Epstein, Flynn, and Martohardjono's presentation of the principal approaches to UG access in L2 acquisition is misleading; they have neglected the possibility that the L1 grammar forms the learner's initial representation of the L2, with subsequent modifications constrained by UG. Furthermore, their experimental data are open to several interpretations and are consistent with a number of different positions in the field.

We consider the various criticisms and requests for clarification made by the commentators of our framework for understanding intentional relations. Our response is organized according to the main themes in the target article: general theory, phylogeny, development, and autism. We also add some discussion of further issues, such as simulation and moral theory, that were not addressed in the target article.

The driving force in the evolution of language and the human mind was the advantage gained in courtship by efficient communicators. Ontogeny recapitulating phylogeny may offer an alternative to Donald's picture of the relative origins of language and mimesis. Very recent evidence is pertinent to dating the origin of language.

The target article advanced the null, unified and widely misinterpreted generative hypothesis regarding second language (L2) acquisition. Postulating that UG (Universal Grammar) constrains L2 knowledge growth does not entail identical developmental trajectories for L2 and first language (LI) acquisition; nor does it preclude a role for the L1. In embracing this hypothesis, we maintain a distinction between competence and performance. Those who conflate the two repeat fundamental and by no means unprecedented misconstruals of the generative enterprise, and more specifically, of the empirical content of the null hypothesis regarding L2 linguistic knowledge growth. We hope to have identified certain common goals, the adoption of which might constitute a firm foundation for continued productive interdisciplinary development of contemporary theoretical and experimental L2 acquisition research.

Loring Brace's assertion that “Neanderthals were just as capable of articulate speech as we are” reflects ignorance of speech anatomy and physiology. Metrical analyses of hyoid bone morphology cannot predict supralaryngeal vocal tract (SVT) shape. Houghton's (1993) “modern” Neanderthal SVT reconstruction yields an impossible creature who had a larynx positioned in his chest. The reconstructed modem SVTs of early fossil Homo sapiens indicate brains that can regulate speech, consistent with Merlin Donalds timetable for the evolution of language.

Jeannerod (1994) advocates studying motor images to understand the representation of action. We identify an unsettled issue that complicates the use of motor images to study the representation of action and present some evidence for a clear absence of equivalence between motor imagery and movement preparation. We then elaborate and emphasize the relevance of the mental practice literature, which was introduced in the first round of commentary. Finally, we suggest two methods that will allow motor imagery theorists to address these points.

By way of commentary on Jeannerod (1994), we propose that (1) intention, response imagery, and actual response processes carry equal weight in inferring from one process to another, (2) memory networks control intention, which interacts with imagery-based processing to control response imagery, and (3) response imagery will demonstrate learning effects better when imagery reconstruction and elaboration are emphasized and neutral retention tests are utilized.

Writing is important not because it “extends memory” but because it invites new concepts. The basic cognitive resources, including memory, have remained unchanged for perhaps a million years but the objects on which it has to work have changed significantly partly because of writing which has tended to turn speech into an object of reflection and analysis.

Jeannerod's target article and a number of commentators stressed the necessity of distinguishing between motor representation and perceptual images. A patient with a lesion of the central somatosensory pathways allowed us to test for this distinction. The outcome suggests that motor images may not be visual and that the “pragmatic” framework proposed by Jeannerod for vision can apply to other sensory modalities.

Donald presents a three-stage theory of the evolution of cognition – episodic, mimetic, symbolic. This commentary is chiefly concerned with his use of the first term “episodic” which conflicts with standard usage in the memory literature. This conflict of usage has more than terminological implications for Donald's theory.

Two issues have been raised. The first concerns whether consciousness is attached to a given type of action. It is argued that purposive actions are represented before being executed and that motor representations can either remain implicit or become explicit according to the task. The second issue concerns whether or not mental imagery of action is independent from action. Recent evidence showing the commonality of neural mechanisms for motor imagery and action, respectively, goes against the idea of independent processes.

The human vocal apparatus is part of a vertically integrated system, and I agree with Licbennan that modern high-speed phonology co-evolved with our capacity for grammar. Olson and I agree that some distinctly human thought skills appear to be fairly recent cultural acquisitions related to the introduction of new symbolic technologies and external (that is, nonbiological) memory storage. Stenning's concern with my use of the term “episodic” can be resolved by distinguishing between episodic storage and retrieval. Baum's suggestions regarding courtship and cognitive evolution seem to apply better to mimetic expression than to language.

We raise three issues concerning the Eichenbaum, Otto & Cohen (1994) model. (1) We argue against the strict division of labor that Eichenbaum et al. attribute to neocortical and limbic regions. (2) We raise the possibility that the anterior and posterior portions of the hippocampus may be important for different types of information processing. (3) We argue that, rather than reflecting relational processing, different neural responses to “match” and “nonmatch” trials may relate to different required spatial responses.

Eichenbaum et al.'s (1994a) theory suffers from a lack of ecological validation. It is not at all clear why the hypothesized faculties would have evolved and what their adaptive value would be. I argue that hippocampal function can only be understood if the animal is seen in its natural context.

Why is consciousness associated with recovery of memories that are initially dependent on the hippocampal system? A hypothesis is proposed that the medial temporal lobe/hippocampal complex (MTL/H) receives as its input only information that is consciously apprehended. By a process termed “cohesion,” the MTL/H binds into a memory trace those neural elements that mediated the conscious experience so that effectively, “consciousness” is an integral part of the memory trace. It is the phenomenological records of events (Conway 1992), integrated consciousness-content packets, that are recovered when memory traces are retrieved.

Eichenbaum et al. (1994a) hypothesized that perceptually distinct items and the relations among them are processed sequentially by the parahippocampal region and the hippocampal formation, respectively. Predictions based solely on their model's sequential-processing feature might prove easier to disconfirm than those based on its representational features. Two such predictions are discussed: (1) double dissociations should be impossible following hippocampal vs. parahippocampal lesions, and (2) hippocampal lesions should not exacerbate impairments that follow complete parahippocampal lesions.

Various apparently incompatible theories of hippocampal function have been proposed but integration is now needed. It is argued that the involvement of the hippocampus is most clearly seen when the animal needs to extrapolate beyond current sensory information. Such control can involve both the initiation of behaviour in the absence of appropriate sensory input and the inhibition of behaviour that might otherwise be triggered by current sensory input.