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1.
J Neurosci ; 42(45): 8508-8513, 2022 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-36351824

RESUMO

Understanding the unique functions of different subregions of primate prefrontal cortex has been a longstanding goal in cognitive neuroscience. Yet, the anatomy and function of one of its largest subregions (the frontopolar cortex) remain enigmatic and underspecified. Our Society for Neuroscience minisymposium Primate Frontopolar Cortex: From Circuits to Complex Behaviors will comprise a range of new anatomic and functional approaches that have helped to clarify the basic circuit anatomy of the frontal pole, its functional involvement during performance of cognitively demanding behavioral paradigms in monkeys and humans, and its clinical potential as a target for noninvasive brain stimulation in patients with brain disorders. This review consolidates knowledge about the anatomy and connectivity of frontopolar cortex and provides an integrative summary of its function in primates. We aim to answer the question: what, if anything, does frontopolar cortex contribute to goal-directed cognition and action?


Assuntos
Cognição , Objetivos , Animais , Humanos , Cognição/fisiologia , Córtex Pré-Frontal/fisiologia , Lobo Frontal/fisiologia , Primatas , Haplorrinos
2.
Neuron ; 110(11): 1869-1879.e5, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35390278

RESUMO

Flexible decision-making requires animals to forego immediate rewards (exploitation) and try novel choice options (exploration) to discover if they are preferable to familiar alternatives. Using the same task and a partially observable Markov decision process (POMDP) model to quantify the value of choices, we first determined that the computational basis for managing explore-exploit tradeoffs is conserved across monkeys and humans. We then used fMRI to identify where in the human brain the immediate value of exploitative choices and relative uncertainty about the value of exploratory choices were encoded. Consistent with prior neurophysiological evidence in monkeys, we observed divergent encoding of reward value and uncertainty in prefrontal and parietal regions, including frontopolar cortex, and parallel encoding of these computations in motivational regions including the amygdala, ventral striatum, and orbitofrontal cortex. These results clarify the interplay between prefrontal and motivational circuits that supports adaptive explore-exploit decisions in humans and nonhuman primates.


Assuntos
Comportamento de Escolha , Estriado Ventral , Animais , Comportamento de Escolha/fisiologia , Tomada de Decisões/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Recompensa , Estriado Ventral/diagnóstico por imagem , Estriado Ventral/fisiologia
3.
Handb Clin Neurol ; 183: 47-62, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34389125

RESUMO

Humans are highly adept at differentiating, regulating, and responding to their emotions. At the core of all these functions is emotional awareness: the conscious feeling states that are central to human mental life. Disrupted emotional awareness-a subclinical construct commonly referred to as alexithymia-is present in a range of psychiatric and neurological disorders and can have a deleterious impact on functional outcomes and treatment response. This chapter is a selective review of the current state of the science on alexithymia. We focus on two separate but related issues: (i) the functional deficits associated with alexithymia and what they reveal about the importance of emotional awareness for shaping normative human functioning, and (ii) the neural correlates of alexithymia and what they can inform us about the biological bases of emotional awareness. Lastly, we outline challenges and opportunities for alexithymia research, focusing on measurement issues and the potential utility of formal computational models of emotional awareness for advancing the fields of clinical and affective science.


Assuntos
Sintomas Afetivos , Emoções , Humanos
4.
J Neurotrauma ; 38(16): 2264-2274, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-33787328

RESUMO

Apathy is a common and impairing sequela of traumatic brain injury (TBI). Yet, little is known about the neural mechanisms determining in which patients apathy does or does not develop post-TBI. We aimed to elucidate the impact of TBI on motivational neural circuits and how this shapes apathy over the course of TBI recovery. Resting-state functional magnetic resonance imaging data were collected in patients with subacute mild TBI (n = 44), chronic mild-to-moderate TBI (n = 26), and nonbrain-injured control participants (CTRL; n = 28). We measured ventromedial prefrontal cortex (vmPFC) functional connectivity (FC) as a function of apathy, using an a priori vmPFC seed adopted from a motivated decision-making study in an independent TBI study cohort. Patients reported apathy using a well-validated tool for assaying apathy in TBI. The vmPFC-to-wholebrain FC was contrasted between groups, and we fit regression models with apathy predicting vmPFC FC. Subacute and chronic TBI caused increased apathy relative to CTRL, replicating previous work suggesting that apathy has an enduring impact in TBI. The vmPFC was functionally connected to the canonical default network, and this architecture did not differ between subacute TBI, chronic TBI, and CTRL groups. Critically, in TBI, increased apathy scores predicted decreased vmPFC-dorsal anterior cingulate cortex (dACC) FC. Last, we subdivided the TBI group based on patients above versus below the threshold for "clinically significant apathy," finding that TBI patients with clinically significant apathy demonstrated comparable vmPFC-dACC FC to CTRLs, whereas TBI patients with subthreshold apathy scores demonstrated vmPFC-dACC hyperconnectivity relative to both CTRLs and patients with clinically significant apathy. Post-TBI vmPFC-dACC hyperconnectivity may represent an adaptive compensatory response, helping to maintain motivation and enabling resilience to the development of apathy after neurotrauma. Given the role of vmPFC-dACC circuits in value-based decision making, rehabilitation strategies designed to improve this ability may help to reduce apathy and improve functional outcomes in TBI.


