UEL Baby Dev Lab

Learning and the autonomic nervous system: understanding interactions between stress, concentration and learning during early childhood.

Wass, S., De Barbaro, K., & Clackson, K. 2016. Frontiers in Neuroscience

Predominant accounts explaining links between early looking behavior and later cognitive outcomes emphasize static individual differences in information encoding; however, work from Aston-Jones and colleagues suggests that looking behavior may be dynamically influenced by ongoing, phasic changes in autonomic arousal. To test the Aston-Jones model, a 20-minute testing battery constituting mixed photos and cartoon clips was shown to 53 typical 12-month-olds. Look duration was recorded to index attention, and continuous changes in arousal were tracked by measuring heart rate, electro-dermal activity and movement levels. Across three analyses we found that continuous changes in arousal tracked simultaneous changes in attention measures, as predicted by the Aston Jones model. We also found that changes in arousal tended to precede (occur before) subsequent changes in attention.

In a second study, we investigated causal interactions between attention and arousal by applying, over a 2-week training period, targeted cognitive training to a cohort of 12-month-old infants, aimed at strengthening the voluntary control of visual attention. Before and after training, and relative to an active control group, infants’ attentional control capacity and autonomic arousal were measured. Training was found to lead to marked changes in infants’ behaviour, across a number of different tasks, but infants’ autonomic arousal was unchanged following training. Changes in autonomic arousal remained as predictive of looking behaviour after training, as before. This suggests that arousal and voluntary attention control have separable influences on looking behaviour in infants.

In a third study we examined whether infants with more labile (sensitive) autonomic arousal patterns showed better, or worse, performance on learning tasks. Previous research has suggested that acute stress attenuates frontal lobe functioning and increases distractibility while enhancing subcortical processes in both human and nonhuman animals (Arnsten, 1998, Arnsten et al., 1998, Skosnik, 1999). To date however these relations have not been examined for their potential effects in developing populations. We examined the relationship between stress reactivity (infants’ heart rate response to watching videos of another child crying) and infant performance on measures of looking duration and visual recognition memory. Our findings indicate that infants with increased stress reactivity showed shorter look durations and more novelty preference. Thus, stress appears to lead to a faster, more stimulus-ready attentional profile in infants. Additional work is required to assess potential negative consequences of stimulus-responsivity, such as decreased focus or distractibility