Key points are not available for this paper at this time.
Two experiments are described that examined the influence of time of day of presentation on immediate and delayed retention, and the potential effects of time of day on retrieval from long‐term memory. Time of presentation was found to influence both the immediate and delayed (28 day) retention of information presented in naturalistic contexts. However, while the trend in immediate memory over the normal waking day found in Expt 1 was exactly that predicted by a unidimensional arousal theory, the results of Expt 2 indicated that different circadian factors may be responsible for the time of presentation effects on immediate and delayed retention. Neither experiment yielded any evidence that time of day affects people's ability to retrieve information from long‐term memory. The results are discussed within a circadian rhythm framework, and would appear to necessitate the adoption of a multifactor theory. It is suggested that further research is needed on (a) the effect of time of presentation on delayed retention, and (b) the nature of the changes in the encoding/storage processes responsible for such effects.
Folkard et al. (Thu,) studied this question.