A facial wearable device for providing external stimuli to a user comprises a foldable frame, a flexible layer, an airbag layer, a plurality of heating pads, a plurality of vibrating motors, and a sensor. The flexible layer may couple to a proximal side of the foldable frame and be configured to couple to a facial area of the user. The airbag layer may be disposed between the foldable frame and the flexible layer and comprise a plurality of inflatable bladders configured to provide pressure to the facial area of the user. The plurality of heating pads may couple to the flexible layer and be configured to provide heat to the facial area of the user. The plurality of vibrating motors may couple to the flexible layer and be configured to provide vibration to the facial area of the user. The sensor may couple to the flexible layer and be configured to detect biometric data of the user. At least one of the plurality of inflatable bladders, the plurality of heating pads, and the plurality of vibrating motors may be controlled based on the biometric data.

Distributed feedforward-circuitry that uses an environmental information as a feedforward variable includes an environmental-information source and remote circuitry that is remote from the environmental-information source and configured to receive environmental information from the environmental-information source. The remote circuitry includes a machine-learning system, a target-feature set, and a controller. The machine-learning system has been trained to correlate environmental information and psychoacoustic features with mental state. The target feature set, which is generated by the machine-learning system, comprises a psychoacoustic feature for inclusion in a music stimulus that is to be provided to the subject. The controller causes formation of the music stimulus based on the psychoacoustic feature.