a waiter’s attention with a "cappuccino, please," or deciding out of the blue to call a friend remain difficult to understand from a scientific, biologically-based standpoint. At the Action and Consciousness Laboratory, we investigate the nature of human action production from an integrative cognitive neuroscience perspective, focusing on both its conscious (e.g., cognitive conflict, urges, working memory) and unconscious brain mechanisms.

One goal of the lab is to home in on the subset of basic neural and cognitive processes that are responsible for conscious states, in order to reveal how the brain yields adaptive action and also maladaptive action, as in the case of some neurological disorders. Investigations at the laboratory tend to fall into three primary research goals: to home in on the (a) neural circuits, (b) cognitive processing, and (c) mental representations associated with conscious states. The research in our lab is untraditional in that we work backwards from overt action to the conscious and unconscious central processes responsible for it, rather than work forward from an external perceptual stimulus to central processing. We use response interference paradigms to learn about the subjective aspects of action production (e.g., urges) and use delayed action tasks to learn about the subjective aspects of working memory-based action control (e.g., imagery, sense of agency).

Here are some photos of the Action and Consciousness Lab The Space; Guests1 2 3. Guest speakers/discussants at the lab include (in alphabetical order) Ozlem Ayduk, Roy Baumeister, Daniel Cervone, Adam Gazzaley, Jeremy Gray, Gary Marcus, Rodolfo Mendoza-Denton, Andrew Poehlman, Travis Seymour, Lisa Son, Lawrence Williams, and Rex Wright.

The Theoretical Approach

Despite the challenges in unraveling how the nervous system gives rise to consciousness, a consensus has been growing that (a) consciousness is associated with only a subset of all nervous regions and processes, and (b) the primary function of consciousness is to integrate processes/information that would otherwise be independent (the integration consensus). Recent research illuminates the subset of areas and processes that are most closely related to conscious processing. These investigations reveal that consciousness serves to integrate only certain kinds of information/processes. Many forms of integration can occur unconsciously. The peculiar form of integration associated with consciousness involves a form of information broadcasting that is intimately related to what is casually referred to as 'voluntary' action and to the skeletal muscle output system. All these developments are synthesized in Supramodular Interaction Theory (SIT).

Much of our research is motivated by SIT. The majority of the mechanisms underlying human action are unconscious. For example, the brain's motor-programs and intersensory processes, as well as the sophisticated actions of the 'dorsal stream,' digestive tract, pupils, and respiratory system, are all consciously-impenetrable. In trying to understand complex unconscious processes, one eventually encounters the thorny question, "Then what is consciousness for?" To address this questions, much of our recent research is based on a theoretical framework (Supramodular Interaction Theory [SIT] and the PRISM principle) explaining the primary function of phenomenal states (Morsella, Psychological Review, 2005).

Regarding conscious processing, SIT is unique in that it explains the primary role of consciousness by comparing the task demands of consciously-penetrable processes (e.g., pain and breathlessness) and consciously-impenetrable processes (e.g., intersensory conflict and the pupillary reflex). Building on the integration consensus (proposing that conscious states integrate processes that would otherwise be independent), SIT proposes that conscious states are necessary to integrate only certain kinds of information in the brain. Specifically, SIT proposes that these states are required to integrate high-level systems in the brain that are vying for (specifically) skeletomotor control, as described by the principle of parallel responses into skeletal muscle (PRISM). From this point of view, consciousness functions above the level of the traditional module to permit crosstalk among specialized, and often multi-modal, systems. For example, regarding a process such as digestion, one is conscious only of those phases of the process that require 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. Thus, consciousness permits a form of crosstalk in the brain that is essential for integrated action-goal selection, a process that has historically been linked to the 'ventral processing stream' of the brain. Importantly, SIT is unique in its ability to explain subjective data from (a) intersensory conflicts, (b) smooth muscle conflicts, and (c) conflicts from action conflicts (e.g., holding one's breath and Stroop-like interference). For video explanation, click Prism Lecture.

The following is a review of the theoretical foundation of research in our lab. "The function of phenomenal states: Supramodular interaction theory," Psychological Review, 112, 1000-1021. Link

Three Forms of Binding in the Brain

In short, of the three (qualitatively distinct) forms of binding in the brain, consciousness is necessary only for efference-efference binding. Conscious 'crosstalk' is not necessary for binding between perceptual features within or between modalities (afference binding as in perceptual feature binding or intersensory illusions), nor is it needed for binding between perceptual and action codes (efference binding), as when a supraliminal or subliminal stimulus elicits a button press (or when one reflexively withdraws one's hand from a painful stimulus or reflexively inhales); but it is required for integrating two conflicting streams of efference binding. Such efference-efference binding results in 'integrated actions' such as holding one's breath, carrying a hot dish of food, performing the Stroop task, suppressing socially-inappropriate behavior, or thus modulating another action plan (Morsella & Bargh, Oxford Handbook of Social Neuroscience). This kind of behavior is based on the aforementioned process of integrated action-goal selection.

Behavioral support for PRISM is listed on the Publications page (the articles in Neurocase, Emotion, Consciousness and Cognition ["Did I Read Or Did I Name?"], and Attention, Perception & Psychophysics); for relevant neuropsychological evidence see article in Neural Networks; for neuroimaging evidence, click here. In collaboration with John Bargh, Adam Gazzaley, Jeremy Gray, and Mark Geisler, we are evaluating SIT using behavioral and neuroimaging techniques. In addition, with the assistance of the neurologist Stephen Krieger and colleagues at the UCSF Memory and Aging center, we are examining the implications that SIT and the lab's research has for disorders of awareness and disorders involving action selection (e.g., frontotemporal dementia). The neural and behavioral investigations at the lab fall into three primary research lines:

Line 1: 'Pre-entry' research: Action-related determinants of what enters consciousness. Representative paradigms and topics: visual masking, refreshing, binocular rivalry, inattentional blindness, and the Sperling task.

Line 2: 'Post-entry' research, the majority of research in the lab, involving Response Interference Paradigms and Delayed Response Tasks. Representative paradigms and topics: self-control, sense of agency, and interference paradigms, such as the Stroop and flanker tasks.

Line 3: Actional components of mental representation. Representative paradigms and topics: indirect cognitive control, ideomotor processing, situated cognition, priming, motor components of semantic representation, and folk theories about action production.