Michael S. Armstrong

A trial of eye movement desensitization compared to image habituation training and applied muscle relaxation in post-traumatic stress disorder

Thirty-six patients with PTSD were randomly allocated to individual treatment with imaginal exposure (image habituation training -- IHT), or applied muscle relaxation (AMR) or eye movement desensitization (EMD). Assessment by a blind independent rater and self-report instruments applied pre and posttreatment and at 3-month follow-up indicated that all groups improved significantly compared with a waiting list and that treatment benefits were maintained at follow-up. Despite a failure to demonstrate differences among groups, there was some suggestion that immediately after treatment EMD was superior for intrusive memories.

An orienting response model of eye movement desensitization.

Dycks (Journal of Behavior Therapy and Experimental Psychiatry, 1993) conditioning model of EMD provides a useful description of failure of habituation in post-traumatic stress disorder, but may not account for some common EMD phenomena. An alternative model proposes that the therapists waving hand--in the presence of a trauma-related cortical set--triggers an intense orienting response (OR). Intrinsic effects of the OR facilitate continuing attention to the memory without avoidance, and provide for effective input of new trauma-related information. The persons neuronal model of the trauma alters to reflect his survival and current safety--as true outcome of the trauma--and associated conditioned responses extinguish. Proposals for experimental evaluation of the model are described.

Expectancy, covert sensitization and imaginal desensitization in compulsive sexuality

ABSTRACT– Twenty subjects were randomly allocated to receive either imaginal desensitization (ID) or covert sensitization (CS) to reduce compulsive anomalous sexual behaviours. It was predicted from a behavioural completion model of compulsive urges, that patients’ response to ID would be at least as good as their response to CS and would correlate with reduction in their general levels of tension following treatment. These predictions were supported. Correlations between patients’ expectancies of treatment success and their response were of moderate strength for expectancy measures taken following the first session of both treatments, but much stronger for expectancy measures following the last session of ID. It was suggested that patients experienced a specific response during the further sessions of ID, which enabled them to improve their prediction of response. As aversive therapies remain the standard behavioural therapy for sexual paraphilias, the finding of the present study that imaginal desensitization without traumatic imagery or aversive physical stimuli is at least as effective would seem to require urgent replication, if only on ethical grounds.

Resistance to treatment of adolescent sex offenders.

Little information is available concerning adolescent sexual offenders and their response to treatment. Of 45 sex offenders treated in two studies, 6 were adolescents and 21 of the 39 adults reported that their deviant behavior had commenced before or during adolescence. All 6 adolescents presented for treatment only following detection of their offenses, which in 3 led to legal charges. Of the 39 adults, 12 sought treatment voluntarily. Subjects were randomly allocated to receive covert sensitization, imaginal desensitization, medroxyprogesterone, or imaginal desensitization plus medroxyprogesterone. The response of the adults was equivalent to the best reported in the literature. Seven of the 39 required additional treatment, 3 being charged for further sexual offenses. Four of the 6 adolescents required additional treatment, 3 being charged with further sexual offenses. These differences were statistically significant. Adolescent sexual offenders may be more resistant to treatment because their sexual urges are under more direct hormonal control whereas in adults sexual urges are in part under the control of behavior completion mechanisms. Sexual offenses in adolescence need to be considered as at least as significant as those of adults, and more intensive follow-up treatment appears indicated in their management.

