Life stressors fog the mind, diverting attention away from daily functions. Typically, this foggy feeling dissipates quickly. However, this feeling can persist in the presence of severe stressors (e.g., traumatic events), as is the case for individuals with posttraumatic stress disorder (PTSD). Criterion A traumatic events encompass “actual or threatened death, serious injury, or sexual violence,” (American Psychiatric Association [APA], 2013:271), including physical/sexual assault, disasters, and war exposure. Lifetime trauma incidence varies worldwide, ranging 28–85% (Benjet et al., 2016), whereas prevalence of PTSD ranges 6.8–9.2% (Kessler et al., 2005; Dückers et al., 2016).

Posttraumatic stress disorder symptoms include intrusive thoughts, avoidance behaviors, hyperarousal, and negative alterations in mood/cognition (American Psychiatric Association [APA], 2013). This debilitating disorder frequently co-occurs with other disorders (Brady et al., 2000) and causes substantial burden, resulting in poor psychosocial (Kuhn et al., 2003) and physical function (Ahmadian et al., 2019). PTSD also impacts society, with an estimated $232.2 billion yearly excess economic burden in the U.S. (Davis et al., 2022). Ostensibly, PTSD has far-reaching effects persisting long after the traumatic event.

First-line PTSD treatments include pharmacologic (e.g., paroxetine, sertraline), and psychological approaches (e.g., prolonged exposure). While current treatments reduce symptoms for many (Hoskins et al., 2015; Watkins et al., 2018), improvements are needed due to small treatment effect sizes (Cipriani et al., 2017), frequent diagnosis retention (Steenkamp et al., 2015), and poor acceptability (Lewis et al., 2020). These limitations may reflect substantial heterogeneity in PTSD (Galatzer-Levy and Bryant, 2013), and/or that current treatments may not target underlying aspects or subtypes of PTSD (Susanty et al., 2022).

Recent research highlights the potential role of altered attention in PTSD (Block and Liberzon, 2016; Punski-Hoogervorst et al., 2023). Attention is “the range of processes that regulate access to capacity-limited systems, such as awareness, higher perceptual processes, and motor action” (National Institute of Mental Health, 2021). Attentional abnormalities could contribute to hyperarousal and intrusive PTSD symptoms, manifesting as emotional reactivity or inattention (Block and Liberzon, 2016). Investigating cross-cutting characteristics of psychiatric disorders, like attention, can improve knowledge of the development, expression, and treatment of PTSD (Scott et al., 2015). Nevertheless, compared to related constructs like memory (Johnsen and Asbjørnsen, 2008), attention-related brain circuits as they relate to PTSD remain underexplored. To date, PTSD research predominantly examines attentional processes under threat cues (Pergamin-Hight et al., 2015) and other emotionally-charged contexts (e.g., neurobehavioral attention biases toward fearful faces Fani et al., 2012). However, a recent systematic review of neuropsychological studies suggests that PTSD-related behavioral attention deficits remain even in neutral settings without emotional stimuli (Punski-Hoogervorst et al., 2023), though the neuroanatomical underpinnings of this relationship are under-researched.

Here, we review current literature on attention-related brain function in individuals with PTSD. First, we briefly overview attention-related brain networks and two well-validated tasks used to study attentional processes. We then summarize recent functional magnetic resonance imaging (fMRI) studies highlighting altered attention-related brain function associated with PTSD symptoms in the absence of emotional cues. Finally, we discuss gaps in the literature and offer future research recommendations.

Across disciplines, attention has been modeled under various frameworks (see Lindsay, 2020 for a review). Electrophysiological studies in non-human primates provide evidence for signal detection theory, suggesting that distinct neuronal mechanisms contribute to different behavioral aspects of attention (e.g., sensitivity and response to stimuli; Luo and Maunsell, 2019). In humans, neurobehavioral studies support a model of three anatomically and functionally distinct attention networks (alerting, orienting, and executive) involving different neuromodulatory systems and brain regions (Petersen and Posner, 2012). Alerting attention refers to the maintenance of an arousal state to temporally process stimuli, while orienting attention describes the ability to spatially attune toward stimuli. Executive attention enables voluntary attentional control, as well as conflicting stimuli detection and resolution.

Norepinephrine facilitates alerting attention with projections from the locus coeruleus (Aston-Jones and Cohen, 2005) to various brain regions in the parietal and frontal cortices (Petersen and Posner, 2012). Acetylcholine modulates orienting attention (Petersen and Posner, 2012) through the dorsal (DAN) and ventral attention networks (VAN; Corbetta and Shulman, 2002; Figure 1A). The DAN exerts top-down attentional control and includes the intraparietal sulcus and frontal eye fields. In contrast, the VAN facilitates bottom-up control to direct attention toward salient stimuli and is anchored by the temporoparietal junction and inferior/middle frontal gyri. Together, these networks interact dynamically in service of flexible attentional control (Vossel et al., 2014).

