"Over the past decades, neuroscientists have devoted substantial effort to understand what visual consciousness is, and which are the neural correlates underlying its content. A critical contribution to consciousness research distinguishes between two concepts of consciousness: phenomenal and access consciousness. According to Block (1996), phenomenal or P-consciousness represents the experiential properties of our perceptions (e.g. sensations, feelings). On the other hand, access or A-consciousness refers to the process by which a phenomenally conscious perception is made available to other cognitive mechanisms (e.g. memory, reasoning). Interestingly, Lamme (2003) proposed a model in which these two types of consciousness are related to different processing stages of the information. At a first stage after a visual stimulus reaches our senses, many visual representations are available in P-consciousness, which is implemented by local recurrent activations between the early visual areas of our brain (Figure 1 yellow lines). The content of P-consciousness has been commonly associated with measures of iconic memory, which is a sort of ""snapshot"" of what we are perceiving (Figure 1a). Subsequently, the activations in the early visual areas feed-forward to higher level visual areas; however, as time passes, these activations lose strength causing a reduction of the high-resolution phenomenal representations created in first stages, giving place to fragile short-term memory content (Sligte, Vandenbroucke, Scholte & Lamme, 2010; Figure 1b). At this stage, the competition between representations increases, and only those engaging in global recurrent activations from visual areas to the frontal part of our brain (Figure 1 red lines) evolve in A-consciousness. At this stage, only part of the original phenomenal experience gains access to higher cognitive processes. The content of A-consciousness has been related to working memory (Figure 1c).
The route from P- to A- consciousness involves several cognitive processes, such as attention, memory, decision-making and metacognition, which are intermingled and spatiotemporally overlaped.
Due to this complex overlap, the study of visual consciousness needs to be carried out in a comprehensive framework. Therefore, the present project pursues two general aims: 1) To dissociate the behavioural responses and neurofunctional correlates of P- and A- consciousness, distinguishing between objective and subjective measures. 2) To elucidate how the cognitive processes of attention, (iconic and working) memory and their interactions are involved in the development of the conscious content. Better understanding of the neural basis of attention, visual consciousness, and metacognition may aid in developing solutions for societal problems by, for example, implementing new devices of road safety and programs of interventions aimed at improving academic success."
