Alexander Joseph Shackman

Alexander Joseph Shackman
University of Maryland, College Park | UMD, UMCP, University of Maryland College Park · Department of Psychology

Ph.D.

About

104
Publications
22,760
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Introduction
Affective and cognitive neuroscience; anxiety, fear, and their application to neuropsychiatric disorders; neural bases of individual differences in temperament and personality. Multimodal neuroimaging (MRI, PET); Peripheral physiology (cortisol, facial EMG, fear-potentiated startle); Experience sampling/ecological momentary assessment (EMA) methods

Publications

Publications (104)
Article
Negative affect is a fundamental dimension of human emotion. When extreme, it contributes to a variety of adverse outcomes, from physical and mental illness to divorce and premature death. Mechanistic work in animals and neuroimaging research in humans and monkeys have begun to reveal the broad contours of the neural circuits governing negative aff...
Preprint
Anxiety and depression are common and challenging to treat. Yet our understanding of the dynamic emotional processes that underlie internalizing illness remains incomplete, thwarting treatment development. Here, we used ecological momentary assessment to understand relations between real-world affective dynamics and specific internalizing facets in...
Article
The central goal of clinical psychology is to reduce the suffering caused by mental health conditions. Anxiety, mood, psychosis, substance use, personality, and other mental disorders impose an immense burden on global public health and the economy. Tackling this burden will require the development and dissemination of intervention strategies that...
Article
The Hierarchical Taxonomy of Psychopathology (HiTOP) is a quantitative nosological system that addresses shortcomings of traditional mental disorder diagnoses, including arbitrary boundaries between psychopathology and normality, frequent disorder co-occurrence, substantial heterogeneity within disorders, and diagnostic unreliability over time and...
Preprint
The central goal of clinical psychology is to reduce the suffering caused by mental health conditions. Anxiety, depression, psychosis, substance use, personality, and other mental disorders impose an immense burden on global public health and the economy. Tackling this burden will require the development and dissemination of intervention strategies...
Article
Shortcomings of approaches to classifying psychopathology based on expert consensus have given rise to contemporary efforts to classify psychopathology quantitatively. In this paper, we review progress in achieving a quantitative and empirical classification of psychopathology. A substantial empirical literature indicates that psychopathology is ge...
Article
Older adults comprise the fastest growing global demographic and are at increased risk of poor mental health outcomes. Although aerobic exercise and sleep are critical to the preservation of emotional well-being, few studies have examined their combined mood-enhancing effects, or the potential neural mechanisms underlying these effects. Here, we us...
Article
When extreme, anxiety—a state of distress and arousal prototypically evoked by uncertain danger—can be debilitating. Uncertain anticipation is a shared feature of situations that elicit signs and symptoms of anxiety across psychiatric disorders, species, and assays. Despite the profound significance of anxiety for human health and wellbeing, the ne...
Article
Steeper rates of temporal discounting—the degree to which smaller-sooner (SS) rewards are preferred over larger-later (LL) ones—have been associated with impulsive and ill-advised behaviors in adolescence. Yet, the underlying neural systems remain poorly understood. Here we used a well-established temporal discounting paradigm and functional MRI (f...
Preprint
Full-text available
Background:Retrospective studies have found that people with elevated social anxiety (SA) show a preference for digital/online communication, which may be due to perceptions of enhanced emotional safety. Whether these preferences for/benefits of digital compared to face-to-face communication manifest in the real world has yet to be explored. Method...
Article
Genetic discovery in psychiatry and clinical psychology is hindered by suboptimal phenotypic definitions. We argue that the hierarchical, dimensional, and data-driven classification system proposed by the Hierarchical Taxonomy of Psychopathology (HiTOP) consortium provides a more effective approach to identifying genes that underlie mental disorder...
Article
Full-text available
Understanding how individuals with varying levels of social anxiety respond to daily positive events is important. Psychological processes that increase positive emotions are being widely used as strategies to not only enhance well-being but also reduce the symptoms and impairment tied to negative emotional dispositions and conditions, including ex...
Article
Objective: Diagnosis is a cornerstone of clinical practice for mental health care providers, yet traditional diagnostic systems have well-known shortcomings, including inadequate reliability, high comorbidity, and marked within-diagnosis heterogeneity. The Hierarchical Taxonomy of Psychopathology (HiTOP) is a data-driven, hierarchically based alte...
