PsychophysiologyVolume 57, Issue 7 e13616 SPECIAL ISSUE: FIFTY YEARS OF P300: WHERE ARE WE NOW? 50+ years of P300: Where are we now? John Polich, Corresponding Author John Polich john@polich.net orcid.org/0000-0002-9900-4719 The Scripps Research Institute, La Jolla, CA, USA Correspondence John Polich, The Scripps Research Institute, La Jolla, CA, USA. Email: john@polich.netSearch for more papers by this author John Polich, Corresponding Author John Polich john@polich.net orcid.org/0000-0002-9900-4719 The Scripps Research Institute, La Jolla, CA, USA Correspondence John Polich, The Scripps Research Institute, La Jolla, CA, USA. Email: john@polich.netSearch for more papers by this author First published: 11 June 2020 https://doi.org/10.1111/psyp.13616Citations: 5 This issue on P300 is dedicated to the memory of Emanuel Donchin. It is difficult to imagine the field of P300 research without his leading. He taught all of us. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume57, Issue7Special Issue: 50+ Years of P300: Where are We Now?July 2020e13616 RelatedInformation

To assess the integration of peripheral (heart rate, HR) and central (event-related potential, P300) measures of cognition, the present study varied inter-stimulus presentation time (ISI) and employed comparable data reduction methods for the HR and ERP data. Young adults (n = 33) performed an auditory oddball count task in which the ISI was varied (short vs. long, to maximize target detection for both measures) and task condition (single stimulus, short-ISI oddball, long-ISI oddball, to assay stimulus presentation condition between HR and P300). The off-line cardiotachometer method parallels signal averaging and was applied to HR data reduction. The main goal was to characterize target vs. standard processing in each measurement type using appropriate recording approaches with respect to differentiating the two stimuli in each task (target vs. silence, target vs. standard short-ISI, target vs. standard long-ISI). Results demonstrated reliable differences between target/standard stimuli for both the biphasic HR (deceleration/acceleration) signal and for P300 amplitude production, with larger amplitudes for target than standard. The short and long ISIs yielded no reliable initial HR deceleration differences, but the late acceleration was observed for the long-ISI condition only. Correlational analysis between HR and P300 measures indicated that people with smaller HR deceleration had larger P300 amplitude suggesting that the larger target/standard differences for HR deceleration and P300 amplitude, observed at an experimental level, are reversed at an individual level. The contributions of simultaneously recording HR and P300 to characterize cognition and theoretical implications are discussed.

Multiple factors should influence decisions about the mix of Army active and reserve component forces, including the capabilities that these forces provide and their respective costs. This report focuses on two critical aspects of capability and cost: (1) the time needed to make forces ready to deploy in a crisis and (2) the costs of active and reserve component forces to sustain the same level of deployed output for rotational missions.

ObjectiveWe evaluated the efficacy of the potent antioxidant C3 to salvage nigrostriatal neuronal function after 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) exposure in nonhuman primates. C3 is a first‐in‐class functionalized water‐soluble fullerene that reduces oxygen radical species associated with neurodegeneration in in vitro studies. However, C3 has not been evaluated as a neuroprotective agent in a Parkinson model in vivo.MethodsMacaque fascicularis monkeys were used in a double‐blind, placebo‐controlled study design. MPTP‐lesioned primates were given systemic C3 (n = 8) or placebo (n = 7) for 2 months starting 1 week after MPTP. Outcomes included in vivo behavioral measures of motor parkinsonism using a validated nonhuman primate rating scale, kinematic analyses of peak upper extremity velocity, positron emission tomography imaging of 6‐[18F]fluorodopa (FD; reflects dopa decarboxylase) and [11C]dihydrotetrabenazine (DTBZ; reflects vesicular monoamine transporter type 2), ex vivo quantification of striatal dopamine, and stereologic counts of tyrosine hydroxylase–immunostained neurons in substantia nigra.ResultsAfter 2 months, C3‐treated monkeys had significantly improved parkinsonian motor ratings, greater striatal FD and DTBZ uptake, and higher striatal dopamine levels. None of the C3‐treated animals developed any toxicity.InterpretationSystemic treatment with C3 reduced striatal injury and improved motor function despite administration after the MPTP injury process had begun. These data strongly support further development of C3 as a promising therapeutic agent for Parkinson disease. Ann Neurol 2014;76:393–402

Long-term Vipassana meditators sat in meditation vs. a control (instructed mind wandering) states for 25 min, electroencephalography (EEG) was recorded and condition order counterbalanced. For the last 4 min, a three-stimulus auditory oddball series was presented during both meditation and control periods through headphones and no task imposed. Time-frequency analysis demonstrated that meditation relative to the control condition evinced decreased evoked delta (2-4 Hz) power to distracter stimuli concomitantly with a greater event-related reduction of late (500-900 ms) alpha-1 (8-10 Hz) activity, which indexed altered dynamics of attentional engagement to distracters. Additionally, standard stimuli were associated with increased early event-related alpha phase synchrony (inter-trial coherence) and evoked theta (4-8 Hz) phase synchrony, suggesting enhanced processing of the habituated standard background stimuli. Finally, during meditation, there was a greater differential early-evoked gamma power to the different stimulus classes. Correlation analysis indicated that this effect stemmed from a meditation state-related increase in early distracter-evoked gamma power and phase synchrony specific to longer-term expert practitioners. The findings suggest that Vipassana meditation evokes a brain state of enhanced perceptual clarity and decreased automated reactivity.

