Dancing in the dark: no role for consciousness in action control

Abstract

CONSCIOUSNESS AND ACTION CONTROL It was Sigmund Freud who put the relative contributions from conscious and unconscious processes to the control of human action on the psychological agenda. Freud (1949) suggested that action control emerges from the interplay between unconscious, automatic, and reward-oriented action tendencies generated by the Id and rational, socially mediated considerations provided by the Ego. While Id processes were assumed to be inaccessible for consciousness in principle, some, but not all Ego operations were claimed to be conscious. This basic logic still provides the blueprint for our current theorizing about action control. Indeed, numerous “dual-route” models in almost all psychological and cognitiveneuroscientific research areas assume that human action emerges from the interplay between consciously inaccessible automatic action tendencies and consciously accessible top-down processes that enforce intentional action goals and social acceptability [for an overview, see Evans and Stanovich (2013)]. Interestingly, many authors associate conscious accessibility with cognitive control (Hommel, 2007). For instance, in the action-control model of Norman and Shallice (1986), automatic, stimulus-driven actions are contrasted with actions that are under “deliberate conscious control,” as if unconscious deliberate control would be inconceivable. In the same spirit, Libet (1985) has suggested that consciousness might have a “veto” that prevents unwanted actions from execution. In the following, I will argue that there is no evidence that consciousness plays a causal or decisive role in action control, so that there is no reason to believe that consciousness is necessary or useful for the control of human actions. EXECUTIVE IGNORANCE If agents would control their actions through the having of conscious experiences, they should be able to report how and based on what information they are exerting such control. However, agents know surprisingly little about their actions (Wegner, 2002). As James (1890, p. 499) put it: “we are only conversant with the outward results of our volition, and not with the hidden inner machinery of nerves and muscles which are what it primarily sets it at work”—a kind of executive ignorance (Turvey, 1977). Numerous examples show that actions can be parameterized and redirected by stimuli that the agent is unable to consciously perceive because of subliminal presentation or lesions in higher perceptual areas [e.g., Prablanc and Pelisson, 1990; for overviews, see Glover (2004); Milner and Goodale, 1995]. Agents can be easily fooled into experiencing artificial effectors as being a part of their own body (Botvinick and Cohen, 1998) and perceiving actions of other people as being carried out by themselves, or vice versa (e.g., Nielsen, 1963). But even higher-level executive-control operations can be triggered by stimuli the conscious perception of which is prevented by masking procedures [for overviews, see van Gaal et al. (2012); Kunde et al., 2012]. Among other things, this holds for the implementation of a task set (Reuss et al., 2011) and the stopping of the planned action (van Gaal et al., 2010), suggesting that executive control does not rely on consciousness. Indeed, there is widespread agreement that generating a conscious experience takes time, at least 300-500milliseconds (e.g., Libet, 2004; Dehaene et al., 2006), which would be way too slow for many everyday actions and most reactions in cognitive-psychological tasks. Hence, not only is our conscious knowledge about action control severely limited, it is also difficult to see at which point in time the application of this knowledge would be useful. One way to save a role for consciousness and action control would be to relate it to the translation of intentions into more specific action plans. Consider, for instance, the seminal study of Libet et al. (1982), who observed that the physiological indicators of action preparation preceded the agent’s conscious urge to act by hundreds of milliseconds. Even though this might be taken against a causal role of conscious experience in the online-generation of actions (Wegner, 2002), it does not rule out such a role in translating instructions into a general action plan at the beginning of the study. Indeed, several authors since Exner (1879) have considered that implementing such a plan delegates control to internal and external stimuli, which might very well operate outside of consciousness (Bargh, 1989; Hommel, 2000). And yet, this would leave a severely limited role of consciousness that is restricted to off-line control. Moreover, it has been claimed that integrating information from and across different informational maps and systems require conscious experience (Baars, 1988) and one might argue that preparatory off-line action planning involves such kind of cross-domain integration. However, recent demonstrations that neither the integration of multimodal event features (Zmigrod and Hommel, 2011) nor the integration of objects with their background (Mudrik et al., 2011) depend on consciousness do not support this possibility.