According to Pylyshyn, depictive representations can be explanatory only if a certain kind of first-order isomorphism exists between the mental representations and real-world displays. What about a system with second-order isomorphism (similarities between different mental representations corresponding with similarities between different real-world displays)? Such a system may help to address whether “depictive” representations contribute to the visual nature of imagery.

Currently there is considerable interest in the notion that dorsal and ventral visual systems might differ in their specializations for thought and action. Behavior invariably involves multiple processes such as perception, judgment, and response execution. It is not clear that characteristics of the dorsal and ventral processing streams, as described by Norman, are entirely of a perceptual nature.

Most psychometricians believe that the significance test is counterproductive. I have read Chow's book to see whether it addresses or rebuts any of the key facts brought out by the psychometricians. The book is empty on this score; it is entirely irrelevant to the current debate. It presents nothing new and is riddled with errors.

Ronan Reilly's connectionist simulation both strengthens and advances the theoretical model presented in my 1991 target article, “Language, Tools, and Brain: The Ontogeny and Phylogeny of Hierarchically Organized Sequential Behavior.” Reilly has tested the whole ontogenetic model with a single simulation study explicitly planned for this purpose. His methodology has established that the various components of the theoretical model imply and are compatible with one another. It has also indicated how learning can actualize a pre-established ontogenetic sequence of combining lingusitic symbols and objects. His simulation suggests that the acquisition of linguistic speech may be facilitated by experience with object manipulation, but not vice versa. This hypothesis can and should be empirically tested through research on behavioral development in the two domains. Finally, Reilly has simulated brain architecture, as well as neural learning. His simulation therefore shows how the development of language and object manipulation can result from an interaction between preprogrammed neural architecture (analogous to network architecture) and experience (analogous to the network's training cycles).

Chow's monograph exhibits four prototypical symptoms of psychology's enduring scientific crisis: (a) it equates empirical science with statistical analysis; (b) it settles for qualitative rather than quantitative theories; (c) it ignores the role of ecological validity in the generalizability of theories; and (d) it puts rigid adherence to arbitrary but documentable rules over critical thinking about the meaning of results.

Mercier & Sperber (M&S) argue for their argumentative theory in terms of communicative abilities. Insights can be gained by extending the discussion beyond human reasoning to rodent and robot navigation. The selection of arguments and conclusions that are mutually reinforcing can be cast as a form of abductive reasoning that I argue underlies the construction of cognitive maps in navigation tasks.

NHSTP is embedded in the research of “cognitive science.” Its use is based on unstated assumptions about the practices of sampling, “operationalizing,” and using group data. NHSTP has facilitated both research and theorizing – research findings of limited interest – diverse theories that seldom complement one another. Alternative methods are available for data acquisition and analysis, and for assessing the “truth- value” of generalizations.

I argue that Perruchet & Vinter's claim that representations are conscious, and processes unconscious, gives too much ground to the cognitive unconscious; and that the boundary between conscious and unconscious mental phenomena is unlikely to fall neatly along these lines. I also propose that in the absence of more detailed models that demonstrably provide a reasonable account of the data, claims that associative mechanisms may underlie all cognition are premature.

The target article can be strengthened by supplementing it with a better theory of mental representation. Given such a theory, there is reason to suppose that, first, even the most primitive representations are mostly of distal affairs; second, the most primitive representations also turn out to be directed two ways at once, both stating facts and directing action.

Mercier and Sperber (M&S) suggest that human reasoning is reflective and has evolved to support social interaction. Cognitive agents benefit from being able to reflect on their beliefs whether they are acting alone or socially. A formal framework for argumentation that has emerged from research on artificial cognitive systems that parallels M&S's proposals may shed light on mental processes that underpin social interactions.

Sussman et al. describe an ecological property of the speech signal that is putatively functional in perception. An important issue, however, is whether their putative cue is an emerging feature or whether the second formant (F2) onset and the F2 vowel actually provide independent cues to perceptual categorization. Regardless of the outcome of this issue, an important goal of speech research is to understand how multiple cues are evaluated and integrated to achieve categorization.

The predictive validity of the ultimatum game (UG) for cross-cultural differences in real-world behavior has not yet been established. We discuss results of a recent meta-analysis (Oosterbeek et al 2004), which examined UG behavior across large-scale societies and found that the mean percent offers rejected was positively correlated with social expenditure.

The drug-reinforcement theory explains why humans get engaged in drug taking behavior. This theory posits that drugs of abuse serve as biological rewards by activating the reinforcement system. Although from a psychological and neurobiological perspective this theory is extremely helpful, it does not tell us about the drug-taking motives and motivation of an individual. The definition of drug instrumentalization goals will improve our understanding of individual drug-taking profiles.