title: Quadratic trend analysis and heartbeat detection.
abstract: In heartbeat detection tasks based on the Method of Constant Stimuli (MCS), subjects judge the simultaneity between their heartbeats and stimuli presented at six intervals ranging from 0 to 500 ms after the R-waves on an electrocardiogram. Because research suggests that subjects do not perceive stimuli at 0 or 500 ms as simultaneous, individual performance was indexed with quadratic trend analysis to test for distributions of simultaneity judgments across intervals that peak between 0 and 500 ms. Further, because some tasks use only two intervals, performance was also indexed using intervals of either 0 and 200 ms or 200 and 500 ms. Continuous performance scores from quadratic trend and two-interval analysis tended to correlate more highly with variables previously shown to correlate with heartbeat detection than scores from the commonly-used chi(2) analysis. These findings support the use of both quadratic trend analysis and two-interval tasks for assessing heartbeat detection ability.
authors.affiliation: State University of New York at Stony Brook, Stony Brook, NY, USA. stefan.wiens@cns.ki.se
authors.forename: S
authors.initials: S
authors.lastname: Wiens
authors.forename: S N
authors.initials: SN
authors.lastname: Palmer
mesh_terms: D000293:Adolescent; D000328:Adult; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D010465:Perception