Behavioral and cardiac responses to emotional stroop in adults with autism spectrum disorders: influence of medication.
Antipsychotic medication reverses the usual link between heart-rate variability and task performance in adults with autism.
01Research in Context
What this study did
Researchers gave adults with autism an emotional Stroop task. They measured heart-rate variability while participants named the ink color of emotion words.
Some adults took antipsychotic meds, others did not. The team compared resting arousal and task responses between groups.
What they found
Adults with autism had lower resting arousal than typical adults. Medication blurred this difference.
The big twist: for medicated adults, higher heart-rate variability linked to worse task speed. For non-medicated adults, the link flipped.
How this fits with other research
van den Broek et al. (2006) and Weissman-Fogel et al. (2015) also saw blunted heart-rate reactivity in autistic adults under social stress. The new study shows pills can flip the usual link between arousal and performance.
Bal et al. (2010) found higher RSA predicted faster emotion recognition in autistic kids. Here, higher RSA predicted slower responses in medicated adults. Same measure, opposite outcome.
Perez et al. (2015) tested stimulants in autistic teens and saw no heart-rate group differences. The 2011 paper shows antipsychotics, not stimulants, change the direction of the RSA-performance tie.
Why it matters
If you test arousal as a marker, always note medication. A calm heart rate can signal either good regulation or drug effects. Before you use heart-rate variability to judge attention or anxiety, check the med sheet. One practical step: run a short baseline task, then compare medicated and non-medicated days within the same client.
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02At a glance
03Original abstract
Researchers have recently hypothesized that autism spectrum disorders (ASD) may be partly characterized by physiological over-arousal. One way to assess physiological arousal is through autonomic measures. Here heart period (HP) and parasympathetic activity measured by respiratory sinus arrhythmia (RSA) were examined in adults with ASD and matched controls at rest and during performance of an emotional Stroop task. Resting HP and RSA were lower in adults with ASD than in matched controls, consistent with hypothesized over-arousal in ASD. However, dividing the ASD group on the basis of antipsychotic medication usage revealed that group differences in autonomic arousal may be related to the effects of these medications or their correlates. Autonomic adjustments for Stroop performance were comparable across groups, but in the control group, larger RSA reductions were correlated with faster responding (i.e., better performance). This relation was reversed in the unmedicated ASD group and absent in the medicated ASD group. Findings highlight the importance of considering medication status in the recently burgeoning area of psychophysiological studies of autism.
Autism research : official journal of the International Society for Autism Research, 2011 · doi:10.1002/aur.176