Modeling stage-sequential change in ordered categorical responses

Although few would dispute the usefulness of looking at behavioral change from a stage-sequential perspective, until recently the lack of appropriate modeling techniques has hampered rigorous empirical tests of stage theories. In particular, for behavioral measurements that are ordinal, there is a need for methods that represent the underlying change processes in the form of qualitative and discontinuous shifts. This article introduces a stage-sequential ordinal model by postulating that at any point in time there are a finite number of latent stages. Panel members may shift among these stages over time. The authors show that the stage-sequential model provides a general approach for both the analysis of ordinal time-dependent data and tests of various competing theories and hypotheses about psychological change processes. An analysis of a 5-year study concerning attitudes toward alcohol consumption by teenagers is presented to illustrate the modeling approach.     

Simultaneous manipulation of propositional and analog codes in picture memory

Revealing a picture as a whole or as momentarily displayed strips presumably manipulated the propositional coding of the picture. Analog manipulation employed superimposition of a grid pattern. Effectiveness of simultaneous manipulations was tested via recognition with three foil categories, each of which presumably tapped the analog or propositional codes mainly, or both of them in detection. While figural units' perspective reversals should presumably be detected via the analog code, their locational displacements should be detected via the propositional code. Foils with novel item substitution should be detected by both codes. On the basis of such presumptions about encoding and recognition manipulations, certain predictions were made for scan and grid effects in "reversal," "displacement," and "novelty" foil categories. Full confirmation of these predictions was then taken as evidence that both analog and propositional codes do exist. Once such evidence was established, other issues were tackled, showing that target detection involves the propositional code only, while foil detection involves both codes. Further, recognition hypermnesia, where performance improves with repeated testing, was obtained only when both codes were attenuated. Data suggested that subjects might be switching from analog to propositional codes when both codes were strong, thereby preventing hypermnesia.     

Performance-psychologic cross-sectional study of young schizophrenic patients with a subchronic and chronic disease course

According to ICD-9 and DSM-III-R-criteria 14 subchronic schizophrenic male patients (duration of illness less than 2 years) and 17 chronically ill male schizophrenics (duration of illness between 5 to 12 years) matched for sex, age, education, type of illness, and medication were with the aid of 4 tests investigated with respect to time characteristics of performance parameters. Whereas subchronic patients revealed performance scores within the normal range of reference scores, chronically ill patients showed dissociative variations in performance (high scores in reasoning, low scores in speed factor). This can be interpreted as instability of brain functioning which characterizes schizophrenics suffering from a long duration of illness. Correlations between prolonged reactions to "crossmodal" choices and subjective basic symptoms in subchronic patients are hints at well established introspection ability of self regarded complaints.     

Psychopathology and criminal personality changes in patients with frontal lobe injuries

Proceeding from H. Cosack (1937), and in view of the fact that since then no further casuistic contributions relating to the crimogenic aspect of the psychopathological frontal brain syndrome or to the forensic psychiatry of persons with frontal brain damage have appeared, we take up the discussion with five of our own cases. Since modern procedures have made it possible to localise exactly the consequences of brain damage, a new round of investigations might be expected to resolve the problems still left open.     

EEG and evoked potential mapping

By spectral EEG-mapping and EP-mapping, especially the topologic dimension of electrical brain activity can be evaluated for clinical use. On the other hand, this method allows the highest solution from all functional imaging procedures within the time dimension of brain activity. On the other hand, the ability of topological solution is limited. But the latter is probably better than hitherto assumed and surprisingly well at least regarding neonates. However, several methodological prerequisites described here must be fulfilled. From the pathophysiological point of view, the limits must be considered besides the diagnostic possibilities. Meanwhile, spectral EEG-mapping and EP-mapping are diagnostically used in all main fields of traditional EEG-analysis, like seizures and in the preadiagnostics of tumors a.o. Also in the diagnostics of cerebrovascular disease including transient ischemic attacks, the EEG-mapping and/or EP-mapping are useful within the total diagnostics. There is a similar situation in the diagnostics of degenerative brain disorders. But the significance of frequently described changes inpsychoses, partly also neuroses and other functional disorders is not clear. Altogether, this non-invasive, economically most favourable method for the functional imaging procedures in brain diagnostics is promising to extent the routine diagnostics also to a more precise manner.     

Is there a "temporal psychosyndrome (Landolt)"?

With reference to features of two cases of grave traumatic temporal cerebral injury, where a "temporal psychosyndrome" as defined by Landolt was not ascertainable, the question is raised whether, apart from temporal-lobe epilepsy, such a syndrome really exists. Computed tomography offers an enhanced objective basis for an investigation embracing an extensive patient population.     

