Details

Autor(en) / Beteiligte

• HORNE, J. A.
• BRASS, C. G.
• PETITT, A. N.

Titel

Circadian performance differences between morning and evening 'types'

Ist Teil von

• Ergonomics, 1980-01, Vol.23 (1), p.29-36

Ort / Verlag

London: Taylor & Francis Group

Erscheinungsjahr

1980

Quelle

Taylor & Francis Journals Auto-Holdings Collection

Beschreibungen/Notizen

• Two groups of subjects identified as either morning (M) or evening (E) types, determined by a self-assessment questionnaire, were measured for performance efficiency at a simulated production-line inspection task given for 15 sessions at different times of the waking day. Systematic fatigue and practice effects were minimised by a random presentation of these sessions over a series of days. Although there were no significant within- or between-group changes with circadian trends for items erroneously rejected, significant differences were apparent with the number of items correctly rejected. M types' correct rejection levels were significantly better than E types' in the morning, whereas they were worse during the evening. Whilst E types showed a steady improvement throughout the day, M types showed a general decline. A post-lunch dip in performance was quite evident for M types, but not for E types. In addition, the circadian trends in correct rejection levels and body temperature were highly positively correlated for E types, but a significant negative relationship between these parameters was found for M types. These findings are discussed.