Isolating neural components of threat bias in pediatric anxiety

Abstract

Background Attention biases towards threat are often detected in individuals with anxiety disorders. Threat biases can be measured experimentally through dot-probe paradigms, in which individuals detect a probe following a stimulus pair including a threat. On these tasks, individuals with anxiety tend to detect probes that occur in a location previously occupied by a threat (i.e., congruent) faster than when opposite threats (i.e., incongruent). In pediatric anxiety disorders, dot-probe paradigms detect abnormal attention biases towards threat and abnormal ventrolateral prefrontal cortex (vlPFC) function. However, it remains unclear if this aberrant vlPFC activation occurs while subjects process threats (e.g., angry faces) or, alternatively, while they process and respond to probes. This magnetoencephalography (MEG) study was designed to answer this question. Methods Adolescents with either generalized anxiety disorder (GAD, n=17) or no psychiatric diagnosis (n=25) performed a dot-probe task involving angry and neutral faces while MEG data were collected. Synthetic Aperture Magnetometry (SAM) beamformer technique was used to determine whether there were group differences in power ratios while subjects processed threats (i.e., angry vs. neutral faces) or when subjects responded to incongruent vs. congruent probes. Results Group differences in vlPFC activation during the response period emerged with a 1-30 Hz frequency band. No group differences in vlPFC activation were detected in response to angry-face cues. Conclusions In the dot-probe task, anxiety-related perturbations in vlPFC activation reflect abnormal attention control when responding to behaviorally-relevant probes, but not to angry faces. Given that motor responses to these probes are used to calculate threat bias, this study provides insight into the pathophysiology reflected in this commonly-used marker of anxiety. In addition, this finding may inform the development of novel anxiety-disorder treatments targeting the vlPFC to enhance attention control to task-relevant demands.

Behavioral and neural stability of attention bias to threat in healthy adolescents

“…To date, fMRI research using the dot-probe task yields generally consistent findings (Britton, 2012; Fani et al, 2012; Monk et al, 2006, 2008; Telzer et al, 2008). On this task, individual differences in anxiety relate to perturbed function in brain regions supporting emotional processing (e.g., amygdala) and attentional control (e.g., ventrolateral prefrontal cortex, vlPFC; dorsolateral prefrontal cortex, dlPFC).…”

“…Moreover, in these imaging studies, some findings emerge for contrasts comparing angry incongruent (different spatial location) and angry congruent (same spatial location) trials (i.e., the Attention Bias to Threat contrast). These studies find that anxiety is associated with greater amygdala (Monk et al, 2008) and greater lateral PFC activation (e.g., Britton et al, 2012; Telzer et al, 2008). Other findings emerge when examining neural activation to any threatening facial expression, collapsing across congruency, compared to neutral facial expressions on the dot-probe task (Monk et al, 2006).…”

Frontolimbic functioning during threat-related attention: Relations to early behavioral inhibition and anxiety in children

“…Studies examining the neural correlates of AB in relation to anxiety commonly employ the dot-probe task (Bar-Haim et al, 2007), in which each trial presents a pair of faces (either both neutral, or a neutral-threat pair) followed by a probe replacing one of the faces (youths: Britton et al, 2012; Monk et al, 2006; 2008; Price et al, 2014; Telzer et al, 2008; adults: Fani et al, 2012; Hardee et al, 2013). Biased attention toward threat is quantified behaviorally in the neutral-threat trials by slower reaction times (RTs) to the probes that replace the neutral face (incongruent trials) compared to the probes that replace the threat face (congruent trials).…”

Stimulus-Driven Attention, Threat Bias, and Sad Bias in Youth with a History of an Anxiety Disorder or Depression

“…Although there is also experimental evidence for a vigilance-avoidance pattern of attention to threatening stimuli in anxious youth (In-Albon, Kossowsky, & Schneider, 2010), the pediatric literature is mixed with many reports of threat vigilance in anxiety (Dalgleish et al, 2003; Roy et al, 2008; Taghavi, Neshat-Doost, Moradi, Yule, & Dalgleish, 1999; Vasey, Daleiden, Williams, & Brown, 1995; Waters, Henry, Mogg, Bradley, & Pine, 2010; Waters, Mogg, Bradley, & Pine, 2008), but also several reports of threat avoidance (Britton et al, 2012; Brown et al, 2013; Monk et al, 2006). More work is needed to determine whether the mixed pediatric literature is partly a result of threat vigilance in studies that measure threat bias at short durations and threat avoidance in studies that measure threat bias at long durations.…”