Study objectives: Visual short-term memory (VSTM) is an important measure of information processing capacity and supports many higher-order cognitive processes. We examined how sleep deprivation (SD) and maintenance duration interact to influence the number and precision of items in VSTM using an experimental design that limits the contribution of lapses at encoding.
Design: For each trial, participants attempted to maintain the location and color of three stimuli over a delay. After a retention interval of either 1 or 10 seconds, participants reported the color of the item at the cued location by selecting it on a color wheel. The probability of reporting the probed item, the precision of report, and the probability of reporting a nonprobed item were determined using a mixture-modeling analysis. Participants were studied twice in counterbalanced order, once after a night of normal sleep and once following a night of sleep deprivation.
Setting: Sleep laboratory.
Participants: Nineteen healthy college age volunteers (seven females) with regular sleep patterns.
Interventions: Approximately 24 hours of total SD.
Measurements and results: SD selectively reduced the number of integrated representations that can be retrieved after a delay, while leaving the precision of object information in the stored representations intact. Delay interacted with SD to lower the rate of successful recall.
Conclusions: Visual short-term memory is compromised during sleep deprivation, an effect compounded by delay. However, when memories are retrieved, they tend to be intact.
Keywords: Capacity limits; sleep deprivation; visual short-term memory.