REM and non-REM dreaming: sleep stages and remembered stories

REM and non-REM describe sleep phases

NICHD describes sleep as cycling between REM and non-REM phases, with three non-REM stages. Their lengths change over the night; later portions generally include longer REM periods. These are physiological descriptions of sleep, not categories assigned from the plot of a dream.

The vocabulary becomes easier to use when you separate a phase from a personal report. “I remember a station” says what remains in memory. “A recording identified REM sleep” says what a measurement found. The second statement requires evidence beyond the station’s appearance.

Reading & context: Eunice Kennedy Shriver National Institute of Child Health and Human Development — What happens during sleep?[1]

Reports of dreaming occur in both phases

A 2017 study by Siclari and colleagues collected reports after awakening while recording brain activity. Reported dreaming was associated with particular measured activity during both REM and non-REM sleep. The study supports studying the experience within a sleep phase rather than treating all of that phase as one uniform mental state.

Its result is not a dictionary for a person’s story. A measured association with an experience does not explain why an imagined station contained your childhood teacher or what you should infer from the meeting. Those questions involve the report and possible personal associations.

Reading & context: Nature Neuroscience; PubMed abstract — The neural correlates of dreaming[2]

Vividness is a useful description, not a stage test

NICHD notes that dreams are generally most vivid in REM sleep while also occurring during non-REM sleep. That general association does not let you identify your own phase from one clear color, voice, or emotional moment.

In an invented example, you recall a bright green platform and a precise voice but little of what happened before them. The entry can accurately preserve both clear features. Adding “therefore this was REM” changes a remembered description into an unsupported measurement claim. You can leave the stage unknown and still have an interesting account.

Reading & context: Eunice Kennedy Shriver National Institute of Child Health and Human Development — What happens during sleep?[1]

A remembered report is not the whole night

Your notebook contains what you can recall and choose to write. A full scene, a fragment, and a blank page are different records, but none is a complete observation of every experience during sleep. Keep the record at the level available to you.

“No dream recalled” leaves more room than “I did not dream.” Similarly, one detailed entry does not establish how often you dreamed that night. This wording is useful because it shows the limit of the observation without treating the limit as a failure.

Read the study method before the headline

When a report links dreaming with a brain region or sleep stage, ask what the researchers measured and when the participant described the experience. Reports collected immediately after planned awakenings differ from stories written hours later, and a laboratory recording adds information a diary alone lacks.

Also ask whether the finding is an association, a proposed explanation, or a tested intervention. Those categories help prevent “linked with” becoming “causes every dream.” A careful explanation can be useful precisely because it states what remains unanswered.

Use notebook labels that match what you know

You can label an entry with the feature you actually noticed: vivid sound, uncertain sequence, awareness of dreaming, or an apparent awakening. These labels help you compare reports without pretending to classify your physiology.

If a later interpretation occurs to you, add it as a separate thought. The original report can remain unchanged while your questions develop. For concerns about sleep quality or persistent daytime effects, a healthcare professional can assess information beyond the dream story; a symbolic reading is not needed first.

• Report: what I remember of the experience.
• Timing: what I know, rather than estimate, about when I woke.
• Measurement: any actual information from a sleep assessment, kept separate.
• Question: what the record leaves open.