Biology subjects

Karns, C. M.

Publications and source records attributed to Karns, C. M..

3 recordsLinked to original sources

bioRxiv2026

EEG Oscillations in Guided Mindfulness versus Mind-Wandering in Young Adults: Effects of Auditory Task Instruction and Naturalistic Video

Alpha and theta band EEG oscillations have been implicated in states of mindfulness meditation. However, results are inconsistent and the influence of testing environment variables is not well-characterized. We used EEG to measure the amplitude of brain oscillations in a mindful-attention versus mind-wandering condition, in which guided auditory instructions were interleaved with periods of silence, with and without accompanying naturalistic video projections. We generated precise measures of alpha and theta in a sample of 20 young-adult non-expert meditators, by identifying each participant's individual alpha peak frequency (IAF) from posterior EEG electrodes and using it to define four individualized frequency bands: two low alpha bands (in 2 Hz increments below the IAF), one upper alpha band (from IAF to 2 Hz above IAF), and one theta band (4 Hz - 6 Hz below IAF). We found that the mindfulness manipulation significantly increased power in alpha ranging between 2 Hz below to 2 Hz above IAF, including peak alpha amplitude, compared with mind-wandering. Meanwhile, central theta amplitude was larger when auditory instructions were on versus off, and naturalistic video did not reliably modulate the EEG effects of mindfulness. We conclude that the acute effects of mindfulness in non-expert meditators are most consistently observed as increases of posterior alpha-band activity, and that auditory task-instructions should be accounted for in studies of guided meditation. Observed alpha increases may reflect induced states of calm or relaxation induced by mindfulness practice, as proposed in previous studies. These results may apply to mindfulness training or biofeedback therapies.

neuroscience↗

bioRxiv2021

The development of attention and distractibility in preschool children from higher and lower socioeconomic status backgrounds

In children, the ability to listen to relevant auditory information and suppress distracting information is a foundational skill for learning and educational achievement. Distractibility is supported by multiple cognitive components (voluntary attention orienting, sustained attention, distraction, phasic arousal, as well as impulsivity and motor control) that may mature at different ages. Here we used the Competitive Attention Test (CAT) to measure these components in 71 4- and 5-year-old children. The goal of this study was to characterize the changes in efficiency of attention during the preschool period, and to explore differences in distractibility in preschool children that could be related to the socioeconomic status (SES) background of the childs family. We found that sustained attention improves from age 4 to 5, while voluntary attention orienting is still immature during the preschool period. In addition, independent of age, task-irrelevant sounds induced distraction, phasic arousal, and impulsivity. Children from lower SES backgrounds showed reduced sustained attention abilities and increased impulsivity. However, 3-year-old children and a minority of 4- and 5-year-olds did not manage to perform the task according to the instructions; the CAT thus seems suitable to assess distractibility only in preschoolers with sufficiently developed sustained attention skills to efficiently complete the task. Taken together, the present findings suggest that distractibility is still developing during the preschool period and is likely to vary depending on the SES background of a childs family.

neuroscience↗

bioRxiv2017

Parasympathetic and sympathetic activity are associated with individual differences in neural indices of selective attention in adults

Multiple theoretical frameworks posit that interactions between the autonomic nervous system and higher-order neural networks are crucial for cognitive regulation. However, few studies have directly examined the relationship between measures of autonomic physiology and brain activity during cognitive tasks, and fewer studies have examined both the parasympathetic and sympathetic autonomic branches when doing so. Here, 93 adults completed an event-related potential (ERP) auditory selective attention task concurrently with measures of parasympathetic activity (high-frequency heart rate variability; HF-HRV) and sympathetic activity (pre-ejection period; PEP). We replicate previous findings showing effects of selective attention on mean amplitude of the N1 ERP component (Hillyard et al., 1973; Coch et al., 2005), and extend this result to show that the effects of selective attention were associated with baseline values of HF-HRV and PEP. Individuals with higher resting HF-HRV and shorter resting PEP showed larger effects of selective attention on their ERPs. Follow-up regression models demonstrated that HF-HRV and PEP accounted for unique variance in selective attention effects on N1 mean amplitude. These results are consistent with the neurovisceral integration model, which posits that greater parasympathetic activity is a marker of increased cognitive capacity, as well as other theoretical models which emphasize the role of heightened sympathetic activity in more efficient attention-related processing. The present findings highlight the importance of autonomic physiology in the study of individual differences in neurocognitive function, and given the foundational role of selective attention across cognitive domains, suggest that both parasympathetic and sympathetic activity may be key to understanding variability in brain function across a variety of cognitive tasks.

neuroscience↗