Lehar misrepresents the Neuron Doctrine and indirect realism. His conclusions on consciousness are unjustified. The Bubble Gestalt perceptual modeling disconnected from neuroscience has no explanatory power.

I reject Jackendoff's view of Universal Grammar as something that evolved biologically but applaud his integration of blackboard architectures. I thus recall the HEARSAY speech understanding system—the AI system that introduced the concept of “blackboard”—to provide another perspective on Jackendoff's architecture.

The advent of functional brain imaging has revolutionized the ability to understand the biological mechanisms underlying decision-making. Although it has been amply demonstrated that assumptions of rationality often break down in experimental games, there has not been an overarching theory of why this happens. I describe recent advances in functional brain imaging and suggest a framework for considering the function of the human reward system as a discrete agent.

Hurford argues that propositions of the form PREDICATE(x) represent conceptual structures that predate language and that can be explicated in terms of neural structure. I disagree, arguing that such predicates are descriptions of limited aspects of brain function, not available as representations in the brain to be exploited in the frog or monkey brain and turned into language in the human.

While the PREDICATE(x) structure requires close coordination of subject and predicate, both represented in consciousness, the cognitive (ventral), and sensorimotor (dorsal) pathways operate in parallel. Sensorimotor information is unconscious and can contradict cognitive spatial information. A more likely origin of linguistic grammar lies in the mammalian action planning process. Neurological machinery evolved for planning of action sequences becomes applied to planning communicatory sequences.

Although Colman's criticisms of orthodox game theory are convincing, his assessment of progress toward construction of an alternative is unnecessarily restrictive and pessimistic. He omits an important multidisciplinary literature grounded in human evolutionary biology, in particular the existence and function of social emotions experienced when facing some strategic choices. I end with an alternative suggestion for modifying orthodox game theory.

Byrne & Hilbert defend color realism, which assumes that: (a) colors are properties of objects; (b) these objects are physical; hence, (c) colors are physical properties. I accept (a), agree that in a certain sense (b) can be defended, but reject (c). Colors are properties of perceptual objects – which also have underlying physical properties – but they are not physical properties.

Jackendoff's major syntactic exemplar is deeply unrepresentative of most syntactic relations and operations. His treatment of language evolution is vulnerable to Occam's Razor, hypothesizing stages of dubious independence and unexplained adaptiveness, and effectively divorcing the evolution of language from other aspects of human evolution. In particular, it ignores connections between language and the massive discontinuities in human cognitive evolution.

Two issues in synapsid brain evolution are discussed: the presumed structure and function of the brain of the Synapsida/Diapsida common ancestral, and the enlargement of dorsal telencephalon. Ecological niches possibly occupied by some Carboniferous tetrapods are considered in order to speculate about evolution of major telencephalic sectors. An alternative interpretation of isocortical origins, based on differences in Pax-6 expression, is suggested for discussion.

This new heuristic model of perceptual analysis raises interesting issues but in the end falls short. Its arguments are more in the Cartesian than Gestalt tradition. Much of the argument is based on setting up theoretical straw men and ignores well known perceptual and brain science. Arguments are reviewed in light of known physiology and traditional Gestalt theory.

Many weaknesses of game theory are cured by new models that embody simple cognitive principles, while maintaining the formalism and generality that makes game theory useful. Social preference models can generate team reasoning by combining reciprocation and correlated equilibrium. Models of limited iterated thinking explain data better than equilibrium models do; and they self-repair problems of implausibility and multiplicity of equilibria.

Lehar's lively discussion builds on a critique of neural models of vision that is incorrect in its general and specific claims. He espouses a Gestalt perceptual approach rather than one consistent with the “objective neurophysiological state of the visual system” (target article, Abstract). Contemporary vision models realize his perceptual goals and also quantitatively explain neurophysiological and anatomical data.

Fossil remains witness the relationship between the appearance of the middle ear and the expansion of the brain in early mammals. Nevertheless, the lack of detachment of ear ossicles in the mammaliaform Morganucodon, despite brain enlargement, points to other factors that triggered brain expansion in early mammals. Moreover, brain expansion in some early mammalian groups seems to have favored brain regions other than the cortex.

Hurford's argument suffers from two major weaknesses. First, his account of neural mechanisms suggests no place in the brain where the two halves of a predicate-argument structure could come together. Second, his assumption that language and cognition must be based on logic is neither necessary nor particularly plausible, and leads him to some unlikely conclusions.

Byrne & Hilbert (B&H) assert that reflectances embody the reality of color, but metamerism smears the authors' “real” color categories into uselessness. B&H ignore this problem, possibly because they implicitly adopt a sort of subjectivism, whereby an object is defined by the percepts (or more generally by the measurements) it engenders. Subjectivism is unwieldy, and hence prone to such troubles.

Jackendoff's Foundations of Language: Brain, Meaning, Grammar, Evolution has many points of similarity with Skinner's analysis of verbal behavior, though the former emphasizes structure whereas the latter emphasizes function. The parallels are explored in the context of a selectionist account of behavior in general and of verbal behavior in particular. Part of the argument is that behavior drives evolution and therefore also drives brain organization. Another concerns itself with the nature of explanation. Recent experimental developments in behavior analysis are reviewed as potential contributions to an understanding of language that incorporates its functional as well as structural dimensions.

We compare Colman's proposed “psychological game theory” with the existing literature on psychological games (Geanakoplos et al. 1989), in which beliefs and intentions assume a prominent role. We also discuss experimental evidence on intentions, with a particular emphasis on reciprocal behavior, as well as recent efforts to show that such behavior is consistent with social evolution.

We argue that any theory of color physicalism must include consideration of ecological interactions. Ecological and sensorimotor contingencies resulting from relative surface motion and observer motion give rise to measurable effects on the spectrum of light reflecting from surfaces. These contingencies define invariant manifolds in a sensory-spatial space, which is the physical underpinning of all subjective color experiences.

Aspects of an example of simulated shared subjectivity can be used both to support Steven Lehar's remarks on embodied percipients and to triangulate in a novel way the so-called “hard problem” of consciousness which Lehar wishes to “sidestep,” but which, given his other contentions regarding emergent holism, raises questions about whether he has been able or willing to do so.

The origin of the isocortex may be seen as a series of gradual changes (each one with an adaptive value) from a reptilian-like cerebral cortex, as proposed by Aboitiz et al., or as a new dorsal pallium derivative in mammals which undergoes a surface expansion concomitant with the expansion of the dorsal tier of the dorsal thalamus.