Since McGhie & Chapman's (1961) pioneering work, there have been continual attempts to clarify the link between attentional disturbances observable in schizophrenics and their schizophrenic symptoms. Venables (1964, 1977) claims that this diminution is a consequence of a badly controlled arousal, resulting in an inadequate filtering at the level of sensory input. Although the notion of a faulty sensory filter is simple and intellectually satisfying, this idea rapidly met with articulate opposition. Broadbent himself, in 1971, revised his model to take into account the way in which semantic aspects influence selective attention, and proposed the existence of a second stage of information processing, coming after the sensory filter. It became increasingly clear that progress in understanding selective attention would depend upon more centrally-directed approaches. In 1935, Stroop developed an ingenious way of studying selective attention. In his task, an "automatic", overlearned task (reading short words aloud) is put into conflict with a slightly more difficult task (colour-naming): the subject has to name the colour of the ink in which a word is printed, but the word itself is the name of a different colour. For instance, when the word "blue" is written in red ink, the correct response is "red". Typically, subjects find it difficult to inhibit the reading response, and take significantly more time to name a colour that forms an incompatible word than take to name the colour of a row of letters "x". This increased reaction time for the incompatible condition is attributed to an "interference" caused by the verbal information contained in the double stimulus.(ABSTRACT TRUNCATED AT 250 WORDS)

Attention↗

PubMedDate not supplied

[Schizophrenia and selective attention].

A comparative study of selective attention was made on 22 schizophrenic inpatients, 18 non schizophrenic inpatients and a control of 22 non psychiatric adults. Signs of schizophrenia were quantified through the BPRS (Brief Psychiatric Rating Scale) and selective attention was expressed as the capacity to resist a distracting stimulus dimension in the Stroop word-colour test. The results indicated higher distractibility in schizophrenic patients, and a positive, significative relation was found between this interference and the "activation" cluster.

Adult↗

PubMedDate not supplied

[Neuropsychology of a psycho-organic syndrome caused by idiopathic hypoparathyroidism. Apropos of a case].

A case of organic psychosis secondary to an idiopathic hypoparathyroidism with intracranial calcifications affecting the basal ganglia and the cortico-medullary junction is described. The results of the skull X-ray, cerebral TACO and nuclear magnetic resonance imaging analyses are presented, as well as a battery of neuropsychological tests. In spite of the extensive calcifications found, deficits on the neuropsychological tests were minimal or non-existent; possible explanations of this discrepancy are discussed.

Adult↗

PubMedDate not supplied

[Hypofrontality and schizophrenia].

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Brain Mapping↗

PubMedDate not supplied

The effect of timing of a standard meal on the pharmacokinetics and pharmacodynamics of the novel atypical antipsychotic agent ziprasidone.

STUDY OBJECTIVE: To evaluate the influence of a high-fat meal on the pharmacokinetics and pharmacodynamics of the novel atypical antipsychotic drug ziprasidone. DESIGN: Open, randomized, three-way crossover study. SETTING: University-based research facility. SUBJECTS: Eight healthy male volunteers. INTERVENTIONS: Ziprasidone 20 mg was administered under fasting conditions (treatment A), and directly after (treatment B) and 2 hours after (treatment C) a standard high-fat breakfast. MEASUREMENTS AND MAIN RESULTS: Serial blood samples were obtained over 36 hours. Three objective psychometric tests were employed to evaluate daytime vigilance at baseline and 2 hours after each dose. Ziprasidone had a significant effect on area under the curve (AUC0-infinity), maximum serum concentration, and half-life (analysis of variance all p<0.05), with the mean AUC0-infinity being significantly greater (627.2 +/- 206.4 vs 371.0 +/- 126.5 ng x hr/ml, ANOVA with Bonferroni's criteria p<0.016) and half-life significantly shorter (4.7 +/- 0.8 vs 6.6 +/- 1.3 hrs, ANOVA with Bonferroni's criteria p<0.016) after treatment B compared with treatment A. Although similar trends were observed after treatment C compared with treatment A, the differences did not reach statistical significance when Bonferroni's correction criteria were applied (p>0.016). CONCLUSION: These data suggest an increase in systemic exposure to the highly lipophilic compound ziprasidone when taken after fatty foods, possibly due to improved drug dissolution and solubilization. The drug's longer half-life under fasting conditions may reflect dissolution-limited absorption, although this could not be directly assessed. Despite postprandial increases in ziprasidone AUC0-infinity and maximum concentration, daytime vigilance was not affected.

Adolescent↗