Article
Full-text available
Background Social anxiety lies on a continuum, and young adults with elevated symptoms are at risk for developing a range of psychiatric disorders. Yet relatively little is known about the factors that govern the hour-by-hour experience and expression of social anxiety in the real world. Methods Here we used smartphone-based ecological momentary a...
Preprint
Understanding how individuals with varying levels of social anxiety respond to daily positive events is important. Psychological processes that increase positive emotions are being widely used as strategies to not only enhance well-being but reduce the symptoms and impairment tied to negative emotional dispositions and conditions, including excessi...
Article
For more than a century, research on psychopathology has focused on categorical diagnoses. Although this work has produced major discoveries, growing evidence points to the superiority of a dimensional approach to the science of mental illness. Here we outline one such dimensional system-the Hierarchical Taxonomy of Psychopathology (HiTOP)-that is...
Preprint
Social anxiety lies on a continuum, and young adults with elevated symptoms are at risk for developing a range of debilitating psychiatric disorders. Yet, relatively little is known about the factors that govern the momentary expression of social anxiety in daily life, close to clinically significant end-points. Here, we used smartphone-based ecolo...
Preprint
When extreme, anxiety can become debilitating. Anxiety disorders, which often first emerge early in development, are common and challenging to treat, yet the underlying mechanisms have only recently begun to come into focus. Here, we review new insights into the nature and biological bases of dispositional negativity, a fundamental dimension of chi...
Article
Full-text available
Borsboom et al. confuse biological approaches with extreme biological reductionism and common-cause models of psychopathology. In muddling these concepts, they mistakenly throw the baby out with the bathwater. Here, we highlight recent work underscoring the unique value of clinical and translational neuroscience approaches for understanding the nat...
Chapter
Full-text available
When extreme, anxiety can become debilitating. Anxiety disorders, which often first emerge early in development, are common and challenging to treat, yet the underlying mechanisms have only recently begun to come into focus. Here, we review new insights into the nature and biological bases of dispositional negativity, a fundamental dimension of chi...
Preprint
When extreme, anxiety can become debilitating. Anxiety disorders, which often first emerge early in development, are common and challenging to treat, yet the underlying mechanisms have only recently begun to come into focus. Here, we review new insights into the nature and biological bases of dispositional negativity, a fundamental dimension of chi...
Preprint
Startle potentiation is a well validated translational measure of negative affect. Startle potentiation is widely used in clinical and affective science and there are multiple approaches for its quantification. The three most commonly used approaches quantify startle potentiation as the increase in startle response from a neutral to threat conditio...
Article
Full-text available
Alcohol use is common, imposes a staggering burden on public health, and often resists treatment. The central extended amygdala (EAc)—including the bed nucleus of the stria terminalis (BST) and the central nucleus of the amygdala (Ce)—plays a key role in prominent neuroscientific models of alcohol drinking, but the relevance of these regions to acu...
Preprint
Emotion is a core feature of the human condition, with profound consequences for health, wealth, and wellbeing. Over the past quarter-century, improved methods for manipulating and measuring different features of emotion have yielded steady advances in our scientific understanding emotional states, traits, and disorders. Yet, it is clear that most...
Article
Children with an extremely inhibited, anxious temperament (AT) are at increased risk for anxiety disorders and depression. Using a rhesus monkey model of early-life AT, we previously demonstrated that metabolism in the central extended amygdala (EAc), including the central nucleus of the amygdala (Ce) and bed nucleus of the stria terminalis (BST),...
Preprint
Full-text available
Alcohol abuse is common, imposes a staggering burden on public health, and is challenging to treat, underscoring the need to develop a deeper understanding of the underlying neurobiology. When administered acutely, ethyl alcohol reduces threat reactivity in humans and other animals, and there is growing evidence that threat-dampening and related ne...
Preprint
Full-text available
Spatial normalization—the process of aligning anatomical or functional data acquired from different individuals to a common stereotaxic atlas—is routinely used in the vast majority of functional neuroimaging studies, with important consequences for scientific inference and reproducibility. Although several approaches exist, multi-step techniques th...
