The adjustable pattern generator (APG) model addresses physiological detail in a manner that renders it eminently testable. However, the problem for which the APG was developed, namely, limb control, may be computationally too complex for this purpose. Instead, it is proposed that recent empirical and theoretical advances in understanding the role of the cerebellum in low-level saccadic control could be used to refine and extend the APG. [HOUK et al.]

Kinematic properties of reaching movements reflect constraints imposed on the joint angles. Contemporary models present solutions to the redundancy problem by a pseudoinverse procedure (Whitney 1969) or without any inversion (Berkenblit et al. 1986). Feldman & Levin suggest a procedure based on a regular inversion. These procedures are considered as an outcome of a more general approach.

Dunbar (1993) emphasizes the role of cooperative language use in the evolution of human linguistic capacity and neglects to consider the role that manipulative language use would have played. I argue that as group size and neocortieal size increased during human evolution, the adaptive value of using language to benefit oneself at the expense of others would also have increased. I discuss how selection pressures for manipulative language use would have operated in the contexts of mating, status striving, and social exchange.

The current conception of the relation between UG and the grammar of a language rules out the no-access hypothesis, but does not distinguish between the full-access and partial-access hypotheses. The former raises the issue of why language acquisition in child and adult should be so different. The evidence presented in Epstein et al.'s target article seems inconclusive regarding a choice between hypotheses.

Gray takes an information-processing paradigm as his departure point, invoking a comparator as part of the system. He concludes that consciousness is to be found “in” the comparator but is unable to point to how the comparison takes place. Thus, the comparator turns out not to be an entity arising out of brain research per se, but out of the logic of the paradigm. In this way, Gray both reinvents dualism and remains trapped in the language game of his own model – ending up dealing with the unknowable.

The work of Sinden et al. suggests that it may be possible to produce improvement in the “highest” areas of brain function by transplanting brain tissue. What appears to be the limiting factor is not the complexity of the mental process under consideration but the discreteness of the lesion which causes the impairment and the appropriateness and accuracy of placement of the grafted tissue.