Assuntos
Apatia/fisiologia , Lesões Encefálicas Traumáticas/fisiopatologia , Lesões Encefálicas Traumáticas/psicologia , Giro do Cíngulo/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Resiliência Psicológica/fisiologia , Adulto , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Mapeamento Encefálico , Estudos de Casos e Controles , Feminino , Giro do Cíngulo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Motivação/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Adulto Jovem
5.
Artigo em Inglês | MEDLINE | ID: mdl-33558195

RESUMO

BACKGROUND: It remains unclear whether executive control (EC) deficits in autism spectrum disorder (ASD) represent a failure in proactive EC (engaged and maintained before a cognitively demanding event) or in reactive EC (engaged transiently as the event occurs). We addressed this question by administering a paradigm investigating components of EC in a sample of individuals with ASD and typically developing individuals during functional magnetic resonance imaging. METHODS: During functional magnetic resonance imaging, 141 participants (64 ASD, 77 typically developing) completed a rapid preparing to overcome prepotency task that required participants to respond to an arrow probe based on the color of an initially presented cue. We examined functional recruitment and connectivity in the frontoparietal task control, cingulo-opercular task control, salience, and default mode networks during cue and probe phases of the task. RESULTS: ASD participants showed evidence of behavioral EC impairment. Analyses of functional recruitment and connectivity revealed that ASD participants showed significantly greater activity during the cue in networks associated with proactive control processes, but on the less cognitively demanding trials. On the more cognitively demanding trials, cue activity was similar across groups. During the probe, connectivity between regions associated with reactive control processes was uniquely enhanced on more-demanding (relative to less-demanding) trials in individuals with ASD but not in typically developing individuals. CONCLUSIONS: The current data suggest that rather than arising from a specific failure to engage proactive or reactive forms of EC, the deficits in EC commonly observed in ASD may be due to reduced proactive EC and a consequent overreliance on reactive EC on more cognitively demanding tasks.


Assuntos
Transtorno do Espectro Autista , Córtex Cerebral , Função Executiva , Humanos , Imageamento por Ressonância Magnética
6.
Emotion ; 21(1): 137-147, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31535883

RESUMO

Humans compute the anticipated reward value of stimuli in their environment in order to behave in an adaptive, goal-directed manner. This reward valuation ability is vital, and its disruption in a range of clinical populations has profound personal and social consequences. However, research has often failed to consider the reward-related functions of a central component of human emotion: conscious emotional experience. Alexithymia-a condition characterized by diminished conscious awareness of one's emotions-offers a unique opportunity to examine the link between emotional awareness and reward valuation. In the present study, we measured both acquired alexithymia and reward valuation ability in a large sample of patients with traumatic brain injuries (N = 112). Behavioral analyses provided evidence for a negative association between alexithymia and reward valuation ability. This association remained significant after controlling for several covariates in the model (anxiety, depression, posttraumatic stress disorder, and IQ). Voxel-based lesion-symptom mapping was carried out to identify brain regions-of-interest (ROIs) that, when damaged, lead to increased alexithymia and impaired reward valuation. Importantly, mediation models computed using the ROIs identified through the voxel-based lesion-symptom mapping revealed a specific indirect effect of left frontoinsular damage on impaired valuation that was mediated by increased levels of alexithymia. This indirect effect was not observed for any of the other candidate ROIs. The present study identifies a network of brain regions likely to be involved in the integration of subjective feelings and reward processes critical for the adaptive control of goal-directed behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Sintomas Afetivos/psicologia , Encéfalo/patologia , Emoções/fisiologia , Lobo Frontal/patologia , Recompensa , Sintomas Afetivos/patologia , Mapeamento Encefálico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
J Psychiatry Neurosci ; 45(6): 430-440, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32869961

