engleski

Cortical neurodynamics: From sensory perception and cognition toward a neural correlate of consciousness

Functional brain imaging methods provide a non-invasive insight into the basic mechanisms of sensory and cognitive processes and characterization of pathologies that impair normal function. Extremely sensitive SQUID-based neuromagnetometers allow for the extracranial measurements of spontaneous and evoked neuromagnetic fields on the order of 100 fT giving a direct, real time, access to the rapidly changing neuronal activity. Spatio-temporal source localization approaches relay on source modeling and inverse problem estimation strategies to track cortical pathways both in space and time. Neuromagnetic studies on the human visual processing have demonstrated, among others, multiple retinotopically organized visual areas [1], stimulus and task specific visual pathways [2], and detailed insight into individual functional neuroanatomy [3]. The study of neuronal correlates of visual and auditory perception has demonstrated a distributed network of cortical activations whose dynamics can be modulated by physical characteristics of the stimuli, task relevance, age, and pathology [e.g., 4]. Since our first MEG demonstration of the primary visual cortex reactivation during a spatial visual attention task via a feedback mechanism [5] such a top-down regulation has been demonstrated in a range of cognitive tasks and has been recently proposed to play an important role in a search for neural correlate of consciousness.

MEG; vision; audition; cognitive neurodynamics; selective visual attention; cortical feedback connections; neural correlate of consciousness

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