Cognitive Neuroscience
January 21, 2014
Anil K. Seth
357 citations
Normal perception makes objects feel real and present in the world, a quality called 'perceptual presence.' Sensorimotor theories explain this by saying perception involves mastering how sensory input changes with movement, but they haven't specified the mechanism and struggle with synesthesia, where concurrents lack presence. Predictive processing theories see perception as probabilistic inference but haven't addressed presence or synesthesia. This paper proposes that generative models for perception include counterfactual elements—predictions of how sensory inputs would change with possible actions, even unperformed ones. Counterfactual richness determines perceptual presence: normal perception has rich models encoding many sensorimotor dependencies, while synesthetic concurrents arise from poor models. The theory also explains differences among dreaming, hallucination, and perception, and may reshape views on perceptual determinacy.
Cognitive Neuroscience
July 1, 2010
Marcello Massimini, Fabio Ferrarelli, Michael J. Murphy et al.
205 citations
During the first REM sleep episode of the night, transcranial magnetic stimulation (TMS) triggered widespread and differentiated patterns of cortical activation on electroencephalography (EEG), similar to those observed during wakefulness. In contrast, during NREM sleep, cortical activations became more local and stereotypical, indicating impaired intracortical dialogue. These findings suggest that TMS combined with high-density EEG can probe the internal dialogue of the thalamocortical system, potentially offering a method to assess brain function in patients who are unable to move or communicate.
Cognitive Neuroscience
April 7, 2015
Anil K. Seth
56 citations
The author argues that perceptual presence—the sense that something is really there—can be explained by predictive models that link perception with action, specifically through the framework of predictive processing of sensorimotor contingencies. The paper re-emphasizes the core commitment to predictive model-based perception, reconsiders how presence relates to objecthood, and refines the target by distinguishing perceptual presence from the phenomenology of absence-of-presence, or phenomenal unreality. This conceptual work requires speculative, blue-sky thinking to advance the theory.
Cognitive Neuroscience
August 18, 2010
Geraint Rees, Anil K. Seth
11 citations
Consciousness research has advanced rapidly through cognitive neuroscience methods that combine multiple experimental techniques. This special journal issue presents five new empirical studies and one theoretical paper with peer commentaries, collectively examining how conscious mental states relate to brain activity patterns.