Comparison of video- and EMG-based evaluations of the magnitude of children's emotion-modulated startle response.

We investigated the reliability and validity of a video-based method of measuring the magnitude of children's emotion-modulated startle response when electromyographic (EMG) measurement is not feasible. Thirty-one children between the ages of 4 and 7 years were videotaped while watching short video clips designed to elicit happiness or fear. Embedded in the audio track of the video clips were acoustic startle probes. A coding system was developed to quantify from the video record the strength of the eye-blink startle response to the probes. EMG measurement of the eye blink was obtained simultaneously. Intercoder reliability for the video coding was high (Cohen's kappa = .90). The average within-subjects probe-by-probe correlation between the EMG- and video-based methods was .84. Group-level correlations between the methods were also strong, and there was some evidence of emotion modulation of the startle response with both the EMG- and the video-derived data. Although the video method cannot be used to assess the latency, probability, or duration of startle blinks, the findings indicate that it can serve as a valid proxy of EMG in the assessment of the magnitude of emotion-modulated startle in studies of children conducted outside of a laboratory setting, where traditional psychophysiological methods are not feasible.

Temperament, tympanum, and temperature: four provisional studies of the biobehavioral correlates of tympanic membrane temperature asymmetries.

Previous research in both humans and nonhuman primates suggests that subtle asymmetries in tympanic membrane (TM) temperatures may be related to aspects of cognition and socioaffective behavior. Such associations could plausibly reflect lateralities in cerebral blood flow that support side-to-side differences in regional cortical activation. Asymmetries in activation of the left and right frontal cortex, for example, are correlates of temperamental differences in child behavior and markers of risk status for affective and anxiety disorders. Tympanic membrane temperatures might thus reflect the neural asymmetries that subserve individual differences in temperament and behavior. This report merged findings from four geographically and demographically distinctive studies, which utilized identical thermometry methods to examine associations between TM temperature asymmetries and biobehavioral attributes of 4- to 8-year-old children (N = 468). The four studies produced shared patterns of associations that linked TM temperature lateralities to individual differences in behavior and socioaffective difficulties. Warmer left TMs were associated with "surgent," affectively positive behaviors, whereas warmer right TMs were related to problematic, affectively negative behaviors. Taken together, these findings suggest that asymmetries in TM temperatures could be associated with behavior problems that signal risk for developmental psychopathology.

Revealing the relation between temperament and behavior problem symptoms by eliminating measurement confounding: expert ratings and factor analyses.

This study examined the hypothesis that item overlap, or measurement confounding, accounts for the correlation between temperament and behavior problem symptoms in children. First, a conceptual approach was taken in which 41 experts rated temperament (Children's Behavior Questionnaire, CBQ) and behavior problem symptom items (Preschool Behavior Questionnaire, PBQ) for their fit to both constructs. With this approach, 10% of temperament and 38% of symptom items were confounded. Second, an empirical approach was taken and CBQ and PBQ items were factor analyzed with data from a multi-informant longitudinal study of 451 children. Using this method, 9% of temperament and 23% of symptom items were confounded. Most importantly, removing the confounded items from the CBQ and PBQ scales did not affect the relation between temperament and symptoms, suggesting that the associations were not due to measurement confounding. In addition, the predictive power of earlier temperament for DSM-IV symptoms (Health and Behavior Questionnaire) remained high with the purified CBQ scale. The findings of this study contribute to the understanding of the relation between normal-range temperament and extreme behavior.