Three problems regarding medical triage

This paper presents preliminary solutions to three conceptual problems posed by the use of triage to sort candidates for scarce medical resources: (1) By what criteria are the candidates grouped? (2) To what extent can triage be justified? (3) Under what conditions are different versions of triage equivalent? Four explicit methods of applying triage are described and compared, with the aid of examples. The extent to which they either maximize expected utility or show cost-benefit dominance is discussed. And cases in which one triage method reduces to another are contrasted with others where no such reduction occurs.     

Conditional mechanisms of decision making

Decision making is an important link in the central part of a reflex—the “mental element” according to Sechenov. The reflex nature of this mental process is revealed in experiments where a voluntary motor reaction is chosen unconsciously as a response to subliminal conditional visual stimuli. Thus, learning which is reflected by “advance” or prior decision making can be performed unconsciously through a conditional reflex. But, once elaborated, temporary connections are preserved only in shortterm memory. They are not transferred to long-term memory, as in the case of recognition of signals. Decision making, being the central mental part of the reflex, like any activity of the brain, is performed in time by a certain cortical structure. Analysis of P₃₀₀ amplitudes shows that decision making is related to local activation of the frontal parts of the cerebral hemispheres. We suggest that the local activation of these areas is induced by conditional excitation of the neuronal mechanisms of focused attention. It provides a “command” to perform a voluntary motor reaction adequate to the conditions at hand. A large part of latency of voluntary motor response of man is spent on decision making, especially in discrimination of signals and in choice of reactions.     

Reaction time measurement errors resulting from the use of CRT displays

Three sources of potential error in reaction time measurement may occur when raster scan CRT displays are used to present stimuli: phosphor persistence, sweep delay, or transmission delay. For most applications, only the third source of error is likely to be significant.     

The relationship of extraversion,neuroticism, and sensation-seeking to questionnaire-derived measures of nervous system properties

Five obliquely rotated factor analyses were performed on items from Eysenck and Eysenck’s (1975) EPQ, Zuckerman’s (1975) Sensation-Seeking Scale, and Strelau’s (1972) temperament inventory (STI), administered to 277 subjects (Ss). The analyses were used to examine the relationships between the personality dimensions E, N, L, P and Sensation-Seeking, which pertain mainly to social situations, attitudes and feelings, and questionnaire-derived measures of nervous system properties, which, while validated on experimental indices of nervous system properties derived from Nebylitsyn’s (1972) model, are expressed as characteristic features of social behavior, work style and activity. Four factors were identified—extraversion/strength of excitation/mobility; self-control of affect/stability/caution; strength of inhibition/verbal control/motor expressiveness/ nonmanipulativeness; and sensation-seeking/nervousness. The results offer support for Eysenck’s claim of some identity between excitatory strength and E, for the reported relationship between E and mobility, and for Eysenck’s conditioning postulate. They also suggest that similar temperamental variables underlie individual differences in both social and occupational/motor activity. Since Strelau’s STI items are validated on experimental indices of nervous system properties, it follows that typological characteristics may be inferred from questionnaire data derived from both behavioral categories.     

A method for the analysis of complex avian song repertoires

A new method for the analysis of complex avian song repertoires is introduced. The method consists of sending a tape-recorded bird-song signal through five narrow band-pass filters and then to a five-channel high-speed pen recorder. A coding method that allows a researcher to convert the output from the pen recorder to numbers for later analysis by computer is described.     

Dynamic visual noise and the stereophenomenon: Interocular time delays,depth, and coherent velocities

Attention, Perception, & Psychophysics - This study concerns the stereophenomenon obtained with binocular viewing of dynamic visual noise with a neutral density filter over one eye. Such a...     

Target-size influences on reaction time with movement time controlled

The variable that affect motor programming time may be studied by changing the nature of the response and measuring the subsequent changes in reaction time (RT). One notion of motor programming suggests that aiming responses with reduced target size and/or increased target amplitude require more "complex" motor programs that require longer RTs. In a series of five experiments which movement time (MT) was experimentally varied target size neither influences RT when the movement amplitude was 2 or 30 cm nor when the target sizes differed by as much as a factor of 16:1. Increasing the movement amplitude from 15 to 30 cm also had no influence on RT. Movement time, however, did affect RT, with 200-msec movements having longer RTs than 120-msec movements. Target size and movement amplitude did not appear to be factors that influence programming time or program complexity.     

The memory drum theory after twenty years: comments on Henry's note

The difference between the Henry "memory-drum" theory and our version is that ours includes, an additional assumption that, after programming has occurred, the resultant representation can be stored in short-term memory. Otherwise, the essential ideas are the same in the two theories. Implications of the presently available data for the distinction between the theories are discussed. Regardless of how one evaluates our added assumption, it is clear that the essential insight of the Henry theory has fared very well in the 20 years since the theory first appeared in print.