Article
The central extended amygdala (EAc)—including the bed nucleus of the stria terminalis (BST) and central nucleus of the amygdala (Ce)—plays a critical role in triggering fear and anxiety and is implicated in the development of a range of debilitating neuropsychiatric disorders. Although it is widely believed that these disorders reflect the coordina...
Article
Full-text available
Dispositional anxiety is a trait-like phenotype that confers increased risk for a range of debilitating neuropsychiatric disorders. Like many patients with anxiety disorders, individuals with elevated levels of dispositional anxiety are prone to intrusive and distressing thoughts in the absence of immediate threat. Recent electrophysiological resea...
Article
Anxiety disorders impose a staggering burden on public health, underscoring the need to develop a deeper understanding of the distributed neural circuits underlying extreme fear and anxiety. Recent work highlights the importance of the central extended amygdala, including the central nucleus of the amygdala (Ce) and neighboring bed nucleus of the s...
Preprint
The central extended amygdala (EAc)—including the bed nucleus of the stria terminalis (BST) and central nucleus of the amygdala (Ce)—plays a key role in orchestrating states of fear and anxiety and is implicated in the development and maintenance of anxiety disorders, depression, and substance abuse. Although it is widely thought that these disorde...
Article
Full-text available
The internalizing spectrum of psychiatric disorders-depression and anxiety-are common, highly comorbid, and challenging to treat. Individuals with childhood onset depression have a particularly poor prognosis. There is compelling evidence that individuals with depression display reduced resting-state EEG activity at sensors overlying the left prefr...
Article
Full-text available
Dispositional negativity—the tendency to experience more frequent or intense negative emotions—is a fundamental dimension of temperament and personality. Elevated levels of dispositional negativity have profound consequences for public health and wealth, drawing the attention of researchers, clinicians, and policymakers. Yet, relatively little is k...
Preprint
Dispositional negativity—the tendency to experience more frequent or intense negative emotions—is a fundamental dimension of temperament and personality. Elevated levels of dispositional negativity have profound consequences for public health and wealth, drawing the attention of researchers, clinicians, and policy makers. Yet, relatively little is...
Article
The central nucleus of the amygdala (CeA) and bed nucleus of the stria terminalis (BNST), two nuclei within the central extended amygdala, function as critical relays within the distributed neural networks that coordinate sensory, emotional, and cognitive responses to threat. These structures have overlapping anatomical projections to downstream ta...
Article
Dispositional negativity—the propensity to experience and express more frequent, intense, or enduring negative affect—is a fundamental dimension of childhood temperament and adult personality. Elevated levels of dispositional negativity can have profound consequences for health, wealth, and happiness, drawing the attention of clinicians, researcher...
Article
Children with an anxious temperament are prone to heightened shyness and behavioral inhibition (BI). When chronic and extreme, this anxious, inhibited phenotype is an important early-life risk factor for the development of anxiety disorders, depression and co-morbid substance abuse. Individuals with extreme anxious temperament often show persistent...
Article
Full-text available
It is widely thought that phasic and sustained responses to threat reflect dissociable circuits centered on the central nucleus of the amygdala (Ce) and the bed nucleus of the stria terminalis (BST), the two major subdivisions of the central extended amygdala. Early versions of this hypothesis remain highly influential and have been incorporated in...
Article
Full-text available
When extreme, anxiety can become debilitating. Anxiety disorders, which often first emerge early in development, are common and challenging to treat, yet the neurocognitive mechanisms that confer increased risk have only recently begun to come into focus. Here we review recent work highlighting the importance of neural circuits centered on the amyg...
Article
Full-text available
Lieberman and Eisenberger (1) claim that the “dorsal anterior cingulate cortex (dACC) is selective for pain.” This surprising conclusion contradicts a large body of evidence showing robust dACC responses to nonpainful conditions. Electrophysiological and optogenetic studies have identified neuronal populations activated during foraging behavior, at...
Article
Full-text available
Startle potentiation is a well-validated translational measure of negative affect. Startle potentiation is widely used in clinical and affective science, and there are multiple approaches for its quantification. The three most commonly used approaches quantify startle potentiation as the increase in startle response from a neutral to threat conditi...
Article
Full-text available
perception loops might be reused for more advanced cognitive abilities such as planning, mindreading, and executive function). This suggests that the same " affective tuning " of neuronal hierarchies naturally biases higher cognitive abilities, too. In sum, various active inference mechanisms reviewed here – embodied predictive coding, precision dy...
