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Locomotor Inactivity During Sleep (LIDS)

Source: R/circadian_lids.R
lids.Rd

Quantifies the ultradian (sleep-cycle) oscillation of inactivity during sleep, following Winnebeck et al. (2018). Within each sleep period the activity is summed into 10-minute bins, transformed to LIDS (100 / (activity + 1)), smoothed with a centered 30-minute moving average, and fit with an ultradian cosine over a scan of candidate periods; the best period is the interior peak that maximises the Munich Rhythmicity Index (MRI).

Usage

lids(
  counts,
  timestamps,
  sleep_periods,
  epoch_length = 60,
  smooth_minutes = 30,
  period_min = 30,
  period_max = 180,
  period_step = 5
)

Arguments

counts

Numeric activity vector.

timestamps

POSIXct (or parseable) timestamps, one per count.

sleep_periods

Data frame with in_bed_time and out_bed_time (same schema as social.jet.lag); one LIDS fit per period.

epoch_length

Epoch length in seconds (default 60).

smooth_minutes

Centered moving-average window in minutes (default 30).

period_min, period_max, period_step

Period scan grid in minutes (defaults 30, 180, 5).

Value

An object of class actiRhythm_lids: a per-period data frame (period in minutes, MRI, amplitude, Pearson r, ...) and the mean period and MRI across periods.

References

Winnebeck EC, Fischer D, Leise T, Roenneberg T (2018). “Dynamics and ultradian structure of human sleep in real life.” Current Biology, 28(1), 49–59. doi:10.1016/j.cub.2017.11.063 .