Neural circuits linking local operations in the cortex and the basal ganglia confer reiterative capacities, expressed in seemingly unrelated human traits such as speech, syntax, adaptive actions to changing circumstances, dancing, and music. Reiteration allows the formation of a potentially unbounded number of sentences from a finite set of syntactic processes, obviating the need for the hypothetical “Narrow Faculty of Language.”

The idea that dreams function as fright-simulations rests on the adaptionist notion that anything that has form has function, and psychological argument relies on the mentalist assumption that dream reports are accurate reports of experienced events. Neither assumption seems adequately supported by the evidence presented.

[Revonsuo]

There are two sorts of scientists: Dionysians, who rely on intuition, and Apollonians, who are more systematic. Self-experimentation is a Dionysian approach that is likely to open new lines of research. Unfortunately, the Dionysian approach does not allow one to predict the results of experiments. That is one reason why self-experimentation is not popular among granting agencies.

This excellent outline of evolutionary hypotheses is compromised by severe reductionism. Other writings succeed in granting theism ontological significance without compromising rigor. The discussion of counterintuitiveness neglects coherence in memory. Bearing in mind our severely limited working memory capacity, susceptibility to religious mythologies may comprise an adaptive heuristic approach to summarizing the contingencies of the most far-reaching of life's problems.

Overall mean performance on intelligence tests by brain-damaged patients with focal lesions can be misleading in regard to localization of intelligence. The widely used WAIS has many subtests that together recruit spatially distant neural “centers,” but individually the subtests reveal localized functions. Moreover, there are kinds of intelligence that defy the localizationist approach inferred from brain damage.

Collerton et al. postulate that in a variety of different clinical conditions, hallucinations are derived from object schema lodged in long-term memory. I review two new experiments in which memory images can be easily triggered in neurologically intact subjects. These examples of making visible items in memory may provide experimental models for genesis of hallucinations.

A radical interpretation of the predictive coding approach suggests that the mind is “seamless” – that is, that cancellation of error signals can propagate smoothly from highest to lowest levels of the control hierarchy, dissolving a distinction between belief and perception. Delusions of alien control provide a test case. Close examination suggests that while they are evidence of predictive coding within the cortex, they are not evidence for the seamless interpretation.

Lewis has missed an excellent opportunity to concisely demonstrate that a dynamical system can provide a bridge between emotion theory and neurobiology.

The target article issues a stirring call for more appropriate treatment of chimpanzees in experimental laboratories. This commentary heartily endorses that position with examples of methods and results found in sign language studies of cross-fostered chimpanzees.

Shors & Matzel provide compelling arguments against a role for hippocampal long-term potentiation (LTP) in mammalian learning and memory. As an alternative, they suggest that LTP is an arousal mechanism. I will argue that this view is not a satisfactory alternative to current conceptions of LTP function.

In recent years, explanations of primate cognition highlighted clever arguments, rather than different ability. In the target article, definitions unify, explanations rely on basic nervous system functioning, theory is built on data that fit, and the emphasis is on evolutionary continuities. This commentary describes complexities inherent in the development of empathy that are not accounted for in Preston & de Waal's theory.

Contra Shepard we argue, first, that his presentation of a three-dimensional representational (psychological or phenomenal) colour space is at odds with many results in colour science, and, second, that there is insufficient evidence for Shepard's stronger claim that the three-dimensionality of colour perception has resulted from natural selection, moulded by the particulars of the solar spectrum and its variations. [Shepard]

Norman's aim to reconcile two longstanding and seemingly opposed philosophies of perception, the constructivist and the ecological, by casting them as approaches to complementary subsystems within the visual brain is laudable. Unfortunately, Norman overreaches in attempting to equate direct perception with dorsal/unconscious visual processing and indirect perception with ventral/conscious visual processing. Even a cursory review suggests that the functional and neural segregation of direct and indirect perception is not as clear as the target article would suggest.