Creating an integrated design space can be successful only if researchers agree on how to define and measure a certain phenomenon of interest. Adversarial collaborations and mathematical modeling can aid in reaching the necessary level of agreement when researchers depart from different theoretical perspectives.

According to Unconscious Thought Theory (UTT: Dijksterhuis & Nordgren, 2006), complex decisions are best made after a period of distraction assumed to elicit “unconscious thought”. Over three studies, respectively offering a conceptual, an identical and a methodologically improved replication of Dijksterhuis et al. (2006), we reassessed UTT’s predictions and dissected the decision task used to demonstrate these predictions. We failed to find any evidence for the benefits of unconscious decision-making. By contrast, we found some evidence that conscious deliberation can lead to better decisions. Further, we identified methodological weaknesses in the UTT decision task: (a) attributes weighting was neglected although attributes were seen as different in importance; (b) the material was not properly counterbalanced; and (c) there was some confusion in the experimental instructions. We propose methodological improvements that address these concerns.

The unconscious-thought effect occurs when distraction improves complex decision making. Recent studies suggest that this effect is more likely to occur with low- than high-demanding distraction tasks. We discuss implications of these findings for Newell & Shanks' (N&S's) claim that evidence is lacking for the intervention of unconscious processes in complex decision making.

Walker proposes that procedural memory formation involves two specific stages of consolidation: wake-dependent stabilization, followed by sleep-dependent enhancement. If sleep-based enhancement of procedural memory formation is now well supported by evidence obtained at different levels of cognitive and neurophysiological organization, wake-dependent mechanisms for stabilization have not been demonstrated as convincingly, and still require more systematic characterization.

In general, we agree with Pothos's claim that similarity and rule knowledge are best viewed as situated on the extreme points of a single representational continuum. However, we contend that a distinction can be made between “rule-like” and “rule-based” knowledge: Rule-based, symbolic knowledge is necessarily conscious when it is applied. Awareness thus provides a useful criterion for distinguishing between sensitivity to functional similarity and knowledge of symbolic rules.

Perruchet and Vinter stop short of fully embracing the implications of their own SOC framework, and hence end up defending an implausible perspective on consciousness. We suggest instead that consciousness should be viewed as a graded dimension defined over quality of representation. This graded perspective eliminates the most problematic aspects of the cognitive unconscious without denying its existence altogether.

Dienes & Perner's target article is not a satisfactory theory of implicit knowledge because in endorsing the representational theory of knowledge, the authors also inadvertently accept that only explicit knowledge can be causally efficacious, and hence that implicit knowledge is an inert category. This conflation between causal efficacy, knowledge, and explicitness is made clear through the authors' strategy, which consists of attributing any observable effect to the existence of representations that are as minimally explicit as needed to account for behavior. In contrast, we believe that causally efficacious and fully implicit knowledge exists, and is best embodied in frameworks that depart radically from classical assumptions.

Stability of activation, while it may be necessary for information to become available to consciousness, is not sufficient to produce phenomenal experience. We suggest that consciousness involves access to information and that access makes information symbolic. From this perspective, implicit representations exist, and are best thought of as subsymbolic. Crucially, such representations can be causally efficacious in the absence of consciousness.

The constructivist notion that features are purely functional is incompatible with the classical computational metaphor of mind. I suggest that the discontent expressed by Schyns, Goldstone & Thibaut about fixed-features theories of categorization reflects the growing impact of connectionism. Their perspective is similar to recent research on implicit learning, consciousness, and development. A hard problem remains, however: how to bridge the gap between subsymbolic and symbolic cognition.