Patients with attention-deficit/hyperactivity disorder (ADHD) show episodic memory deficits especially in complex memory tasks. We investigated the neural correlates of memory formation in ADHD and their modulation by stimulus salience.
We recorded event-related functional magnetic resonance imaging during an episodic memory paradigm with neutral and emotional pictures in 12 male ADHD subjects and 12 healthy adolescents.
Emotional salience did significantly augment memory performance in ADHD patients. Successful encoding of neutral pictures was associated with activation of the anterior cingulate cortex (ACC) in healthy adolescents but with activation of the superior parietal lobe (SPL) and precuneus in ADHD patients. Successful encoding of emotional pictures was associated with prefrontal and inferior temporal cortex activation in both groups. Healthy adolescents, moreover, showed deactivation in the inferior parietal lobe.
From a pathophysiological point of view, the most striking functional differences between healthy adolescents and ADHD patients were in the ACC and SPL. We suggest that increased SPL activation in ADHD reflected attentional compensation for low ACC activation during the encoding of neutral pictures. The higher salience of emotional stimuli, in contrast, regulated the interplay between ACC and SPL in conjunction with improving memory to the level of healthy adolescents.
"The relatively limited literature suggests that EAM can be impaired in children with ADHD. Krauel et al. (2007) showed that emotional salience, or the tendency of individuals to remember more information surrounding an emotional event than surrounding a nonemotional one, significantly improved EAM performance in children with ADHD (Kensinger, Garoff-Eaton, & Schacter, 2007). Skowronek, Liechtman, and Pillermer (2008) showed that children with ADHD performed worse than peers on all working memory tasks, and performed as well as children without ADHD on episodic memory measures. "
[Show abstract][Hide abstract] ABSTRACT: Background Episodic autobiographical memory (EAM) has not been extensively investigated in children with attention-deficit/hyperactivity disorder (ADHD). The objective of this study was to examine EAM in school age children with ADHD in reference to the encoding period: recent memories (previous school years) and remote memories (first years of life).
Methods A sample of 29 children with ADHD and 29 typically developing children, matched for age and gender, completed a questionnaire to assess EAM. These participants were recruited from an initial sample of 572 participants. Developmental differences in accessing and recalling specific personal events and episodic details in groups with ADHD were predicted.
Results The control group showed a typical trend of EAM with fewer remote and episodic memories than recent ones. The ADHD groups showed a general EAM deficit. More precisely, the ADHD-I group performed equally poorly on remote and recent EAMs, whereas the ADHD-C group showed a higher number of remote EAMs than recent ones.
Conclusions The findings suggest that EAM can be impaired in children with ADHD. Clinical and medicolegal implications of these results and the relation between age and childhood amnesia are discussed.
"In stark contrast to ASD, children with ADHD had equally strong ventral striatum activation to both social and monetary reward, which was accompanied by ADHDspecific medial prefrontal overactivation under social reward conditions. This is consistent with earlier findings of greater behavioral sensitivity to social incentives, including social rewards, in children with ADHD (Geurts et al., 2008; Kohls et al., 2009a; Krauel et al., 2007; Matthys et al., 1998). As mentioned above, to the best of our knowledge the current study is the first to investigate reward circuit responsivity to social reward in ADHD. "
[Show abstract][Hide abstract] ABSTRACT: Although attention deficit hyperactivity disorders (ADHD) and autism spectrum disorders (ASD) share certain neurocognitive characteristics, it has been hypothesized to differentiate the two disorders based on their brain’s reward responsiveness to either social or monetary reward. Thus, the present fMRI study investigated neural activation in response to both reward types in age and IQ-matched boys with ADHD versus ASD relative to typically controls (TDC). A significant group by reward type interaction effect emerged in the ventral striatum with greater activation to monetary versus social reward only in TDC, whereas subjects with ADHD responded equally strong to both reward types, and subjects with ASD showed low striatal reactivity across both reward conditions. Moreover, disorder-specific neural abnormalities were revealed, including medial prefrontal hyperactivation in response to social reward in ADHD versus ventral striatal hypoactivation in response to monetary reward in ASD. Shared dysfunction was characterized by fronto-striato-parietal hypoactivation in both clinical groups when money was at stake. Interestingly, lower neural activation within parietal circuitry was associated with higher autistic traits across the entire study sample. In sum, the present findings concur with the assumption that both ASD and ADHD display distinct and shared neural dysfunction in response to reward.
"Immediately after encoding, a first retrieval session was carried out to achieve a recognition baseline. The introduction of a baseline session was necessary since children with ADHD not only display deficits in sustained attention in general  but also specific deficits in the encoding of visual stimulus material for later memory formation , . In order to control for each individual level of encoding, 40 old and 40 new pictures were used, and participants were asked to rate whether or not they recognized pictures from the encoding session. "
[Show abstract][Hide abstract] ABSTRACT: Fronto-limbic brain activity during sleep is believed to support the consolidation of emotional memories in healthy adults. Attention deficit-hyperactivity disorder (ADHD) is accompanied by emotional deficits coincidently caused by dysfunctional interplay of fronto-limbic circuits. This study aimed to examine the role of sleep in the consolidation of emotional memory in ADHD in the context of healthy development. 16 children with ADHD, 16 healthy children, and 20 healthy adults participated in this study. Participants completed an emotional picture recognition paradigm in sleep and wake control conditions. Each condition had an immediate (baseline) and delayed (target) retrieval session. The emotional memory bias was baseline-corrected, and groups were compared in terms of sleep-dependent memory consolidation (sleep vs. wake). We observed an increased sleep-dependent emotional memory bias in healthy children compared to children with ADHD and healthy adults. Frontal oscillatory EEG activity (slow oscillations, theta) during sleep correlated negatively with emotional memory performance in children with ADHD. When combining data of healthy children and adults, correlation coefficients were positive and differed from those in children with ADHD. Since children displayed a higher frontal EEG activity than adults these data indicate a decline in sleep-related consolidation of emotional memory in healthy development. In addition, it is suggested that deficits in sleep-related selection between emotional and non-emotional memories in ADHD exacerbate emotional problems during daytime as they are often reported in ADHD.
PLoS ONE 05/2013; 8(5):e65098. DOI:10.1371/journal.pone.0065098 · 3.23 Impact Factor
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