RESUMO
Adolescent risk-taking has been attributed to earlier-developing motivational neurocircuitry that is poorly controlled by immature executive-control neurocircuitry. Functional magnetic resonance imaging findings of increased ventral striatum (VS) recruitment by reward prospects in adolescents compared to adults support this theory. Other studies found blunted VS recruitment by reward-predictive cues in adolescents compared to adults. Task features may explain this discrepancy but have never been systematically explored. Adolescents and adults performed a novel reward task that holds constant the expected value of all rewards but varies whether rewards are dependent on vigilance-intensive responding versus making a lucky choice during a relaxed response window. We examined group by sub-task contrast differences in activation of VS and more motoric regions of striatum in response to anticipatory cues. Reward anticipation in both task conditions activated portions of striatum in both groups. In voxel-wise comparison, adults showed greater anticipatory recruitment of VS in trials involving choice during a relaxed time window, not in the more vigilance-demanding trials as hypothesized. In accord with our hypotheses, however, adults showed greater activation in dorsal striatum and putamen volumes of interest during reward anticipation under vigilance-demanding conditions. Following trial outcome notifications, adolescents showed greater activation of the VS during reward notification but lower activation during loss notification. These data extend findings of cross-sectional age-group differences in incentive-anticipatory recruitment of striatum, by demonstrating in adults relatively greater recruitment of motor effector regions of striatum by attentional and motor demands.
Assuntos
Atenção , Corpo Estriado , Imageamento por Ressonância Magnética , Recompensa , Humanos , Adolescente , Masculino , Feminino , Imageamento por Ressonância Magnética/métodos , Atenção/fisiologia , Adulto Jovem , Adulto , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/fisiologia , Antecipação Psicológica/fisiologia , Sinais (Psicologia) , Mapeamento Encefálico/métodosRESUMO
BACKGROUND: Self-reported physical activity is often inaccurate. Wearable devices utilizing multiple sensors are now widespread. The aim of this study was to determine acceptability of Fitbit Charge HR for children and their families, and to determine best practices for processing its objective data. METHODS: Data were collected via Fitbit Charge HR continuously over the course of 3 weeks. Questionnaires were given to each child and their parent/guardian to determine the perceived usability of the device. Patterns of data were evaluated and best practice inclusion criteria recommended. RESULTS: Best practices were established to extract, filter, and process data to evaluate device wear, r and establish minimum wear time to evaluate behavioral patterns. This resulted in usable data available from 137 (89%) of the sample. CONCLUSIONS: Activity trackers are highly acceptable in the target population and can provide objective data over longer periods of wear. Best practice inclusion protocols that reflect physical activity in youth are provided.
Assuntos
Monitores de Aptidão Física , Dispositivos Eletrônicos Vestíveis , Criança , Adolescente , Humanos , Acelerometria , Punho , Exercício FísicoRESUMO
Suicide attempts (SA) are increasing in the United States, especially in veterans. Discovering individual cognitive features of the subset of suicide ideators who attempt suicide is critical. Cognitive theories attribute SA to facile schema-based negative interpretations of environmental events. Over-general autobiographical memory and facile solutions in problem solving tasks in SA survivors suggest that aversion to expending cognitive effort may be a neurobehavioral marker of SA risk. In veterans receiving care for mood disorder, we compared cognitive effort discounting and evidence-gathering in a beads task between veterans with (SAHx+; n = 26) versus without (SAHx-; n = 22) a history of SA. Groups did not differ in depressed mood or in a proxy metric of premorbid intelligence. Compared to SAHx- participants, SAHx+ participants self-reported significantly more severe cognitive problems in most domains, and also eschewed choice to earn higher monetary reward if earning it required a slightly increased working memory (WM) demand relative to an easy WM task. There was no group difference, however, in extent of evidence-gathering before declaring a conclusion in a beads task. These preliminary data suggest that aversion to expenditure of cognitive effort, potentially as a component of cognitive difficulties, may be a marker for SA risk.
