No abstract

Research into mental processes has generally focused on the average response and treated individual variability as noise (cf. Plomin & Kosslyn, 2001). The application of this method to fear learning has yielded general principles that indicate fear conditioning in most people when a stimulus is followed by an aversive event as well as fear extinction over time when this threat ceases (e.g., Mineka & Oehlberg, 2008). However, researchers have recognized that such a mean learning pattern can reflect an artifact of group averaging and is unlikely to represent the response pattern of any given individual (e.g., Kristjansson, Kircher, & Webb, 2007;Pamir et al., 2011). Individual differences may be especially pertinent to understanding pathological fear learning, given that psychopathology, by definition, reflects a deviation from the mean. Researchers have advocated that to understand mechanisms of abnormal (fear) learning, it is necessary to relate naturally occurring variation in individual dispositions (e.g., traits) to variation in learning (e.g., Kosslyn et al., 2002). Accordingly, our aim in the present study was to examine how selected individual differences in personality are related to variability in fear learning.Cronbach's (1957) classic article on the two disciplines of scientific psychology invited researchers to purposefully seek Aptitude (i.e., personality characteristics) × Treatment (i.e., fear-learning phase) interactions. In line with this call, most notably Eysenck (1965) and several 535914C PXXXX10.

Individual differences in fear learning are a crucial prerequisite for the translational value of the fearconditioning model. In a representative sample (N = 936), we used latent class growth models to detect individual differences in associative fear learning. For a series of subsequent test phases varying in ambiguity (i.e., acquisition, extinction, generalization, reinstatement, and re-extinction), conditioned responding was assessed on three response domains (i.e., subjective distress, startle responding, and skin conductance). We also associated fear learning across the different test phases and response domains with selected personality traits related to risk and resilience for anxiety, namely Harm Avoidance, Stress Reaction, and Wellbeing (MPQ; Tellegen and Waller, 2008). Heterogeneity in fear learning was evident, with fit indices suggesting subgroups for each outcome measure. Identified subgroups showed adaptive, maladaptive, or limited-responding patterns. For subjective distress, fear and safety learning was more maladaptive in the subgroups high on Harm Avoidance, while more adaptive learning was observed in subgroups with medium Harm Avoidance and the limited-or non-responders were lowest in Harm Avoidance. Distress subgroups did not differ in Stress Reaction or Wellbeing. Startle and SCR subgroups did not differ on selected personality traits. The heterogeneity in fear-learning patterns resembled risk and resilient anxiety development observed in real life, which supports the associative fear-learning paradigm as a useful translational model for pathological fear development.

A valuable experimental model for the pathogenesis of anxiety disorders is that they originate from a learned association between an intrinsically non-aversive event (Conditioned Stimulus, CS) and an anticipated disaster (Unconditioned Stimulus, UCS). Most anxiety disorders, however, do not evolve from a traumatic experience. Insights from neuroscience show that memory can be modified post-learning, which may elucidate how pathological fear can develop after relatively mild aversive events. Worrying - a process frequently observed in anxiety disorders - is a potential candidate to strengthen the formation of fear memory after learning. Here we tested in a discriminative fear conditioning procedure whether worry strengthens associative fear memory. Participants were randomly assigned to either a Worry ( n = 23) or Control condition ( n = 25). After fear acquisition, the participants in the Worry condition processed six worrisome questions regarding the personal aversive consequences of an electric stimulus (UCS), whereas the Control condition received difficult but neutral questions. Subsequently, extinction, reinstatement and re-extinction of fear were tested. Conditioned responding was measured by fear-potentiated startle (FPS), skin conductance (SCR) and UCS expectancy ratings. Our main results demonstrate that worrying resulted in increased fear responses (FPS) to both the feared stimulus (CS + ) and the originally safe stimulus (CS − ), whereas FPS remained unchanged in the Control condition. In addition, worrying impaired both extinction and re-extinction learning of UCS expectancy. The implication of our findings is that they show how worry may contribute to the development of anxiety disorders by affecting associative fear learning.