Institut Jean-Nicod. Pavillon Jardin, Ecole normale supérieure, 29, rue d’Ulm 75005 Paris.
Friday 16 May
10:00-11:15 Ian Phillips (St. Anne’s College, Oxford),
Block on Unconscious Seeing
Block (2012: 11-12) argues that conscious and unconscious seeing are of the same fundamental kind, and that this is a substantial, not merely verbal, issue. As well as noting considerations adduced by Burge (2010), Block contends, ‘One kind of dramatic evidence that conscious and unconscious seeing is of the same kind involves cases in which a single perceptual state involves integration of both conscious and unconscious elements.’ I explain why the relevant studies of neglect patients (Ro and Rafal 1996, Vuilleumier and Landis 1998) do not provide compelling evidence for the same fundamental kind claim. I further argue that the same is true of work on priming in neglect (e.g. Marshall and Halligan 1988, McGlinchey-Berroth et al. 1993). I then pose a more general dilemma which faces any empirically-based argument for the same fundamental kind claim, a dilemma which is especially stark if (like Block) we abjure access constraints on phenomenal consciousness. I note in closing a doubt about even the conceptual gap between consciousness and seeing.
11:15 Coffee break
11:45-13:00 Tim Bayne (University of Manchester, Manchester)
In introducing the notions of phenomenal consciousness and access consciousness, Block described sensations as the paradigms of phenomenal consciousness and thoughts as theparadigms of access consciousness. However, he left open the question of whether thoughts are indeed phenomenally conscious, and the related question of what the phenomenal consciousness of thought might consist in. In this paper I employ the debate about the nature of conscious thought as a lens through which to examine questions about the nature of phenomenal consciousness, access consciousness, and cognitive accessibility.
14:30-15:45 Catherine Tallon-Baudry (LNC, ENS, Paris)
Toward a biological explanation of subjective experience?
Conscious vision is accompanied by both enhanced cognitive abilities and a subjective experience. I will present here experimental evidence revealing that those two aspects of consciousness can be dissociated both at the neural and behavioral levels. I will propose that the first person perspective necessary for subjective experience is linked to a self-centered referential, based on physiological monitoring processes, and show that experimentally, fluctuations in neural responses to heartbeats before stimulus onset predict fluctuations in visual consciousness.
16:15-17:30 David Carmel, (University of Edinburgh)
Attentional attractors and visual awareness
The relationship between attention and awareness is hotly debated. In particular, a current controversy revolves around whether attention is a condition (either necessary or sufficient) for conscious experience. In this talk I will argue that the debate itself is misguided, and rooted in an erroneous conception of the way attention functions. Spatial attention is often likened to a spotlight, but this metaphor is inadequate: It cannot account for the reduced sensitivity at unattended locations that accompanies perceptual facilitation at attended locations, nor for the flexibility of attention, which can be divided over several peripheral locations. Here, I will describe recent psychophysical work that systematically explored the effects of both the validity and number of peripheral cues. A series of experiments demonstrated that dividing attention impairs sensitivity at the cued locations, but improves it at uncued locations. These findings are consistent with a model in which attentional cues act as attractors for spatially-tuned receptive channels: Cueing alters channels’ spatial tuning, increasing their density near a cue and decreasing it elsewhere. Multiple cues pull in different directions, reducing both of these effects. Attentional attractors thus account for these and various other findings, and offer a viable mechanism for attention’s effects. Importantly, if attention is simply a change in the spatial tuning of retinotopic channels, then the baseline state is not inattention but rather an unbiased distribution of channels. Changing the distribution of channels in retinotopic space thus constitutes attention – and in the absence of a biologically plausible scenario in which all channels are withdrawn from a specific location, there is no point in talking about a condition in which attention is absent. Instead, I will use the results of a different recent study demonstrating the independence of attention and emotion in access to awareness to propose that efforts should be focused on defining the causal clusters (or, to use Mackie’s term, INUS conditions) that lead to conscious perceptual experience.
17:30 General discussion
Saturday 17 May
10:00-11:15 Sid Kouider (LSCP, ENS, Paris)
How rich is consciousness in infants?
Recent work using electrophysiological recordings has revealed that, similarly to adults, infants show a two-stage pattern reflecting a linear and nonconscious accumulation of sensory evidence followed by a later non-linear stage of conscious access. I will here discuss whether, on the one side, these neural signatures are reliable estimates of conscious access and, on the other side, whether the large patterns of early neural activity reflect preconscious or or rather phenomenal stages in the infant brain.
11:30-12:45 James Stazicker (University of Reading, Reading)
Introspection, Overflow and Mental Paint
Ned Block champions the use of introspective evidence together with the formal data. Using this method, he defends two different claims about visual consciousness: (i) that visual consciousness is independent of cognitive access; (ii) that the phenomenal character and representational content of visual consciousness are distinct. On the face of it Block's arguments for (i) and (ii) are independent of one another. I suggest that the argument for (i) in fact depends on (ii), and I explore some consequences for appeals to introspection in this area.