In light of divergent developmental difference findings between neuroimaging incentive paradigms (as well as at different stages within the same task), these data suggest that maturational differences in incentive-motivational neurocircuitry: 1) may be sensitive to nuances of incentive tasks or stimuli, such as behavioral or learning contingencies, and 2) may be specific to the component of the instrumental behavior (such as anticipation versus notification).

To test whether adolescents showed increased NAcc activation by cues for rewards, or by delivery of rewards, we scanned 24 adolescents (age 12–17) and 24 adults age (22–42) with functional magnetic resonance imaging while they performed a monetary incentive delay (MID) task. The MID task was configured to temporally disentangle potential reward or potential loss anticipation-related brain signal from reward or loss notification-related signal. Subjects saw cues signaling opportunities to win or avoid losing $0, $.50, or $5 for responding quickly to a subsequent target. Subjects then viewed feedback of their trial success after a variable interval from cue presentation of between 6 to17 s. Adolescents showed reduced NAcc recruitment by reward-predictive cues compared to adult controls in a linear contrast with non-incentive cues, and in a volume-of-interest analysis of signal change in the NAcc. In contrast, adolescents showed little difference in striatal and frontocortical responsiveness to reward deliveries compared to adults.

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This experiment was intended to advance understanding of maturational differences in incentive neurocircuitry by separately assessing mesolimbic responses to instrumental cues versus mesolimbic responses to instrumental behavior outcomes. It is a modification of our initial study [13] , with improved methodology in several aspects. Most importantly, we altered the MID task to include an extended, variable interval between presentation of the response-anticipatory cue and the trial outcome notification. Second, we augmented the statistical power of the variable event timing by sampling the striatum once per second instead of every two seconds. Third, we upgraded from a quadrature head coil to an 8-channel head coil for better signal detection. Fourth, we doubled the sample size. Finally, we adopted a recently-developed, mixed-effects meta/multi-level analysis (MEMA) software designed for outlier-resistant calculation and comparison of group-wise data. Based on our preliminary study [13] , we hypothesized that adolescents would show reduced right NAcc activation by reward-anticipatory cues in the MID task, but adolescents would show greater NAcc activation by reward deliveries.

If reward notifications were temporally-separated from anticipatory cues, might the MID task reveal greater reward notification-elicited VS recruitment in adolescents compared to adults? Critically, no developmental-comparison fMRI studies to date have featured variable timing between the reward-predictive cue at the start of the instrumental trial and the subsequent reward notification event of that trial, so as to isolate time series signal change [29] , [30] elicited by these different components of the instrumental trial. Modified MID tasks with jittered events within the trial, however, have recently shown success in characterizing activation by reward anticipation cues versus notification-elicited feedback [15] , [25] , [31] .

We note that these age differences in activation reported in most studies were primarily in conjunction with behavior execution or outcome. Conversely, in [8] , early VS responses to the initial reward-predictive cue appeared increased in adults relative to adolescents. This underscores the importance of disentangling different components of instrumental behavior. Indeed, using an incentivized anti-saccade task, Geier et al [28] reported that developmental differences in VS recruitment by instrumental behavior varied in directionality within-task depending on what component of the instrumental behavior sequence is being assessed. In particular, adults showed relatively greater VS signal ostensibly linked to incentive cue presentation (anticipation), but adolescents later showed greater activation ostensibly elicited by oculomotor response preparation.

Few neuroimaging studies to date have explored maturational differences in subcortical incentive neurocircuitry between adolescents and adults, and extant findings are mixed. In a preliminary study of developmental differences in VS recruitment by instrumental reward-predictive cues of the MID task [13] , adolescents showed reduced right VS recruitment by reward cues compared to adults, with no age group differences in VS or mFC recruitment by reward notifications. In contrast, adolescents showed greater left VS activation by notification of money won in a probabilistic gambling task compared to adults [22] . Similarly, rewarded trials in decision-making tasks elicited a nonlinear developmental pattern of VS recruitment [8] , [26] . In the Galvan study [8] , once associations between cues and rewarding outcomes had become learned, adolescents showed greater VS activation by rewarding trials compared to responses of adults or younger children. In the Van Leijenhorst study [26] , mid-adolescents showed greater VS activation by risky gains than younger children or young adults. Finally, in a slot machine task, where outcomes were predetermined, mid-adolescents also showed more VS activation by reward-predictive cues than younger children and young adults [27] .

