With some help from the commentators, a few adjustments to the characterizations of A-consciousness and P-consciousness can avoid some trivial cases of one without the other. But it still seems that the case for the existence of P without A is stronger than that for A without P. If indeed there can be P without A, but not A without P, this would be a remarkable result that would need explanation.

Some cases of prosopagnosia involve a highly circumscribed loss of A-consciousness. When seen in this way they offer further support for the arguments made in Block's target article.

In Feeling of Knowing cases, subjects have a form of consciousness about the presence of a content (such as an item of information) without having access to it. If this phenomenon can be correctly interpreted as having to do with consciousness, then there would be a P-conscious mental experience which is dissociated from access.

Blocks distinction between “phenomenal feel” consciousness and “thought/cognition” consciousness is a cultural construction. Consciousness (and its “subspecies”) is not a natural kind. Some crosscultural data are presented to support this.

If phenomenal consciousness is distinct from the computationally based access-consciousness that controls overt behavior, how can I tell which things (other than myself) enjoy phenomenal consciousness? And if phenomenal consciousness 'plays no role in controlling overt behavior, how do human bodies come to write target articles arguing for the existence of phenomenal consciousness?

It is argued that there is no fallacy in the reasoning in the example of the thirsty blindsight subject, on one reconstruction of that reasoning. Neither the case of orgasm nor the case of a visual versus an auditory experience as of something overheard shows that phenomenal content is not representational.

Block has attempted to reduce the confusion and controversy concerning the term “consciousness” by suggesting that there are two forms or types of consciousness, each of which has several characteristics or properties. This suggestion appears to further becloud the topic, however. Perhaps consciousness cannot be defined adequately and should not be considered as a topic that can be studied scientifically.

In response to the objection that his “access-consciousness” is not really consciousness but a matter of the availability of certain information for certain kinds of processing, Block will probably have to argue that consciousness in a more basic, familiar, traditional sense is an essential component of any instance of access-consciousness and thus justifies the name.

A-consciousness may be regarded as the visibility of information that is the output of a process within a community of other processes. The most prominent function of “public” dissemination of information is giving access to it to processes whose relevance is not clear at the moment of dissemination. The function of P-consciousness may be outside the realm of cognition.

I criticize Block's examples of P-consciousness and A-consciousness for being flawed and the notion of A-consciousness for not being a notion of consciousness at all. I argue that an empirically important distinction can be made between behavior that is supported by an underlying conscious experience and behavior that is brought about by nonconscious action-control mechanisms. This distinction is different from that made by Block.

Block's P-/A-consciousness distinction rules out P's involving a specific kind of cognitive access and commits him to a “strong” Pconsciousness. This not only confounds plausible research in the area but betrays an anosognosia about Wittgenstein's diagnosis about our philosophical “introspection” of mysterious inner processes.

Block's cases of superblindsight, the pneumatic drill, and the Sperling experiments do not show that P-consciousness and Aconsciousness can come apart. On certain tendentious but not implausible construals of the concepts of P- and A-consciousness, they refer to the same psychological phenomenon.

Basically agreeing with Block regarding the need for a distinction between P- and A-consciousness, I characterize the problem somewhat diflerently, relating it more directly to the explanatory gap. I also speculate on the relation between the two forms of consciousness, arguing that some notion of access is essentially involved in phenomenal experience.

The information processing that constitutes accessconsciousness is not sufficient to make a representational state conscious in any sense. Standard examples of computation without consciousness undermine A-consciousness, and Block's cases seem to derive their plausibility from a lurking phenomenal awareness. That is, people and other minded systems seem to have access-consciousness only insofar as the state accessed is a phenomenal one, or the state resulting from access is phenomenal, or both.

Block contends that the concept of consciousness is a mongrel concept and that researchers go astray by conflating different notions of “consciousness.” This is certainly true. In fact, it is truer than Block acknowledges, because his own notion of P-consciousness runs together two, or arguably three, quite different and separable features of a sensory state.

In common sense consciousness has a fairly determinate content – the (single) way an experience feels, the (single) line of thought being consciously followed. The determinacy of the object may be achieved by linking Block's two concepts, so that as long as we hold on to the determinacy of content we are unable to separate P and A.

One can share Block's aim of distinguishing “phenomenal” experience from cognitive function and agree with much in his views, yet hold that the inclusion of representational content within phenomenal content, if only in certain spatial cases, obscures this distinction. It may also exclude some modular theories, although it is interestingly suggestive of what may be the limits of the phenomenal penetration of the representational mind.

This commentary offers two criticisms of Block's account of phenomenal consciousness and a brief sketch of a rival account. The negative points are that monitoring consciousness also involves the possession of certain states and that phenomenal consciousness inevitably involves some sort of monitoring. My positive suggestion is that “phenomenal consciousness” may refer to our ability to monitor the rich but preconceptual states that retain perceptual information for complex processing.

Although not the main point of his target article, Block defends the view that perception and awareness of perception could be functions of different brain systems. I will argue that the available data do not support this view, and that Block's defense of the view rests on problematic eonstruals of the “executive system” and of the components of information-processing models.

Should we distinguish between access and phenomenal consciousness? Block says yes and that various pathologies of consciousness support and clarify the distinction. The commentary charge that the distinction is neither supported nor clarified by the clinical data. It recommends an alternative reading of the data and urges Block to clarify the distinction.

A “fallacy” is something like the sense-datum fallacy, involving a logically invalid argument. A “conflation” is something like Block's conflation of the (alleged) raw feel of an experience with what it is like to have the experience. Trivially, a self is conscious of something only if it accesses it. Substantive issues concern the nature of the conscious self and the nature of access.

