Adult age differences in the speed and capacity of information processing: 2. An electrophysiological approach.

A total of 60 subjects performed different variants of the Sternberg memory search task in an experiment designed to evaluate aging differences in the speed of the human information-processing system. The present study examined the nature of the age-related slowing using convergent methodologies of Sternberg's additive factors logic, the speed-accuracy trade-off, and the P300 component of the event-related brain potential. These methodologies revealed that a substantial component of slowing was manifest in perceptual encoding, response criterion adjustment, and response execution, with a lesser component related to memory search speed.

Age differences in the speed and capacity of information processing: 1. A dual-task approach.

Sixty subjects, spanning the age range from 20 to 65, performed a series of tasks designed to evaluate the effects of aging on the speed and capacity of the human information-processing system. A tracking task was performed alone and concurrently with different versions of a Sternberg memory search task that varied the degree of resource competition with the tracking task. A dichotic-listening task, a tracking-task measure of perceptual-motor speed, and a complex transcription task were also performed. The data revealed a monotonic decrease in processing speed with age but no difference in time-sharing abilities between age groups. The latter conclusion was supported by a factor analysis of the test scores, which revealed that scores on the factor defining time-sharing did not differ with age.

Towards an internal model in pilot training.

Optimal decision making requires an information seeking behavior which reflects the comprehension of the overall system dynamics. Research in the area of human monitors in man-machine systems supports the notion of an internal model with built-in expectancies. It is doubtful that the current approach to pilot training helps develop this internal model in the most efficient way. But this is crucial since the role of the pilot is changing to a systems' manager and decision maker. An extension of the behavioral framework of pilot training might help to prepare the pilot better for the increasingly complex flight environment. This extension is based on the theoretical model of schema theory, which evolved out of psychological research. The technological advances in aircraft simulators and in-flight performance measurement devices allow investigation of the still-unresolved issues.

[Intraoperative liver biopsy for gall-bladder disorders (author's transl)]. / Zur Frage der intraoperativen Leberbiopsie bei Gallenwegserkrankungen.

447 liver biopsy samples were taken during surgery for gall bladder disorders. Defined relations between histologic gallbladder and liver findings and also between duration of illness and liver changes could not be established. In more than 90% of the cases there were only minor pathologic findings so that a routine application of this method is not necessary and should be restricted to selected cases.

[Recurrent gastrointestinal hemorrhage in a gastric neuroma]. / Rezidivierende gastrointestinale Blutung bei einem Magenneurom.

Ulceration of the gastric mucous membrane and acute gastric haemorrhage are feared complications of a gastric neuroma. It is reported on a patient of 42 years who had recurrent gastrointestinal haemorrhage in spite of the resection of his stomach. By gastroscope an ulcus was proved paracardially in the upper corpus. The ulcus rendered post operationem as exulcerized neuroma by histologic test.