Bradley C. Taber-Thomas

Arrested development: early prefrontal lesions impair the maturation of moral judgement

Learning to make moral judgements based on considerations beyond self-interest is a fundamental aspect of moral development. A deficit in such learning is associated with poor socialization and criminal behaviour. The neural systems required for the acquisition and maturation of moral competency are not well understood. Here we show in a unique sample of neurological patients that focal lesions involving ventromedial prefrontal cortex, acquired during development, result in an abnormally egocentric pattern of moral judgement. In response to simple hypothetical moral scenarios, the patients were more likely than comparison participants to endorse self-interested actions that involved breaking moral rules or physically harming others in order to benefit themselves. This pattern (which we also found in subjects with psychopathy) differs from that of patients with adult-onset ventromedial prefrontal cortex lesions--the latter group showed normal rejection of egocentric rule violations. This novel contrast of patients with ventromedial prefrontal cortex lesions acquired during development versus during adulthood yields new evidence suggesting that the ventromedial prefrontal cortex is a critical neural substrate for the acquisition and maturation of moral competency that goes beyond self-interest to consider the welfare of others. Disruption to this affective neural system early in life interrupts moral development.

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

Children with behavioral inhibition (BI), a temperament characterized by biologically-based hyper-vigilance to novelty, display threat-related attention biases (AB) that shape developmental trajectories of risk for anxiety. Here we explore the relations between BI, neural function, and anxiety. Fifty-six 9-12-year-olds (23 behaviorally inhibited) performed the dot-probe task while undergoing fMRI. AB scores were not associated with BI group or parent-rated anxiety symptoms. Trials requiring attention orienting away from threat engaged an executive and threat-attention network (dlPFC, vlPFC, mPFC, and amygdala). Within that network, behaviorally inhibited children showed greater activation in the right dlPFC. Heightened dlPFC activation related to increased anxiety, and BI levels accounted for the direct relation between dlPFC activation and anxiety. Behaviorally inhibited children may engage the executive attention system during threat-related processing as a compensatory mechanism. We provide preliminary evidence that the link between PFC functioning and anxiety might be attributed to early-emerging temperamental vulnerabilities present before the emergence of clinical anxiety.

Neural correlates of attention biases, behavioral inhibition, and social anxiety in children: An ERP study

Behavioral inhibition (BI) is a biologically-based temperament characterized by vigilance toward threat. Over time, many children with BI increasingly fear social circumstances and display maladaptive social behavior. BI is also one of the strongest individual risk factors for developing social anxiety disorder. Although research has established a link between BI and anxiety, its causal mechanism remains unclear. Attention biases may underlie this relation. The current study examined neural markers of the BI-attention-anxiety link in children ages 9–12 years (N = 99, Mean = 9.97, SD = 0.97). ERP measures were collected as children completed an attention-bias (dot-probe) task with neutral and angry faces. P2 and N2 amplitudes were associated with social anxiety and attention bias, respectively. Specifically, augmented P2 was related to decreased symptoms of social anxiety and moderated the relation between BI and social anxiety, suggesting that increasing attention mobilization may serve as a compensatory mechanism that attenuates social anxiety in individuals with high BI. The BI by N2 interaction found that larger N2 related to threat avoidance with increasing levels of BI, consistent with over-controlled socio-emotional functioning. Lastly, children without BI (BN) showed an augmented P1 to probes replacing angry faces, suggesting maintenance of attentional resources in threat-related contexts.

Temperament and Attention as Core Mechanisms in the Early Emergence of Anxiety

Anxiety is a pervasive, impairing, and early appearing form of psychopathology. Even when anxiety remits, children remain at a two- to threefold increased risk for the later emergence of a mood disorder. Therefore, it is imperative to identify and examine underlying mechanisms that may shape early emerging patterns of behavior that are associated with anxiety. One of the strongest and first visible risk factors is childhood temperament. In particular, children who are behaviorally inhibited or temperamentally shy are more likely to exhibit signs of anxiety by adolescence. However, not all shy children do so, despite the early risk. We know that attention mechanisms, particularly the presence of attention biases toward or away from threat, can play a critical role in the emergence of anxiety. The current chapter will bring together these separate lines of research to examine the ways in which attention can modulate the documented link between early temperament and later anxiety. In doing so, the chapter will highlight multiple levels of analysis that focus on the behavioral, cognitive, and neural mechanisms in the temperament-attention-anxiety network. The chapter will help identify both markers and mechanisms of risk, supporting future work aimed at improving theory and intervention by focusing on attention biases to environmental threat.

Maternal anxiety predicts attentional bias towards threat in infancy.

Although cognitive theories of psychopathology suggest that attention bias toward threat plays a role in the etiology and maintenance of anxiety, there is relatively little evidence regarding individual differences in the earliest development of attention bias toward threat. The current study examines attention bias toward threat during its potential first emergence by evaluating the relations between attention bias and known risk factors of anxiety (i.e., temperamental negative affect and maternal anxiety). We measured attention bias to emotional faces in infants (N = 98; 57 male) ages 4 to 24 months during an attention disengagement eye-tracking paradigm. We hypothesized that (a) there would be an attentional bias toward threat in the full sample of infants, replicating previous studies; (b) attentional bias toward threat would be positively related to maternal anxiety; and (c) attention bias toward threat would be positively related to temperamental negative affect. Finally, (d) we explored the potential interaction between temperament and maternal anxiety in predicting attention bias toward threat. We found that attention bias to the affective faces did not change with age, and that bias was not related to temperament. However, attention bias to threat, but not attention bias to happy faces, was positively related to maternal anxiety, such that higher maternal anxiety predicted a larger attention bias for all infants. These findings provide support for attention bias as a putative early mechanism by which early markers of risk are associated with socioemotional development.

The impact of negative affect on attention patterns to threat across the first 2 years of life.

The current study examined the relations between individual differences in attention to emotion faces and temperamental negative affect across the first 2 years of life. Infant studies have noted a normative pattern of preferential attention to salient cues, particularly angry faces. A parallel literature suggests that elevated attention bias to threat is associated with anxiety, particularly if coupled with temperamental risk. Examining the emerging relations between attention to threat and temperamental negative affect may help distinguish normative from at-risk patterns of attention. Infants (N = 145) ages 4 to 24 months (M = 12.93 months, SD = 5.57) completed an eye-tracking task modeled on the attention bias “dot-probe” task used with older children and adults. With age, infants spent greater time attending to emotion faces, particularly threat faces. All infants displayed slower latencies to fixate to incongruent versus congruent probes. Neither relation was moderated by temperament. Trial-by-trial analyses found that dwell time to the face was associated with latency to orient to subsequent probes, moderated by the infant’s age and temperament. In young infants low in negative affect longer processing of angry faces was associated with faster subsequent fixation to probes; young infants high in negative affect displayed the opposite pattern at trend. Findings suggest that although age was directly associated with an emerging bias to threat, the impact of processing threat on subsequent orienting was associated with age and temperament. Early patterns of attention may shape how children respond to their environments, potentially via attention’s gate-keeping role in framing a child’s social world for processing.