ausblenden:
Schlagwörter:
Perceptual awareness, conscious somatosensory perception, fMRI, neural network, graph theory
Zusammenfassung:
Does stimulus awareness modulate the brain’s functional network topology? If network topologies have explanatory power beyond local BOLD signal changes, they will serve as promising candidates for a neural account of awareness as suggested by the global workspace theory (Baars, 1988). I will present fMRI results of a somatosensory detection task where participants had to report the perception of near-threshold electrical pulses and their decision confidence. Despite local positive BOLD changes in a frontoparietal network for hits compared to misses, we did not observe a graph-theoretical network modulation as recently reported for visual awareness (Godwin et al., 2015). Interestingly misses compared to correct rejections showed different patterns: (a) early sensory and frontal areas showed a larger signal for misses than correct rejections while (b) parietal areas showed a lower signal for misses than correct rejections. This might be an indicator for local fluctuations in neural excitability and hence access to consciousness.
