Both Block and the commentators who accepted his P versus A distinction readily recognize examples of P without A but not vice versa. As an example of A without P, Block hypothesized a “zombie,” computationally like a human but without subjectivity. This would appear to describe the disconnected right hemisphere of the split-brain subject, unless one alternatively opts for two parallel mechanisms for P?

Several issues are raised concerning the notion that a single strategy explains Fitts' law and the linear speed/accuracy trade-off. Two additional concerns are discussed: (1) distance is programmed, (2) the fact that movements produced without the aid of vision obey Fitts' law does not mean that sighted movements must be explained without regard to vision.

This commentary centres around the system of human visual attention. Although generally supportive of the position advocated in the target article, we suggest that the detailed account overestimates the capacities of active human vision. Limitations of peripheral search and saccadic accuracy are discussed in relation to the division of labour between covert and overt attentional processes.

I urge return by the lights of logic and commonsense to a dialectical tabula rasa – according to which: (1) consciousness, in the ordinary pre-analytic sense of the term, is identified with P-consciousness, and “A-consciousness” is supplanted by suitably configured terms from its Blockian definition; (2) the supposedly fallacious Searlean argument for the view that a function of P-consciousness is to allow flexible and creative cognition is enthymematic and, when charitably specified, quite formidable.

Questions about the validity of eye fixations in the blocks task as a memory indicator are discussed. Examples from reading research illustrate the influence of extraneous factors.

To cover as much as possible the various questions raised by the commentators, I have divided my Response into three major sections. In section R1, I reply to the major comments and remarks dealing with the basic hypothesis upon which the kinematic theory is built (Plamondon 1993b; 1993c; 1995a; 1995b). I focus on linearity, determinism, kinematics, and the biological significance of the model parameters. I conclude this section by showing how, from a practical point of view, the delta-lognormal law can be used to group similar data prior to proceeding with further statistical analysis. In section R2, I address the main comments and remarks dealing with the speed/accuracy tradeoffs. First, I focus on the origin of speed/accuracy tradeoffs and the effect of visual feedback. Then I clarify some terminology problems and mathematical misinterpretations prior to providing new support for the theory using the experiments and data referred to by some commentators. I devote section R3 to a generalization of the kinematic theory and to some potential applications. I first provide new explanations of some classical experiments; then I show how more complex movements can be analyzed using the delta-lognormal law. I focus on perturbed and oscillatory movements as well as on cursive script and signature analysis. I conclude this section and my Response by showing some possible applications to the study of movement learning in children as well as to the study of aging phenomena in movement control. I complete my Response by recalling some technical problems that still need further analysis. Throughout the text, I try to convince the reader that the kinematic theory provides a new window on old and new data in the field.

Block's (1995) cognitive conception of consciousness might be introduced in the service of two different projects. In one, the explanatory gap between science and folklore remains. In the other, a reductive claim is advanced, but the intuitive idea of consciousness is abandoned.

I question (1) whether Karmiloff-Smith's (1994a,r) criticisms of modularity hit the target and (2) how much better the representational redescription model is. In both cases, “the mystery of the cognitive clock” is problematic for her account.

Ballard et al.'s is a plausible and useful model. Leaving aside some unnecessary constraints, the model would probably be valid through a wider gamut of interactions between the self and the environment than the authors envision.

Although A-consciousness and P-consciousness are conceptually distinct, a refined notion of A-consciousness makes it plausible that the two are empirically inseparable. I suggest that the notion of direct availability for global control can play a central role here, and draw out some consequences.

P-Consciousness (P) is to be understood in terms of an immediate fluctuating continuum that is a presentation of raw experiential matter against which A-consciousness (A) acts to objectify, impose form or make determinate “thinkable” contents. A representationalises P but P is not itself representational, at least in terms of some concepts of “representation.” Block's arguments fall short of establishing that P is representational and, given the sort of cognitive science assumptions he is working with, he is unable to account for the aspect of phenomenal content that he thinks goes beyond “representational” content. BBS discussion reveals the need for greater analysis and justification for a representationalist thesis of P.

Ballard et al. claim that fixations bind variables to cognitive pointers. I comment on three aspects of this claim: (1) its contribution to the interpretation of indexical language; (2) empirical support for the use of very few deictic pointers; (3) nonetheless, abstract pointers cannot be taken as prototypical cognitive representations.

Representational redescription (Karmiloff-Smith 1994a; 1994) translates implicit, procedural knowledge into explicit, declarative knowledge. Explicit knowledge is an enabling condition of cognitive flexibility. The articulation and inferential integration of knowledge are important in explaining flexibility. There is an interesting connection to the availability of knowledge for verbal report, but no clear explanatory work is done by the idea of knowledge that is available to consciousness.

There are a number of elements in the representational redescription (RR) theory which elude definition, including behavioural success, implicit information, endogenous metaprocesses, and the detail of the representational levels. This commentary proposes an information processing approach to the development of cognitive flexibility – the Recursive Re-Representation (3Rs) model (Spensley 1995) – which redefines the developmental process and thereby eliminates these problematic concepts.

Block (1995t) has argued for a noncognitive and non- representational notion of phenomenal consciousness, but his putative examples of this phenomenon are conspicuous in their representational and functional properties while they do not clearly possess other phenomenal properties.

Deictic coding offers a useful model for understanding the interactions between the dorsal and ventral streams of visual processing in the cerebral cortex. By extending Ballard et al.'s ideas on teleassistance, I show how dedicated low-level visuomotor processes in the dorsal stream might be engaged for the services of high-level cognitive operations in the ventral stream.

I respond to three continuing commentaries on Beyond modularity, two concerning the representational redescription (RR) framework and its attempts to account for the growing flexibility of human intelligence, and one relating to the putative mysteries of developmental timing. I discuss misunderstandings about the RR framework as well as some of its shortcomings. I strongly reject the notion of a genetic clock and go on to argue for epigenetic outcomes in which genes and environment interact during the protracted period of postnatal brain development.

We argue that Block's charge of fallacy remains ungrounded so long as the existence of P-consciousness, as Block construes it, is independently established. This, in turn, depends on establishing the existence of “phenomenal properties” that are essentially not representational, cognitive, or functional. We argue that Block leaves this fundamental thesis unsubstantiated. We conclude by suggesting that phenomenal consciousness can be accounted for in terms of a hybrid set of representational and functional properties.

Ballard et al. model eye position as a deictic pointer for spatial perception. Evidence from research on gaze control indicates, however, that shifts in actual eye position are neither necessary nor sufficient to produce shifts in spatial perception. Deictic context is instead provided by the interaction between two deictic pointers; one representing actual eye position, and the other, intended eye position.

Ballard et al.'s principle of deictic coding as exemplified in the analysis of fixation patterns relies on a functional dichotomy between foveal and extrafoveal vision based on the well-known dependency of spatial resolution on eccentricity. Experimental evidence suggests that for processes of pattern learning and recognition such a dichotomy may be less warranted because its manifestation depends on the learning state of the observer. This finding calls for an explicit consideration of learning mechanisms within deictic coding schemes.