P300 and Psychiatric Vulnerability in University-Students

Roth and Cannon (1972) reported the first study of late positive P300S to infrequent auditory stimuli. Levit et al. (1973) examined P300 in both schizophrenics and psychotic depressives, using visual and auditory stimuli, and found that the schizophrenics had significantly smaller P300 components than depressives and normal controls. Verleger and Cohen (1978) replicated these findings, and also reported habituation of P300 in schizophrenic patients. Habituation was not seen in the control subjects. Josiassen et al. (1981) have recently shown that P300 amplitude is also reduced in schizophrenic patients when somatosensory stimuli are employed. A recent study compared the response to auditory stimuli of schizophrenics and normal controls in a reaction time task and a no-task condition (Roth et al., 1980b). P300 amplitude was significantly less in schizophrenics than controls when loud (100 dB) white noise stimuli were presented in the no-task condition. This was also the case with infrequent tones in the reaction time task. Further analysis employing averages sorted by reaction time and response-synchronized averages indicated that P300 latency variability could not account for this difference (Roth et al., 1980~) . One possible source for the observed reduction in P300 amplitude in schizophrenia is a failure on the part of schizophrenics to generate trial-to-trial expectancies in a series of random stimuli, an important variable in the determination of P300 amplitude (Duncan-Johnson and Donchin, 1977). This hypothesis was examined by DuncanJohnson and colleagues, who found no evidence that schizophrenics are impaired in their ability to formulate expectancies. An overall reduction in P300 amplitude in the schizophrenic group was associated with a tendency towards slower reaction times (Duncan-Johnson et al., 1981). Evidence for a relationship between impaired attention and P300 amplitude attenuation was found in a study in which event-related potentials were recorded during the administration of the Continuous Performance Test. Attentional impairment in the acute schizophrenic patients studied was found both behaviorally and using the P300 amplitude as a cortical measure of attention (Pass et al., 1980). In an experiment where subjects were instructed to count the number of rare, target stimuli, P300 amplitude in the schizophrenic group was significantly correlated with their counting performance, providing further evidence of relationship between P300 amplitude and behavioral measures of attention (Cohen et al., 1981). Friedman et al. (1980) recorded the P300 to auditory stimuli in children of schizophrenic parents, considered to be at “high risk” for developing schizophrenia, and in the children of nonpsychiatrically disturbed parents. They used either an infrequent pitch change or stimulus omission to elicit P300, and found the amplitude of

Creativity, divergent and allusive thinking in students and visual artists

Visual artists of acknowledged creativity but not students with divergent thinking showed allusive (loose) thinking on an Object Sorting Test. It was concluded that high but not low level creativity in some fields may be associated with a predisposition to schizophrenia.

Allusive thinking, the Word Halo and verbosity

The concept of allusive thinking is briefly reviewed and a Pavlovian model of thinking advanced. It is hypothesized that allusive, as compared with non-allusive thinkers, have a broader but less intense attention process associated with weaker inhibition. From this model it was predicted that on word tests which require judgements of similarity of meaning, allusive thinkers would tend to choose more remote or unusual words as similar in meaning. The Word Halo Test and the Word Sorting Test were administered to 63 university students using the Object Sorting Test as a measure of allusive thinking. The prediction that allusive thinkers would choose more unusual words as similar in meaning was supported. A tendency for allusive thinkers to be more verbose than non-allusive thinkers was also noted.

Auditory Hallucinations and the Verbal Transformation Effect

In an attempt to replicate findings reported by Slade (1976), 12 hallucinating and 12 non-hallucinating shcizophrenic subjects were compared on tests of verbal ability, personality and mental imagery variables and the Verbal Transformation Effect. No significant differences between the groups was demonstrated. When the data from both groups of schizophrenics were combined, a significant correlation was found between 2 measures of the Verbal Transformation Effect and the P-score of the Eysenck Personality Questionnaire.

Reduced p200 latency and allusive thinking: An auditory evoked potential index of a cognitive predisposition to schizophrenia?

Auditory evoked potentials were recorded in healthy medical students who were grouped according to whether they obtained a high or low score on an Object Sorting Test (OST), on which schizophrenics also obtain high scores. High-OST scoring male students compared to Low-OST scoring male students showed reduced P200 latency. This finding was replicated in a second study of medical students. The authors believe these results support the hypothesis that schizophrenic thought disorder and an equivalent loosening of thinking in nonschizophrenic populations (allusive thinking) have a neurophysiological basis in common, namely a relative weakness of inhibition operating on cortical and subcortical structures.

Inhibition of hypervigilance in the treatment of traumatic simple phobias: three case examples

Objective: In traumatic simple phobia (TSP) fear of retraumatisation tends to be enduring and may show little reduction with time despite frequent and prolonged exposure. This paper describes how hypervigilant behaviour may account for this enduring response by interfering with exposure. Method: Three case histories illustrating the clinical features of TSP and its treatment using in vivo exposure coupled with direct inhibition of hypervigilance are presented. Result: In all three cases, reduction of anxiety occurred with spontaneous generalisation of improvement. Conclusions: The efficacy of in vivo therapeutic exposure for fear of retraumatisation may be enhanced by the use of strategies to inhibit hypervigilant behaviour.