Representational redescription (Karmiloff-Smith 1994a; 1994) translates implicit, procedural knowledge into explicit, declarative knowledge. Explicit knowledge is an enabling condition of cognitive flexibility. The articulation and inferential integration of knowledge are important in explaining flexibility. There is an interesting connection to the availability of knowledge for verbal report, but no clear explanatory work is done by the idea of knowledge that is available to consciousness.

The cognitive impairments shown by brain-damaged patients emphasize the role of task difficulty as a major determinant for performance. We discuss the proposal of Kurzban et al. in light of our findings on right-hemisphere–damaged patients, who show increasing awareness deficits for the contralesional hemispace when engaged with resource-consuming dual tasks. This phenomenon is readily explained by the assumption of unspecific depletable resources.

Shors & Matzel provide compelling arguments against a role for hippocampal long-term potentiation (LTP) in mammalian learning and memory. As an alternative, they suggest that LTP is an arousal mechanism. I will argue that this view is not a satisfactory alternative to current conceptions of LTP function.

Contra Shepard we argue, first, that his presentation of a three-dimensional representational (psychological or phenomenal) colour space is at odds with many results in colour science, and, second, that there is insufficient evidence for Shepard's stronger claim that the three-dimensionality of colour perception has resulted from natural selection, moulded by the particulars of the solar spectrum and its variations. [Shepard]

Current evidence shows that “talent” is an unreliable concept, but the competing concept of “expertise” suffers from inadequacies too: its research designs are structurally incomplete (talent and training are confounded) and individual factors are largely ignored. The deliberate practice account should be advanced by investigating in more detail the motivational and individual determinants of successful practice.

Norman's aim to reconcile two longstanding and seemingly opposed philosophies of perception, the constructivist and the ecological, by casting them as approaches to complementary subsystems within the visual brain is laudable. Unfortunately, Norman overreaches in attempting to equate direct perception with dorsal/unconscious visual processing and indirect perception with ventral/conscious visual processing. Even a cursory review suggests that the functional and neural segregation of direct and indirect perception is not as clear as the target article would suggest.

In the first year of life, infants' utterances change from high-intensity crying to low-intensity acoustic sound strings, acoustically labelling the first word. This transition implies: (1) decoding of phonetic sounds, (2) encoding of phonetic sounds, and (3) a unique linking of an articulated sound to a specific object. Comparative, ontogenetic, and phylogenetic aspects are considered for multilevel selective pressures.

The authors reject a computationally powerful unconscious. Instead, they suggest that simple unconscious processes give rise to complex conscious representations. We discuss evidence showing contrastive effects of conscious and unconscious processes, suggesting a distinction between these types of processes. In our view, conscious processes often serve to correct or control negative consequences of relatively simple unconscious processes.

To fully understand teaching, we need to know how it develops ontogenetically. Developmental questions about the emergence of different types of teaching behaviour in young humans and the psychological capabilities that underpin them are currently overlooked. Incorporating the individual's development from learner to teacher would expand the scope and impact of Kline's useful framework.

Shared knowledge of intentionality as well as shared knowledge of anything depends on the organism's understanding of itself, others, and the possible relations between self and other. This understanding involves mental representations of me, which emerges in the second half of the second year in the human infant, and it is this ability that gives rise to humanlike social understanding and complex self-conscious emotions.

We raise and discuss two issues for clarification. First, over what timescale is cultural group selection proposed to have been active? Unprecedented cooperation is inferred to have arisen in hunter-gather life well before the recent period on which Richerson et al. focus. Second, what is the unit of selection? Groups (of human individuals)? Or cultural entities along the lines of “meme-complexes”?

We ask what cerebellum and basal ganglia “do,” arguing that cerebellum tunes motor schemas and their coordination. We argue for a synthesis of models addressing the real-time role and error signaling roles of climbing fibers. “Synthetic PET” bridges between regional and neuro-physiological studies, while “synaptie eligibility” relates the neurochemis-try of learning to neural and behavioral levels. [CRÉPEL et al.; HOUK et al.; KANO; LINDEN; SIMPSON et al.; SMITH; THACH; VINCENT]