Modality shift effect in psychiatric disorders - a new look at an old paradigm.

Background: There is a long tradition of reaction time studies in experimental psychopathology. Even though a diminishing interest in this paradigm has been seen over the last years, it is in line with more recent biological approaches to examine psychiatric disorders cross-diagnostically.

Methods: Patients (n=95) with a positive subtype of schizophrenia (n=22), a negative subtype of schizophrenia (n=18), a full major depressive episode (n=19), a full manic episode (n=16), or a mood disorder in remission (n=20) and subjects with no known psychiatric disorder (n=30), respectively, participated in a computer-based reaction time test consisting of four trials with 55 short visual and auditory stimuli presented in a random sequence.

Is the modality-shift effect specific for schizophrenia patients?

Several studies have found that the reaction time of schizophrenia patients is longer when successive imperative stimuli are of different modality (e.g., light followed by sound) than when they are identical (e.

A method for measurement of the bubble formation threshold in biological liquids.

Liquid under pressure is saturated with a given gas, such as argon, nitrogen, or air, by circulation through a column of gas exchangers. A sample of the gas-saturated liquid is isolated in a test chamber, the volume of which can be increased by means of a moving piston. The piston motion is cyclical with a variable frequency.

The international reference preparation of influenza virus haemagglutinin (type A).

This paper describes the international collaborative assay that led to the establishment in 1967 of the International Reference Preparation of Influenza Virus Haemagglutinin (Type A) and the studies completed during the following years on the use of the preparation for evaluating the haemagglutinin content of 46 influenza virus vaccines in terms of international units. The WHO Expert Committee on Biological Standardization (1967) defined the International Unit as 0,09361 mg of the International Reference Preparation.Altogether 14 laboratories in 12 countries took part in one or both studies, using a total of 24 methods (HA titrations and, in a few cases CCA titrations).