Modifiers and Mechanisms of Loneliness Interventions

UCLA Loneliness Scale Version 3, which assesses self-reported loneliness. 20 items, rated as to how often the participant has felt a certain way in the prior month (e.g., "How often do you feel alone?") -- "never" (1), "rarely" (2), "sometimes" (3), or "often" (4). Higher scores indicate greater loneliness. However, some individual items must be reverse-coded so that higher total scores reflect greater loneliness (i.e., 1=4, 2=3, 3=2, 4=1). These items (e.g., "How often do you feel there are people you can turn to?") are items 1,5,6,9,10,15,16,19,20. Total scores range from 20 to 80, with higher scores representing a worse outcome (i.e., greater loneliness).

HF-HRV is derived by spectral analysis of the electrocardiograph (ECG) waveform collected during a rest period, and is a measure of parasympathetic control of the heart; Higher resting HF-HRV (absolute power of the high-frequency band (0.15-0.4 Hz) in ms-squared) reflects greater parasympathetic regulation of the heart.

Difference in response times (in milliseconds) to dots appearing in the location of a previously shown negative versus the neutral face.

Mean valence score during negatively valenced social pictures. The Self-Assessment Manikin is a non-verbal pictorial assessment technique that directly measures a person's affect in response to positive, negative, and neutrally valenced pictures. Affect valence is measured on a 9-point scale: 1 (very unpleasant) - 9 (very pleasant).

Difference in response time (ms) to judgments of semantic meaning (positive or negative) of spoken, socially-relevant words between congruent (e.g., negative social word-negative vocal tone) versus incongruent (e.g., positive social word-negative vocal tone) trials, indicating cognitive interference.

During the trials, a decision needs to be made about whether the orientation of a central stimulus is congruent or incongruent with a set of flanking arrows. Selective attention/cognitive inhibition is indicated by difference between response time (millisecond) on the congruent and incongruent conditions.

During each trial, the participant is required to match a stimulus on the top of the screen to one of two stimuli in the lower corners of the screen. In task-homogeneous blocks, the examinee performs either Task A (e.g., classifying shapes) or Task B (e.g., classifying colors). In task-heterogeneous blocks, the examinee alternates between the two tasks pseudo-randomly. Cognitive flexibility (or capacity for task switching) is derived as the difference in response time (milleseconds) between homogeneous and heterogenous blocks.