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Story of the Human Brain
Published in Junichi Takeno, Self-Aware Robots, 2022
When the primary visual cortex of the occipital lobe has a lesion, humans cannot see their outside world. It has been reported, however, that even with the visual area damaged, part of the visual information was transmitted to the parietal lobe, and by virtue of this information the subject reached out his hands toward a strong light although he could not visually see the light. This is called blindsight or cortical blindness. In this case, the subject was not conscious of the light but reached out his hands toward it.
Beyond the neural correlates of consciousness: using brain stimulation to elucidate causal mechanisms underlying conscious states and contents
Published in Journal of the Royal Society of New Zealand, 2021
Corinne A. Bareham, Matt Oxner, Tim Gastrell, David Carmel
Such suppression abolishes reported stimulus awareness, but objective discrimination performance – e.g. reporting which of two possible stimuli was presented – may remain above-chance (Allen et al. 2014; Koenig and Ro 2019). This has been termed ‘TMS-induced blindsight’, implying that the preserved visual performance may arise through similar mechanisms as in blindsight patients, who have damage to early visual cortex but are able to perform visual tasks despite reporting no visual experience (Weiskrantz 1996). The neural basis of this preserved performance remains controversial (Koenig and Ro 2019): it may be due to spared residual activity in visual cortex that could be sufficient for stimulus discrimination but not for awareness, but may also be due to alternative visual pathways that bypass early visual cortex (e.g. via the midbrain) and enable stimulus discrimination but do not give rise to conscious experience.