Each trial began with presentation of one of five anticipatory cues. The cue signaled the opportunity to either win money (circle series), avoid losing money (square series), or win/lose no money (triangle) by recording a button press while the following white square target was presented on the screen. After target presentation, the subject then waited across a variable delay for notification (feedback) of whether he or she hit the target. During this delay, a lexical filler stimulus (“Did you hit?”) was presented. Intervals between trial stimuli were pseudorandomly varied as indicated, and trials were also separated by a 1–5 s variable intertrial interval (ITI) following each notification.

Characterizing developmental differences in VS functioning is of particular interest because the VS responds to learned reward-predictive cues in primates [11] , and in humans can reflect individual differences in motivation by instrumentally-conditioned stimuli [12] . The most widely-adopted probes of human incentive-motivational neurocircuitry are variants of the monetary incentive delay (MID) task ( Figure 1 ), wherein learned cues that signal an imminent opportunity to respond for monetary rewards reliably recruit the VS in proportion to potential reward magnitude [13] , [14] , [15] , [16] , [17] , [18] , [19] . Conversely, the VS is not as robustly recruited by cues for reward deliveries that require no behavioral response in either the MID task [20] or other incentive tasks [21] . In addition, the VS [13] , [16] , [22] as well as ventral mesiofrontal cortex (mFC) [13] , [19] , [23] , [24] , [25] are activated by notification of reward, typically as a contrast with notification of nonreward.

Framed in the context of instrumental behavior, adolescent impulsivity could result in part from exaggerated mesolimbic responsiveness to either reward-predictive cues (motivation or orienting), or to reward deliveries (consummation or reinforcement). For example, enhanced responsiveness of VS motivational neurocircuitry toward reward-predictive cues may bias behavior choice toward potentially-rewarding activities, irrespective of potential for a harmful outcome. Enhanced VS responsiveness to reward delivery may promote a greater degree of consumption of risk-laden rewards- such as number alcoholic drinks at a party, or the speed of a car (and resultant “rush”) in a street race. Enhanced VS responsiveness to reward deliveries may also bias future choice toward highly-rewarding but riskier alternatives.

Developmental neuroimaging findings have detected structural changes in striatum [2] and frontal cortex [3] across adolescence, where frontocortical gray matter morphology maturation continues into the mid 20 s [4] , relatively later than other cortex (reviewed in [5] ). This has led to speculation that adolescent risk-taking results in part from immature frontocortical cognitive control neurocircuitry that fails to sufficiently monitor or inhibit risky behavior (e.g. [6] , [7] ). In particular, an opponent-process theory of adolescent impulsivity posits that subcortical incentive-motivational neurocircuitry in the ventral striatum (VS), including the nucleus accumbens (NAcc) functionally matures sooner than top-down frontocortical behavior control circuitry [8] , [9] . This ostensibly results in a problematic imbalance of “go” versus “stop” neurocircuitry during adolescence (relative to younger childhood and adulthood). For example, behavioral tasks have shown a biphasic pattern of risk-taking from young childhood to adulthood- with a peak in risky choice under “hot” (emotion-elicited) experimental conditions during adolescence [10] .

American adolescents suffer substantial morbidity and mortality due to behavioral causes (primarily acts of violence or motor vehicle accidents), even compared to similarly healthy young adults (U.S. Centers for Disease Control). Advances in developmental neuroscience have raised an important question: Might increased adolescent risk-taking be attributable in part to maturational differences from adults (or younger children) in regional brain structure or function? This possibility has profound policy implications [1] , and has been invoked not only as justification for graduated drivers licensing, but has also been cited in amicus briefs to the U.S. Supreme Court concerning whether to incarcerate for decades (Pittman v. South Carolina), or even execute (Roper v. Simmons) persons for crimes committed while an adolescent.