Dopamine and serotonin govern executive attention under two distinct networks: the cingulo-opercular (CON) and frontoparietal networks (FPN; Dosenbach et al., 2008; Figure 1B). The CON provides stable surveillance of attentional performance and involves the dorsal anterior cingulate cortex (dACC), anterior insula, and thalamus. The FPN, anchored by the dorsolateral prefrontal cortex and inferior parietal lobule, initiates and adjusts attention and may also control spatial orienting and emotional regulation processes (Dosenbach et al., 2008; Scolari et al., 2015). Opposing these executive attention networks is the default-mode network (DMN; Figure 1C), which deactivates during tasks and activates during rest periods. The DMN facilitates internally-directed mental activity and includes the ventromedial/dorsomedial prefrontal cortices and posterior cingulate cortex/precuneus (Raichle, 2015).

The salience network (SN; Figure 1D) shares a similar role to the VAN in detecting salient stimuli (e.g., threats, rewards). The anterior insula and dACC anchor the SN, but can also incorporate subcortical structures (e.g., the amygdala). Notably, the SN, VAN, and CON are sometimes used interchangeably in the literature, likely due to their closely related roles and anatomical overlap (Gratton et al., 2018). However, evidence suggests that these networks are functionally distinct (Seeley, 2019; Uddin et al., 2019). Specifically, the SN recruits task-control networks and facilitates the switch between the FPN and DMN, whereas the CON provides stable task performance monitoring (Seeley et al., 2007; Menon, 2015; Seeley, 2019). The SN also broadly detects salient information, including interoceptive stimuli, whereas the VAN detects exogenous stimuli (Uddin et al., 2019). For further discussion, see Gratton et al., 2018; Seeley, 2019; Uddin et al., 2019.

Several fMRI tasks measure attention-related brain and behavioral responses across different domains (see Tables 3, 4 in Block and Liberzon, 2016). Widely used, continuous performance tasks (CPT) capture sustained attention through repeated stimuli presentation over long time periods (Figure 2A). During a CPT, participants respond to target stimuli while inhibiting responses to others. In line with signal detection theory, the CPT can provide separable measures of participants’ ability to detect target stimuli (i.e., sensitivity) and appropriate initiation or inhibition toward stimuli (i.e., response; Evans et al., 2022).

The Attention Network Test (ANT; Fan et al., 2002) concurrently evaluates alerting, orienting, and executive attention networks (Figures 2B–E). In the ANT, participants identify the direction of a central target arrow, which is flanked by cues facing the same or opposite direction and measures executive attention. Some trials are preceded by a warning cue to signal the incoming target and may indicate its future location, which measures alerting and orienting attention, respectively.

Here, we review four fMRI studies highlighting the role of non-emotionally driven attention in PTSD.

Recent research links PTSD to altered attention-related behavior, even when emotional stimuli are absent (Punski-Hoogervorst et al., 2023); however, the current neuroanatomical understanding of this relationship is limited. Here, we examined four recent studies that highlight attention-related brain function in individuals with PTSD symptoms in the presence of non-emotional cues. Findings indicate that PTSD symptoms are associated with poorer orienting attention (Block et al., 2017), possibly due to lesser spatial cue utilization (Block et al., 2020), suboptimal sustained attention performance (Evans et al., 2022), and/or overall attentional impairment (Esterman et al., 2020). FMRI analyses showed that PTSD symptoms are associated with altered brain-behavior correlations within or between three core attentional-control networks: the DAN, VAN, and SN. Together, these studies support a general impairment in fundamental attentional processes and altered network function in individuals with PTSD symptoms.

The behavioral data evidence PTSD-related sustained and orienting attention deficits. Evans et al. (2022) suggest that PTSD-related sustained attention deficits may contribute to functional impairments (e.g., maintaining employment). Block et al. (2020) propose that PTSD-related effects on orienting attention contribute to contextual processing differences, potentially explaining the abnormal fear responses in neutral, non-threatening environments reported in PTSD. Altered visual processing may disrupt attention networks and contribute to these difficulties (or vice versa; Mueller-Pfeiffer et al., 2013). Interestingly, recent evidence links structural ventral visual stream covariance to flashback and nightmare symptoms after a traumatic event, and the integrity of these areas predicts future PTSD symptom severity (Harnett et al., 2022). Future studies should investigate the role of visual processing in attention-related brain function and behavior in individuals with PTSD.

