Ricerc@Sapienza

Once questioned the assumption that dreaming depends on REM sleep, subsequent studies focused on the neural correlates of dream recall (DR). Considering the indirect access to the sleep mentation, this chapter reviews the main neuropsychological, neuroimaging, and electrophysiological findings on DR. Compelling evidence supports the idea that shared mechanisms between sleep and wakefulness underline the encoding and retrieval of episodic memory, studying DR as amnestic trace. On the other side, several observations suggest that higher cortical activation is crucial to dreaming.

Brain and sleep maturation covary across different stages of life. At the same time, dream generation and dream recall are intrinsically dependent on the development of neural systems. The aim of this paper is to review the existing studies about dreaming in infancy, adulthood, and the elderly stage of life, assessing whether dream mentation may reflect changes of the underlying cerebral activity and cognitive processes.

Several findings underlined that the electrophysiological (EEG) background of the last segment of sleep before awakenings may predict the presence/absence of dream recall (DR) in young subjects. However, little is known about the EEG correlates of DR in elderly people. Only an investigation found differences between recall and non-recall conditions during NREM sleep EEG in older adults, while—surprisingly—no EEG predictor of DR was found for what concerns REMsleep.

The distinction between phenomenal and access consciousness is central to debates about consciousness and its neural correlates. However, this distinction has often been limited to the domain of perceptual (visual) experiences. On the basis of dream phenomenology and neuroscientific findings this paper suggests a theoretical framework which extends this distinction to dreaming, also in terms of plausible neural correlates.

L’osservazione empirica delle caratteristiche dei sogni ha rilevato che i contenuti onirici possono essere tra loro molto vari, sia da un punto di vista qualitativo che quantitativo. Per alcuni decenni la ricerca scientifica sul dreaming ha attribuito tali differenze alla specifica azione esercitata dallo stadio di sonno REM (Rapid Eye Movement) e dallo stadio di sonno NREM (Non-Rapid Eye Movement). In seguito, vari studi hanno cercato di superare la questione relativa alla dicotomia REM/NREM in merito alla produzione dei sogni. Fra questi, i