No abstract

Earlier work has provided experimental evidence for the existence of the primary and secondary process mental organization posited by Freud and has demonstrated that primary process effects are the more active unconsciously (Brakel et al. 2000). Primary and secondary processes were assessed by a categorization test in which qualitatively different principles could be used. In new experiments using the same stimuli, another significant implication of Freud's model was tested: that primary process mental organization has developmental priority. In these experiments, which studied 559 participants ranging in age from 3 to 80, it was found (1) that primary process mentation predominates in preschoolers; (2) that it is not until around age 7 that primary process organization is supplanted by secondary process organization; and (3) that after age 7 the predominance of secondary process organization remains remarkably stable throughout the life span.

The authors report on two experiments designed to test an important feature of the primary process: unconscious categorisation by attributes rather than by relations. These experiments were designed to provide support, independently of the clinical situation, for the presupposition of a psychological unconscious and for the presupposition that unconscious mentation is organised along primary-process lines. Their results were encouraging. They found that (1) unconscious similarity judgements could be made; and (2) these judgements were based on attributes (a primary-process mechanism) rather than relationships (a secondary-process mechanism). This independent evidence, obtained in controlled experimental studies supporting two fundamental psychoanalytic presuppositions, should be welcome news to psychoanalysts, given the continuing criticism from many quarters that basic psychoanalytic ideas lack independent validation. This paper begins with an overview of the primary processes with a special focus on the role of categorisation by attribute, the particular aspect of primary process explored in this study. Next a brief history of previous empirical investigations of primary process is given, following which the current experiments are presented.

Analysis of event-related potentials (ERPs) using signal processing tools has become extremely widespread in recent years. Nonstationary signal processing tools such as wavelets and time-frequency distributions have proven to be especially effective in characterizing the transient phenomena encountered in event-related potentials. In this paper, we focus on the analysis of event-related potentials collected during a psychological experiment where two groups of subjects, spider phobics and snake phobics, are shown the same set of stimulus: A blank stimulus, a neutral stimulus and a spider stimulus. We introduce a new approach, based on time-frequency distributions, for analyzing the ERPs. The difference in brain activity before and after a stimulus is presented is quantified using distance measures as adapted to the time-frequency plane. Three different distance measures, including a new information theoretic distance measure, are applied on the time-frequency plane to discriminate between the responses of the two groups of subjects. The results illustrate the effectiveness of using distance measures combined with time-frequency distributions in differentiating between the two classes of subjects and the different regions of the brain.

Our approach is based on a tri-partite method of integrating psychodynamic hypotheses, cognitive subliminal processes, and psychophysiological alpha power measures. We present ten social phobic subjects with three individually selected groups of words representing unconscious conflict, conscious symptom experience, and Osgood Semantic negative valence words used as a control word group. The unconscious conflict and conscious symptom words, presented subliminally and supraliminally, act as primes preceding the conscious symptom and control words presented as supraliminal targets. With alpha power as a marker of inhibitory brain activity, we show that unconscious conflict primes, only when presented subliminally, have a unique inhibitory effect on conscious symptom targets. This effect is absent when the unconscious conflict primes are presented supraliminally, or when the target is the control words. Unconscious conflict prime effects were found to correlate with a measure of repressiveness in a similar previous study (Shevrin et al., 1992, 1996). Conscious symptom primes have no inhibitory effect when presented subliminally. Inhibitory effects with conscious symptom primes are present, but only when the primes are supraliminal, and they did not correlate with repressiveness in a previous study (Shevrin et al., 1992, 1996). We conclude that while the inhibition following supraliminal conscious symptom primes is due to conscious threat bias, the inhibition following subliminal unconscious conflict primes provides a neurological blueprint for dynamic repression: it is only activated subliminally by an individual's unconscious conflict and has an inhibitory effect specific only to the conscious symptom. These novel findings constitute neuroscientific evidence for the psychoanalytic concepts of unconscious conflict and repression, while extending neuroscience theory and methods into the realm of personal, psychological meaning.