RESUMO

Background: Functional underpinnings of cognitive control deficits in unbiased samples (i.e., all comers) of patients with psychotic spectrum disorders (PSD) remain actively debated. While many studies suggest hypofrontality in the lateral prefrontal cortex (PFC) and greater deficits during proactive relative to reactive control, few have examined the full hemodynamic response. Methods: Patients with PSD (n = 154) and healthy controls (n = 65) performed the AX continuous performance task (AX-CPT) during rapid (460 ms) functional neuroimaging and underwent full clinical characterization. Results: Behavioural results indicated generalized cognitive deficits (slower and less accurate) across proactive and reactive control conditions in patients with PSD relative to healthy controls. We observed a delayed/prolonged neural response in the left dorsolateral PFC, the sensorimotor cortex and the superior parietal lobe during proactive control for patients with PSD. These proactive hemodynamic abnormalities were better explained by negative rather than by positive symptoms or by traditional diagnoses according to the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision (DSM-IV-TR), with subsequent simulations unequivocally demonstrating how these abnormalities could be erroneously interpreted as hypoactivation. Conversely, true hypoactivity, unassociated with clinical symptoms or DSM-IV-TR diagnoses, was observed within the ventrolateral PFC during reactive control. Limitations: In spite of guidance for AX-CPT use in neuroimaging studies, one-third of patients with PSD could not perform the task above chance and were more clinically impaired. Conclusion: Current findings question the utility of the AX-CPT for neuroimaging-based appraisal of cognitive control across the full spectrum of patients with PSD. Previously reported lateral PFC "hypoactivity" during proactive control may be more indicative of a delayed/prolonged neural response, important for rehabilitative purposes. Negative symptoms may better explain certain behavioural and hemodynamic abnormalities in patients with PSD relative to DSM-IV-TR diagnoses.


Assuntos
Função Executiva/fisiologia , Neuroimagem Funcional/normas , Lobo Parietal/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Desempenho Psicomotor/fisiologia , Transtornos Psicóticos/fisiopatologia , Córtex Sensório-Motor/fisiopatologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Lobo Parietal/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Transtornos Psicóticos/diagnóstico por imagem , Córtex Sensório-Motor/diagnóstico por imagem , Adulto Jovem
8.
Psychol Sci ; 31(7): 881-889, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32603213

RESUMO

Implementing motivated behaviors on the basis of prior reward is central to adaptive human functioning, but aberrant reward-motivated behavior is a core feature of neuropsychiatric illness. Children from disadvantaged neighborhoods have decreased access to rewards, which may shape motivational neurocircuits and risk for psychopathology. Here, we leveraged the unprecedented neuroimaging data from the Adolescent Brain Cognitive Development (ABCD) study to test the hypothesis that neighborhood socioeconomic disadvantage shapes the functional recruitment of motivational neurocircuits in children. Specifically, via the ABCD study's monetary-incentive-delay task (N = 6,396 children; age: 9-10 years), we found that children from zip codes with a high Area Deprivation Index demonstrate blunted recruitment of striatum (dorsal and ventral nuclei) and pallidum during reward anticipation. In fact, blunted dorsal striatal recruitment during reward anticipation mediated the association between Area Deprivation Index and increased attention problems. These data reveal a candidate mechanism driving elevated risk for psychopathology in children from socioeconomically disadvantaged neighborhoods.


Assuntos
Antecipação Psicológica/fisiologia , Motivação , Recrutamento Neurofisiológico/fisiologia , Recompensa , Mapeamento Encefálico , Criança , Comportamento Infantil/fisiologia , Feminino , Humanos , Comportamento Impulsivo/fisiologia , Imageamento por Ressonância Magnética , Masculino , Neostriado/fisiopatologia , Tempo de Reação/fisiologia , Classe Social , Populações Vulneráveis
9.
Cortex ; 129: 314-328, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32554227

