Language representation in the human brain: evidence from cortical mapping

The manner in which the human brain processes grammatical-syntactic and lexical-semantic functions has been extensively debated in neurolinguistics. The discreteness and selectivity of the representation of syntactic-morphological properties in the dominant frontal cortex and the representation of the lexical-semantics in the temporo-parietal cortex have been questioned. Three right-handed adult male neurosurgical patients undergoing left craniotomy for intractable seizures were evaluated using various grammatical and semantic tasks during cortical mapping. The sampling of language tasks consisted of trials with stimulation (experimental) and without stimulation (control) from sites in the dominant fronto-temporo-parietal cortex The sampling of language implicated a larger cortical area devoted to language (syntactic-morphological and lexical-semantic) tasks. Further, a large part of the fronto-parieto-temporal cortex was involved with syntactic-morphological functions. However, only the parieto-temporal sites were implicated with the ordering of lexicon in sentence construction. These observations suggest that the representation of language in the human brain may be columnar or multilayered.     

Termination in family therapy—developing a structural approach

Termination is a neglected topic within the major schools of family therapy that draw upon systemic frameworks. This paper attempts to develop a conceptual framework for understanding termination as a process which, if handled correctly, may have a surprising degree of therapeutic potential. Termination is therefore seen not just as a passive process of ending therapy, but as a potentially empowering process which can help clients from slipping back into old ways of functioning. Follow-up sessions can therefore be reconceptualized as integral steps in an active termination process which can be extended over a number of months. The precipitate ending of sessions may be justifiable from a theoretical point.of view within certain models, but within a structural framework (which places such a strong emphasis on joining) the effects of rapid termination may not only be counter-productive but may reflect underlying problems that reflect the needs of the therapist rather than the needs of the family that is in therapy.     

Dextrorphan effects on cocaine and brainstem perturbation

Dextrorphan is a noncompetitive blocker of N-methyl-D-aspartate (NMDA) receptors. Since NMDA blockers are known to reduce the locomotor stimulatory and toxic effects of cocaine, it was speculated that dextrorphan would attenuate cocaine-induced behavioral excitatory motor activity associated with and without mechanical perturbation of the brainstem. Technique: Motor activity was recorded following dextrorphan and/or cocaine challenge in 25 SHR rats. Ten were naive subjects. Mini-osmotic pumps delivering cocaine (2.5 mg/0.49 ul/hr) were placed in 15 subjects, and infusion was halted after the third infusion day. On the fifth day either a dextrorphan (25 mg/kg, subcutaneous) or a dextrorphan and cocaine (40 mg/kg, intraperitoneal) challenge was done. Ten rats had bipolar electrode implants in the bilateral brainstem. Five were treated with DC current lesions in each of 12 days over a 3-week period. The effects of brainstem lesions on escape behavior were also evaluated in those five subjects. Results: In the naive subjects, dextrorphan reduced motor activity (P=.0001), whereas combined cocaine and dextrorphan increased motor activity (P=0.04). In lesioned subjects, dextrorphan decreased motor activity (P=0.0001). In electrode implant subjects, combined dextrorphan and cocaine challenge decreased the motor activity (P=0.04). Hyperactivity in the electrode implant group was greater than in the lesioned subjects. Midbrain electrolytic lesions attenuated escape behavior. A variety of behaviors were produced by brainstem lesions. Conclusions: Dextrorphan and brainstem lesions reduced motor hyperactivity and escape behavior. In electrode implant subjects dextrorphan counteracted the expected cocaine excitatory motor effects. Dextrorphan did not activate nor facilitate seizures.     

Limbic stimulation-induced hypersexuality

Postictal sexual drive levels induced by limbic discharges were studied in eight adult male cats. Although sexual drive was exclusively dependent upon the presence or absence of testosterone, the level or degree of drive was dependent on the relative amounts of circulating testosterone and catecholamines in addition to the bioelectric state of the testosterone-binding cells. The limbic discharge was thought to induce postictal hypersexuality by its propagated discharge, suppressing the association neocortex and simultaneously activating the sexual hormone-binding cells of the diencephalon. The dissociation of the neocortex from the diencephalon was considered as a functional postictal diaschisis. These postictal physiologic changes were thought to account for the irrational automatic behavior and memory loss characteristic of patients with psychomotor seizures.