Invited reviewExecutive function and PTSD: Disengaging from trauma
Highlights
► We review neuropsychological findings related to executive functioning in PTSD. ► Studies find PTSD is associated with inhibitory and attention regulation deficits. ► We discuss how inhibitory deficits could contribute to PTSD clinical symptoms. ► Neuropsychological research may provide avenues for enhancing treatment of PTSD.
Introduction
An estimated 50–60% of people will experience a serious trauma—as a result of combat, sexual assault, major accidents, or other real-life horrors—at some point in their lives (Kessler et al., 1995). However, only 5–10% of people are estimated to develop symptoms qualifying them for diagnosis of posttraumatic stress disorder (PTSD). This observation has led researchers to consider what factors other than the trauma itself may contribute to, or protect against, the development and maintenance of PTSD symptoms. Neuropsychological approaches may provide an important insight into susceptibility and resiliency factors by identifying pre-trauma cognitive functions that relate to subsequent development of PTSD as well as posttraumatic cognitive processes that may influence development or maintenance of the disorder. Finally, understanding these cognitive processes may provide new approaches for treatment to improve long-term outcomes of individuals with PTSD.
Although much of neuropsychological research in PTSD has focused on learning and memory, there has also been an accumulation of research examining potential “frontal lobe” or executive dysfunction. William James, in The Principles of Psychology, defined attention as “the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought” (James, 1890). He went on to say that “…It implies withdrawal from some things in order to deal effectively with others.” In the modern world of neuropsychology and cognitive neuroscience, there are many disagreements about distinct and common definitions of attention, working memory, and executive function. For the purposes of this manuscript, we will focus on concepts that have been considered throughout the literature to be involved in maintaining successful “executive function”, or the control of complex goal-directed behavior (Royall et al., 2002, Alvarez and Emory, 2006, McCabe et al., 2010). This includes 1) attention, or the voluntary allocation of processing resources or focusing of one’s mind on a particular stimulus within the environment, 2) working memory, or the active maintenance and manipulation of information in one’s mind over a short period of time, 3) sustained attention, or the maintenance of attention on one set of stimuli or a task for a prolonged period, 4) inhibitory function, involving the inhibition of automatic responses to maintain goal-directed behavior, 5) flexibility/switching, or the ability to switch between two different tasks or strategies, and 6) planning, or the ability to develop and implement strategic behaviors to obtain a future goal (Smith and Jonides, 1999, McCabe et al., 2010, Carlson et al., 2005, Salthouse et al., 2003, Miyake and Shah, 1999, Repovs and Baddeley, 2006).
We chose to focus on attentional and executive functions for the current review, rather than learning and memory, for two primary reasons. First, there have been several recent reviews summarizing findings related to learning and memory in PTSD—both in regards to neutral information as well as emotional information, such as with fear conditioning and extinction (Rubin et al., 2008, Johnsen and Asbjornsen, 2008, Moore, 2009). The second reason we chose to focus on executive and attentional functions is because recent research indicates that attentional modification programs may be beneficial in the treatment of anxiety disorders (Amir et al., 2009a, Li et al., 2008, Schmidt et al., 2009, Amir et al., 2009b, Najmi and Amir, 2010, Amir et al., 2008). This suggests that research related to attention and working memory function may not only increase our understanding of PTSD, but may also lead to more effective treatments for these patients.
The majority of neuropsychological research in PTSD uses cross-sectional designs from which it is impossible to determine whether any observed cognitive dysfunctions represent pre-trauma risk and resiliency factors or if they represent responses to the experience of trauma or PTSD. We therefore begin our review by discussing results from longitudinal and twin studies that may shed some light on this issue. We then synthesize results from cross-sectional studies concerning “frontal lobe” dysfunction associated with PTSD, focusing on simple attention and working memory, “higher-order” executive functions, flexibility, and inhibition, and the effects of emotional context on attention and executive function. The focus of this discussion will be on how difficulties regulating attention and inhibiting responses to stimuli (particularly emotional or trauma-related stimuli) could contribute to the clinical profile of PTSD—for example, leading to the development of alternative, potentially maladaptive, coping mechanisms. We will also discuss research concerning potential neural substrates of executive dysfunction, and the relationship between treatment and cognitive dysfunction, in PTSD. This review will not discuss the issue of comorbid disorders (e.g., traumatic brain injury, substance use disorders) and their potential influence on neurocognitive function in PTSD. We recognize the significant influence comorbid conditions can have on neurocognitive function and refer to recent articles focusing on this important and complex issue (Stein and McAllister, 2009, Samuelson et al., 2006).