Assuntos
Recompensa , Tentativa de Suicídio , Humanos , Estados Unidos , Tentativa de Suicídio/psicologia , Resolução de Problemas , CogniçãoRESUMO
BACKGROUND: Impulsivity is an established risk factor for substance use disorder (SUD). Integral to SUD recovery is proactive control (leveraging information about a potential need for behavioral restraint to marshal increased cognitive resources toward inhibition) when cues for drug use are unavoidable. However, proactive control is little studied in SUD, and is merely inferred from post-error performance adjustments. METHODS: We probed covert neurocircuit signatures of proactive control in persons with SUD, as well as the moderating effects of incentives for successfully exerting proactive control. We administered a Monetary Incentive Stop Task (MIST) during functional magnetic resonance imaging of adults with cocaine use disorder (CUD; n = 21) and healthy controls (n = 21). The MIST blended the reward and loss-anticipatory cues of the Monetary Incentive Delay (MID) Task with a variant of the Stop-Signal Task, in which target color signaled whether or not withholding a response might be necessary. RESULTS: In controls, but not in CUD participants, targets that signaled a potential need to stop (as a contrast with targets that signaled no need to stop) activated portions of right operculum akin to activation commonly elicited by stop signals, despite no actual stop signal. Across all participants, this proactive control activation did not relate to task behavior or to questionnaire impulsivity. Anticipatory incentive cues did not recruit ventral striatum. CONCLUSIONS: These data suggest that persons with CUD show blunted covert signatures of attention and proactive control. This potentially accounts in part for the role of poor executive function in relapse vulnerability.
Assuntos
Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Inibição Psicológica , Adulto , Córtex Cerebral/fisiopatologia , Cocaína , Sinais (Psicologia) , Função Executiva/fisiologia , Feminino , Humanos , Comportamento Impulsivo , Imageamento por Ressonância Magnética/métodos , Masculino , Motivação , Recompensa , Transtornos Relacionados ao Uso de Substâncias/psicologiaRESUMO
BACKGROUND AND OBJECTIVES: Substance misuse is increasing in the older population, which may have differing effects on behavior compared to younger substance participants. Differences in trait and state impulsivity were assessed in younger and older cocaine-dependent participants. METHODS: Thirty-one younger cocaine-dependent participants (n = 31) and 21 older cocaine-dependent participants (n = 21) were assessed using the Barrett Impulsiveness Scale-11 and the Immediate Memory Task. RESULTS: Younger participants showed higher trait impulsivity than older participants (p =.027). However, older participants demonstrated higher state impulsivity than younger participants (p =.018). CONCLUSION: Higher state impulsivity in older cocaine participants suggests that cocaine use may have accelerating effects on the aging brain. SCIENTIFIC SIGNIFICANCE: This preliminary study adds the limited research on how cocaine use affects normal aging. Current treatments are based on younger adults, therefore the needs of older adults should be taken into consideration and studied more. (Am J Addict 2018;27:557-559).
Assuntos
Envelhecimento , Tomada de Decisões/efeitos dos fármacos , Comportamento Impulsivo/efeitos dos fármacos , Memória de Curto Prazo/efeitos dos fármacos , Adulto , Fatores Etários , Envelhecimento/efeitos dos fármacos , Envelhecimento/psicologia , Transtornos Relacionados ao Uso de Cocaína/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise e Desempenho de TarefasRESUMO
Substance use disorders (SUD) can be considered developmental disorders in light of their frequent origins in substance initiation during adolescence. Cross-sectional functional magnetic resonance imaging (fMRI) studies of adolescent substance users or adolescents with SUD have indicated aberrations in brain structures or circuits implicated in motivation, self-control, and mood-regulation. However, attributing these differences to the neurotoxicological effects of chronic substance use has been problematic in that these circuits are also aberrant in at-risk children, such as those with prenatal substance exposure, externalizing disorders (such as conduct disorder), or prodromal internalizing disorders such as depression. To better isolate the effects of substance exposure on the adolescent brain, the newly-launched Adolescent Brain Cognitive Development (ABCD) study, funded by the National Institutes of Health, will follow the neurodevelopmental trajectories of over 11,000 American 9/10-year-olds for 10 years, into emerging adulthood. This study will provide a rich open-access dataset on longitudinal interactions of neurodevelopment, environmental exposures, and childhood psychopathology that confer addiction risk. The ABCD twin study will further clarify genetic versus experiential influences (e.g., substance use) on neurodevelopmental and psychosocial outcomes. Neurocircuitry thought to regulate mood and behavior has been directly normalized by administration of psychoactive medications and by cognitive therapies in adults. Because of this, we contend that ABCD project data will be a crucial resource for prevention and treatment of SUD in adolescence because its cutting-edge neuroimaging and childhood assessments hold potential for discovery of additional targetable brain differences earlier in development that are prognostic of (or aberrant in) SUD. The ABCD sample size will also have the power to illuminate how sex differences, environmental interactions and other individual differences interact with neurodevelopment to inform treatment in different groups of adolescents.