William D.S. Killgore

Bio: William D.S. Killgore is an academic researcher from University of Arizona. The author has contributed to research in topics: Sleep deprivation & Medicine. The author has an hindex of 55, co-authored 282 publications receiving 11156 citations. Previous affiliations of William D.S. Killgore include Hospital of the University of Pennsylvania & Walter Reed Army Institute of Research.

Effects of sleep deprivation on cognition

Abstract: Sleep deprivation is commonplace in modern society, but its far-reaching effects on cognitive performance are only beginning to be understood from a scientific perspective. While there is broad consensus that insufficient sleep leads to a general slowing of response speed and increased variability in performance, particularly for simple measures of alertness, attention and vigilance, there is much less agreement about the effects of sleep deprivation on many higher level cognitive capacities, including perception, memory and executive functions. Central to this debate has been the question of whether sleep deprivation affects nearly all cognitive capacities in a global manner through degraded alertness and attention, or whether sleep loss specifically impairs some aspects of cognition more than others. Neuroimaging evidence has implicated the prefrontal cortex as a brain region that may be particularly susceptible to the effects of sleep loss, but perplexingly, executive function tasks that putatively measure prefrontal functioning have yielded inconsistent findings within the context of sleep deprivation. Whereas many convergent and rule-based reasoning, decision making and planning tasks are relatively unaffected by sleep loss, more creative, divergent and innovative aspects of cognition do appear to be degraded by lack of sleep. Emerging evidence suggests that some aspects of higher level cognitive capacities remain degraded by sleep deprivation despite restoration of alertness and vigilance with stimulant countermeasures, suggesting that sleep loss may affect specific cognitive systems above and beyond the effects produced by global cognitive declines or impaired attentional processes. Finally, the role of emotion as a critical facet of cognition has received increasing attention in recent years and mounting evidence suggests that sleep deprivation may particularly affect cognitive systems that rely on emotional data. Thus, the extent to which sleep deprivation affects a particular cognitive process may depend on several factors, including the magnitude of global decline in general alertness and attention, the degree to which the specific cognitive function depends on emotion-processing networks, and the extent to which that cognitive process can draw upon associated cortical regions for compensatory support.

Loneliness: A signature mental health concern in the era of COVID-19.

Abstract: In response to the COVID-19 pandemic, most communities in the United States imposed stay-at-home orders to mitigate the spread of the novel coronavirus, potentially leading to chronic social isolation. During the third week of shelter-in-place guidelines, 1,013 U.S. adults completed the UCLA Loneliness Scale-3 and Public Health Questionnaire (PHQ-9). Loneliness was elevated, with 43% of respondents scoring above published cutoffs, and was strongly associated with greater depression and suicidal ideation. Loneliness is a critical public health concern that must be considered during the social isolation efforts to combat the pandemic.

Impaired decision making following 49 h of sleep deprivation.

Abstract: Sleep deprivation reduces regional cerebral metabolism within the prefrontal cortex, the brain region most responsible for higher-order cognitive processes, including judgment and decision making. Accordingly, we hypothesized that two nights of sleep loss would impair decision making quality and lead to increased risk-taking behavior on the Iowa Gambling Task (IGT), which mimics real-world decision making under conditions of uncertainty. Thirty-four healthy participants completed the IGT at rested baseline and again following 49.5 h of sleep deprivation. At baseline, volunteers performed in a manner similar to that seen in most samples of healthy normal individuals, rapidly learning to avoid high-risk decks and selecting more frequently from advantageous low-risk decks as the game progressed. After sleep loss, however, volunteers showed a strikingly different pattern of performance. Relative to rested baseline, sleep-deprived individuals tended to choose more frequently from risky decks as the game progressed, a pattern similar to, though less severe than, previously published reports of patients with lesions to the ventromedial prefrontal cortex. Although risky decision making was not related to participant age when tested at rested baseline, age was negatively correlated with advantageous decision making on the IGT, when tested following sleep deprivation (i.e. older subjects made more risky choices). These findings suggest that cognitive functions known to be mediated by the ventromedial prefrontal cortex, including decision making under conditions of uncertainty, may be particularly vulnerable to sleep loss and that this vulnerability may become more pronounced with increased age.

Psychological resilience during the COVID-19 lockdown.

Abstract: Some individuals are more psychologically resilient to adversity than others, an issue of great importance during the emerging mental health issues associated with the COVID-19 pandemic. To identify factors that may contribute to greater psychological resilience during the first weeks of the nation-wide lockdown efforts, we asked 1,004 U.S. adults to complete assessments of resilience, mental health, and daily behaviors and relationships. Average resilience was lower than published norms, but was greater among those who tended to get outside more often, exercise more, perceive more social support from family, friends, and significant others, sleep better, and pray more often. Psychological resilience in the face of the pandemic is related to modifiable factors.

Conn: A Functional Connectivity Toolbox for Correlated and Anticorrelated Brain Networks

Abstract: Resting state functional connectivity reveals intrinsic, spontaneous networks that elucidate the functional architecture of the human brain. However, valid statistical analysis used to identify such networks must address sources of noise in order to avoid possible confounds such as spurious correlations based on non-neuronal sources. We have developed a functional connectivity toolbox Conn (www.nitrc.org/projects/conn) that implements the component-based noise correction method (CompCor) strategy for physiological and other noise source reduction, additional removal of movement, and temporal covariates, temporal filtering and windowing of the residual blood oxygen level-dependent (BOLD) contrast signal, first-level estimation of multiple standard functional connectivity magnetic resonance imaging (fcMRI) measures, and second-level random-effect analysis for resting state as well as task-related data. Compared to methods that rely on global signal regression, the CompCor noise reduction method all...