Libet's (2000) arguments in defense of his interpretation of his experimental results are insufficient. The claims of my critical review (Gomes, 2008) do not suffer with his new statements.

The major findings by Libet et al. are briefly summarized. The criticisms and alternative proposals by Trevena and Miller, Pockett, and Gomes are analyzed and found to be largely unwarranted.

An object in continuous motion is perceived ahead of the briefly flashed object, although the two images are physically aligned , the phenomenon called flash-lag effect. Flash-lag effects have been found also with other continuously changing features such as color, pattern entropy, and brightness as well as with streamed pre- and post-target input without any change of the feature values of streaming items in feature space . We interpret all instances of the flash-lag as a consequence of a more fundamental (...) property of conscious perception in general: acceleration of the speed with which samples of perceptual information become represented in explicit format immediately after the stimulation onset. Decreased visual latency of the samples of stimulus information from the streamed input leads to the relative perceptual lag for the separately flashed stimulus because it is not preceded by adjacent sensory input that would have accelerated its perception. Experimental support for the notion of perceptual acceleration is reviewed. (shrink)

This issue of Consciousness and Cognition presents four target articles and eight commentaries on the target articles. The present article presents comments on those commentaries, grouped into backward referral and volition categories. Regarding backward referral: I disagree with my fellow commentators and take the unpopular position of defending Libet's notion of backward referral. I join my fellow commentators in critiquing Libet's notion of a 500-ms delay. I examine several of the hypotheses suggested by other commentators for why cortical and lateral (...) meniscus stimulation give very different timing results. I suggest a simple experiment to help discriminate among the hypotheses. I comment on why temporal reordering is more likely to occur late rather than early in mental processing. Regarding Libet's volition experiments, I ask what is the root of the controversy, given the general agreement on the data. I agree with a commentator that Libet's chronotheology rather than his chronoscience is the cause of much of the controversy. Rather than joining others in criticizing Libet for his chronotheology I point out that he is making a respectable philosophical point regarding nondeterministic Free Will, but one that is easily misunderstood. I discuss two ways by which Libet's viewpoint can be brought into mainstream science. (shrink)

Principles of design composition are commonly understood to pertain to geometrical systems for arranging parts in assembling a formal whole. Connection to socio-cultural 'meaning' and relevance arguably occurs primarily via the assumed divinity or universality of these systems. In the contemporary architectural world, where explicitly held beliefs in fundamental, geometrically defined principles or values have dissipated, guiding principles of composition appear to be obsolete. This seems particularly true in relation to work that highlights process - or change, responsiveness, interactivity and (...) adaptability - since this implies that the composition remains in flux and unable to be grounded in the composition of form. While processually inflected architecture (referred to here as 'processual architecture'), has been an active field since at least the 1960s, it has been significa ntly developed since design experiments involving digital computation intensified in the 1990s. For this field of work, both highly celebrated and criticised as superficial or unethical, any connection to 'meaning' or value that might be offered by principles of composition would appear especially lost. This thesis reviews, counterpoises and reorients these assumptions, arguing a case for the value of processual architectural that has not been previously articulated. After the last 10 to 15 years of digital experimentation, it is clear that digital technology in itself is not the primary issue, but simply part of a complex equation. The thesis articulates this 'equation' through the model of emergence, which has been used in the field with increasing prominence in recent years. Through both practice-based research and theoretical development, a processually inflected theory of composition is proposed. This offers pathways through which the potential of processual architecture might be productively developed, aiming to open this field of work into a deeper engagement with pressing contemporary socio-political issues. The thesis demonstrates how the cultivation of particular modes of attention and engagement, found to hold an implicit but nevertheless amplified significance within processual architecture, make it possible to develop an embodied awareness pertaining to an 'ethico-aesthetic know-how'. This know-how is acquired and matured through attention to the affective dimensions that arise through design activity. The thesis highlight aspects of design process and products that are routinely suppressed in architectural discourse, generating new insights into the importance of affect for design process, design products and the relations between them. The ethical dimensions of such an approach become especially poignant through the explicit connection made between design activity and the practices of everyday life. Relationships between architecture and the social become re-energised, in a radically alternative manner to the social agendas of modernism or the more literary critiques of post-modernism. Through detailed discussions of the specific, local conditions with a series of design projects I have undertaken, I argue how and why close attention to the affective dimensions of design process offers new and productive ways to approach research through design practice. This offers a response to the calls for new 'post-critical' forms of research through empowering both sides of a previously held divide: theory and practice. (shrink)

Trevena and Miller provide further evidence that readiness potentials occur in the brain prior to the time that participants claim to have initiated a voluntary movement, a contention originally forwarded by Libet, Gleason, Wright, and Pearl . In their examination of this issue, though, aspects of their data lead them to question whether their measurement of the initiation of a voluntary movement was accurate. The current article addresses this concern by providing a direct analysis of biases in this task. This (...) was done by asking participants to make subjective timing decisions regarding a stimulus that could be measured objectively. Our findings suggest that their timing task was indeed biased such that participants' tend to report events as happening approximately 70 ms later than they actually happened. Implications for the original Libet et al. claims are discussed. (shrink)

The conclusions drawn by Benjamin Libet from his work with collegues on the timing of somatosensorial conscious experiences has met with a lot of praise and criticism. In this issue we find three examples of the latter. Here I attempt to place the divide between the two opponent camps in a broader perspective by analyzing the question of the relation between physical timing, neural timing, and experiential timing. The nervous system does a sophisticated job of recombining and recoding messages from (...) the sensorial surfaces and if these processes are slighted in a theory, it might become necessary to postulate weird operations, including subjective back-referral. Neuroscientifically inspired theories are of necessity still based on guesses, extrapolations, and philosophically dubious manners of speech. They often assume some neural correlate of consciousness as a part of the nervous system that transforms neural activity in reportable experiences. The majority of neuroscientists appear to assume that the NCC can compare and bind activity patterns only if they arrive simultaneously at the NCC. This leads to a search for synchrony or to theories in terms of the compensation of differences in neural delays . This is the main dimension of the Libet discussion. Examples from vision research, such as “temporal-binding-by-synchrony” and the “flash-lag” effect, are then used to illustrate these reasoning patterns in more detail. Alternatively one could assume symbolic representations of time and space that are not coded in their own dimension . Unless such tags are multiplexed with the quality message , one gets a binding problem for tags. One of the hidden aspects of the discussion between Libet and opponents appears to be the following. Is the NCC smarter than the rest of the nervous system, so that it can solve the problems of local sign and timing on its own, or are these pieces of information coded symbolically early on in the system? A supersmart NCC appears to be the assumption of Libet's camp . The wish to distribute the smartness evenly across all stages of processing in the nervous system appears to motivate the opponents. I argue that there are reasons to side with the latter group. (shrink)