Memory and Time of Day

Abstract

Subjects performed a memory task on two occasions, one in the morning and the other in the afternoon. The task comprised two components, one involved immediate recall of sequences of nine digits, the other involved the repeated item technique devised by Hebb (1961), in which one nine-digit sequence is surreptitiously repeated, each repetition being separated by two non-repeated sequences. Performance on the immediate memory task was better in the morning than the afternoon. The repeated item was recalled more accurately than non-repeated items, but this effect was not influenced by time of day. An explanation in terms of the relationship between arousal and memory reported by Kleinsmith and Kaplan (1963) is suggested.

Time of day and level of processing

“…In the case of immediate retention, presentation in the morning has fairly consistently been found to result in superior performance to presentation later in the day (e.g., Baddeley, Hatter, Scott, & Snashall, 1970;Blake, 1967;Folkard & Monk, 1979;Folkard, Monk, Bradbury, & Rosenthall, 1977;Gates, 1916aGates, , 1916bHockey, Davies, & Gray, 1972;Laird, 1925). In contrast, the available evidence indicates that delayed retention is superior following presentation in the afternoon or evening (Baddeley et a1., 1970;Hockey et al, 1972;Folkard & Monk, in press;Folkard et a1., 1977;.…”

Investigation of task performance variations according to task requirements and alertness across the 24-h day in shift workers

“…Strategy changes in relation to arousal changes have also been proposed to account for performance variations observed in laboratory studies. In the morning, when arousal was low, performance was shown to peak in those tasks involving more automatic processing, while increasing arousal across the day would favour more elaborate processing, like processing of semantic aspects from long-term memory (Baddeley et al, 1970;Folkard, 1979;Folkard et al, 1976;Folkard & Monk, 1980;Lorenzetti & Natale, 1996;Oakhill & Davies, 1989). This hypothesis was favoured by the finding of significant correlations between operators' self-rated alertness and their task performance.…”

“…A reduction in response speed during the night coincident with an increase in response accuracy, suggested a strategy change rather than a global nocturnal performance drop (Monk & Carrier, 1997). When the emphasis was on short-term memory processing, superior performance was reported in the morning, while for longterm memory tasks performance peaks were observed on the late afternoon (Baddeley, Hatter, Scott & Snashall, 1970;Folkard, Knauth, Monk, & Rutenfranz, 1976;Folkard & Monk, 1980; Oakhill & Davies, 1989).…”

Circadian rhythms in cognitive performance: implications for neuropsychological assessment

“…42,43 Baddeley et al 44 proposed a model of working memory that includes three storage components: phonologic, visuospatial, and an episodic buffer. The phonologic component stores verbal information, the visuospatial component stores visual information in a spatial map, and the episodic buffer component is a limited capacity temporary storage that integrates information from different sources into coherent episodes.…”