Scholars@Duke
Ken Roberts

Ken Roberts

Associate In Research
Center for Cognitive Neuroscience
ken.roberts@duke.edu
Box 90999, Durham, NC 27708-0999
B242 LSRC, Durham, NC 27708

Scholarly Works

Translational Methods for Wearable Heart Rate Variability Monitoring in Older Adults: Preoperative Risk Stratification and Postoperative Monitoring.

Journal article J Cardiovasc Transl Res · February 5, 2026 Low preoperative heart rate variability (HRV) is associated with adverse cardiovascular outcomes and delirium after geriatric surgery, but in-person testing is burdensome and impractical. To evaluate wrist-based wearables for remotely capturing preoperativ ... Full text Link to item Cite

Developing Topics.

Journal article Alzheimers Dement · December 2025 BACKGROUND: Postoperative delirium (POD), characterized by acute fluctuations in consciousness and attention, is associated with increased risk of Alzheimer's disease and related dementias. However, the neural mechanisms underlying attention impairments in ... Full text Link to item Cite

Associations between anaesthetic dose-adjusted intraoperative EEG alpha power, processing speed, and postoperative delirium: analysis of data from three prospective studies.

Journal article Br J Anaesth · July 2025 BACKGROUND: We previously have shown that low intraoperative EEG alpha power is associated with impaired preoperative cognition, a delirium risk factor, and that intraoperative anaesthetic-dose-adjusted EEG bispectral index values were associated with a fo ... Full text Link to item Cite

The Role of Sleep Apnea in Postoperative Neurocognitive Disorders Among Older Noncardiac Surgery Patients: A Prospective Cohort Study.

Journal article Anesth Analg · January 1, 2025 BACKGROUND: Obstructive sleep apnea is associated with increased dementia risk, yet its role in postoperative neurocognitive disorders is unclear. Here, we studied whether the severity of untreated obstructive sleep apnea is associated with the severity of ... Full text Open Access Link to item Cite

Electrical brain activations in preadolescents during a probabilistic reward-learning task reflect cognitive processes and behavior strategies.

Journal article Front Hum Neurosci · 2025 Both adults and children learn through feedback to associate environmental events and choices with reward, a process known as reinforcement learning (RL). However, tasks to assess RL-related neurocognitive processes in children have been limited. This stud ... Full text Link to item Cite

Electrical brain activations in preadolescents during a probabilistic reward-learning task reflect cognitive processes and behavioral strategy.

Journal article bioRxiv · July 1, 2024 Both adults and children learn through feedback which environmental events and choices are associated with higher probability of reward, an ability thought to be supported by the development of fronto-striatal reward circuits. Recent developmental studies ... Full text Link to item Cite

Exploring the Association Between EEG Microstates During Resting-State and Error-Related Activity in Young Children.

Journal article Brain topography · July 2024 The error-related negativity (ERN) is a negative deflection in the electroencephalography (EEG) waveform at frontal-central scalp sites that occurs after error commission. The relationship between the ERN and broader patterns of brain activity measured acr ... Full text Cite

Preoperative electroencephalographic alpha-power changes with eyes opening are associated with postoperative attention impairment and inattention-related delirium severity.

Journal article Br J Anaesth · January 2024 BACKGROUND: In the eyes-closed, awake condition, EEG oscillatory power in the alpha band (7-13 Hz) dominates human spectral activity. With eyes open, however, EEG alpha power substantially decreases. Less alpha attenuation with eyes opening has been associ ... Full text Link to item Cite

Exploring the association between EEG microstates during resting-state and error-related activity in young children.

Journal article Res Sq · May 2, 2023 The error-related negativity (ERN) is a negative deflection in the electroencephalography (EEG) waveform at frontal-central scalp sites that occurs after error commission. The relationship between the ERN and broader patterns of brain activity measured acr ... Full text Link to item Cite

EEG pre-burst suppression: characterization and inverse association with preoperative cognitive function in older adults.

Journal article Front Aging Neurosci · 2023 The most common complication in older surgical patients is postoperative delirium (POD). POD is associated with preoperative cognitive impairment and longer durations of intraoperative burst suppression (BSup) - electroencephalography (EEG) with repeated p ... Full text Link to item Cite

Spatiotemporal dynamics of EEG microstates in four- to eight-year-old children: Age- and sex-related effects.

Journal article Developmental cognitive neuroscience · October 2022 The ultrafast spatiotemporal dynamics of large-scale neural networks can be examined using resting-state electroencephalography (EEG) microstates, representing transient periods of synchronized neural activity that evolve dynamically over time. In adults, ... Full text Open Access Cite

Postoperative changes in cognition and cerebrospinal fluid neurodegenerative disease biomarkers.

Journal article Ann Clin Transl Neurol · February 2022 OBJECTIVE: Numerous investigators have theorized that postoperative changes in Alzheimer's disease neuropathology may underlie postoperative neurocognitive disorders. Thus, we determined the relationship between postoperative changes in cognition and cereb ... Full text Open Access Link to item Cite

Perioperative neurocognitive and functional neuroimaging trajectories in older APOE4 carriers compared with non-carriers: secondary analysis of a prospective cohort study.

Journal article Br J Anaesth · December 2021 BACKGROUND: Cognitive dysfunction after surgery is a major issue in older adults. Here, we determined the effect of APOE4 on perioperative neurocognitive function in older patients. METHODS: We enrolled 140 English-speaking patients ≥60 yr old scheduled fo ... Full text Open Access Link to item Cite

Preoperative EEG: A Potential Predictor of Postoperative Delirium in Older Adults

Conference JOURNAL OF THE AMERICAN GERIATRICS SOCIETY · April 2021 Link to item Cite

Electroencephalogram-Based Complexity Measures as Predictors of Post-operative Neurocognitive Dysfunction.

