The effects of priming with age stereotypes on a PC-based mail-sorting task.

OBJECTIVE: This study examines whether unconscious priming of attitudes towards older age might change the self-efficacy of older employees, and thus modify their performance at work. METHODS: Three age- and gender-matched groups of 20 participants were primed with positive, negative or no age stereotypes by means of the scrambled sentence task, and were then transferred to a cognitively demanding PC-based mail-sorting task. RESULTS: Participants' accuracy on the latter task was significantly higher in the positively primed group than in the unprimed group, and was significantly lower in the negatively primed group than in the unprimed group, except for one parameter. CONCLUSIONS: These findings indicate that the performance of older workers may indeed be modifiable by unconscious priming. Practitioner Summary: This study analyses whether unconscious priming attitudes towards older age might modify work performance. Participants were primed with the scrambled sentence task and then conducted a cognitive mail-sorting task. The findings indicate that the performance of older workers may indeed be modifiable by unconscious negative as well as positive priming.

Relation between Multiple Markers of Work-Related Fatigue.

BACKGROUND: Work-related fatigue has a strong impact on performance and safety but so far, no agreed upon method exists to detect and quantify it. It has been suggested that work-related fatigue cannot be quantified with just one test alone, possibly because fatigue is not a uniform construct. The purpose of this study is therefore to measure work-related fatigue with multiple tests and then to determine the underlying factorial structure. METHODS: Twenty-eight employees (mean: 36.11; standard deviation 13.17) participated in five common fatigue tests, namely, posturography, heart rate variability, distributed attention, simple reaction time, and subjective fatigue before and after work. To evaluate changes from morning to afternoon, t tests were conducted. For further data analysis, the differences between afternoon and morning scores for each outcome measure and participant (Δ scores) were submitted to factor analysis with varimax rotation and each factor with the highest-loading outcome measure was selected. The Δ scores from tests with single and multiple outcome measures were submitted for a further factor analysis with varimax rotation. RESULTS: The statistical analysis of the multiple tests determine a factorial structure with three factors: The first factor is best represented by center of pressure (COP) path length, COP confidence area, and simple reaction time. The second factor is associated with root mean square of successive difference and useful field of view (UFOV). The third factor is represented by the single Δ score of subjective fatigue. CONCLUSION: Work-related fatigue is a multidimensional phenomenon that should be assessed by multiple tests. Based on data structure and practicability, we recommend carrying out further studies to assess work-related fatigue with manual reaction time and UFOV Subtest 2.

On the relationship between subjective and objective measures of fatigue.

OBJECTIVE: Objective and subjective methods have been used in the past to assess workplace fatigue, but little is known about correlations between them. We examine correlations between subjective and objective measures, including measures collected in a workplace scenario. METHODS: 15 young and 17 older participants were assessed before and after work with four types of fatigue measure: objective physical (posturography), objective mental (psychomotor vigilance task), subjective physical and mental (self-assessment), objective and subjective realistic (oculomotor behaviour, observer-rated facial expression, typing performance). RESULTS: Pre- and post-test scores were analysed with an ANOVA, significant differences were submitted to a factor analysis. It yielded three factors: one representing posturography, the second self-rated mental and physical fatigue and the third observer-rated facial expression. CONCLUSIONS: Results advocate the existence of three independent fatigue components: Objective physical fatigue, introspective and extrospective fatigue. Practitioner Summary: This study analyses correlations between different subjective and objective fatigue markers to better understand the complex nature of workplace fatigue. Measurements were conducted directly at the workplace. Results reveal that fatigue comprises three independent fatigue components: Objective physical fatigue, introspective and extrospective fatigue.

Body Sway as a Possible Indicator of Fatigue in Clerical Workers.

BACKGROUND: Fatigue has a strong impact on workers' performance and safety, but expedient methods for assessing fatigue on the job are not yet available. Studies discuss posturography as an indicator of fatigue, but further evidence for its use in the workplace is needed. The purpose of the study is to examine whether posturography is a suitable indicator of fatigue in clerical workers. METHODS: Thirty-six employees (Ø 34.8 years, standard deviation = 12.5) participated in postural tasks (eyes open, eyes closed, arm swinging, and dual task) in the morning and afternoon. Position of their center of pressure (COP) was registered using a Nintendo Wii Balance Board and commercial software. From registered COP time series, we calculated the following parameters: path length (mm), velocity (mm/s), anterior-posterior variance (mm), mediolateral variance (mm), and confidence area (mm(2)). These parameters were reduced to two orthogonal factors in a factor analysis with varimax rotation. RESULTS: Statistical analysis of the first factor (path length and velocity) showed a significant effect of time of day: COP moved along a shorter path at a lower velocity in the afternoon compared with that in the morning. There also was a significant effect of task, but no significant interaction. CONCLUSION: Data suggest that postural stability of clerical workers was comparable in the morning and afternoon, but COP movement was greater in the morning. Within the framework of dynamic systems theory, this could indicate that the postural system explored the state space in more detail, and thus was more ready to respond to unexpected perturbations in the morning.