We explored whether potential reward anticipation or reward notification-elicited activation correlated directly with age or with sexual maturation as indexed by Tanner scores. To reduce comparisons, we analyzed activation in high-reward ($5) trials only. Age correlated with net reward-anticipatory signal change (calculated as difference from non-incentive trials) in the right NAcc (Spearman r = .35, p<.05; Figure 7 , part E), but not in left NAcc ( Figure 7 , Part F). When net self-reported excitement about high-reward cues (difference from excitement about nonincentive cues) was entered in a regression model as a second independent variable, NAcc net peak reward-anticipatory signal increase also positively correlated with chronological age across all subjects in right NAcc (Beta = .36, p<.05) but not left NAcc (Beta = .14, n.s.). In contrast, self-reported excitement over high-reward cues did not partially correlate with reward-anticipatory activation in either left or right NAcc (Beta <.15, n.s.). In an analysis of the adolescents alone, neither chronological age nor Tanner 1 nor Tanner 2 scale scores partially or bivariately correlated with reward-anticipatory or reward delivery-elicited NAcc activation (all Beta/r<.23, n.s.).

Peak outcome-elicited signal change in the NAcc VOI masks ( Figure 8 , parts A and B) indicated a main effect of trial outcome (F(1,45) = 22.823, P<.0001), with greater BOLD signal following notification of target hits (rewards or avoided losses) than following misses (missed rewards or losses) overall. A significant magnitude X outcome interaction (F(1,45) = 7.071, P<.05) indicated that the outcome-sensitive activation was more pronounced in $5 trials compared to 50¢ trials. Finally, a significant group X magnitude X outcome X side interaction effect (F(1,45) = 4.083, P<.05) indicated that in the left NAcc, success-dependence of signal change with increasing incentive amount was more pronounced in the adolescents. Simple effect t-tests of age group differences indicated no difference between age groups in NAcc recruitment by reward notification.

Time series data were extracted from a two-voxel mask in Talairach space in each of right and left NAcc (inset), for each trial type separately. Group mean peak modeled anticipatory signal changes (∼6 s post-cue) are presented as absolute signal change from baseline in parts A and B, and as a net difference from the signal change following presentation of the nonincentive cue (parts C and D). Net signal change elicited by high-reward cues correlated with age in right (E) but not left (F) NAcc. * denotes P<.10 and ** denotes P<.05 per simple-effect t-test.

Mean peak modeled BOLD signal change in the NAcc VOI masks in all trial types is illustrated in Figure 7 , parts A and B. The net signal change (difference from non-incentive trials) in the incentivized trials is illustrated in Figure 7 , parts C-F. These main effect of age group did not reach significance (F(1,45) = 2.854, P<.10). Simple-effect independent t-tests of net signal change indicated significantly reduced net activation in adolescents. There were main effects of both incentive valence (F(1,45) = 24.786, P<.00001) and incentive magnitude (F(1,45) = 34.276, P<.000001) on net anticipatory NAcc recruitment, with greater NAcc recruitment by prospective rewards than by prospective losses, and by $5 incentives compared to the 50¢ incentives. In addition, there was also a valence by magnitude interaction effect (F(1,45) = 4.297, P<.05), with more magnitude sensitivity in reward trials than in loss-avoidance trials. Complete hemodynamic time-course responses to anticipatory cues are plotted in supplemental Figure S2 .

Notification of rewards (contrasted with notification of failure to win reward) activated the VS and mesofrontal cortex (mFC) in both adolescents (A,C) and in adults (B,D). Notification of all losses (versus notification of successful loss avoidance) did not activate any voxels above threshold in adolescents (E), but activated anterior cingulate cortex in adults (F).

Anticipation of responding to avoid losses contrasted with anticipation of responding for no incentive activated striatal voxels in both adolescents (A,C) and in adults (B,D). In the inset uncorrected map of the direct voxel-wise age-group difference in activation by this contrast, relatively lower VS activation in adolescents is depicted in cool colors.

Anticipation of responding to potentially avoid losses versus anticipation of responding for no incentive activated the VS, lateral thalamus, mesial occipital cortex, supplementary motor cortex, mesial cerebellum, and bilateral pre/postcentral gyri in both adolescents and adults ( Table 2 ; Figure 5 ). Adults showed a more anterior extent of suprathreshold activation in cingulate cortex, relative to adolescents. The statistical map of the direct voxelwise group difference in this contrast, however, also indicated a decrement in adolescent activation relative to adults in right NAcc ( Figure 5 , inset). As with potential reward anticipation, there were no voxels across the remaining scan coverage that showed an FDR-corrected age group difference in activation by this contrast.