All reviewed studies reported PTSD-related alterations within and between crucial top-down and bottom-up attentional control networks (i.e., the DAN, VAN, and SN). Evans et al. (2022) findings of PTSD-related reductions in DAN synchronization are intriguing, considering the DAN’s top-down control over visuospatial attention. Individuals with PTSD in Block et al.’s studies (2017, 2020) exhibited (1) an absent but expected brain-behavior correlation between orienting attention and DAN-SN rs-FC and (2) a relationship between the validity effect and SN activity. Given the DAN, VAN, and SN orchestrate attentional resources (Corbetta et al., 2008), these findings suggest that salient stimuli detected by the VAN/SN may fail to appropriately redirect attentional control by interrupting the DAN’s processes in individuals with PTSD. These networks also control the DMN, with the DAN/SN suppressing activity (Zhou et al., 2018) and the SN facilitating the FPN-DMN switch (Uddin, 2014). Therefore, these network alterations may indicate an inability to redirect attention away from internal stimuli and toward exogenous demands. Future studies should further investigate this phenomenon.

Interestingly, SN dysfunction may be a shared feature across disorders, as meta-analyses comparing patients with various Axis I disorders to HC reveal consistent patterns of gray matter loss and abnormal activation in the insula and other SN nodes (Goodkind et al., 2015; McTeague et al., 2017). Considering PTSD frequently co-occurs with other disorders (Brady et al., 2000), the reported effects of PTSD on attention-related brain-behavior function could represent cross-cutting psychopathology. Additionally, PTSD-related effects on attentional processes may be due to significant symptom heterogeneity (Galatzer-Levy and Bryant, 2013), suggesting subtypes may better characterize PTSD and treatment response (France and Jovanovic, 2023). Esterman et al. (2020) identified a PTSD subtype hallmarked by attentional impairments and lower within-VAN rsFC, potentially contributing to other cognitive disruptions (e.g., memory) by increasing distractions or intrusions (Vasterling et al., 1998). Furthermore, trauma-exposed controls did not differ significantly from PTSD or HC groups (c.f. Block et al., 2020), suggesting that altered attentional processes represent a pre-existing vulnerability, and/or that trauma exposure itself may induce such alterations. For example, interpersonal early-life trauma, rather than PTSD, was found to contribute to neurobehavioral attention abnormalities in a sample of veterans (Fortenbaugh et al., 2017). Together, these ideas necessitate studies to disentangle the role of trauma exposure, PTSD expression, comorbidities, and/or pre-existing vulnerabilities in attentional processes.

Attention difficulties are common in PTSD and extend beyond threat bias to affect general cognition, yet current treatments often fail to target these symptoms (Susanty et al., 2022). Further, attentional impairments may maintain symptoms and interfere with treatment response (Esterman et al., 2020). Punski-Hoogervorst et al. (2023) propose that attention-targeting treatments (e.g., methylphenidate, attention training) may fill gaps in current approaches by addressing cognitive dysfunction in PTSD. Research utilizing non-emotional stimuli would elucidate the role of cognitive attention in PTSD symptom maintenance and treatment response, and potentially enhance interventions. Used alongside emotional stimuli, this research could disentangle the cognitive and emotional mechanisms driving the complex neurobiology of PTSD.

Emerging evidence supports the link between PTSD symptoms and general attentional abnormalities; yet, several questions remain unanswered. Three out of four studies included predominantly white, male veterans, which limits the generalizability of findings. Future investigations should include individuals who are female, from diverse racial/ethnic backgrounds, and exposed to civilian trauma. The lack of research conducted during substantial attention network development (e.g., childhood; Saito et al., 2022) is significant. Notably, most individuals (61–68%) experience trauma during developmental periods (Copeland et al., 2007; McLaughlin et al., 2013), and many psychiatric disorders–including PTSD–originate during this time (De Lijster et al., 2017). Furthermore, early life trauma, particularly interpersonal trauma, impacts attentional processes with observable effects well into adulthood (Fortenbaugh et al., 2017), though trauma’s impact during development is under-researched. Consequently, it is imperative to investigate the impact of trauma exposure and/or PTSD on attention network development.

To date, few neuroimaging studies employing non-emotional cues to investigate attentional processes have been conducted. This review provides preliminary evidence that PTSD symptoms impact brain-behavior correlations even in the absence of emotional cues, suggesting a broad impairment in attention-related brain networks. It is crucial for future research to both examine brain-based subtypes of attentional alterations associated with PTSD and untangle the effects of PTSD, trauma exposure, comorbidities, and other significant factors such as childhood trauma. Nevertheless, this review contributes to the growing neuropsychological evidence highlighting the prevalence of attention deficits among individuals with PTSD and emphasizes the need for further research in this area to inform treatment strategies.

SE and HM were involved in the initial conceptualization of the topic and produced the first drafts of the manuscript. CZ, LG, JE, AB, CC, and MS all provided valuable insights in the formation of the topic. All authors critically reviewed and revised the manuscript and figures, and approve of the manuscript’s submission.