Section snippets
Cognitive risk factors versus sequelae of PTSD
Although historically considered a controversial issue, research examining cognitive risk and resilience factors could be invaluable in understanding mechanisms for PTSD and in developing better preventive and treatment interventions. Lower IQ (often measured via military aptitude test performance) and educational achievement pre-trauma has been reported to relate to PTSD symptoms post-trauma (Gale et al., 2008, Macklin et al., 1998, Green et al., 1990, Pitman et al., 1991, Thompson and
Attention and working memory
Attention and working memory are often measured using digit span, one-trial word recall (e.g., CVLT Trial 1), and spatial span (e.g., Crosi blocks) (Milner, 1971) tasks. These tasks require individuals to attend to a series of presented digits, words, or spatial locations and immediately recreate sequentially what was presented. Tasks such as digit span backward and letter-number sequencing (Wechsler, 1997a, Wechsler, 2008) require increased working memory load, as they involve greater
Neural correlates of attention and executive function in PTSD
Neuroimaging studies (using positron emission tomography [PET] or functional magnetic resonance imaging [fMRI]) in PTSD have primarily focused on symptom provocation or responses to trauma-related or emotional stimuli. These results have been discussed in recent reviews (Shin and Liberzon, 2010, Liberzon and Sripada, 2008, Francati et al., 2007) and meta-analyses (Etkin and Wager, 2007) and suggest hyperactivation within limbic regions (particularly amygdala and insula) and hypoactivation of
Treatment and cognitive function in PTSD
Cognitive processes may relate to treatment in a number of different ways. First, cognitive function may be used as a predictor of treatment outcome, or as a treatment outcome measure in and of itself. Second, cognitive factors may themselves be treatment targets to improve clinical symptoms. Thus far, there has been one study published to examine the predictive utility of cognitive function in the treatment of PTSD. Wild et al. (Wild and Gur, 2008) reported that performance on immediate recall
Discussion
Although PTSD does not have a substantial effect on general cognition, neuropsychological research provides evidence for subtle deficits concerning inhibition of automatic responses and the regulation of attention—in both emotional and non-emotional contexts (Falconer et al., 2008, Pineles et al., 2007, Pineles et al., 2009, McNally et al., 1990, Kimble et al., 2010, Leskin and White, 2007). In particular, PTSD has been associated with difficulty disengaging attention from one stimulus to focus
Conclusion
There is evidence for subtle deficits in attentional and inhibitory functions in PTSD that may predate trauma exposure, serve as risk factors for the development of PTSD, and relate to the severity of symptoms. We propose that such dysfunction could contribute to hypervigilance and arousal symptoms and the reliance on avoidant coping strategies, which are considered hallmark symptoms of PTSD. Further neuropsychological and neuroimaging research is needed to determine the exact nature of these
References (149)
- et al.
The effect of retrieval on recall of information in individuals with posttraumatic stress disorder
J. Anxiety Disord.
(2009) - et al.
Basic operations in working memory: contributions from functional imaging studies
Behav. Brain Res.
(2010) - et al.
PTSD symptoms and cognitive performance in recent trauma survivors
Psychiatry Res.
(2002) - et al.
Neural correlates of the classic color and emotional stroop in women with abuse-related posttraumatic stress disorder
Biol. Psychiatry
(2004) - et al.
Lateral prefrontal cortex mediates the cognitive modification of attentional bias
Biol. Psychiatry
(2010) - et al.
Neural networks of information processing in posttraumatic stress disorder: a functional magnetic resonance imaging study
Biol. Psychiatry
(2005) - et al.
Effect of psychological treatment on cognitive bias in motor vehicle accident-related posttraumatic stress disorder
J. Anxiety Disord.
(2004) - et al.
Emotion-attention network interactions during a visual oddball task
Brain. Res. Cogn. Brain. Res.
(2004) - et al.
Consistent impaired verbal memory in PTSD: a meta-analysis
J. Affect. Disord.
(2008) - et al.
