Attended but unseen: Visual attention is not sufficient for visual awareness

Abstract

. (2008) 'Attended but unseen : visual attention is not su cient for visual awareness. ', Neuropsychologia., 46 (3). pp. 864-869. Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Figure 1).The rights of our subjects were fully protected, following the procedures laid out by the relevant local ethical committee. All gave informed consent before participating in the studies reported here. Abstract.Does any one psychological process give rise to visual awareness? One candidate is selective attention -when we attend to something it seems we always see it. But if attention can selectively enhance our response to an unseen stimulus then attention cannot be a sufficient precondition for awareness. Kentridge, Heywood & Weiskrantz (1999, 2004) demonstrated just such a dissociation in the blindsight subject GY. Here we test whether the dissociation generalizes to the normal population. We presented observers with pairs of coloured discs, each masked by the subsequent presentation of a coloured annulus. The discs acted as primes, speeding discrimination of the colour of the annulus when they matched in colour and slowing it when they differed. We show that the location of attention modulated the size of this priming effect. However, the primes were rendered invisible by metacontrast-masking and remained unseen despite being attended. Visual attention could therefore facilitate processing of an invisible and cannot, therefore, be a sufficient precondition for visual awareness.

Functional neuroanatomy underlying the clinical subcategorization of minimally conscious state patients

“…MCS-seems characterized by a partially preserved functioning brainstem and right hemisphere with impaired left cortical networks encompassing Broca's and Wernicke's regions, posterior parietal, presupplementary motor, sensorimotor and premotor cortices. Phylogenetically, the midbrain is capable of driving the eyes to track objects [19,20], and the human phenomenon of blindsight in the absence of occipital lobe function suggests that tracking could be coordinated in the optic tectum [21]. Command following requires a series of cognitive and motor skills, including language comprehension, memory, volition, and motor execution, each depending on the functional integrity of multiple neuronal networks.…”

Threefoldness

“…Second, we attend to some but not all the objects and properties we see (Mack and Rock 1998;Simmons and Chabris 1999). The relation between these two distinctions is complicated because the relation between attention and consciousness Threefoldness 165 is complicated: it is not clear whether attention is necessarily conscious, for example (probably not, see Cohen et al 2012;Jiang et al 2006;Kentridge et al 1999Kentridge et al , 2008. In order to bypass these worries, I will focus on the distinction between attending to something we see and not attending.…”

Cortical networks involved in visual awareness independent of visual attention

“…During the last 15 y, it has become well established that awareness and attention can be separated. It is possible for people to attend to a visual stimulus, as measured by standard attention tasks such as the spatial Posner cuing task, while reporting no subjective awareness of the stimulus (12)(13)(14)(15). Attention and awareness are, however, closely linked.…”