P. Verstraten

De Blauwe Kamer Theofaan Groep, Regional Center Eindhoven,
Castiliëlaan 8,
 5629 CH Eindhoven,
 phone: +31 40 290 2626
 fax:+31 40 248 8789
e-mail: p_verstraten@theofaan.nl
The Netherlands

Purpose

The connections found between contents and circumstances of CBS-hallucinations will support the use of neural network models in understanding the nature of CBS.

Methods

In a newly designed tool for psychological assessment of CBS the circumstances in which CBS-hallucinations occur and the content(s) of these hallucinations will be gathered in an unequivocal manner by several psychologists of Dutch rehabilitation centers for visually impaired people. Hypotheses will be formulated regarding ‘logical’ connections between contents and circumstances and be tested with empirical data. Some expected connections are: seeing flowers while watching TV; trees, bushes, moss or straw while walking; buildings and brick walls while sitting in a moving car.

Results

On empirical grounds it seems plausible to differentiate between (bottom up) hallucinations that arise as a direct consequence of external sensory triggers and (top down) hallucinations that develop as a result of decreasing visual attention. Sensory deprivation can be seen as a predisposing factor for both types. At least in the latter case decreasing visual attention leads to the crossing of a threshold that leads to the onset of hallucinations.

Conclusions

Preliminary results (the above research still has to be started) support our idea that subtypes of the CBS can be described and that neural network models are applicable.