Rendell and Whitehead argue persuasively that individual foraging specializations, if socially learned, are examples of cetacean culture. However, they discount ecological variation experienced by individuals within a population as a factor in such behavior. I suggest that ecological variation may play an important role in individual foraging specializations and describe several ecological parameters that may help us understand the high frequency of this interesting behavior in the marine habitat.

A profound problem in viewing operant learning as selection appears to be the identification of replicators. Given the lack of consensus on what constitutes the appropriate unit of analysis for behavior, there may be multiple levels at which the metaphor of selection may be usefully applied. A final difficulty: The elements of selection in the evolution of species are objects. In behavior, they are events.

Positing the importance of sensorimotor contingencies for perception is by no means denying the presence and importance of representations. Using the evidence of mirror neurons we will show the intrinsic relationship between action control and representation within the logic of forward models.

Dawson's provocative comment makes three connected points: (1) to be falsifiable, theories that assume flexible features must constrain their feature creation and mechanisms, (2) the explanatory power of such functional theories is rooted in the properties of their underlying physical mechanisms, and (3) to derive the relevant constraints of feature creation from these mechanisms, it is critical to avoid the scope slip. We will argue here that even though we agree with (1) and (2), (3) confuses two different levels of analysis of computational systems: the functional identification and the physical implementation of relevant constraints.

Cowan assumes a unitary capacity-limited attentional focus. We argue that two main problems need to be solved before this assumption can complement theoretical knowledge about human cognition. First, it needs to be clarified what exactly the nature of the elements (chunks) within the attentional focus is. Second, an elaborated process model needs to be developed and testable assumptions about the proposed capacity limitation need to be formulated.

Hull et al. argue that information and replication are both essential ingredients in any selection process. But both information and replication are found in only some selection processes, and should not be included in abstract descriptions of selection intended to help researchers discover and describe selection processes in new domains.

The evidence of high cognitive abilities in cetaceans does not stand up to close scrutiny under the standards established by laboratory researchers. This is likely to lead to a sterile debate between laboratory and field researchers unless fresh ways of taking the debate forward are found. A few suggestions as to how to do this are proposed.

O'Regan & Noë mistakenly identify visual processing with visual experience. I outline some reasons why this is a mistake, taking my data and arguments mainly from the literature on subliminal processing.

The limited capacity for unrelated things is a fact that needs to be explained by a general theory of memory, rather than being itself used as a means of explaining data. A pure storage capacity is therefore not the right assumption for memory research. Instead an explanation is needed of how capacity limitations arise from the interaction between the environment and the cognitive system. The ACT-R architecture, a theory without working memory but a long-term memory based on activation, may provide such an explanation.

Twisting definitions of a concept to serve one's purposes is rarely a fruitful exercise and the demonstration of culture is, necessarily, a two-step procedure: (1) documenting a behavioral difference between populations, (2) demonstrating that this difference has spread through the group by means of social learning. This will avoid putting the cart before the horse.

O'Regan & Noë run into some difficulty in trying to reconcile their “seeing as acting” proposal with the perception and action account of the functions of the two streams of visual projections in the primate cerebral cortex. I suggest that part of the problem is their reluctance to acknowledge that the mechanisms in the ventral stream may play a more critical role in visual awareness and qualia than mechanisms in the dorsal stream.

This commentary takes issue with the idea that replication is a “fundamental element” in natural selection. Such an assumption is based on a traditional, mechanistic view of evolution. A symbiogenetic theory of evolution offers an alternative to traditional theories, emphasizing reproduction and qualitative development rather than replication and quantitative development. The issues raised by the symbiogenetic alternative may be extended to discussions of behavioral development.

Cowan's analysis of human short-term memory (STM) and attention in terms of processing limits in the range of 4 items (or “chunks”) is discussed from the point of view of cognitive neuroscience. Although, Cowan already provides many important theoretical insights, we need to learn more about how to build further bridges between cognitive psychology and cognitive neuroscience.

Operant conditioning is not a selection process. According to Hull et al., selection processes require entities that reproduce to form lineages. However, since operant behaviors do not reproduce, operant conditioning is not a selection process.

I like Cowan's review of STM properties and especially his suggestions on the role of attention. I missed, however, a consideration of studies which provide evidence for STM properties in animals. In my commentary, I argue that such evidence can elucidate the biological basis of storage limitations, validating this view by discussing mechanisms which constrain the acquisition of serial information in songbirds.

While the evidence that cetaceans exhibit behaviours that are every bit as cultural as those recognised in chimpanzees is unequivocal, I argue that it is unlikely that either taxon has the social cognitive mechanisms required to underpin the more advanced forms of culture characteristic of humans (namely those that depend on shared meaning).

The theoretical proposal that perceptual experience be thought of as expectancies about sensorimotor contingencies, rather than as expressions of mental representations, is endorsed; examples that effectively enforce that view are discussed; and one example (of perceptual coupling) that seems to demand a mental representation, with all of the diagnostic value such a tool would have, is raised for consideration.

Cowan has written a meticulous and thought-provoking review of the literature on short-term memory. However, reflections on one area of evidence, that of working memory span, shows the extent to which the research debate can be circumscribed by choice of experimental paradigms.

Natural selection in the sense of Darwin always means physical propagation (positive case) or disappearance (negative case) of living organisms due to differential reproduction. If one concentrates on this simple materialist principle, one arrives at a much better method of discerning true selection processes from largely nonrandom processes of internal rearrangement (somatic mutations) and reorganisation (operant learning).

Culture among cetaeceans has important philosophical implications. Three receive attention here. First, these animals are more like humans than we had previously thought. Even so, we must affirm and respect their otherness. Second, only a fresh approach to research makes this kind of information available. Third, whales and dolphins should now be included with us in an extended moral community.