Interactions of alcohol and caffeine on human reaction time.

Eight naive subjects (4 males and 4 females) took part in an experiment to investigate the direction of the interactive effects of alcohol and caffeine on reaction time. Subjects were tested under each of four conditions on separate occasions: no alcohol + no caffeine; no alcohol + caffeine; alcohol + no caffeine; and alcohol + caffeine. Alcohol was given in the form of 65.5 degrees proof vodka in the quantity of 2.2 ml/kg body weight; caffeine was given in the form of crushed 150-mg tablets in decaffeinated coffee. Under these conditions the experiment demonstrated that caffeine has a synergistic interaction with alcohol. Furthermore, using Sternberg's (37) additive-factor method, it was shown that the effects of both alcohol and alcohol + caffeine occur mainly at the peripheral stages of information processing (i.e. at the stimulus input and response output) rather than centrally.

Kidney donation--where some of the problems lie.

If a viable kidney transplant programme is to be continued on a national basis, many of the problems at present surrounding organ transplantation must be tackled urgently. This paper discusses the psychological and emotional problems which are presently seen to hinder a successful renal transplantation policy, and considers the relative advantages and disadvantages of the kidney donor card scheme.

The role of social space requirements in ergonomics.

This paper argues that, in addition to physical limitations inherent in the situation, account must be taken of social space requirements when designing systems in which people are placed in close proximity to each other. Personal space and territoriality are discussed to illustrate such problems.

Passenger comfort--an overview.

In transport it is axiomatic that passenger comfort is extremely important. This paper considers the concept of comfort and its relationship to the passenger's other travel experiences. The papers which follow in this special issue are then introduced and briefly discussed. The paper concludes with a section which considers factors in the transport environment likely to influence comfort but which have not been covered elsewhere in this issue. These factors include: temperature, ventilation, illumination, photic stimulation, pressure changes on the ear, journey length and task impairment.

Vibration and passenger comfort: Can data from subjects be used to predict passenger comfort?

This paper presents a review of both field and laboratory studies of human reaction to vibration, to try to answer the question whether laboratory based studies may be used to predict comfort levels for passenger vehicles. The conclusion is reached that such studies may be used, provided their restrictions are understood. Finally, tentative suggestions are made for acceptable levels of vibration in passenger transport vehicles.

The anatomy of a volunteer blood donation system.

This paper describes a questionnaire and interview study to determine motivational factors important in blood donor, nondonor and exdonor behaviors. From the results, a model of blood donor behavior was developed from which certain predictions of donor behavior could be made.

Techniques available for the assessment of passenger comfort.

This paper considers the many techniques which are available to the ergonomist for the assessment of passenger comfort. It is argued that the initial question to be answered asks whether the system as a whole is to be investigated or whether specific aspects of the journey are under consideration. If the answer is the former, then a questionnaire technique is suggested. If an investigation of a more specific nature is required, then consideration should be given to whether it is to be conducted in the 'field' using passengers, in the 'field' using subjects, or in the laboratory. Techniques such as rating scales, observation, paired comparison, and the semantic differential are described, although many other laboratory based techniques are available.

Vibration and passenger comfort.

The problems of maintaining the well-being of passengers travelling by public transport are complex. They include psychological, physical and organisational considerations all of which may interact to provide an overall, individual comfort reaction. Since it is a fundamental feature of vehicle design, the paper considers the effects of vehicular vibration on passenger comfort. The results of a series of questionnaire investigations to examine both the qualitative and quantitative effects of vibration are reported.

Examples of the use of rating scales in ergonomics research.

The majority of ergonomics investigations using rating scales employ either an analogue or a category type of scale. Both have their limitations. This paper discusses a method of combining the two scales to produce a valuable assessment tool for the ergonomist. Examples of its use in both laboratory and field situations are discussed, as are its limitations.

Questionnaire surveys of passenger comfort.

This paper discusses the quantitative assessment of data obtained from questionnaire surveys. Examples are adduced from surveys carried out from Swansea. After discussing the validity of information derived in this way, general methods of assessment are described. The paper continues with a detailed examination of questionnaire methods of the subjective assessment of environmental stimuli, and concludes with examples of the pitfalls which may be inherent in such assessment.