Cognitive Dedifferentiation in Eidetics and Synaesthesia: Hunting for the Ghost Once More

Abstract

Both synaesthesia and eidetics have a common characteristic of cognitive dedifferentiation. Synaesthesia (e.g. colour-hearing) entails the dedifferentiation of the sensory modalities, while eidetic imagery entails the dedifferentiation of imagery and perception. One can profitably gain by investigating both within the same study. Moreover, some of the same issues have arisen in these, hitherto, separate research literatures. This behoves a common framework for analysis and investigation. We applied a technique previously used for identifying child eidetikers, for screening the adult population, looking at both phenomena in the same sample. After screening, we selected a total of twenty-nine individuals for controlled testing of both phenomena and their variants (structural eidetic imagery, typographic eidetic imagery, colour-hearing synaesthesia, colour-mood synaesthesia). Our participants also completed a number of questionnaires of relevance (absorption, dissociation, and hallucination). We found that the personality trait of absorption underlies the commonality of experience tapped by both typographic and structural eidetic imagery. Furthermore, the latter phenomena were found to have a common pseudohallucinatory experiential base. For subjects scoring relatively high on the absorption scale, there is a negative correlation between structural eidetic imagery and colour-mood synaesthetic differentiation, replicating to a degree results reported earlier.

Symbolic and Syncretic Cognition Among Schizophrenics and Visual Artists

“…Werner (1948) discussed such eidetic imagery as entailing the fusion of imagery and perception, hence the syncretic nature of the phenomenon. Our procedure is based on that described by Marks and McKellar (1982) and was previously employed by Glicksohn et al (1992;Glicksohn et al, 1999). We limited the test to 1 min for each of two colors (blue and yellow), and performance was indexed as the number of distinguishable content shifts in the participant's response.…”

“…We assessed syncretic cognition with the aid of three tasks: one measuring performance, a second evoking experience, and a third assessing personality. These, in turn, were expected to be correlated (Glicksohn et al, 1999).…”

“…Werner (1948) marked one dimension of development as that moving from a syncretic level to a discrete one; that is, from a "state of relative globality and lack of differentiation to a state of increasing differentiation" (Werner, 1957(Werner, /1978a. Syncretic cognition entails a dedifferentiation of perceptual qualities in subjective experience, the most predominant example being synaesthesia (Glicksohn, Salinger, & Roychman, 1992;Glicksohn, Steinbach, & Elimalach-Malmilyan, 1999). Thus, in synaesthesia (e.g., color-taste), the two perceptual modalities become dedifferentiated (what Baron-Cohen, Harrison, Goldstein, & Wyke, 1993, referred to as a breakdown of modularity).…”

“…Two key constructs are syncretic cognition (Glicksohn et al, 1999) and symbolic cognition (Glicksohn, 1998). Syncretic cognition, as noted earlier, refers to cognitive dedifferentiation.…”

Synaesthesia quotient: operationalising an individual index of phenotypic expressivity of developmental synaesthesia

“…Along the latter two lines of research, many experimental paradigms and self-report inventories have been borrowed from other major domains of neuroscientific research such as investigations into memory, attention, imagery, creativity, ability, etc. (e.g., Yaro and Ward 2007;Domino 1989;Glicksohn et al 1999).…”