In these and subsequent statistical maps: 1) all images are right-left reversed per radiological convention, 2) the underlay is a T1-weighted structural image from a representative subject, 3) the Talairach coordinate of the image plane is indicated, 4) illuminated voxels in group-wise maps feature contrast activation that survives false discovery rate (FDR) correction to P<.05, and 5) illuminated voxels in the inset group-difference t-statistic maps do not survive FDR correction, but illustrate differences in NAcc recruitment as the structure of a priori interest. Anticipation of responding for rewards contrasted with anticipation of responding for no incentive activated portions of ventral striatum (VS) insula, and posterior mesofrontal cortex in both adolescents (A,C) and in adults (B,D). In the inset uncorrected map of the direct voxel-wise age-group difference in activation by this contrast, relatively lower VS activation in adolescents is depicted in cool colors.

Anticipation of responding for potential reward versus anticipation of responding for no incentive activated the VS, bilateral insula, thalamus, mesial occipital cortex, supplementary motor cortex, and voxel clusters that flanked the central sulcus bilaterally in both adolescents and adults ( Table 1 ; Figure 4 ). Adults, but not adolescents showed suprathreshold activation of the anterior cingulate cortex (ACC) and mesial cerebellum. In the NAcc, which was our a priori region-of-interest, the direct voxelwise t-test group difference in activation by this contrast was significant, with reduced adolescent activation relative to adults in right NAcc ( Figure 4 , inset). There were no brain regions, however, that showed a significant age-group difference that survived FDR correction in the remaining voxels of scan coverage. Results of an exploratory post hoc analysis directly contrasting anticipation of potential rewards with anticipation of potential punishments are presented in supplemental Figure S1 .

On a post-scan questionnaire, participants reported greater happiness (A) and excitement (B) when seeing anticipatory cues as the potential reward amounts increased. There were no significant main or interactive effects of age group on positive affect ratings. Similarly, subjects reported greater unhappiness (C) and fearfulness (D) as potential loss amounts increased. There were main effects of group (F(1,46) = 5.338, p<.05) on unhappiness ratings across the combined non-incentive and loss-trial types, with greater self-reported unhappiness in adolescents compared to adults. There were no other significant main or interaction effects of age group negative affect ratings. * denotes P<.10 and ** denotes P<.05 per simple-effect t-test.

There were also significant main effects of incentive magnitude on each of the four affective ratings ( Figure 3 ), where participants reported greater happiness (F(2,92) = 49.033, P<.000001) and excitement (F(2,92) = 119.173, P<.000001) as potential reward amounts signaled by the cue increased from $0 to 50¢ to $5. There were no significant main or interactive effects of age group on positive affect ratings. Similarly, subjects reported greater unhappiness (F(2,92) = 17.831, P<.000001) and fearfulness (F(2,92) = 80.104, P<.000001) as potential loss amounts increased from $0 to 50¢ to $5. A main effect of group (F(1,46) = 5.338, P<.05) on unhappiness ratings indicated greater self-reported unhappiness (across the combined non-incentive and loss-trial types) in adolescents compared to adults. There were no other significant main or interaction effects of age group on negative affect ratings.

Mean reaction time (RT) to targets (A) showed significant main effects of trial incentive and time. Specifically, subjects responded more quickly over time, from runs 1 to 3 of the task, and subjects responded more quickly to incentivized, compared to non-incentivized targets. Accordingly, there was a significant main effect of incentive amount on overall task hit rates (B), with a greater proportion of incentivized versus non-incentivized targets hit. There were no main or interactive effects of age group on either RT or hit rates. ** denotes P<.05 per simple-effect t-test.

There were no significant main or interaction effects of age group or sex on head-motion correction measures (generated by the volume registration step). No subject moved his or her head more than 3 mm across the whole session or more than 1 mm between successive acquisitions. There was a main effect of time on reaction time (RT) to task targets- in both reward trials (F(2,92) = 7.791, P<.001) and in loss-avoidance trials (F(2,92) = 5.263, P<.01), where subjects showed faster target RT as the task progressed from run 1 to run 3 ( Figure 2 , part A). Accordingly, for many subjects we reduced the range of uniform distribution of target display durations between task runs, to promote a 67% hit rate for the entire task. Finally, there was a main effect of incentive magnitude in both reward trials (F(2,92) = 22.996, P<.000001) and in loss-avoidance trials (F(2,92) = 21.162, P<.000001), where mean RT decreased as incentive magnitudes increased from $0 to 50¢ to $5. There were no main or interactive effects of age group on RT (all P≥.3) nor were there any other higher-order interaction effects on RT. Because RT quickened (within-subject) as incentive amounts increased, target hit rates also increased with incentive magnitude, as seen in main effects of magnitude in both reward (F(2,92) = 37.945, P<.000001) and loss-avoidance (F(2,92) = 25.136, P<.000001) trials ( Figure 2 , part B). However, there were no main or interactive effects of age group on hit rates.