Abstract : This monograph reports results of a research project on personnel stability and turbulence among unit leaders in the Reserve Components (RCs) of the U.S. Army. Stability of personnel is highly valued in all military forces, especially in units that are preparing for deployment. Nevertheless, previous RAND research (Lippiatt and Polich, 2010) documented a considerable amount of personnel turbulence soldiers leaving the unit and being replaced by others during preparation for deployment. A particular concern is turbulence among the unit leadership. Even if the service must live with turbulence among the bulk of unit members, the Army would prefer to have unit officers and noncommissioned officers (NCOs) in place to plan and oversee training of the troops with whom they will deploy. Therefore, senior U.S. Department of Defense (DoD) officials asked the RAND Corporation to conduct a study to determine the level of turbulence among unit leadership and to address several related questions: What causes leader turbulence? What effects might it have on training and preparation for future missions that may require RC units? What steps, if any, could be taken to mitigate it? This document is the final report of the research project titled Options to Enhance Leadership Stability in RC Units, sponsored by the Assistant Secretary of Defense for Reserve Affairs. The research was conducted within the Forces and Resources Policy Center of the RAND National Defense Research Institute, a federally funded research and development center sponsored by the Office of the Secretary of Defense, the Joint Staff, the Unified Combatant Commands, the Navy, the Marine Corps, the defense agencies, and the defense Intelligence Community.

Neuroelectric and imaging studies of meditation are reviewed. Electroencephalographic measures indicate an overall slowing subsequent to meditation, with theta and alpha activation related to proficiency of practice. Sensory evoked potential assessment of concentrative meditation yields amplitude and latency changes for some components and practices. Cognitive event-related potential evaluation of meditation implies that practice changes attentional allocation. Neuroimaging studies indicate increased regional cerebral blood flow measures during meditation. Taken together, meditation appears to reflect changes in anterior cingulate cortex and dorsolateral prefrontal areas. Neurophysiological meditative state and trait effects are variable but are beginning to demonstrate consistent outcomes for research and clinical applications. Psychological and clinical effects of meditation are summarized, integrated, and discussed with respect to neuroimaging data.

P3a and P3b event-related brain potentials (ERPs) were elicited with an auditory three-stimulus (target, distracter, and standard) discrimination task in which subjects responded only to the target. Distracter stimuli consisted of white noise or novel sounds with stimulus characteristics perceptually matched. Target/standard discrimination difficulty was manipulated by varying target/standard pitch differences to produce relatively easy, medium, and hard tasks. Error rate and response time increased with increases in task difficulty. P3a was larger for the white noise compared to novel sounds, maximum over the central/parietal recording sites, and did not differ in size across difficulty levels. P3b was unaffected by distracter type, decreased as task difficulty increased, and maximum over the parietal recording sites. The findings indicate that P3a from white noise is robust and should be useful for applied studies as it removes stimulus novelty variability. Theoretical perspectives are discussed.

Recognition memory was examined for visual affective stimuli using behavioral and event-related brain potential (ERP) measures. Images from the International Affective Picture System (IAPS) that varied systematically in arousal level (low, high) and valence direction (unpleasant, pleasant) were first viewed passively. Then, during a response phase, the original images were intermixed with an equal number of new images and presented, and participants were instructed to press a button to indicate whether each stimulus picture was previously viewed (target) or new (foil). Participants were more sensitive to unpleasant- than to pleasant-valence stimuli and were biased to respond to high-arousal unpleasant stimuli as targets, whether the stimuli were previously viewed or new. Response times (RTs) to target stimuli were systematically affected by valence, whereas RTs to foil stimuli were influenced by arousal level. ERP component amplitudes were generally larger for high than for low arousal levels. The P300 (late positive component) amplitude was largest for high-arousal unpleasant target images. These and other amplitude effects suggest that high-arousal unpleasant stimuli engage a privileged memory-processing route during stimulus processing. Theoretical relationships between affective and memory processes are discussed.

Background: An interspersed-stimulus paradigm (ISP) for event-related potential (ERP) recordings in which different sensory modality stimuli are presented within the same test session was developed to minimize recording time and facilitate modality comparison. The present study compared the ISP with a single-stimulus paradigm (SSP), using auditory, visual, and olfactory stimuli.Method: Normal participants (n = 16) were assessed on two independent test occasions to obtain data on inter-paradigm and test-retest reliability. Peak amplitude/latency and area measures were obtained for the N1, P2 and P3 peaks for each paradigm.Results: Except for larger auditory and visual P3 peaks and smaller visual P2 peaks in the ISP, no significant differences in amplitudes or latencies were found between the two paradigms. Correlation coefficients between paradigms were generally fairly high (amplitude mean r = 0.76; latency r = 0.42). Test retest reliability within paradigms for amplitudes (ISP r = 0.70; SSP r = 0.68) and latencies (ISP r = 0.44; SSP r = 0.42) was similar across paradigms.Conclusion: The findings suggest that the ISP, compared to the SSP, produces, in general, highly comparable auditory, visual, and olfactory peak amplitudes and latencies, and comparable reliability estimates, even though the ISP takes much less time to record (25 vs. 50 min). The larger auditory and visual P3 peaks and smaller visual P2 peaks in the ISP may be attributable to a less predictable stimulus environment. Thus, this method enables systematic comparisons of ERP peaks across sensory modalities while reducing testing time. Practical implications are discussed. (C) 2011 Elsevier B.V. All rights reserved.