The role of the ventromedial prefrontal cortex (vmPFC) in human pavlovian threat conditioning has been relegated largely to the extinction or reversal of previously acquired stimulus-outcome associations. However, recent neuroimaging evidence questions this view by also showing activity in the vmPFC during threat acquisition. Here we investigate the casual role of vmPFC in the acquisition of pavlovian threat conditioning by assessing skin conductance response (SCR) and declarative memory of stimulus-outcome contingencies during a differential pavlovian threat-conditioning paradigm in eight patients with a bilateral vmPFC lesion, 10 with a lesion outside PFC and 10 healthy participants (each group included both females and males). Results showed that patients with vmPFC lesion failed to produce a conditioned SCR during threat acquisition, despite no evidence of compromised SCR to unconditioned stimulus or compromised declarative memory for stimulus-outcome contingencies. These results suggest that the vmPFC plays a causal role in the acquisition of new learning and not just in the extinction or reversal of previously acquired learning, as previously thought. Given the role of the vmPFC in schemarelated processing and latent structure learning, the vmPFC may be required to construct a detailed representation of the task, which is needed to produce a sustained conditioned physiological response in anticipation of the unconditioned stimulus during threat acquisition.

The ability to generalize from and distinguish between aversive memories and novel experiences is critical to survival. Previous research has revealed mechanisms underlying generalization of threat-conditioned defensive responses, but little is known about generalization of episodic memory for threatening events. Here we tested if aversive learning influences generalization of episodic memory for threatening events in human adults. Subjects underwent Pavlovian threat-conditioning in which objects from one category were paired with a shock and objects from a different category were unpaired. The next day, subjects underwent a recognition memory test that included old, highly similar, and entirely novel items from the shock-paired and shock-unpaired object categories. Results showed that items highly similar to those from the object category previously paired with shock were mistaken for old items more often than items from the shock-unpaired category. This finding indicates that threat learning promotes generalization of episodic memory, and is consistent with the idea that threat generalization is an active process that may be adaptive for avoiding a myriad of potential threats following an emotional experience. Enhanced generalization of aversive episodic memories may be maladaptive, however, when old threat memories are inappropriately reactivated in harmless situations, exemplified in a number of stress- and anxiety-related disorders.

Detecting behavioral errors is critical for optimizing performance. Here, we tested whether error monitoring is enhanced in emotional task contexts, and whether this enhancement depends on processing internal affective states. Event-related potentials were recorded in individuals with low and high levels of alexithymia-that is, individuals with difficulties identifying and describing their feelings. We administered a face word Stroop paradigm (Egner, Etkin, Gale, & Hirsch, 2008) in which the task was to classify emotional faces either with respect to their expression (happy or fearful; emotional task set) or with respect to their gender (female or male; neutral task set). The error-related negativity, a marker of rapid error monitoring, was enhanced in individuals with low alexithymia when they adopted the emotional task set. By contrast, individuals with high alexithymia did not show such an enhancement. Moreover, in the high-alexithymia group, the difference in the error-related negativities between the emotional and neutral task sets correlated negatively with difficulties identifying their own feelings, as measured by the Toronto Alexithymia Scale. These results show that errormonitoring activity is stronger in emotional task contexts and that this enhancement depends on processing internal affective states.

No abstract

Individuals with high levels of alexithymia, a personality trait marked by difficulties in identifying and describing feelings and an externally oriented style of thinking, appear to require more time to accurately recognize intense emotional facial expressions (EFEs). However, in everyday life, EFEs are displayed at different levels of intensity and individuals with high alexithymia may also need more emotional intensity to identify EFEs. Nevertheless, the impact of alexithymia on the identification of EFEs, which vary in emotional intensity, has largely been neglected. To address this, two experiments were conducted in which participants with low (LA) and high (HA) levels of alexithymia were assessed in their ability to identify static (Experiment 1) and dynamic (Experiment 2) morphed faces ranging from neutral to intense EFEs. Results showed that HA needed more emotional intensity than LA to identify static fearful – but not happy or disgusted – faces. On the contrary, no evidence was found that alexithymia affected the identification of dynamic EFEs. These results extend current literature suggesting that alexithymia is related to the need for more perceptual information to identify static fearful EFEs.