Anticipatory representations of reward and threat in perceptual areas from preadolescence to late adolescence

Enhanced late positive potential to conditioned threat cue during delayed extinction in anxious youth

BACKGROUND

Deficits in threat learning relate to anxiety symptoms. Since several anxiety disorders arise in adolescence, impaired adolescent threat learning could contribute to adolescent changes in risk for anxiety. This study compared threat learning among anxious and non-anxious youth using self-reports, peripheral psychophysiology measures, and event-related potentials. Because exposure therapy, the first-line treatment for anxiety disorders, is largely based on principles of extinction learning, the study also examined the link between extinction learning and treatment outcomes among anxious youth.

METHODS

Clinically anxious (n = 28) and non-anxious (n = 33) youth completed differential threat acquisition and immediate extinction. They returned to the lab a week later to complete a threat generalization test and a delayed extinction task. Following these two experimental visits, anxious youth received exposure therapy for 12 weeks.

RESULTS

Anxious as compared to non-anxious youth demonstrated elevated cognitive and physiological responses across acquisition and immediate extinction learning, as well as greater threat generalization. In addition, anxious youth showed enhanced late positive potential response to the conditioned threat cue compared to the safety cue during delayed extinction. Finally, aberrant neural response during delayed extinction was associated with poorer treatment outcomes.

CONCLUSIONS

The study emphasizes differences between anxious and non-anxious youth in threat learning processes and provides preliminary support for a link between neural processing during delayed extinction and exposure-based treatment outcome in pediatric anxiety.

Potentiated perceptual neural responses to learned threat during Pavlovian fear acquisition and extinction in adolescents

Adolescents' experience of heightened anxiety and increased vulnerability to develop anxiety disorders is believed to partly result from blunted fear extinction processes. However, whether this anxiety is mediated by adolescent-specific differences in perceptual responses to learned threat is not known. To investigate this, we used EEG to examine reinforcement-dependent changes in early visual event-related potentials in adolescents (N = 28, 13-14 years) and adults (N = 23, 25-26 years old) during a differential Pavlovian fear conditioning task, with one conditioned stimulus (CS+) paired with an aversive sound (unconditioned stimulus [US]) on 50% of trials, and another (CS-) never paired with the US. An immediate extinction phase followed, where both CSs were presented alone. We found age-dependent dissociations between explicit and implicit measures of fear learning. Specifically, both adolescents and adults demonstrated successful fear conditioning and extinction according to their explicit awareness of changes in CS contingencies and their evaluative CS ratings, and their differential skin conductance responses. However, for the first time we show age differences at the neural level in perceptual areas. Only adolescents showed greater visual P1 and N1 responses to the CS+ compared to the CS- during acquisition, a dissociation that for the N1 was maintained during extinction. We suggest that the adolescent perceptual hyper-responsivity to learned threat and blunted extinction reported here could be an adaptive mechanism to protect adolescents from harm. However, this hyper-responsivity may also confer greater vulnerability to experience pathological levels of anxiety at this developmental stage.

Emotional Contexts Modulate Anticipatory Late Positive Component and Reward Feedback Negativity in Adolescents With Major Depressive Disorder

BACKGROUND

Neuroimaging research has determined deficits in the dopaminergic circuit of major depressive disorder (MDD) during adolescence. This study investigated how emotional contexts modulate the temporal dynamics of reward anticipation and feedback in adolescents.

METHODS

EEG data from 35 MDD and 37 healthy adolescents were recorded when they conducted a gambling task after being presented with emotional pictures.

RESULTS

The results demonstrated that both MDD and healthy adolescents exhibited the largest late positive component (LPC) in positive contexts at the frontal sites and the largest LPC in negative contexts at the central sites; however, MDD adolescents exhibited anticipatory LPC hypoactivation than healthy adolescents. However, MDD adolescents exhibited smaller gain feedback negativity (FN) than healthy adolescents independent of emotional contexts, positively correlating with the trait anhedonia according to the consummatory aspect of the Temporal Experience of Pleasure Scale. In contrast, MDD adolescents exhibited greater FN loss in positive and neutral contexts than healthy adolescents while no difference in FN loss was found between the two groups in negative contexts. Moreover, the FN loss amplitudes negatively correlated with hedonic tone according to the Snaith-Hamilton Pleasure Scale over the past week.

CONCLUSIONS

These findings suggest that MDD adolescents exhibited dissociable deficits in reward anticipation and gain or loss feedback that are distinctly modulated by emotional contexts, and they deepen our understanding of the modulation of emotional contexts on the temporal dynamic reorganization of the reward circuit in MDD adolescents.

Tick-tock goes the croc: a high-density EEG study of risk-reactivity and binge-drinking

Links between individual differences in risk processing and high-risk behaviors such as binge-drinking have long been the focus of active research. However, investigations in this area almost exclusively utilize decision-making focused paradigms. This emphasis makes it difficult to assess links between risk behaviors and raw risk reactivity independent of decision and feedback processes. A deeper understanding of this association has the potential to shed light on the role of risk reactivity in high-risk behavior susceptibility. To contribute toward this aim, this study utilizes a popular risk-taking game, the crocodile dentist, to assess links between individual differences in decision-free risk-reactivity and reported binge-drinking frequency levels. In this task, participants engage in a series of decision-free escalating risk responses. Risk-reactivity was assessed by measuring late positive potential responses toward risk-taking action initiation cues using high-density 256-Channel EEG. The results indicate that, after controlling for overall alcohol consumption frequency, higher rates of reported binge-drinking are associated with both increased general risk-taking responsivity and increased risk-reactivity escalation as a function of risk level. These findings highlight intriguing links between risk reactivity and binge-drinking frequency, making key contributions in the areas of risk-taking and affective science.