Individual differences in the effects of time of day and passage difficulty on prose memory in adults

The study under report examined the effects of time of day on prose recall in morning‐ and evening‐type individuals. Subjects listened to two easy and two difficult passages at either 09.00, 14.00 or 20.00. Immediately after listening to a taperecorded version of each story, subjects were asked to write their recalls. The results indicated that recall decreased across time of day for morning types but increased for evening types. The effects of importance level were similar for passages at both difficulty levels at all times of day; however, time‐of‐day effects were largest for highly important‐idea units from difficult passages. The results demonstrated that time of day influences immediate recall of prose in adults, and the pattern of these effects depended upon whether the subject was a morning or evening type. It was suggested that subsequent examinations of time of day and prose memory should utilize concurrent measures of encoding effort to assess whether processing strategies change across time of day.