Journal article Front Syst Neurosci · 2021 Physiologic signals such as the electroencephalogram (EEG) demonstrate irregular behaviors due to the interaction of multiple control processes operating over different time scales. The complexity of this behavior can be quantified using multi-scale entrop ... Full text Open Access Link to item Cite

The MARBLE Study Protocol: Modulating ApoE Signaling to Reduce Brain Inflammation, DeLirium, and PostopErative Cognitive Dysfunction.

Journal article J Alzheimers Dis · 2020 BACKGROUND: Perioperative neurocognitive disorders (PND) are common complications in older adults associated with increased 1-year mortality and long-term cognitive decline. One risk factor for worsened long-term postoperative cognitive trajectory is the A ... Full text Open Access Link to item Cite

Toward direct MRI of neuro-electro-magnetic oscillations in the human brain.

Journal article Magn Reson Med · June 2019 PURPOSE: Neuroimaging techniques are widely used to investigate the function of the human brain, but none are currently able to accurately localize neuronal activity with both high spatial and temporal specificity. Here, a new in vivo MRI acquisition and a ... Full text Link to item Cite

The INTUIT Study: Investigating Neuroinflammation Underlying Postoperative Cognitive Dysfunction.

Journal article J Am Geriatr Soc · April 2019 BACKGROUND/OBJECTIVES: Every year, up to 40% of the more than 16 million older Americans who undergo anesthesia/surgery develop postoperative cognitive dysfunction (POCD) or delirium. Each of these distinct syndromes is associated with decreased quality of ... Full text Open Access Link to item Cite

Cortical and Subcortical Coordination of Visual Spatial Attention Revealed by Simultaneous EEG-fMRI Recording.

Journal article J Neurosci · August 16, 2017 Visual spatial attention has been studied in humans with both electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) individually. However, due to the intrinsic limitations of each of these methods used alone, our understanding of th ... Full text Link to item Cite

Intraoperative Frontal Alpha-Band Power Correlates with Preoperative Neurocognitive Function in Older Adults.

Journal article Front Syst Neurosci · 2017 Each year over 16 million older Americans undergo general anesthesia for surgery, and up to 40% develop postoperative delirium and/or cognitive dysfunction (POCD). Delirium and POCD are each associated with decreased quality of life, early retirement, incr ... Full text Open Access Link to item Cite

Orchestrating Proactive and Reactive Mechanisms for Filtering Distracting Information: Brain-Behavior Relationships Revealed by a Mixed-Design fMRI Study.

Journal article J Neurosci · January 20, 2016 Given the information overload often imparted to human cognitive-processing systems, suppression of irrelevant and distracting information is essential for successful behavior. Using a hybrid block/event-related fMRI design, we characterized proactive and ... Full text Link to item Cite

Cross-modal stimulus conflict: the behavioral effects of stimulus input timing in a visual-auditory Stroop task.

Journal article PLoS One · 2013 Cross-modal processing depends strongly on the compatibility between different sensory inputs, the relative timing of their arrival to brain processing components, and on how attention is allocated. In this behavioral study, we employed a cross-modal audio ... Full text Open Access Link to item Cite

The involvement of the dopaminergic midbrain and cortico-striatal-thalamic circuits in the integration of reward prospect and attentional task demands.

Journal article Cereb Cortex · March 2012 Reward has been shown to promote human performance in multiple task domains. However, an important debate has developed about the uniqueness of reward-related neural signatures associated with such facilitation, as similar neural patterns can be triggered ... Full text Link to item Cite

The cross-modal spread of attention reveals differential constraints for the temporal and spatial linking of visual and auditory stimulus events.

Journal article J Neurosci · June 1, 2011 The integration of multisensory information has been shown to be guided by spatial and temporal proximity, as well as to be influenced by attention. Here we used neural measures of the multisensory spread of attention to investigate the spatial and tempora ... Full text Link to item Cite

Multisensory conflict modulates the spread of visual attention across a multisensory object.

Journal article Neuroimage · August 15, 2010 Spatial attention to a visual stimulus that occurs synchronously with a task-irrelevant sound from a different location can lead to increased activity not only in the visual cortex, but also the auditory cortex, apparently reflecting the object-related spr ... Full text Link to item Cite

Component structure of event-related fMRI responses in the different neurovascular compartments.

Journal article Magn Reson Imaging · April 2007 In most functional magnetic resonance imaging (fMRI) studies, brain activity is localized by observing changes in the blood oxygenation level-dependent (BOLD) signal that are believed to arise from capillaries, venules and veins in and around the active ne ... Full text Link to item Cite

The neural circuitry underlying the executive control of auditory spatial attention.

Journal article Brain Res · February 23, 2007 Although a fronto-parietal network has consistently been implicated in the control of visual spatial attention, the network that guides spatial attention in the auditory domain is not yet clearly understood. To investigate this issue, we measured brain act ... Full text Link to item Cite

The neural bases of momentary lapses in attention.

Journal article Nat Neurosci · July 2006 Momentary lapses in attention frequently impair goal-directed behavior, sometimes with serious consequences. Nevertheless, we lack an integrated view of the brain mechanisms underlying such lapses. By investigating trial-by-trial relationships between brai ... Full text Link to item Cite

The spread of attention across modalities and space in a multisensory object.

Journal article Proc Natl Acad Sci U S A · December 20, 2005 Attending to a stimulus is known to enhance the neural responses to that stimulus. Recent experiments on visual attention have shown that this modulation can have object-based characteristics, such that, when certain parts of a visual object are attended, ... Full text Link to item Cite