The Behavioral and brain sciences
April 21, 2025
Stephen M Fleming, Matthias Michel
26 citations
Conscious vision is surprisingly slow, with unconscious integration windows lasting up to 400 milliseconds, as shown by postdictive effects. Because it is slow, conscious vision cannot guide online actions; instead, it evolved to support offline cognition, such as planning and internal simulation. This shift likely accompanied the water-to-land transition, where larger terrestrial visual horizons made model-based planning advantageous over the fast, reflexive actions typical of aquatic environments. The capacity for internal simulation created pressure for reality monitoring—distinguishing internal from external signals and solving when to stop integrating evidence to fix a model of reality. This reality monitoring function is linked to the emergence of consciousness, in line with higher-order theories. The account generates novel predictions about conscious versus unconscious vision in aquatic and terrestrial animals.
Open mind : discoveries in cognitive science
January 1, 2024
Pietro Amerio, Matthias Michel, Stephan Goerttler et al.
5 citations
Comparing conscious and unconscious perception is central to consciousness science, but many studies fail to control for criterion biases when assessing awareness. In this study, observers tried to discriminate subjectively invisible offsets of Vernier stimuli, with visibility probed using a bias-free task. Stimuli were made less visible by backward masking or very brief presentation (1-3 milliseconds) using a modern tachistoscope. Some behavioral indicators of perception without awareness appeared, but no conclusive evidence emerged. Bayesian observer model simulations, including models generating visibility judgments alongside type-1 judgments, best fit observers with slightly suboptimal conscious access to sensory evidence. The stimuli and manipulations produced mild blindsight-like behavior, suitable for future investigation.
Neuroscience and biobehavioral reviews
November 19, 2025
Daniel K Freeman, Brian Odegaard, Seung-Schik Yoo et al.
Transcranial focused ultrasound (tFUS) can stimulate the human brain non-invasively with millimeter-scale precision, targeting both cortical and deep structures. This new tool offers a potential breakthrough for studying the neural correlates of conscious perception, overcoming the coarse spatial resolution and limited depth of traditional electrical or magnetic stimulation. Because tFUS requires extensive preparation and regulatory approvals, careful experimental planning is essential. The authors provide a roadmap for using tFUS in humans to explore the neural substrate of conscious perception.