Kids, candy, brain and behavior: Age differences in responses to candy gains and losses

Abstract

The development of reward-related neural systems, from adolescence through adulthood, has received much recent attention in the developmental neuroimaging literature. However, few studies have investigated behavioral and neural responses to both gains and losses in pre-pubertal child populations. To address this gap in the literature, in the present study healthy children aged 7–11 years and young-adults completed an fMRI card-guessing game using candy pieces delivered post-scan as an incentive. Age differences in behavioral and neural responses to candy gains/losses were investigated. Adults and children displayed similar responses to gains, but robust age differences were observed following candy losses within the caudate, thalamus, insula, and hippocampus. Interestingly, when task behavior was included as a factor in post-hoc mediation analyses, activation following loss within the caudate/thalamus related to task behavior and relationships with age were no longer significant. Conversely, relationships between response to loss and age within the hippocampus and insula remained significant even when controlling for behavior, with children showing heightened loss responses within the dorsal/posterior insula. These results suggest that both age and task behavior influence responses within the extended reward circuitry, and that children seem to be more sensitive than adults to loss feedback particularly within the dorsal/posterior insula.

Depression Risk Predicts Blunted Neural Responses to Gains and Enhanced Responses to Losses in Healthy Children

“…However, our results indicated a stronger relationship between MDD risk and response to loss than to gain, a pattern consistent with behavioral/neural findings indicating greater salience of loss in late childhood more generally. 23,24,26 Another set of key findings were the unique and opposing relationships anhedonic and negative mood symptom severity showed with gain-loss feedback responses. These effects were largely driven by blunted deactivation to loss in children reporting elevated anhedonia and enhanced deactivation to loss in children reporting elevated negative mood.…”

“…Further, individual differences in the severity of core depressive symptoms, anhedonia and negative mood, showed strong and opposing relations to loss responsiveness, while neither symptom construct significantly related to gain responsiveness. Given these results, and that childhood is normatively a time of increased sensitivity to loss, 23,24,56 identifying mechanisms for reducing reactivity to loss of reward/negative stimuli and negative mood may prove to be a useful, preventative strategy for mental health intervention in childhood.…”

“…23,39 Children guessed whether the number on a mystery card (represented by a “?”) was more or less than five after which candy was won for correct guesses, lost for incorrect guesses, or neither won nor lost if the card number was five. Participants chose whether to play for Skittles or M&Ms and received a lump sum of candy at the conclusion of the experiment.…”

“…7,15 The normative developmental literature, while small, consistently highlights elevated behavioral/neural response to loss/punishment in childhood/adolescence relative to adulthood, with children showing strong loss-avoidance behavior. 23–26 Thus, enhanced responsiveness to loss may be particularly characteristic of childhood MDD risk. As such, we would expect high-risk children to show greater ventral striatal deactivation and potentially greater amygdala activation to loss.…”

Neural responses to social and monetary reward in early adolescence and emerging adulthood

“…Some evidence suggests that earlier development of the ventral striatum relative to the medial prefrontal cortex underlies heightened reward sensitivity during this period (Casey, Jones, & Hare, 2008; Galvan, 2010; Van Leijenhorst et al, 2010). The majority of studies investigating reward processing in adolescence have focused exclusively on monetary or other non-social rewards (Cohen et al, 2010; Lukie, Montazer-Hojat, & Holroyd, 2014; Luking, Luby, & Barch, 2014), yet adolescence marks the beginning of a shift in which social interactions and feedback from peers become paramount (Parker, Rubin, Erath, Wojslawowicz, & Buskirk, 2015; Vaillancourt, Brittain, McDougall, & Duku, 2013). This suggests that establishing reliable measures of neural response to social incentives will be critical to understanding developmental shifts in reward sensitivity.…”