Modulation of baseline behavior in rats by putative serotonergic agents in three ethoexperimental paradigms

The present study adopts an ethoexperimental approach to examine the deportment subsequent to alteration in serotonin (5-HT) neurotransmission following treatment with site-specific neuropharmacological probes. The impact of perturbation in (5-HT) neurotransmission on baseline behavior was analyzed employing three animal models of anxiety, i.e., hole-board, elevated plus maze, and bright/dark arena. Inbred male rats (Wistar strain, weighing between 150 and 200 g) were used in this study. The vivarium and the behavioral laboratory were specially designed to permit operation of reversed light-dark cycle and all experiments were performed during the dark period. Pharmacological tools selected to influence 5-HT levels include (1) a combination of tranylcypromine and tryptophan (TCP + TRYPT) (0.75 mg/kg + 40 mg/kg) which augments 5-HT biosynthesis; (2) p-chlorophenylalanine (PCPA: 200 mg/kg), an inhibitor of 5-HT biosynthesis; and (3) 5-HT reuptake blockers, namely zimelidine (ZIM) (40 mg/kg) and fluoxetine (FLU) (10 mg/kg). Rats under the influence of PCPA exhibited anxiolytic response, whereas those under treatments to raise 5-HT levels, viz., TCP + TRYPT, ZIM and FLU, displayed anxiogenic-like reactions. Several other agents known to specifically interact with 5-HT receptor subtypes were also tested. 5-HT2 receptor stimulants, such as quipazine (5 mg/kg) and MK 212 (0.5 mg/kg), were found to be anxiogenic. Buspirone (2 mg/kg), a 5-HT1 agonist, surmounted normal behavioral inhibition. However, another 5-HT1 stimulant, 8-OH-DPAT (0.025 mg/kg), had anxiogenic action. Pretreatment with 5-HT3 antagonists [zacopride (2 mg/kg) and GR 38032F (0.1 mg/kg)] and putative 5-HT1 antagonist [propranolol (10 mg/kg)] resulted in borderline disinhibition of normal behavioral inhibition to novel environments. In contrast, cyproheptadine (0.5 mg/kg), a 5-HT2 antagonist, provoked anxiogenic-like behavior. Altogether, uniform results were obtained for each probe in all the three models, suggesting that the battery of anxiety tests chosen in this study is reliable and sensitive to detect unknown pharmacological responses. The results support the hypothesis that stimulation of serotonergic neurotransmission heightens normal anxiety, whereas its blockade releases normal behavioral inhibition. Furthermore, this work establishes the validity of using the three paradigms in evaluating the involvement of multiple neurotransmitter receptors in the control of behavior of rodents under natural circumstances and also detects any aberration following exposure to novelty and stress.     

A quantitative study of dendrite complexity in selected areas of the human cerebral cortex

This study seeks relationships between the degree of dendrite complexity of four areas of the human cerebral cortex and the type of function subserved by those areas. Quantitative studies of basilar dendrite patterns in the trunk and hand-finger receptive zones of areas 3 and 1, superior gyrus of the prefrontal cortex (area 9), and supramarginal gyrus (area 39) of the parietal lobe, in the left hemisphere of 10 subjects are reported. Measurements of dendrite complexity were based on the Sholl method of counting dendrite intersections with a series of superimposed concentric rings centered on the middle of the neuron soma. The data were analyzed graphically to show (1) characteristic dendrite profiles generated by cells in each of these areas, (2) comparisons between dendrite systems of two paired areas, i.e., trunk vs. hand-finger, and hand-finger vs. supramarginal, and (3) cumulative dendrite-ring intersection patterns for all areas studied. The data provided only partial support for our working hypothesis suggesting a relationship between complexity of the dendrite arbor and the nature of the computational tasks performed by the area. However, complexity of dendrite systems in the trunk area was found to be generally less than that of any other. In addition, there were suggestive associations between the complexity of dendrite systems of the hand-finger zone of the primary sensory receptive area and the nature of the work with which the individual had been associated during his/her working life. It proved more difficult to discern relationships between structure and function in the cortical associative areas. The study underlines the large degree of interindividual variation in dendrite structure and the need for much more extensive information about the life history of individuals who serve as subjects for this type of study.     

Patterns of self-initiated smoking cessation among young adults

Prochaska and DiClemente's (1984) cyclic-stage model of self-initiated smoking cessation divides the cessation process into five stages. This model was applied to a young adult population to determine the cross-sectional distribution of stages and the frequency and pattern of changes among stages over time. Compared to older adults, the distribution of the stages differed substantially: There were twice as many relapsers and only half as many maintainers among young adults. One-year changes in stages were examined using a static model, which did not take into account the cyclic nature of the change process, and a more realistic dynamic model, which did. Both models, especially the dynamic model, suggested substantially more movement among stages in younger than in older adults.