Psychogenic Nonepileptic Seizures

Neurological, neurodiagnostic, and neuropsychological aspects of psychogenic nonepileptic seizures (PNES) are reviewed, including psychosocial, psychiatric, cognitive, and MMPI-2 findings.     

Dynamics of the knowledge instinct: Effects of incoherence on the cognitive system

We successfully replicated a study about aesthetic emotions in a different socio-cultural environment. The present results suggest that incoherence is a strong inhibitor for aesthetic chills and verify a positive correlation between pleasure and meaning. These results allow for a scientific study of aesthetic emotions as it is now possible for the experimenter to have two groups of subjects, both exposed to the same stimulation, one group experiencing measurable aesthetic emotions whereas the other does not. We review the literature on the problem of both positive and negative psychogenic shivering and relate this phenomenon to the instinct of knowledge. We discuss the implications of our findings, stress the importance of studying the psychological and physiological effects of incoherence on the central nervous system, introduce a series of hypotheses to be tested in further research and conclude with a plausible explanation for the relation between temperature and cognition in humans.     

Increased variability in spiral drawing in patients with functional (psychogenic) tremor

Increased variability is a characteristic clinical and physiologic feature of functional (psychogenic) tremor. In this study, we use computerized spiral analysis to show that the variability of a motor task is a quantifiable characteristic of functional tremor. We compare functional tremor patients to phenomenologically similar dystonic tremor patients and to normal controls. We used the spiral severity score, a measure that does not incorporate spiral tightness, as a marker of spiral drawing performance, and inter-spiral tightness variability (based on the 25–75%^ile range in tightness across ten spirals) to evaluate the effects of functional tremor on drawing spirals. The spirals of 74 participants: 22 functional tremor, 21 dystonic tremor, and 31 normal controls were analyzed. Spiral severity was higher in both tremor groups compared to controls, but did not differentiate them. Inter-spiral variability, however, was higher in the functional tremor group compared to both other groups. Thus, spiral analysis captures variability of a motor task and may be used as an objective test for functional tremor. The effect of functional tremor in other motor tasks should be investigated.