Validation of the interoceptive accuracy scale (IAS) supports distinction between self-reported interoceptive accuracy and awareness

Abstract

Measures of the perception of the state of one’s own body (‘interoception’) can be categorized as one of several types. Most commonly, these measures are of: 1) the ability to form an accurate percept of the body’s state, 2) confidence in the accuracy of a specific interoceptive percept at a particular point in time, and 3) trait differences in the degree to which one is aware of interoceptive information. At present, however, there is a paucity of measures designed to assess trait differences in self-perceived interoceptive accuracy. This paper reports on the development of such a measure, the Interoceptive Accuracy Scale (IAS). Across six studies we report on the IAS factor structure, test-retest reliability, and its relationship with measures of trait interoceptive awareness, accuracy of interoceptive percepts, confidence in the accuracy of specific interoceptive percepts, and metacognition with respect to interoceptive accuracy (‘interoceptive insight’). Results support the distinction between individual differences in awareness of interoceptive information and in the accuracy of interoceptive perception, and suggest that both accuracy and awareness can be measured using both objective measures and self-report instruments such as the IAS.