Block's notion of P-consciousness catches too much in its net. He would do better to exclude all states that do not have a sensory component. I question what he says about my work with the “blind” monkey, Helen.

Additional experiments show that P-consciousness and A consciousness can be empirically dissociated for the theoretically so phisticated observer. Phenomenal consciousness can have several degrees that are indirectly measurable.

Propositions as to the nature of consciousness, based on disorders of perception that result from brain damage, and taking insufficient account of the numerous ways in which normal subjects may deviate from that “usual” sequence of events (input → subjective awareness → output) risk increasing rather than diminishing any existing confusion about the function of consciousness.

Block's distinction between phenomenal and access consciousness is accepted, and it is agreed that one may be found without the other, but his account of the distinction is challenged. Phenomenal consciousness is perceptual consciousness, and it is a matter of gaining information of a detailed, nonverbal sort about the subject's body and environment. Access consciousness is good, old-fashioned introspection.

Block seems to propose untested answers to empirical questions. Whether consciousness is a “mongrel problem,” rather than a single core fact with many facets, is an empirical issue. Likewise, the intimate relationship between personal consciousness and global access functions cannot be decided pretheoretically. This point is demonstrated by the reader's private experience of foveal versus parafoveal vision, and for conscious versus unconscious representation of the many meanings of common words.

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. (shrink)

The most compelling evidence for Epstein et al.'s central thesis that adult second language acquisition is constrained by the innate cognitive structures that constrain native language acquisition would be evidence of poverty of the stimulus. Although there are studies that point to such evidence, Epstein et al.'s primary form of argumentation, targetlike performance by second-language acquiring adults, is much less convincing.

This commentary addresses two pervasive misconceptions which emerge in Epstein et al.'s target article: (1) that study of second language acquisition (SLA) began in the mid-twentieth century; (2) that SLA has only recently become able to contribute to linguistic theory. There is abundant historical counterevidence; I argue that (1) and (2) obscure the legitimacy of Epstein et al.'s “full access” hypothesis.

This target article is mostly a presentation of experimental research devoted to the larger issue of the role of Universal Grammar in second language learning. Deliberately excluding the aspects of human cognition that makes second language (L2) so variant, Epstein et al. focus on what the learners may know and how they come to know it. This is the aspect of Epstein et al.'s work which is more limiting, and potentially more interesting.

Our results support the idea that adults have access to the principles and parameters of Universal Grammar (UG), contrary to Epstein et al.'s misrepresentation of our work as involvingpartial access toUG. For both LI and L2 acquisition, functional projections appear to develop in a gradual fashion, but in L2 acquisition there ispartial transferin that the lowest projection (VP) is transferred from the speaker's LI.

Epstein et al.'s theory of SLA is heavily dependent on assumptions about both the nature of the acquisition device and the grammar that it produces. This commentary briefly explores the consequences of an alternative set of assumptions, focusing on the possibility that the acquisition device does not include UG and that syntactic representations do not contain functional projections.

The range of hypotheses considered is surprising in that the most arguably plausible one is not included: the invariant principles of language are available for life, while the parameters of variation cannot be set after puberty. This hypothesis provides a better explanation than the author's for both the deep similarities and the vast differences between child “language growth” and adult language acquisition.

Curiously, two central areas are unaddressed by Epstein et al.: (i) L1A–L2A differences; (ii) L2 development. Here, findings relevant to (i) and (ii) – as well as their significance – are discussed. Together these form the basis for contesting Epstein et al.'s “Full Access” approach, but nonetheless analyses of the L2 data argue for UG-constrained L2A. Also discussed is the inadequacy of accounts (like Epstein et al.'s) without an explicit and prominent role for the L1.

The role of metalinguistic ability in L2 development is seriously underestimated. It may be seen both (1) as a means of initiating or boosting the flow of primary linguistic data and (2) as a generator of substitute knowledge (derived, but epistemologically distinct from domain-specific knowledge) that may compete with or compensate for perceived gaps in the learners current underlying competence. It cannot serve as a simple means of distinguishing the rival theoretical positions.

Epstein et al.'s “full access to Universal Grammar” position is conceptually and empirically problematic. Its shortcomings are illustrated through a brief discussion of the following issues: (1) initial versus final states of grammatical knowledge in a second language, (2) knowledge of gradience of grainmaticality, (3) optionality and retention in non-native grammars, and (4) the empirical measurement of syntactic knowledge.

L2 learners may access UG principles because these are realized in all natural languages. Since this is not the case for the parametrized aspects of language, parameter setting may be progressively replaced by restructuring mechanisms which are specifically related to the process of representational redescription because L2 learners are not sensitive to the [±] features which define parameters.

Epstein et al. take as given that, (1) a hypothetical Universal Grammar (UG) exists that allows children effortlessly to acquire their first language; they then argue (2) that critical or sensitive periods do not block the UG from second language acquisition. Therefore, why can't we all effortlessly “acquire” Tibetan in six months or so? Data concerning the neural bases of language are also noted.

Epstein et al. attribute second language learning to the forces of transfer and language universals. They show that transfer is minimally involved in certain types of learning and therefore conclude that universals are involved. However, they forget to consider the important role of learning in second language acquisition.

If Epstein et al. are right that adult second language learners have full access to UG, then all of the following should be true: adults should be able to consciously transform their I-Language; adults should be able to transform pidgins into Creoles; adults should be as likely as children to restructure their grammars on the basis of “functional” pressure. All the foregoing are false, however, which seriously calls into question the correctness of their hypothesis.

This commentary focuses on whether the full set of categories is available to beginning L2 learners. After critiquing Epstein et al.'s experimental evidence for the presence of functional categories, I outline the results of an experiment involving English speakers learning Japanese as a second language that does indeed point toward the early presence of fuuctional categories.