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: email@example.com.Show MeSH
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Mentions: Next, we examined phasic changes relative to experimenter-determined, external events. In order to examine this, a segment of our testing battery was excerpted. This segment was the stimulus change at the start of a “visual paired comparison” experiment, which is similar to the dishabituation measure widely used in infant research (e.g. Sokolov, 1963). Infants were habituated to a picture of a child’s face. Once the infant had reached habituation point (as judged using standard infant-controlled habituation criteria (Colombo & Mitchell, 2009), the stimulus changed and was replaced by the previously habituated picture together with a novel, previously unseen, picture of another child’s face. The moment of stimulus change is marked as time 0 in Fig. 7. A segment from 8 s prior to the stimulus change to 10 s after the stimulus change was excerpted. 3 blocks were presented per infant, at different stages of the testing protocol, and results were averaged across blocks (see Fig. 1).
Affiliation: Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK. Electronic address: firstname.lastname@example.org.