Conscious somatosensory perception and its neural network correlates
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.
May 29, 2017 | 04:00 PM