Cortex Features
Cortex processes mindLAMP data through three tiers. Raw features fetch sensor and activity data from the LAMP API into a consistent format. Primary features are sparse, event-based โ they identify discrete events or periods (e.g., individual trips, screen-on bouts, location clusters) with variable counts per time range. Secondary features are dense, time-windowed โ they aggregate data into exactly one value per fixed time window (controlled by the resolution parameter, default 1 day), producing regular time-series suitable for statistical analysis.
Feature Tiersโ
Pipeline Overviewโ
Raw features virtualize low-level data streams into a consistent format, handling iOS/Android harmonization automatically. Primary features produce sparse output โ a variable number of discrete events per time range (e.g., a list of trips or screen-on bouts, each with start/end timestamps). Secondary features produce dense output โ exactly one value per time window (e.g., total daily screen time, daily step count), making them directly suitable for statistical analysis and clinical reporting.
Cortex automatically manages dependencies โ requesting a secondary feature like hometime triggers computation of all required primary and raw features. Raw features handle iOS/Android harmonization automatically, so downstream features receive uniform data regardless of the source platform.
Some features (screen_unlocks, text_number, visit_time, etc.) depend on iOS SensorKit data, available only on devices enrolled in Apple-approved research studies. Most deployments use the standard sensor equivalents instead. See the Secondary Features page for details.