Temporal consciousness and confabulation: is the medial temporal lobe "temporal"?
Since the early descriptions of this phenomenon, there is a large consensus on the distinction between two forms of confabulation. Provoked confabulations are plausible minor memory distortions in response to direct questioning, whereas spontaneous confabulations are unprovoked, often implausible, memories. However, as we show with the analysis of 284 provoked and 52 spontaneous confabulations produced by eight patients with confabulatory syndromes of different aetiologies, the provoked/spontaneous distinction fails to capture the quality of the great majority of confabulations that clearly do not fall in either of the two poles of the distinction. In this study, the majority of provoked (52%) and spontaneous (73%) confabulations consisted of what we refer to as "general memories, habits, and misplacements", i.e., either true episodes misplaced in time and place, or personal habits and routines which are considered by the patient as specific personal episodes. These observations are discussed within the framework of the Memory, Consciousness, and Temporality Theory. According to this theory, confabulation reflects an abnormal functioning of temporal consciousness (TC). The integrity of the medial temporal lobe (MTL) and related structures is crucial for the normal functioning of TC. Data from the literature show that what confabulators have in common is not a specific lesion site but rather the integrity of the MTL, which is consistent with the idea that the MTL is essential for the function of normal and confabulatory TC. In this sense the MTL is "temporal", because its integrity allows individuals to be consciously aware of a personal past, present and future. A better understanding of TC, including its neurobiological correlates, will help to better understand confabulation avoiding theoretically untenable and experimentally undemonstrated explanatory idols like memory traces and unconscious monitoring.
Dalla Barba
Gianfranco
G
INSERM Unit 610, Université Pierre et Marie Curie, Paris 6, France. dallabarba@chups.jussieu.fr
Boisse
Marie-Francoise
MF
D000328:Adult; D000368:Aged; D001931:Brain Mapping; D003243:Consciousness; D003702:Delusions / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology* / Q000523:psychology; D011939:Mental Recall; D008875:Middle Aged; D013702:Temporal Lobe / Q000503:physiopathology*