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Katherine Maclean

Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, United States.

4 papers in the library · 156 citations · publishing 2013-2018

Papers

Future directions in meditation research: Recommendations for expanding the field of contemplative science

PLoS ONE November 7, 2018 Cassandra Vieten, Helané Wahbeh, B Rael Cahn et al. 124 citations

A survey of 1120 meditators found that most report having had anomalous and extraordinary experiences during meditation, such as mystical, transpersonal, or difficult phenomena. While meditation research has largely focused on clinical effectiveness and neural correlates, these less-studied experiences may be crucial for psychological and spiritual development, act as mediators of meditation's benefits, or be important outcomes themselves. A task force of researchers and teachers developed recommendations to expand research into these areas, which represent largely uncharted scientific terrain suitable for rigorous investigation.

Modulation of event-related potentials of visual discrimination by meditation training and sustained attention

Anthony Paul Zanesco, Brandon King, Chivon Powers et al. 20 citations

Sustained attention tasks often reduce the ability to discriminate goal-relevant stimuli over time. Intensive training in shamatha (focused-attention) meditation can improve perceptual discrimination of difficult-to-see visual stimuli. In two 3-month meditation retreats, participants performed a continuous performance task at three time points. In Retreat 1, the target difficulty was adjusted to match each participant's improving perceptual capacity, and no training effects on brain activity were observed. In Retreat 2, the target difficulty was held constant, leading to earlier onset of sensory brain signals and reduced performance decline over time. Changes in later processing stages correlated with improvements in perceptual threshold. The findings suggest that meditation-related improvements in perceptual discrimination can alter electrophysiological markers of attention and perception, but only when task demands allow discrimination capacity to exceed target difficulty.

LC-MS/MS quantification of salvinorin A from biological fluids.

Analytical methods : advancing methods and applications December 21, 2013 Michael J Caspers, Todd D Williams, Kimberly M Lovell et al. 6 citations

A method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) measures the hallucinogen salvinorin A in non-human primate cerebrospinal fluid (CSF) and human plasma. For CSF, simple dilution with acetonitrile and formic acid replaces solid phase extraction. Human plasma requires centrifugation, then loading onto a C18 SPE column. A shallow acetonitrile/water gradient elutes the compound. Limits of quantification are 0.0125 ng/mL for CSF and 0.05 ng/mL for plasma. Interday precision and accuracy are below 1.7% and 9.42% for CSF and 3.47% and 12.37% for plasma. The method determined salvinorin A concentrations in a Rhesus monkey study and a human trial using behaviorally active doses.

Cognitive Aging and Long-Term Maintenance of Attentional Improvements Following Meditation Training

Anthony Paul Zanesco, Brandon King, Katherine Maclean et al. 6 citations

Intensive meditation training over three months improved sustained attention and response inhibition, and these gains were partially maintained up to seven years later. Continued meditation practice during the follow-up period moderated age-related declines in response inhibition accuracy and reaction time variability. The findings suggest that dedicated mental training can produce lasting benefits for cognitive health and alter long-term cognitive trajectories as people age.