Executive deficits in chronic PTSD related to political violence
J. Anxiety. Disord.
(2007)
Does the modified stroop effect exist in PTSD? Evidence from dissertation abstracts and the peer reviewed literature
J. Anxiety Disord.
Eye tracking and visual attention to threating stimuli in veterans of the Iraq war
J. Anxiety Disord.
Measures of prefrontal system dysfunction in posttraumatic stress disorder
Brain Cogn.
Executive function and memory in posttraumatic stress disorder: a study of Bosnian war veterans
Eur. Psychiatry.
Memory and executive dysfunctions associated with acute posttraumatic stress disorder
Psychiatry Res.
Continual training of attentional bias in social anxiety
Behav. Res. Ther.
Cortisol, learning, memory, and attention in relation to smaller hippocampal volume in police officers with posttraumatic stress disorder
Biol. Psychiatry
Selective processing of threat cues in anxiety states
Behav. Res. Ther
Abnormal stimulus processing in posttraumatic stress disorder
Biol. Psychiatry
Abnormal recruitment of working memory updating networks during maintenance of trauma-neutral information in post-traumatic stress disorder
Psychiatry Res.
Neural systems for executive and emotional processing are modulated by symptoms of posttraumatic stress disorder in Iraq war veterans
Psychiatry Res.
The role of trauma-related distractors on neural systems for working memory and emotion processing in posttraumatic stress disorder
J. Psychiatry Res.
Impact of emotion on cognition in trauma survivors: what is the role of posttraumatic stress disorder?
J. Affect. Disord.
Executive function and the frontal lobes: a meta-analytic review
Neuropsychol. Rev.
The effect of a single-session attention modification program on response to a public-speaking challenge in socially anxious individuals
J. Abnorm. Psychol.
Attention modification program in individuals with generalized anxiety disorder
J. Abnorm. Psychol.
Stop-signal inhibition disrupted by damage to right inferior frontal gyrus in humans
Nat. Neurosci.
Neural systems underlying approach and avoidance in anxiety disorders
Dialog. Clin. Neurosci.
Cognitive functioning and posttraumatic stress disorder
Am. J. Psychiatry
Emotion, decision making and the orbitofrontal cortex
Cereb. Cortex
Role of the amygdala in decision-making
Ann. N. Y. Acad. Sci.
Trail making test performance in Vietnam combat veterans with and without posttraumatic stress disorder
J. Trauma. Stress
Neural mechanisms underlying selective attention to threat
Ann. N. Y. Acad. Sci.
Hypotheses and controversies related to effects of stress on the hippocampus: an argument for stress-induced damage to the hippocampus in patients with posttraumatic stress disorder
Hippocampus
The posttraumatic stress disorder project in Brazil: neuropsychological, structural and molecular neuroimaging studies in victims of urban violence
BMC Psychiatry
Learning and memory impairment in PTSD: relationship to depression
Depress. Anxiety
The counting stroop: an interference task specialized for functional neuroimaging–validation study with functional MRI
Hum. Brain Mapp.
Less is more: executive function and symbolic representation in preschool children
Psychol. Sci.
Behavioral inhibition and activation in posttraumatic stress disorder
J. Nerv. Ment. Dis.
Compelled attention: the effects of viewing trauma-related stimuli on concurrent task performance in posttraumatic stress disorder
J. Trauma. Stress
Responses to rare visual target and distractor stimuli using event-related fMRI
J. Neurophysiol.
Paying attention to emotion: an fMRI investigation of cognitive and emotional stroop tasks
Cogn. Affect Behav. Neurosci.
Conners' Continuous Performance Test Computer Program User's Guide
Neuropsychological findings in combat-related posttraumatic stress disorder
Clin. Neuropsychol.
Evidence-based treatments for PTSD, new directions, and special challenges
Ann. N. Y. Acad. Sci.
Patterns of processing bias for emotional information across clinical disorders: a comparison of attention, memory, and prospective cognition in children and adolescents with depression, generalized anxiety, and posttraumatic stress disorder
J. Clin. Child Adolesc. Psychol.
Integrating clinical assessment with cognitive neuroscience: construct validation of the California Verbal Learning Test
J. Consult. Clin. Psychol
Delis-Kaplan Executive Function System (D-KEFS): Examiner's Manual
Neural plasticity in response to attention training in anxiety
Psychol. Med.
Functional neuroimaging of anxiety: a meta-analysis of emotional processing in PTSD, social anxiety disorder, and specific phobia
Am. J. Psychiatry
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