Siclari group

General description research

We try to understand how the brain generates dreams – vivid and complex experiences that occur in the absence of sensory input from the external world. To this aim we sample experiences during sleep using serial awakening paradigms and record brain activity noninvasively with high-density EEG, allowing for refined signal analysis (high-density EEG). This approach has allowed us to image broad dream contents (faces, places, speech, etc.), to identify dream patterns that occur independently of sleep stage, and to predict, in real time, whether someone is dreaming. We have also studied patient populations to understand how the feeling of deeply being asleep comes about, what sleepwalkers experience, and how their behavior relates to brain activity. With our current projects, we try and manipulate arousal circuits during sleep (using sensory stimuli, closes loop acoustic stimulation and pharmacology) to causally test their relation with dreaming.

Psychiatric symptoms (or disorders) the group is interested in

Dreaming shares several features with some psychiatric disorders, including

• vivid hallucinations
• delusions (false beliefs)
• reduced insight into the hallucinatory and delusional nature of dreams

The question therefore naturally arises of whether dreaming is a physiological, reversible type of psychosis, akin to a default cognitive mode, which is pathologically and perhaps partially reactivated in some disorders. Such disorders include schizophrenia, Korsakoff syndrome (which also shares the amnesia and spatio-temporal orientation of dreams) and acute psychotic states. It would be interesting to perform a systematic comparison of the phenomenology and of brain activity between these disorders and dreaming to obtain answers to this question.
In addition, some psychiatric disorders, such as Posttraumatic Stress Disorder, are associated with recurrent dreams/nightmares. This condition could offer unique insights into the brain signatures of individual dreams and the pathophysiology underlying sleep-related pathological reactivations of experience. Additionally, I would be interested in studying the link between psychotic symptoms and sleep quality.

Technical approaches

• Questionnaires, semi-structured interviews (micro-phenomenology) and  linguistic analysis of wake and sleep (dream) reports in healthy controls and psychotic patients
• Noninvasive monitoring of activity/rest cycles using actigraphy (wrist-worn device)
• High-density EEG with source modeling, this imaging approach can be extended to fMRI in humans, in collaboration with other groups at the NIN
• Analysis of movement patterns in sleep and wakefulness (wearable sensors)
• I would be interested in collaborating with researchers working on animal models of psychosis

Keywords: sleep, dream, consciousness, perception, high-density EEG, sleep disorders, insomnia, parasomnia, pharmacology, closed loop acoustic stimulation
 
List of  the matching research domains and/or disorders 
Negative Valence
Cognitive systems
Arousal and regulatory systems
Sensorimotor systems (innate motor patterns in parasomnia)