RESUMO

Sensorimotor synchronization (SMS) is frequently dependent on coordination of excitatory and inhibitory activity across hemispheres, as well as the cognitive control over environmental distractors. However, the timing (motor planning versus execution) and cortical regions involved in these processes remain actively debated. Functional magnetic resonance imaging data were therefore analyzed from 34 strongly right-handed healthy adults performing a cued (to initiate motor planning) SMS task with either their right or left hand (motor execution phase) based on spatially congruent or incongruent visual stimuli. Behavioral effects of incongruent stimuli were limited to the first stimulus. Functionally, greater activation was observed in left sensorimotor cortex (SMC) and right cerebellar Lobule V for congruent versus incongruent stimuli. A negative blood-oxygen level dependent response, a putative marker of neural inhibition, was present in bilateral SMC, right supplemental motor area (SMA) and bilateral cerebellar Lobule V during the motor planning, but not execution phase. The magnitude of the inhibitory response was greater in right cortical regions and cerebellar Lobule V. Homologue connectivity was associated with inhibitory activity in the right SMA, suggesting that individual differences in intrinsic connectivity may mediate transcallosal inhibition. In summary, results suggest increased inhibition (i.e., greater negative BOLD response) within the right relative to left hemisphere, which was released once motor programs were executed. Both task and intrinsic functional connectivity results highlight a critical role of the left SMA in interhemispheric inhibition and motor planning.


Assuntos
Córtex Motor , Adulto , Cerebelo , Sinais (Psicologia) , Mãos , Humanos , Imageamento por Ressonância Magnética , Desempenho Psicomotor
10.
J Abnorm Psychol ; 129(5): 517-527, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32406696

RESUMO

Although autism spectrum disorder (ASD) is characterized by deficits in cognitive control, our previous work has shown that preparatory, goal-directed cognitive processing (proactive control) may be preserved in children with ASD. We investigated whether proactive control is intact in adolescents and young adults with ASD, as well as how symptoms of ASD (repetitive behaviors) and psychopathology (Depressive, Anxiety, and Attention-Deficit/Hyperactivity Problems) are related to proactive control. Participants were adolescents and young adults with ASD (N = 44) and typical development (TD; N = 44). Proactive control was assessed using a picture-word Stroop paradigm where participants named animals depicted in drawings while ignoring a superimposed written animal word. Interference effects (reaction time (RT) differences between more difficult incongruent trials, where animal pictures and words prompted different responses, and simpler congruent trials, where animal pictures and words prompted the same response) were calculated for two versions of the Stroop Task: a mostly congruent (MC) block, where the majority of trials were congruent, and a mostly incongruent (MI) block, where most trials were incongruent. Proactive control was calculated as the reduction in interference in the MI block in comparison to the MC block. Proactive control did not differ between groups, indicating that proactive control is not impaired in adolescents and young adults with ASD. In ASD, depression symptoms were associated with reduced proactive control. Future research should investigate the effects of interventions targeting depression as well as interventions targeting proactive control processes in individuals with ASD and comorbid depression. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Transtorno do Espectro Autista/psicologia , Depressão/psicologia , Adolescente , Criança , Cognição/fisiologia , Função Executiva/fisiologia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Teste de Stroop , Adulto Jovem
11.
J Autism Dev Disord ; 50(4): 1310-1323, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31902056

RESUMO

Research has observed evidence for both hypo-(supposedly due to a broken mirror neuron system) and hyper-(thought to be the result of deficits in adaptive control) imitation in autism spectrum disorder (ASD). This work sought to adjudicate between these findings using an automatic imitation (AI) paradigm with the novel manipulation of the need to engage adaptive control of imitation. Results demonstrated that ASD participants do not display a specific deficit in AI capability, are able to engage in proactive control of AI, and that relative to a well-matched effector condition, AI is not selectively associated with ASD symptom severity. These data cast doubt upon the notion of impairments in imitation or its control in ASD.


