Glossolalia is an effect in which a person finds themselves involuntarily speaking and/or thinking in nonsensical speech which is structured in a manner that resembles an actual language.   This is often defined by linguists as a melodic and fluid vocalizing of speech-like syllables that lack any readily comprehended meaning.   It is important to note that this effect is distinctly different from the thought disorganization characterized by a schizophrenic's word salad.   Although there is a litany of research describing this effect in a religious context, this setting is not required; two types of glossolalia have been suggested:  
- Type A (Calm): Occurs in private, mundane settings. Context-dependent with the person self-aware while ‘speaking’ i.e. they can attend to other claims on attention. Appears frequently (daily or several times weekly).
- Type B (Excited): Occurs in public settings as an intense uprush of vocalizations that is a product of a religious altered state. This person is not self-aware and cannot attend to others’ claims on attention. Appears occasionally (weekly or less).
- Newberg, A. B., Wintering, N. A., Morgan, D., & Waldman, M. R. (2006). The measurement of regional cerebral blood flow during glossolalia: a preliminary SPECT study. Psychiatry Research: Neuroimaging, 148(1), 67-71. | https://doi.org/10.1016%2Fj.pscychresns.2006.07.001
-  Grady, B., & Loewenthal, K. M. (1997). Features associated with speaking in tongues (glossolalia). British Journal of Medical Psychology, 70(2), 185-191. | https://doi.org/10.1111%2Fj.2044-8341.1997.tb01898.x
- Goodman, F. D. (1969). Phonetic analysis of glossolalia in four cultural settings. Journal for the Scientific Study of Religion, 227-239. | https://doi.org/10.2307%2F1384336
- Kavan, H. (2004). Glossolalia and altered states of consciousness in two New Zealand religious movements. Journal of Contemporary Religion, 19(2), 171-184. | https://doi.org/10.1080%2F1353790042000207692