Discussion

We explored maturational differences between adolescents and adults in motivational and consummatory components of incentive neurocircuitry. Both adolescents and adults showed significant recruitment of VS and mFC by the standard contrasts of the MID task, in accord with previous experiments on human incentive processing [8], [12], [14], [15], [16], [17], [19], [20], [23]. We report here some additional evidence that developmental differences in limbic recruitment by instrumental behavior may depend on the component or stage of instrumental behavior [28]. Chiefly, in accord with our hypothesis, we found that adolescents showed mildly reduced activation of the right NAcc by anticipation of responding for gains or to avoid losses, where in the VOI analysis, there was a mild positive correlation across all participants between age and net reward cue-elicited activation in the right NAcc. In contrast with our second hypothesis, adolescents did not show appreciable differences from adults in NAcc or mFC reactivity to reward deliveries. These findings essentially replicate results of our previous developmental comparison using the MID task [13]. Our results were not appreciably affected when 12-year-old subjects (n = 3) were excluded from analysis (supplemental Figures S3 and S4).

An ancillary finding was that suprathreshold activation of ACC by loss outcomes (as a contrast with avoided losses) was present in adults but not adolescents. Despite how the direct group-wise activation difference did not survive FDR correction, we retain mention of this difference as a preliminary finding due to the extensive implication of this portion of ACC in error monitoring [32]. In particular, adolescents have shown decrements relative to adults in ACC recruitment by pre-decision conflict when opting for rewards with a potential for error [6], [7].

Among adolescent participants, neither recruitment of the NAcc by reward cues nor recruitment by reward deliveries correlated with either age or Tanner scores. Indeed, as illustrated in Figure 7 (parts E and F), there was greater variation of NAcc responses to potential reward within age group than between age groups. Extensive individual differences in VS responsiveness to fMRI task rewards has been found in other studies (e.g. [33]). It may be that incentive neurocircuitry is essentially well-developed in the human brain by mid-to late- adolescence (the majority of adolescents were of Tanner stage 4+), with little remaining development-based variance. Surveying children across a wider (i.e. younger) age range or Tanner stage may be necessary to reveal clear developmental trends prior to adulthood.

Collectively, these findings, on the surface, do not generally support the opponent-process developmental account [8], [9] of adolescent risky behavior. We found essentially no evidence for increased mesolimbic responsiveness to either reward-predictive instrumental cues, or to actual reward deliveries in adolescents compared to adults. However, we note that any developmental deficit in behavior control resulting from some combination of overactive reward processing and deficient inhibitory processing would operate in an incentive- or context-specific manner—i.e. when the individual is offered a particular real-world risky incentive. It may be that other incentive paradigms may naturalistically reflect risky incentive scenarios (thus invoking maturationally-deficient dual-processing) better than the MID task.

The MID task features several unique characteristics compared to other incentive paradigms used in children that may explain divergent findings. First, the expected values (contingencies) signaled by anticipatory cues are trained in advance, such there is no discovery or learning in the task, except for discovery of trial-wise success. In particular, adolescents showed increased NAcc responsiveness to rewards of uncertain (secret) magnitude compared to adults [8], whereas subjects in this experiment were explicitly shown the exact (modest) amounts of money they won in a trial. Second, MID task visual stimuli are mundane compared to those of other incentive tasks (e.g. the pirate cartoons of [8] and slot-machine wheels of [27]). We note too that other tasks often feature risky decision-making and waiting for the outcomes of gambles [22], [26], akin to placing a roulette wheel bet, and this is probably more entertaining than a simple MID reaction-time task. Third, the MID task requires unusual vigilance and anticipatory motor preparation- especially for high-incentive targets. Indeed, we cannot rule out that reduced attentional capacity contributed to blunted anticipatory NAcc activation in adolescents. Critically, impaired sleep is common among adolescents [34], and has been linked to deficient striatal recruitment during reward anticipation [35]. In addition, both adults [36] and adolescents [37] with attention-deficit disorder have shown reduced reward-anticipatory activity in the MID task. It can be argued, however, that focused attention is simply one downstream manifestation of motivation, and that adolescents were simply not as motivated as adults to execute the instrumental responses. Finally, we note that in contrast to comparisons between mid-adolescents and very young adults (e.g. [26], [27]), we selected a somewhat older, post-college age group of adults that markedly differs from adolescents in general incidence of behavior-related mortality and morbidity (U.S. Centers for Disease Control).

