Poster #17 - Neural Processing of Reward in Adults With and Without a History of Maltreatment

• In Event: 1-115 - Poster Session 03
  In Poster Session: PS 03 Section - Biological Processes: Neuroscience and Genetics

Integrative Statement

Childhood maltreatment is a prevalent phenomenon with major social costs. More than 10% of US children experienced some form in 2008 alone (Finkelhor, Turner, Ormrod, & Hamby, 2009). Maltreatment has been associated with a host of disruptions to behavioral and biological development, resulting in decreased adaptive functioning in adulthood (Cicchetti & Toth, 2005). Widespread changes in brain structure and activity have been observed in adults with a history of childhood adversity, including in the context of reward and loss (e.g. Dillon et al., 2009). However, it is unclear how to attribute these brain differences to specific forms of stress. The current study compares brain activity during reward processing in 37 adults with a history of childhood maltreatment, and 35 adults closely matched in demographics and other childhood stressors, including socioeconomic status. This unique sample allows us to disentangle the effects that may be specific to the experience of childhood maltreatment.
Participants completed two runs of a monetary incentive delay task (MID) while undergoing fMRI scanning. During the task, subjects viewed a cue shape that signaled whether the trial would entail a large reward, small reward, large loss, small loss, or no incentive. The cue was followed by an anticipatory delay period of approximately 2 to 2.5 seconds, and then by a target square. Participants were instructed to make a button press while the target was on the screen. Target duration was titrated for each participant to achieve a 66% hit rate, based on performance in a practice run. Accuracy feedback (win, loss, or no change) was presented on a subsequent screen (see Figure 1). The present study examined brain activity during the anticipatory delay for reward trials compared to the anticipatory delay for no incentive trials.
The comparison group showed greater bilateral activity in inferior frontal regions, and greater activation of the left insula and operculum (p<.005; see Figure 2) for reward trials versus no incentive trials. Inferior frontal activation has been associated with response inhibition, suggesting that participants in the comparison group may be recruiting inhibitory control systems to a greater extent than the maltreated group for response inhibition. The insula and operculum have been associated with negative emotion processing. It is possible that the comparison group may have a stronger desire not to miss the target. These findings are consistent with previous research using the MID task in adolescents and adults, which found insula activation in anticipation of reward (Bjork et al., 2010). Greater activation in the inferior frontal cortex in the control sample is consistent with literature finding maltreatment-related deficits in executive function (Elton et al., 2013). Understanding the mechanisms by which maltreatment leads to altered reward-related brain activation will help to clarify trajectories of maladaptive functioning following early life adversity, and importantly, to identify the unique impacts of maltreatment over other forms of stress. Further analyses of our data will allow us to tease apart these effects in other regulatory and reward-related regions, and investigate differential activation during loss trials.

Authors

• Shreya Lakhan-Pal, University of Minnesota
  Presenting Author

• Ruskin H. Hunt, University of Minnesota
  Non-Presenting Author

• Dante Cicchetti, University of Minnesota
  Non-Presenting Author

• Fred Rogosch, University of Rochester
  Non-Presenting Author

• Kathleen M. Thomas, University of Minnesota
  Non-Presenting Author