... there are cases in which on the basis of a temporally extended content of consciousness a unitary apprehension takes place which is spread out over a temporal interval (the so-called specious present). ... That several successive tones yield a melody is possible only in this way, that the succession of psychical processes are united "forthwith" in a common structure.

My purpose in this article is to propose an explicitly naturalized account of the experience of present nowness on the basis of two complementary sources: phenomenological analysis and cognitive neuroscience. What I mean by naturalization, and the role cognitive neuroscience plays will become clear as the paper unfolds, but the main intention is to use the consciousness of present time as a study case for the phenomenological framework presented by Depraz in this Special Issue.

Do we need light to see? I argue that the black experience of a man in a perfectly dark cave is a representation of an absence of light, not an absence of representation. There is certainly a difference between his perceptual knowledge and that of his blind companion. Only the sighted man can tell whether the cave is dark just by looking. But perhaps he is merely inferring darkness from his failure to see. To get an unambiguous answer, I switch (...) the focus from perceptual knowledge to non-epistemic seeing. My conclusion is that we see even in the limiting case of absolute darkness - regardless of whether we believe we are seeing. We see little of pratical interest. But in terms of basic information, we see about as much as we do when the lights are on. Depending on what has gone before and after, we may even see ordinary objects. (shrink)

The emulation theory of representation is developed and explored as a framework that can revealingly synthesize a wide variety of representational functions of the brain. The framework is based on constructs from control theory (forward models) and signal processing (Kalman filters). The idea is that in addition to simply engaging with the body and environment, the brain constructs neural circuits that act as models of the body and environment. During overt sensorimotor engagement, these models are driven by efference copies in (...) parallel with the body and environment, in order to provide expectations of the sensory feedback, and to enhance and process sensory information. These models can also be run off-line in order to produce imagery, estimate outcomes of different actions, and evaluate and develop motor plans. The framework is initially developed within the context of motor control, where it has been shown that inner models running in parallel with the body can reduce the effects of feedback delay problems. The same mechanisms can account for motor imagery as the off-line driving of the emulator via efference copies. The framework is extended to account for visual imagery as the off-line driving of an emulator of the motor-visual loop. I also show how such systems can provide for amodal spatial imagery. Perception, including visual perception, results from such models being used to form expectations of, and to interpret, sensory input. I close by briefly outlining other cognitive functions that might also be synthesized within this framework, including reasoning, theory of mind phenomena, and language. Key Words: efference copies; emulation theory of representation; forward models; Kalman filters; motor control; motor imagery; perception; visual imagery. (shrink)

Exclusively focused on data that are consistent with the proposed ideas, the target article misses an opportunity to review data that are inconsistent with them. Weaknesses of the emulation theory become especially evident when one tries to incorporate physiologically realistic muscle and reflex mechanisms into it. In particular, it fails to resolve the basic posture-movement controversy.

an der Universität Göttingen gehaltenen Vcwlesung über Hauptstücke aus der Phänomenologie und Theorie der Erkenntnis,l ist annähernd voll­ ständig erhalten; die Blätter des V cwlesungsmanuskripts zur Phänomenologie des inneren Zeitbewußtseins liegen verstreut in den Konvoluten F I 6 und 2 F I 8 des Husserl-Archivs zu Löwen. Allerdings fußt der Erste Teil des Erstdrucks, dessen Bezeichnung als Die Vorlesungen über das innere Zeit­ bewußtsein aus dem Jahre 1905 gleichwohl auch in vcwliegender Neuausgabe beibehalten wurde, nur zum Teil noch, und auch (...) in diesem Teil mit be­ trächtlichen Abweichungen, auf dem Text des ursprünglichen Vcwlesungs­ manuskripts des Jahres I905; und umgekehrt hat nur ein Teil des Textes des ursprünglichen Vcwlesungs-Manuskripts - mit den erwähnten Abwand­ lungen - Eingang in den Ersten Teil des Erstdrucks gefunden. Wo der Text dieses Ersten Teils des Erstdrucks dem des ursprünglichen Vcwlesungs­ manuskripts entspricht, wurde er er mit diesem verglichen, und ollensicht­ liche Irrtümer im Erstdruck wurden berichtigt; in den Textkritischen Anmer­ kungen ist dann mit dem Vermerk nach dem Ms. verbessert die Text­ fassung des Erstdrucks wiedergegeben. Ferner wurde in den Textkritischen Anmerkungen vcwliegender Neuausgabe überall der ursprüngliche und voll­ ständige· Text des Vorlesungsmanuskripts von I905 wiedergegeben, auf dessen Zusammenhang die entsprechenden Teile des Erstdrucks zurückgehen, wo dieser von ienem abweicht. Einige zum V cwlesungsmanuskript gehörige Blätter, deren Text sich iedoch nicht zusammenhängend dem übrigen einfügt, wurden im vcwliegenden Band unter B (S. 135-382) mit abgedruckt. Die 1 Vgl. oben die "Einleitung des Herausgebers", S. XIV-XVII. (shrink)

