Tonic and phasic co-variation of peripheral arousal indices in infants.
Bottom Line: Tonic pupil size showed significant positive covariation, but phasic pupil changes were inconsistent.We conclude that: (i) there is high covariation between autonomic indices in infants, but that EDA may only be sensitive at extreme arousal levels, (ii) that tonic pupil size covaries with other indices, but does not show predicted patterns of phasic change and (iii) that motor activity appears to be a good proxy measure of ANS activity.The strongest patterns of covariation were observed using epoch durations of 40s per epoch, although significant covariation between indices was also observed using shorter epochs (1 and 5s).
Affiliation: Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK. Electronic address: firstname.lastname@example.org.Show MeSH
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Mentions: The battery lasted approximately 20 min per participant (see Fig. 1) and involved static images and infant-appropriate animations and TV clips. It was generally presented unbroken in one block, although if the infant had become distressed a break was taken during testing and the battery re-commenced. Viewing materials consisted of: (i) five television clips taken from infant- and child-directed BBC television programs; (ii) two clips of smiling infants and two clips of crying infants; (iii) five blocks of a sequence learning task; (iv) three blocks of a familiarisation and visual paired comparison task; (v) three blocks of a reversal learning task; (vi) a series of calibration and pupil size checks. Subsequent analyses will examine arousal changes relative to different cognitive tasks. The present analyses focus on the degree to which changes in one arousal index tended to be associated with changes in another, and have therefore been conducted on data pooled across all tasks.
Affiliation: Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK. Electronic address: email@example.com.