Taken together with results from our previous experiment [13], these results indicate that if adolescents tend to have greater mesolimbic sensitivity to rewards, this does not generalize to all contexts or tasks. We believe that rather than being a source of confusion, these divergent findings present an intriguing avenue for future research. In particular, if adolescents show reduced motivational neurocircuitry recruitment in the context of mundane work for explicit rewards, but increased activation in the context of more entertaining tasks or non-explicit rewards, this could represent a maturational risk factor for behavior-related mortality and morbidity in adolescence within the domain of reward processing alone—all in the context of reduced top-down executive control. Put differently, in adolescents, there may be unusually great appeal in trying to win $10 racing the adjacent car to the next stoplight as opposed to earning it raking leaves. Of great interest are future experiments that parametrically modulate these different aspects of an incentive task within-subject, across the course of a scan, so see if adolescents show greater modulation (interaction) of mesolimbic activation as a function of entertaining task features.

This study has limitations that should be considered. First, this experiment used explicit amounts of money as the incentive. As with any study of groupwise differences in mesolimbic recruitment by monetary incentives, we cannot rule out that observed differences resulted from the amounts of money at stake being more intrinsically valuable in one group compared to another. Therefore, these data may not generalize to other incentives. However, we note that there were no group differences in self-reported excitement or happiness at the prospect of winning money, or in reaction-time to incentivized targets. Also, the directionality of the observed difference in reward-anticipatory activation runs counter to an assumption that the monetary rewards would be more valuable to an adolescent compared to an adult wage-earner.

Second, there was a pronounced effect of incentive magnitude on RT, and by extension, on hit rates because the distribution of target durations for each task run was not varied across incentive amounts. It may be that the slower pace of this variant of the MID task made it easier, and enabled maximization of attentional resources of all subjects for the occasional high-value targets. This may also explain the lack of a correlation here between individual differences in self-reported excitement about high-reward cues and NAcc recruitment, which is often found in experiments using the original (briskly-paced) MID task (e.g. [13], [16], [19]) The slow pace of trials, however, was the necessary trade-off in task design to promote separate detection of anticipation- versus notification-elicited BOLD signal. Third, the psychologically healthy adolescents scanned in this experiment are not at particular risk for adverse psychiatric outcomes. Rather, it is youth with histories of conduct disorder or other externalizing symptomatology who are most likely to engage in risky behaviors [38], including substance abuse [39], [40]. Notably, in another recent experiment [19], we found that unmedicated teens with externalizing disorders had significantly greater NAcc activation by notification of rewards and greater NAcc deactivation by missed rewards, compared to age- and gender-matched controls.

Finally, we note that these and other neurodevelopmental brain research findings are merely descriptive and correlational. Accordingly, we can only speculate that observed age-group differences in structure or function of incentive-related brain regions play a role in the increased behavior-related mortality and morbidity of adolescents. It may be that the maturation of incentive neurocircuitry by adolescence is essentially sufficient for rational decision-making, and that psychosocial or cultural factors may underlie increased engagement in risky behaviors among American adolescents [41]. For example, within an economic, expected-utility framework, adolescent risk-taking has been described as rational in the context of social reinforcement contingencies unique to adolescence [42]. However, in light of the extensively-documented maturational differences in structure and function of brain regions extensively implicated in incentive processing and in top-down executive control (reviewed in [43]), we nevertheless raise the possibility that these neurodevelopmental differences may contribute to vulnerability of adolescents to mortality and morbidity to behavioral causes.

In conclusion, this experiment largely replicates findings from our initial investigation [13], where adolescents showed reduced recruitment of the right NAcc by reward-predictive cues, but similar activation of mesolimbic incentive-motivational neurocircuitry to reward notifications. In addition, we found significant recruitment of ACC by notification of losses in adults but not adolescents. Future experiments could expand on these findings by artificially manipulating instrumental trial outcomes (such as omissions of expected rewards), and could reconcile divergent findings of maturational differences in incentive processing by modulating stimulus or other features of incentive tasks.