Grush has proposed a fairly comprehensive version of the idea of internal models within the framework of the emulation theory of representation. However, the formulation suffers from assumptions that render such models biologically infeasible. Here I present some problems from physiological principles of human movement production to illustrate why. Some alternative views to emulation are presented.

& Functional brain imaging offers new opportunities for the begin with single-subject (preprocessed) scan series, and study of that most pervasive of cognitive conditions, human consider the patterns of all voxels as potential multivariate consciousness. Since consciousness is attendant to so much encodings of phenomenal information. Twenty-seven subjects of human cognitive life, its study requires secondary analysis from the four studies were analyzed with multivariate of multiple experimental datasets. Here, four preprocessed methods, revealing analogues of phenomenal structures, datasets from the (...) National fMRI Data Center are considered: particularly the structures of temporality. In a second Hazeltine et al., Neural activation during response competi- interpretive approach, artificial neural networks were used tion; Ishai et al., The representation of objects in the human to detect a more explicit prediction from phenomenology, occipital and temporal cortex; Mechelli et al., The effects of namely, that present experience contains and is inflected by presentation rate during word and pseudoword reading; and past states of awareness and anticipated events. In all of 21 Postle et al., Activity in human frontal cortex associated with subjects in this analysis, nets were successfully trained to spatial working memory and saccadic behavior. The study of extract aspects of relative past and future brain states, in consciousness also draws from multiple disciplines. In this comparison with statistically similar controls. This exploratory article, the philosophical subdiscipline of phenomenology study thus concludes that the proposed methods for provides initial characterization of phenomenal structures ‘‘neurophenomenology’’ warrant further application, includ- conceptually necessary for an analysis of consciousness. These ing the exploration of individual differences, multivariate structures include phenomenal intentionality, phenomenal differences between cognitive task conditions, and explora- superposition, and experienced temporality.. (shrink)

The question of whether time is its own best representation is explored. Though there is theoretical debate between proponents of internal models and embedded cognition proponents (e.g. Brooks R 1991 Artificial Intelligence 47 139–59) concerning whether the world is its own best model, proponents of internal models are often content to let time be its own best representation. This happens via the time update of the model that simply allows the model’s state to evolve along with the state of the (...) modeled domain. I argue that this is neither necessary nor advisable. I show that this is not necessary by describing how internal modeling approaches can be generalized to schemes that explicitly represent time by maintaining trajectory estimates rather than state estimates. Though there are a variety of ways this could be done, I illustrate the proposal with a scheme that combines filtering, smoothing and prediction to maintain an estimate of the modeled domain’s trajectory over time. I show that letting time be its own representation is not advisable by showing how trajectory estimation schemes can provide accounts of temporal illusions, such as apparent motion, that pose serious difficulties for any scheme that lets time be its own representation. (shrink)

Although connectionism is advocated by its proponents as an alternative to the classical computational theory of mind, doubts persist about its _computational_ credentials. Our aim is to dispel these doubts by explaining how connectionist networks compute. We first develop a generic account of computation—no easy task, because computation, like almost every other foundational concept in cognitive science, has resisted canonical definition. We opt for a characterisation that does justice to the explanatory role of computation in cognitive science. Next we examine (...) what might be regarded as the “conventional” account of connectionist computation. We show why this account is inadequate and hence fosters the suspicion that connectionist networks aren’t genuinely computational. Lastly, we turn to the principal task of the paper: the development of a more robust portrait of connectionist computation. The basis of this portrait is an explanation of the representational capacities of connection weights, supported by an analysis of the weight configurations of a series of simulated neural networks. (shrink)

The emulation theory of representation articulated in the target article is further explained and explored in this response to commentaries. Major topics include: the irrelevance of equilibrium-point and related models of motor control to the theory; clarification of the particular sense of “representation” which the emulation theory of representation is an account of; the relation between the emulation framework and Kalman filtering; and addressing the empirical data considered to be in conflict with the emulation theory. In addition, I discuss the (...) further empirical support for the emulation theory provided by some commentators, as well as a number of suggested theoretical applications. (shrink)