Introspective physicalism as an approach to the science of consciousness

Abstract

Most 'theories of consciousness' are based on vague speculations about the properties of conscious experience. We aim to provide a more solid basis for a science of consciousness. We argue that a theory of consciousness should provide an account of the very processes that allow us to acquire and use information about our own mental states -the processes underlying introspection. This can be achieved through the construction of information processing models that can account for 'Type-C' processes. Type-C processes can be specified experimentally by identifying paradigms in which awareness of the stimulus is necessary for an intentional action. The Shallice (1988b) framework is put forward as providing an initial account of Type-C processes, which can relate perceptual consciousness to consciously performed actions. Further, we suggest that this framework may be refined through the investigation of the functions of prefrontal cortex. The formulation of our approach requires us to consider fundamental conceptual and methodological issues associated with consciousness. The most significant of these issues concerns the scientific use of introspective evidence. We outline and justify a conservative methodological approach to the use of introspective evidence, with attention to the difficulties historically associated with its use in psychology.

Unconscious Activation of the Cognitive Control System in the Human Prefrontal Cortex

“…This is an interesting result because traditionally higher cognitive control functions are considered to require consciousness and attention (Norman and Shallice, 1986;Jack and Shallice, 2001). Activations in the mid-DLPFC have been associated with attentionally demanding tasks (Duncan and Owen, 2000;Lau et al, 2004) and conscious visual perception (Lau and Passingham, 2006).…”

“…Activations in the mid-DLPFC have been associated with attentionally demanding tasks (Duncan and Owen, 2000;Lau et al, 2004) and conscious visual perception (Lau and Passingham, 2006). It has also been proposed that this area forms part of a network for conscious processing (Jack and Shallice, 2001;Rees et al, 2002;Dehaene et al, 2003a).…”

“…Inspired by recent advances in neuroimaging research that also draw attention to the strength and depth of subliminal priming (Dehaene et al, 1998;Hannula et al, 2005;Naccache et al, 2005;Gaillard et al, 2006), we attempted to create a situation in which subliminally presented stimuli influence the establishment of tasksets. This constitutes a strong test for the traditional assumption that higher cognitive functions require consciousness (Jack and Shallice, 2001). We performed a behavioral test to see whether such "unconscious" priming was possible and went on to investigate whether it involved the activation of the cognitive control system in the prefrontal cortex.…”

“…Traditionally, higher cognitive control functions are thought to require consciousness and attention (Norman and Shallice, 1986;Jack and Shallice, 2001). Although stimuli presented subliminally can prime specific motor responses (Dehaene and Naccache, 2001), it is assumed that such stimuli cannot influence which task the brain should prepare to do.…”

“…This operation of establishing a particular taskset is an example of the highest form of cognitive control (Miller and Cohen, 2001;Koechlin et al, 2003) and is associated with activations in the prefrontal cortex Passingham, 2003, 2006). The prefrontal cortex is believed to form part of a network for conscious processes (Jack and Shallice, 2001;Rees et al, 2002;Dehaene et al, 2003a). Typically, subliminally presented stimuli do not activate this system (Badgaiyan, 2000;Rees et al, 2002).…”