Assuntos
Transtorno do Espectro Autista/psicologia , Comportamento Imitativo/fisiologia , Motivação , Adolescente , Transtorno do Espectro Autista/fisiopatologia , Cognição , Feminino , Humanos , Masculino , Neurônios-Espelho , Adulto Jovem
12.
Artigo em Inglês | MEDLINE | ID: mdl-31676207

RESUMO

BACKGROUND: The degree to which individuals with autism spectrum disorder (ASD) evidence impairments in episodic memory relative to their typically developing (TD) counterparts remains unclear. According to a prominent view, ASD is associated with deficits in encoding associations between items and recollecting precise context details. Here, we evaluated behavioral and neural evidence for this impaired relational binding hypothesis using a task involving relational encoding and recollection during functional magnetic resonance imaging. METHODS: Adolescents and young adults (nASD = 47, nTD = 60) performed the Relational and Item-Specific Encoding task during functional magnetic resonance imaging, including item and associative recognition testing. We modeled functional recruitment within the medial temporal lobes (MTLs), and connectivity between MTL and the posterior medial (PM) network thought to underlie relational memory. The impaired relational binding model would predict a behavioral deficit driven by aberrant recruitment and connectivity of MTL and the PM network. RESULTS: The ASD and TD groups showed indistinguishable item and associative recognition performance. During relational encoding, the ASD group demonstrated increased hippocampal recruitment, and decreased connectivity between MTL and PM regions relative to the TD group. Within ASD, hippocampal recruitment and MTL-PM connectivity were inversely correlated. CONCLUSIONS: The lack of a behavioral deficit in ASD does not support the impaired relational binding hypothesis. Instead, the current data suggest that increased recruitment of the hippocampus compensates for decreased MTL-PM connectivity to support preserved episodic memory in ASD. These findings suggest a compensatory neurodevelopmental mechanism that may support preserved cognitive domains in ASD: local hyperrecruitment may offset connectivity aberrations in individuals with ASD relative to TD subjects.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Transtorno do Espectro Autista/psicologia , Hipocampo/fisiopatologia , Memória Episódica , Adolescente , Mapeamento Encefálico , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rememoração Mental/fisiologia , Adulto Jovem
13.
J Abnorm Psychol ; 127(4): 429-435, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29745707

RESUMO

Proactive control refers to the active representation of contextual information to bias cognitive processing and facilitate goal-directed behavior. Despite research suggesting that proactive control may be impaired in autism spectrum disorder (ASD), the associations between proactive control and clinical symptoms of ASD remain underspecified. Here, we combined a children's version of the AX Continuous Performance Task (AX-CPT) with gold standard clinical assessments in children with ASD (N = 34) or typical development (TYP; N = 45). After controlling for full-scale IQ (FSIQ), measures of proactive control were similar between ASD and TYP. However, specifically within ASD we observed paradoxical relationships between proactive control and clinical symptoms. Increased reliance on proactive control was associated with reduced attention problems and increased restricted and repetitive behaviors in ASD. Therefore, proactive control appears to represent a double-edged sword in ASD: improved attentional control at the cost of heightened behavioral inflexibility. This represents a compelling and new characterization of the specific association between cognitive control processes isolated in computerized laboratory tasks and the multidimensional cognitive symptoms characteristic of ASD. (PsycINFO Database Record


Assuntos
Transtorno do Espectro Autista/psicologia , Função Executiva , Atenção , Criança , Cognição , Feminino , Humanos , Masculino , Testes Neuropsicológicos
14.
Biol Psychiatry ; 84(4): 287-294, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-29523413

RESUMO

BACKGROUND: Internalizing symptoms like anxiety and depression are common and impairing in autism spectrum disorder (ASD). Here, we test the hypothesis that aberrant functional connectivity among three brain networks (salience network [SN], default mode network [DMN], and frontoparietal network [FPN]) plays a role in the pathophysiology of internalizing in ASD. METHODS: We examined the association between resting-state functional connectivity and internalizing in 102 adolescents and young adults with ASD (n = 49) or typical development (n = 53). Seed-to-target functional connectivity was contrasted between adolescents and young adults with ASD and typically developing subjects using a recent parcellation of the human cerebral cortex, and connections that were aberrant in ASD were analyzed dimensionally as a function of parent-reported internalizing symptoms. RESULTS: Three connections demonstrated robust overconnectivity in ASD: 1) the anterior insula to the retrosplenial cortex (i.e., SN-DMN), 2) the anterior insula to the frontal pole (i.e., SN-FPN), and 3) the dorsolateral prefrontal cortex to the retrosplenial cortex (i.e., FPN-DMN). These differences remained significant after controlling for age, and no age-related effects survived correction. The SN-DMN connection was associated with greater internalizing in ASD, mediated by a bigger difference between self- and parent-reported internalizing. Control analyses found that the other two connections were not associated with internalizing, and SN-DMN connectivity was not associated with a well-matched control measure (externalizing symptoms). CONCLUSIONS: The present findings provide novel evidence for a specific link between SN-DMN overconnectivity and internalizing in ASD. Further, the mediation results suggest that intact anterior insula-retrosplenial connectivity may play a role in an individual's generating insight into his or her own psychopathology.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Córtex Cerebral/fisiopatologia , Vias Neurais/fisiopatologia , Adolescente , Transtornos de Ansiedade/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
15.
Neuropsychologia ; 111: 229-240, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29360519

