, 1952). It is easy to take for granted that audiovisual events are always synchronised and integrated correctly. But here, we present the first ever confirmed case of a patient (PH) who hears peoples’ voices before he sees their lips move. Testing this individual in comparison with neurologically healthy participants gave us the unique opportunity to address two issues: Firstly, we ask whether PH’s auditory Panobinostat leading phenomenon is selective for subjective synchrony or whether his audiovisual integration is also affected. This addresses a current debate over whether optimal integration depends
on achieving subjective synchrony, or whether integration obeys independent temporal constraints ( Arnold et al., 2005; Martin et al., 2013; Munhall et al., 1996; Soto-Faraco and Alsius, 2007 and Soto-Faraco and Alsius, 2009; van Wassenhove et al., 2007). Secondly, PH’s pathological desynchronisation might provide insight into the deeper question of how (or indeed whether) sensory synchronisation is normally achieved, which has long perplexed neuroscientists and philosophers ( Dennett and Kinsbourne, 1995; Harris et al.,
2008; Keetels and Vroomen, 2012; Spence and Squire, 2003; Vroomen and Keetels, 2010; Zeki and Bartels, 1998). We consider this issue first. The problem of synchronisation is exemplified by the maxim known as Segal’s law: ‘With one clock you always know the time; with two you are never sure’. Does the brain also have multiple clocks, and if Apoptosis Compound Library so, does this create a similar uncertainty? There are many multimodal convergence zones in the brain ( Bushara et al., 2001; Cappe et al., 2009; Driver and Noesselt, 2008; Ghazanfar and Schroeder, 2006; Macaluso and Driver, 2005; Meredith et al., 1987; Stevenson et al., 2010), and to get there, auditory and Sunitinib mouse visual signals must traverse different routes and distances, thus most likely arriving at different times ( Arnold et al., 2001; Aschersleben and Prinz, 1995; Halliday and Mingay, 1964; Moutoussis and Zeki, 1997; Stone et al., 2001). Consequently each area will have different information
about when visual and auditory events occurred ( Scharnowski et al., 2013). This entails a ‘multiple-clocks’ uncertainty for knowing the absolute and relative timing of external events. Despite such systemic and intrinsic asynchrony, subjects still often recognise when auditory and visual sources are approximately synchronous (Harris et al., 2008), at least for proximal if not always for distal stimuli (Alais and Carlile, 2005; Arnold et al., 2005; Heron et al., 2007; King, 2005; Kopinska and Harris, 2004; Stone et al., 2001; Sugita and Suzuki, 2003; Vroomen and Keetels, 2010). Shifts in subjective simultaneity following adaptation to asynchrony are consistent with the existence of mechanisms functioning at least locally to resynchronise temporal discrepancies between modalities (Fujisaki et al., 2004; Hanson et al., 2008; Miyazaki et al.
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