High Stakes in Small Mistakes: Abused Youths’ Brains Show Hypersensitivity to Errors

Emotional and behavioral problems are common among adultswhoweremaltreated as children (1).Thesemaladaptive outcomes appear, at least in part, to reflect enduring changes in brain structure and function that emerge in the wake of severe stressors, such as childhood physical abuse (2). Research that clarifies the extent to which such changes stem from the experience of abuse itself as opposed to the psychiatric conditions that maltreated children often develop, such as posttraumatic stress disorder and depressive disorders, is important. Indeed, a specific understanding of the path from maltreatment to adverse outcomes could inform maltreatmentrelated policy and practice, enabling us to implement both more effectively and efficiently. It could, for instance, help us determine where we should target scarce resources in order to best decreasemaltreatment and its negative consequences. Do we invest in across-the-board services for all maltreated youths, or do we focus some resources more heavily on individuals who show abuse-related psychopathology? It could also guide our selection of interventions or preventive approaches that aremost likely to benefit particular people. If a patient presents with a history of maltreatment but only subthreshold psychiatric symptoms, might one intervention approach be more efficient and effective than another? Research thathelpsus to answer suchquestionsdecisively could have a striking impact on public health. Why, then, are there so few studies that yield clear evidence about maltreatment and whether it leads directly to changes in brain activity patterns or engenders such changes indirectly, by provoking symptoms that in turn alter the brain? One reason is that research that supports confident inferences about whether neural changes stem from life experiences, fromsymptoms, or fromboth ishard to conduct. Recruitment alone is unusually challenging, because participants should ideally be distributed across multiple otherwise-matched groups (non-maltreated/psychiatric disorder, maltreated/psychiatric disorder, non-maltreated/disorderfree, and maltreated/disorder-free). However, although the fourth group (maltreated/disorder-free) is theoretically possible, it is rare to find people with maltreatment histories who are entirely resilient to psychopathology. Thus, including such a group is both impractical andunlikely to yield data that are relevant to more than a few individuals. In addition, researchers must carefully exclude participants with experiences (e.g., drug abuse, brain injury) and characteristics (e.g., neurological anomalies) that could muddy results or introduce irrelevant but potentially influential differences between group members’ brains. The process of selecting cognitive tasks that facilitate meaningful behavioral and neural comparisons among group members introduces further challenges. Optimal tasks tap discrete cognitive processes that are vulnerable to disruption byearly-lifemaltreatmentandalsoelicit robust, reliableneural responsepatterns.Furthermore, ideal tasksadapt interactively to each participant’s ability level, becoming harder when a person performs well and easier when a person performs poorly. This feature ensures that no participants experience the same task as particularly difficult or easy. These are just a few of the issues that complicate studies of neural function andmaltreatment; this work is not for the faint of heart. It is thus exciting to see studies that address these issues head-on come to publication. Lim and colleagues, who describe just such a study in this issueof theJournal (3), are tobecommended forwhat they have achieved. Lim et al. used functional neuroimaging to examine neural activity, indexed as the ratio of deoxygenated to oxygenated blood, throughout the brain while adolescents executed or withheld motor responses in response to rapidly presented cues on a computer screen. Importantly, the task was designed to adjust stimulus presentation rates so that each participant succeeded on only half of the trials when they were cued to withhold a response. The unsuccessful, or “failed inhibition,” trials were of particular interest, because maltreated participants were expected, given their histories of persistent, harsh punishment early in life, to show a distinctive neural hypersensitivity to their own errors. To test the hypothesis that maltreated youths’ brains would respond more sensitively to behavioral errors than would the brains of non-maltreated youths, the authors compared neuroimaging data obtained during this stop-signal task in three demographically matched, unmedicated/drugfree groups of adolescents—one with documented histories of A specific understanding of the path from maltreatment to adverse outcomes could inform maltreatmentrelated policy and practice, enabling us to implement both more effectively and efficiently.