Active processing of declarative knowledge during REM-sleep dreaming

Area of Science:

• Cognitive Neuroscience
• Sleep Science

Background:

• Sleep plays a role in processing recently acquired knowledge.
• The extent of sleeper control over this processing, particularly non-volitional and non-conscious aspects, remains an area of investigation.

Purpose of the Study:

• To investigate whether and how cognitive concerns from prior waking influence the processing of recently acquired declarative knowledge during sleep.
• To determine if these concerns affect the accessibility and incorporation of learned information into dream content.

Main Methods:

• A delayed recall task involving 12 subjects who heard nonsense sentences before three sleep onsets.
• Awakenings during rapid eye movement (REM) sleep to collect dream reports and recall the last heard sentence.
• Comparison of sentence incorporation frequency during REM sleep with control conditions.

Main Results:

• Sentences heard before sleep onsets were more frequently incorporated into dream content compared to control sentences.
• The frequency of incorporation was higher for sentences associated with cognitive concerns.
• The manner or modalities of dream content elaboration did not differ based on sentence incorporation.

Conclusions:

• Cognitive concerns during waking can direct the access and processing of recently learned declarative knowledge during sleep.
• While concerns influence what information is processed, they do not alter how it is elaborated within dreams.
• This processing during sleep, guided by cognitive concern, may contribute to the consolidation of knowledge.