Grush makes an important contribution to a promising way of viewing mental representation: as a component activity in sensorimotor processes. Grush shows that there need be no entities in our heads that would count as representations, but that, nevertheless, the process of representation can be defined so as to include both natural and artificial (e.g., linguistic or pictorial) representing.

Andrews et al. argue for adaptationism in cognitive research. However, the problem of evolvability brings into question the number of genes required for the evolution of cognitive mechanisms. Are there enough? Also, greater consideration should be given to alternative vicarious selection processes, which may produce cognitive mechanisms. Finally, identifying constraints with optimality arguments is more difficult than the authors think.

An important form of innovation involves use of the voice in a new way, usually to solve some environmental problem. Vocal innovation occurs in humans and other animals, including chimpanzees. The framework outlined in the target article, appropriately modified, may permit new perspectives on the use of others as tools, especially by infants, and the evolution of speech and language.

Clahsen's theory raises problems that make it seem untenable. As an alternative, a constructivist neural network model is reported that develops a modular architecture and in which a single associative mechanism produces all inflections, displaying an emergent dissociation between regular and irregular verbs. Thus, Clahsen's rejection of associative models of inflection concerns only a subgroup of these models.

Results from our laboratories show clear frequency effects for regularly inflected forms in both German and English. Moreover, there does not seem to be sufficient evidence to treat the -s plural as the default plural in German. Together, these data do not support a dual modular structure of the language faculty.

Assuming our understanding of the brain continues to advance, we will at some point have a computational theory of how access consciousness works. Block's supposed additional kind of consciousness will not appear in this theory, and continued belief in it will be difficult to sustain. Appeals to “what it's like” to experience such-and-such will carry little weight when we cannot locate a subject for whom it might be like something.

Environment can provide information used in development – information that can appear to be genetically given and that was previously assumed to be so. Examples include growth of the eye until it achieves good focus, and structuring of receptive fields in the visual cortex by environmental information. The process can be called one-generation Lamarckism because information acquired from the environment is used to structure the organism and because the capacity to acquire this information is inherited.

Andrews et al.'s analysis suffers from a series of conceptual confusions they inherit from Gould's work. Their proposal that adaptations can be distinguished from exaptations essentially by specific design criteria fails because exaptations are often maintained and secondarily adapted by natural selection and therefore, over evolutionary time, can come to have similar levels of design specificity to adaptations.

Game theory poses problems for modeling rational belief, but it does not need a new theory of rationality. Experimental results that suggest otherwise often reveal difficulties in testing game theory, rather than mistakes or paradoxes. Even though the puzzles Colman discusses show no inadequacy in the standard theory of rationality, they show that improved models of belief are needed.

Somewhat in contrast to their proposal of two separate somatosensory streams, Dijkerman & de Haan (D&dH) propose that tactile recognition involves active manual exploration, and therefore involves parietal cortex. I argue that interactions from perception for action to object recognition can be found also in vision. Furthermore, there is evidence that perception for action and perception for recognition rely on similar processing principles.

Mercier and Sperber's (M&S's) theory of reasoning cannot predict reasoning in the absence of an argumentative context. Applying the theory to hypothesis testing behavior, I propose that hypothesis testing is often motivated by determining the true inference and that reasoning models should account for utilities (affected by various motives, including the wish to convince) of reasoning outcomes.

I argue that a dynamical framing of the emulation theory of representation may be at odds with its articulation in Grush's information-processing terms. An architectural constraint implicit in the emulation theory may have consequences not envisaged in the target article. In my view, “how the emulator manages to implement the forward mapping” is pivotal with regard to whether we have an emulation theory of representation, as opposed to an emulation theory of (mere) applied forces.

The target article distinguishes between modal and amodal emulators (the former predict future sensory states from current sensory states and motor actions, the latter operate on more abstract descriptions of the environment), and motor and environment emulators (the former predict the results of one's own actions, the latter predict all changes in the environment). I question the applicability of modal emulators, and the generalization to environment emulators.

Ontogenetic factors constrain the evolution of species-typical traits. Because human infants are born “prematurely” relative to other primates, the development of handedness during infancy can reveal important ontogenetic influences on handedness that may have contributed to the evolution of the human species-typical trait of a population-level right-hand dominance.

We applaud Gintis's attempt to provide an evolutionary-based framework for the behavioral sciences, and note a number of similarities with our own recent cultural evolutionary structure for the social sciences. Gintis's proposal would be further strengthened by a greater emphasis on additional methods to evolutionary game theory, clearer empirical predictions, and a broader consideration of cultural transmission.

We applaud the spirit of MacNeilage's attempts to better explain the evolution and cortical control of speech by drawing on the vast literature in nonhuman primate neurobiology. However, he oversimplifies motor cortical fields and their known individual functions to such an extent that he undermines the value of his effort. In particular, MacNeilage has lumped together the functional characteristics across multiple mesial and lateral motor cortex fields, inadvertantly creating two hypothetical centers that simply may not exist.

The connection between selfish genes and selfish goals is not merely metaphorical. Many goals that shape contemporary cognition and behavior are psychological products of evolutionarily fundamental motivational systems and thus are phenotypic manifestations of genes. An evolutionary perspective can add depth and nuance to our understanding of “selfish goals” and their implications for human cognition and behavior.

In perception science, an alternative to focusing on individual sensory systems is to describe the environment to be perceived. We focus on the emergent dynamics of human-environment interactions as an important category of the environment to be perceived. We argue that information about such dynamics is available in subtle patterns of movement variability that, of necessity, stimulate multiple sensory systems.

Atran reifies Fodor's metaphor of modularity to create a truth-producing apparatus to generate a priori taxonomies or natural kinds that lock a tautology in place.

The foundational theme of the target article is that processes of self-deception occur in a functional context: a social one through which self-deceptive processes enhance fitness by affecting an actor's performances. One essential component of this context not addressed explicitly is that audiences should have been selected to resist, where possible, enhancements falsely bolstered by self-deception. Theoretical implications follow.