Both the global workspace theory and Block’s distinction between phenomenal and access consciousness, are central in the current debates about consciousness and the neural correlates of consciousness. In this article, a unifying global workspace model for phenomenal and access consciousness is proposed. In the model, recurrent neural interactions take place in distinct yet interacting access and phenomenal brain loops. The effectiveness of feedback signaling onto sensory cortical maps is emphasized for the neural correlates of phenomenal consciousness. Two forms of top-down (...) attention, attention for perception and attention for access, play differential roles for phenomenal and access consciousness. The model is implemented in a neural network form, with the simulation of single and multiple visual object processing, and of the attentional blink. (shrink)

The distinction between phenomenal and access consciousness is central to debates about consciousness and its neural correlates. However, this distinction has often been limited to the domain of perceptual experiences. On the basis of dream phenomenology and neuroscientific findings this paper suggests a theoretical framework which extends this distinction to dreaming, also in terms of plausible neural correlates. In this framework, phenomenal consciousness is involved in both waking perception and dreaming, whereas access consciousness is weakened, but not fully eliminated, during (...) dreaming. However, access consciousness is more active during lucid dreaming. The proposed framework accounts for different aspects of dream phenomenology, including levels of integration of perceptual, cognitive and affective features in dreams, bizarreness, dream amnesia and the occurrence of meta-awareness and accessibility in lucid dreaming. Self-related experiences and their neural substrates are suggested to be differently involved in waking cognition and dreaming. Further, phenomenal consciousness during both waking and dream experiences involve widespread recurrent interactions and convergence-divergence zones in the thalamo-cortico-limbic system, activated before conscious access in global workspace areas. Finally, we discuss the relationships of the proposed framework with other neurocognitive theories and models of consciousness and major theories of dreaming, and propose novel experimental predictions. (shrink)