RESUMO

The clinical relevance of alexithymia, a condition associated with difficulties identifying and describing one's own emotion, is becoming ever more apparent. Increased rates of alexithymia are observed in multiple psychiatric conditions, and also in neurological conditions resulting from both organic and traumatic brain injury. The presence of alexithymia in these conditions predicts poorer regulation of one's emotions, decreased treatment response, and increased burden on carers. While clinically important, the aetiology of alexithymia is still a matter of debate, with several authors arguing for multiple 'routes' to impaired understanding of one's own emotions, which may or may not result in distinct subtypes of alexithymia. While previous studies support the role of impaired interoception (perceiving bodily states) in the development of alexithymia, the current study assessed whether acquired language impairment following traumatic brain injury, and damage to language regions, may also be associated with an increased risk of alexithymia. Within a sample of 129 participants with penetrating brain injury and 33 healthy controls, neuropsychological testing revealed that deficits in a non-emotional language task, object naming, were associated with alexithymia, specifically with difficulty identifying one's own emotions. Both region-of-interest and whole-brain lesion analyses revealed that damage to language regions in the inferior frontal gyrus was associated with the presence of both this language impairment and alexithymia. These results are consistent with a framework for acquired alexithymia that incorporates both interoceptive and language processes, and support the idea that brain injury may result in alexithymia via impairment in any one of a number of more basic processes.


Assuntos
Sintomas Afetivos/etiologia , Sintomas Afetivos/fisiopatologia , Lesões Encefálicas Traumáticas/complicações , Idioma , Córtex Pré-Frontal/lesões , Córtex Pré-Frontal/fisiopatologia , Lesões Encefálicas Traumáticas/fisiopatologia , Lesões Encefálicas Traumáticas/psicologia , Emoções/fisiologia , Traumatismos Cranianos Penetrantes/complicações , Traumatismos Cranianos Penetrantes/fisiopatologia , Traumatismos Cranianos Penetrantes/psicologia , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Autoimagem , Veteranos , Guerra do Vietnã
16.
Artigo em Inglês | MEDLINE | ID: mdl-28924621

RESUMO

We investigated how cognitive neuroscientific studies during the last decade have advanced understanding of cognitive control from adolescence to young adulthood in individuals with autism spectrum disorder (ASD). To do so, we conducted a selective review of the larger structural, resting state, and diffusion imaging studies of brain regions and networks related to cognitive control that have been conducted since 2007 in individuals with ASD and typical development (TYP) ages 10 to 30 years that examined how these regions and networks support behavioral and task-based fMRI performance on tasks assessing cognitive control during this period. Longitudinal structural studies reveal overgrowth of the anterior cingulate (ACC) and slower white matter development in the parietal cortex in adolescents with ASD versus TYP. Cross-sectional studies of the salience, executive control and default mode resting state functional connectivity networks, which mediate cognitive control, demonstrate patterns of connectivity that differ from TYP through adolescence. Finally, white matter tracts underlying these control-related brain regions continue to show reduced diffusion properties compared to TYP. It is thus not surprising that cognitive control tasks performance improves less during adolescence in ASD versus TYP. This review illustrates that a cognitive neuroscientific approach produces insights about the mechanisms of persistent cognitive control deficits in individuals with ASD from adolescence into young adulthood not apparent with neuropsychological methods alone, and draws attention to the great need for longitudinal studies of this period in those with ASD. Further investigation of ACC and fronto-parietal neural circuits may help specify pathophysiology and treatment options.

