The question of why helpers help is debated in the cooperative breeding literature. Recent reevaluations of inclusive fitness theory have important implications for traditional populations in which the provisioning of young occurs in the context of intergenerational transfers. These transfers link older and younger generations in an economic relationship that both minimizes the demand for help and the cost of helping.

The intriguing observation that left-cerebral dominance for vocalization is ancient, occurring in frogs, birds, and mammals, grounds Corballis's argument that the predominance of right-handedness may result from an association between manual gestures and vocalization in the evolution of language. This commentary supports the general thesis that language evolved “From hand to mouth” (Corballis 2002), while offering alternatives for some of Corballis's supporting arguments.

Leibovich et al. overlook numerous human infant studies pointing to an early emerging number sense. These studies have carefully manipulated continuous magnitudes in the context of a numerical task revealing that infants can discriminate number when extent is controlled, that infants fail to track extent cues with precision, and that infants find changes in extent less salient than numerical changes.

Pylyshyn's effort in establishing the cognitive impenetrability of early vision is welcome. However, his view about the role of attention in early vision seems to be oversimplified. The allocation of focal attention manifests its effect among multiple stages in the early vision system, it is not just confined to the input and the output levels.

Ruchkin et al. make a strong claim about the neural substrates of active information. Some qualifications on that conclusion are: (1) Long-term memories and neural substrates activated for perception of information are not the same thing; (2) humans are capable of retaining novel information in working memory, which is not long-term memory; (3) the content of working memory, a dynamically bound representation, is a quantity above and beyond the long-term memories activated, or the activity in perceptual substrates.

Carruthers considers and rejects a mixed position according to which we have interpretative access to unconscious thoughts, but introspective access to conscious ones. I argue that this is too hasty. Given a two-level view of the mind, we can, and should, accept the mixed position, and we can do so without positing additional introspective mechanisms beyond those Carruthers already recognizes.

Molday and Hsu review results from in vitro experiments, which indicate that Ca-bound calmodulin reduces the cGMP sensitivity of the cyclic nucleotide-gated channel of photoreceptor cells, and speculate about the role they might play in the recovery of the light response. We discuss results from in vivo experiments that argue against the participation of Ca-calmodulin in photorecovery.

I question whether chaotic itinerancy is anything new or different to existing research on heteroclinic cycles (cycling-chaos), and blow-out bifurcations (attractor-bubbling) that provide more detailed and better definition for nonlinear phenomena occurring in neural systems. I give a brief description of this research for comparison and expansion, and see it as an important component in dynamical models of neural activity.

Cultural evolutionary accounts of shamanism must explain the cross-cultural recurrence and variation in associated practices. We suggest that Singh's account of shamanism would be strengthened by considering the social functions of shamanism in groups. Shamanism increases social group cohesion, making it distinct from other magico-religious practices.

The unified framework for addiction (UFA) formulated by Redish et al. is a tour de force. It uniquely predicts that there should be multiple addiction syndromes and pathways – a diversity that would reflect the complexity of the mammalian brain decision system. Here I explore some of the evolutionary and developmental ramifications of UFA and derive several new avenues for research.

Generative linguistics' search for linguistic universals (1) is not comparable to the vague explanatory suggestions of the article; (2) clearly merits a more central place than linguistic typology in cognitive science; (3) is fundamentally untouched by the article's empirical arguments; (4) best explains the important facts of linguistic diversity; and (5) illuminates the dominant component of language's “biocultural” nature: biology.

Firestone & Scholl (F&S) consider the distinction between judgment and perception to be clear and intuitive. Their intuition is based on considerations about visual perception. That such a distinction is clear, or even existent, is less obvious in nonvisual modalities. Failing to distinguish between perception and judgment is therefore not a flaw in investigating top-down effects of cognition on perception, as the authors suggest. Instead, it is the result of considering the variety of human perception.

We consider the significance of high-dimensional transitory dynamics in the brain and mind. In particular, we highlight the roles of high-dimensional chaotic dynamical systems as an “adequate language” (Gelfand 1989), which should possess both explanatory and predictive power of description. We discuss the methods of description of dynamic behavior of the brain. These methods have been adopted to capture the averaged or deterministic complexity, and further to allow for discussion of a new approach to capture the complexity of the deviation from such an averaged complexity and also the complexity of interactive modes. We also give arguments in defense of our models for dynamic memory with chaotic itinerancy and Cantor coding. In addition, we discuss the reality that a model of the brain and mind should reflect.