Article
Full-text available
Understanding the heritability of neural systems linked to psychopathology is not sufficient to implicate them as intergenerational neural mediators. By closely examining how individual differences in neural phenotypes and psychopathology cosegregate as they fall through the family tree, we can identify the brain systems that underlie the parent-to...
Article
Full-text available
Dispositional anxiety is a well-established risk factor for the development of anxiety and other emotional disorders. These disorders are common, debilitating, and challenging to treat, pointing to the need to understand the more elementary neurocognitive mechanisms that confer elevated risk. Importantly, many of the maladaptive behaviors character...
Article
Full-text available
Recent years have witnessed the emergence of powerful new tools for assaying the brain and a remarkable acceleration of research focused on the interplay of emotion and cognition. This work has begun to yield new insights into fundamental questions about the nature of the mind and important clues about the origins of mental illness. In particular,...
Article
Full-text available
Some individuals are endowed with a biology that renders them more reactive to novelty and potential threat. When extreme, this anxious temperament (AT) confers elevated risk for the development of anxiety, depression and substance abuse. These disorders are highly prevalent, debilitating and can be challenging to treat. The high-risk AT phenotype...
Article
Evidence from imaging and anatomical studies suggests that the midcingulate cortex (MCC) is a dynamic hub lying at the interface of affect and cognition. In particular, this neural system appears to integrate information about conflict and punishment in order to optimize behavior in the face of action-outcome uncertainty. In a series of meta-analys...
Article
Anxious temperament (AT) is identifiable early in life and predicts the later development of anxiety disorders and depression. Neuropeptide Y (NPY) is a putative endogenous anxiolytic neurotransmitter that adaptively regulates responses to stress and might confer resilience to stress-related psychopathology. With a well-validated nonhuman primate m...
Article
Full-text available
Compassion is a key motivator of altruistic behavior, but little is known about individuals' capacity to cultivate compassion through training. We examined whether compassion may be systematically trained by testing whether (a) short-term compassion training increases altruistic behavior and (b) individual differences in altruism are associated wit...
Article
Full-text available
Children with an anxious temperament (AT) are at risk for developing psychiatric disorders along the internalizing spectrum, including anxiety and depression. Like these disorders, AT is a multidimensional phenotype and children with extreme anxiety show varying mixtures of physiological, behavioral, and other symptoms. Using a well-validated juven...
Article
Full-text available
Dispositional anxiety is a well-established risk factor for the development of psychiatric disorders along the internalizing spectrum, including anxiety and depression. Importantly, many of the maladaptive behaviors characteristic of anxiety, such as anticipatory apprehension, occur when threat is absent. This raises the possibility that anxious in...
Conference Paper
Full-text available
Background / Purpose: Evidence from imaging and anatomical connectivity studies has motivated claims that the dorsal cingulate cortex lies at the interface between affect and cognition; that it exploits information about negative feedback and punishment to optimize behavior in the face of uncertainty. Main conclusion: Here, we show how recent...
Article
Background : Cortisol is a stress-related hormone that interacts with peripheral and neural systems. Although cortisol is important for short-term stress responses, chronically high cortisol is hypothesised to underlie the long-term effects of chronic stress, including decreased dendritic arborisation in rodent prefrontal cortex (PFC). Here we exam...
Article
Rationale/statement of the problem : In the central nervous system, the serotonin (5HT) neurotransmitter system plays a key role in the regulation of mood and emotion. Alterations in the 5HT system are thought to contribute to psychopathologies. In addition, drugs targeting the 5HT system are effective in the treatment of depression and anxiety dis...
Conference Paper
Background / Purpose: Anxious temperament (AT) is of interest because it is a phenotype that increases the risk of later developing anxiety and depression. Neuropeptide Y (NPY) is a putative endogenous anxiolytic neurotransmitter that may play an important role in responses to stress. Using a non-human primate model of AT, we examined whether alt...
Article
Full-text available
Schizophrenia is a devastating illness with an indeterminate pathophysiology. Several lines of evidence implicate dysfunction in the thalamus, a key node in the distributed neural networks underlying perception, emotion, and cognition. Existing evidence of aberrant thalamic function is based on indirect measures of thalamic activity, but dysfunctio...