17.
Cereb Cortex ; 27(2): 1401-1408, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-26740488

RESUMO

Apathy is defined by reduced goal-directed behavior, and is common in patients with damage to the ventromedial prefrontal cortex (vmPFC). Separately, in neuroeconomics research, the vmPFC has been shown to play a role in reward processing-namely, in "stimulus valuation," or the computation of the subjective reward value of a stimulus. Here, we used a sample of patients with focal brain lesions (N = 93) and matched healthy controls (N = 21) to determine whether the association between vmPFC damage and increased apathy is driven by impaired valuation. An auction task was used to measure valuation, and apathy was assessed via caregiver ratings of patients' day-to-day behavior. Lesion-symptom mapping identified the locus of impaired valuation in the vmPFC, and patients with damage to this region demonstrated increased apathy relative to patients with damage to dorsomedial prefrontal cortex (dmPFC), patients with damage to other brain regions, and healthy controls. Critically, the association between vmPFC damage and apathy was mediated by impaired valuation, with no effect as a function of dmPFC damage. Our results implicate a valuation-based mechanism underlying the relationship between vmPFC integrity and apathy, bridging findings from both the clinical literature and neuroeconomics research.


Assuntos
Apatia/fisiologia , Mapeamento Encefálico , Tomada de Decisões/fisiologia , Córtex Pré-Frontal/fisiopatologia , Recompensa , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Negociação/psicologia , Córtex Pré-Frontal/lesões
18.
Soc Cogn Affect Neurosci ; 10(7): 1003-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25481003

RESUMO

The control of neurological networks supporting social cognition is crucially important for social interaction. In particular, the control of imitation is directly linked to interaction quality, with impairments associated with disorders characterized by social difficulties. Previous work suggests inferior frontal cortex (IFC) and the temporoparietal junction (TPJ) are involved in controlling imitation, but the functional roles of these areas remain unclear. Here, transcranial direct current stimulation (tDCS) was used to enhance cortical excitability at IFC and the TPJ prior to the completion of three tasks: (i) a naturalistic social interaction during which increased imitation is known to improve rapport, (ii) a choice reaction time task in which imitation needs to be inhibited for successful performance and (iii) a non-imitative control task. Relative to sham stimulation, stimulating IFC improved the context-dependent control of imitation-participants imitated more during the social interaction and less during the imitation inhibition task. In contrast, stimulating the TPJ reduced imitation in the inhibition task without affecting imitation during social interaction. Neither stimulation site affected the non-imitative control task. These data support a model in which IFC modulates imitation directly according to task demands, whereas TPJ controls task-appropriate shifts in attention toward representation of the self or the other, indirectly impacting upon imitation.


Assuntos
Comportamento Imitativo/fisiologia , Lobo Parietal/fisiologia , Córtex Pré-Frontal/fisiologia , Lobo Temporal/fisiologia , Atenção/fisiologia , Comportamento de Escolha , Feminino , Humanos , Relações Interpessoais , Masculino , Neurônios-Espelho/fisiologia , Rede Nervosa/fisiologia , Tempo de Reação/fisiologia , Autoimagem , Percepção Social , Estimulação Transcraniana por Corrente Contínua , Adulto Jovem
19.
Cereb Cortex ; 25(8): 2076-82, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24532320

RESUMO

During social interactions, there is a tendency for people to mimic the gestures and mannerisms of others, which increases liking and rapport. Psychologists have extensively studied the antecedents and consequences of mimicry at the social level, but the neural basis of this behavior remains unclear. Many researchers have speculated that mimicry is related to activity in the human mirror system (HMS), a network of parietofrontal regions that are involved in both action execution and observation. However, activity of the HMS during reciprocal social interactions involving mimicry has not been demonstrated. Here, we took an electroencephalographic (EEG) index of mirror activity-mu-suppression during action observation-in a pretest/post-test design with 1 of 3 intervening treatments: 1) social interaction in which the participant was mimicked, 2) social interaction without mimicry, or 3) an innocuous computer task, not involving another human agent. The change in mu-suppression from pre- to post-test varied as a function of the intervening treatment, with participants who had been mimicked showing an increase in mu-suppression during the post-treatment action observation session. We propose that this specific modulation of HMS activity as a function of mimicry constitutes the first direct evidence for mirror system involvement in real social mimicry.


Assuntos
Encéfalo/fisiologia , Comportamento Imitativo/fisiologia , Percepção de Movimento/fisiologia , Comportamento Social , Estimulação Acústica , Percepção Auditiva/fisiologia , Eletroencefalografia , Emoções/fisiologia , Feminino , Humanos , Masculino , Música , Testes Neuropsicológicos , Estimulação Luminosa , Distribuição Aleatória , Inquéritos e Questionários , Adulto Jovem
20.
Artigo em Inglês | MEDLINE | ID: mdl-24634653

RESUMO

In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.'s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature.

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