A Psychophysiological Study of Perception and Retrival after Repeated "Subliminal" Stimulation

Norbert Roth and Günther Roscher

Istitut für Physiologie, Medizinische Akademie

Institut für Neurobiologie

Akademie der Wissenschaften

Magdeburg, G. D. R.

It is a trivial fact that perception is not simply the uptake of information inte the "central processor", but a highly active and very intricate function. Any systematic approach to the study of behavior more or less directly faces the problem of memory retrieval processes (Anochin, 1967; Grossberg & Stone, 1986; Roth, 1980). A number of external variables, as physical characteristics of stimuli (e.g. intensity, duration, contrast, extent of the receptor area stimulated), or of internal factors (arousal level, organic state, motivation and the like) may affect the processing of input information at any given instant. In almost all cases, the intake of information from the surrounding world is "selective", i.e., the behavioral meaning of stimuli is judged and this appraisal in torn acts on the perceptual process.

This assumption of control mechanisms working at a very early stage of processing is supported by a large number of empirical reports (see Dixon, 1981; Emrich, 1983; Kostandov, 1983). Most of these authors deal with the problem of so-called subconscious or preconscious perception and the relevant control mechanisms which may or may not activate a memory content and thus lead to conscious identification of an event.

Dixon (1981) postulates that because of different control mechanisms "the brain can monitor and analyse sensory inflow which may never achieve phenomenal representation " and "... in brief then, selective processes operating preconsciously may be initiated by conscious volition and/or parameters of the external stimulus. By the same token, preconscious responses to these two sorts of influence are also interactive with four organismic variables - need state, the disposition to emotional reactions to particular items of sensory inflow, information stored in unconscious long-term memory and organic state.”

Our present study is devoted to the investigation of these “interface”-functions between (unconscious) long-term memory (LTM) and conscious experience. Since very short or degraded stimuli are known to affect the processing of information (e.g., in semantic priming experiments, Neely, 1976), we developed a paradigm in which extremely short stimuli had to be repeatedly presented for conscious recognition.

Be so kind and contact

ICS Dr. G. Roscher GmbH
Dr.-Ing., Dipl.-Math. Günther Roscher 
Manager
Am Kirchberg 6
D - 39326 Klein Ammensleben
Tel.: +49 39 202/52 12-6
webmaster@ICSRoscher.de

for more information