Cognition, Behavior, and Memory
Author: Francisco T Gallo | email: frgallo@itba.edu.ar
Francisco T Gallo 1°6°, Ignacio Spiousas 2°, Antonela Tommasel 3°, Nerea L Herrero 1°6°, Luis I Brusco 4°, Daniela Godoy 3°, Cecilia Forcato 1°6°, Pablo M Gleiser 5°6°
1° Laboratorio de Sueño y Memoria, Departamento de Ciencias de la vida, Instituto Tecnológico de Buenos Aires (ITBA).
2° Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes.
3° ISISTAN – Instituto Superior de Ingeniería de Software Tandil (CONICET/UNCPBA), Tandil.
4° Centro de Neuropsiquiatría y Neurología de la Conducta- CENECON, Facultad de Ciencias Médicas, Universidad de Buenos Aires.
5° Laboratorio de Neurociencia de Sistemas Complejos, Instituto Tecnológico de Buenos Aires (ITBA). 6° Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET)
Recently, it was discovered using graph theory that measurements of network structure can predict ratings of dream complexity, with more connectedness and less randomness being seen as dream report complexity increases. This approach proved to be useful to differentiate dream reports in the pathological population as well as NREM and REM dream reports, but it has not yet been used to study different oneiric experiences. During lucid dreaming (LD), subjects know they are dreaming and can control the dream content. Another type of aware dream experience is the out-of-body experience (OBE) initiated from sleep paralysis. Although the differences between non-LD, LD and OBEs are evident, some authors claim OBEs are a kind of LDs. In this work, we analyze dream reports that include non-lucid, lucid dreams and out-of-body experiences initiated from sleep paralysis. We collected a set of 1014 dream reports (824 non-LDs, 122 LDs and 68 OBEs) obtained from 60 participants that kept a dream journal for two months. The collected reports were transformed into directed graphs, where each different word plays the role of a node, and consecutive words are connected by a directed, unweighted edge. We analyze different network measures to compare the graphs. Overall, we found that lematized OBE reports are significantly different from lucid and non-lucid dream reports on indirect measures of connectivity and recursion, allowing for a categorization of different dream experiences.