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1.
Ann Neurol ; 94(4): 632-646, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37431188

RESUMEN

OBJECTIVE: Microtubule-associated protein tau (MAPT) mutations cause frontotemporal lobar degeneration, and novel biomarkers are urgently needed for early disease detection. We used task-free functional magnetic resonance imaging (fMRI) mapping, a promising biomarker, to analyze network connectivity in symptomatic and presymptomatic MAPT mutation carriers. METHODS: We compared cross-sectional fMRI data between 17 symptomatic and 39 presymptomatic carriers and 81 controls with (1) seed-based analyses to examine connectivity within networks associated with the 4 most common MAPT-associated clinical syndromes (ie, salience, corticobasal syndrome, progressive supranuclear palsy syndrome, and default mode networks) and (2) whole-brain connectivity analyses. We applied K-means clustering to explore connectivity heterogeneity in presymptomatic carriers at baseline. Neuropsychological measures, plasma neurofilament light chain, and gray matter volume were compared at baseline and longitudinally between the presymptomatic subgroups defined by their baseline whole-brain connectivity profiles. RESULTS: Symptomatic and presymptomatic carriers had connectivity disruptions within MAPT-syndromic networks. Compared to controls, presymptomatic carriers showed regions of connectivity alterations with age. Two presymptomatic subgroups were identified by clustering analysis, exhibiting predominantly either whole-brain hypoconnectivity or hyperconnectivity at baseline. At baseline, these two presymptomatic subgroups did not differ in neuropsychological measures, although the hypoconnectivity subgroup had greater plasma neurofilament light chain levels than controls. Longitudinally, both subgroups showed visual memory decline (vs controls), yet the subgroup with baseline hypoconnectivity also had worsening verbal memory and neuropsychiatric symptoms, and extensive bilateral mesial temporal gray matter decline. INTERPRETATION: Network connectivity alterations arise as early as the presymptomatic phase. Future studies will determine whether presymptomatic carriers' baseline connectivity profiles predict symptomatic conversion. ANN NEUROL 2023;94:632-646.


Asunto(s)
Demencia Frontotemporal , Proteínas tau , Humanos , Estudios Transversales , Proteínas tau/genética , Encéfalo/diagnóstico por imagen , Mutación/genética , Sustancia Gris/diagnóstico por imagen , Imagen por Resonancia Magnética , Demencia Frontotemporal/genética , Biomarcadores
2.
J Cogn Neurosci ; 29(11): 1908-1917, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28707571

RESUMEN

We cannot see the minds of others, yet people often spontaneously interpret how they are viewed by other people (i.e., meta-perceptions) and often in a self-flattering manner. Very little is known about the neural associations of meta-perceptions, but a likely candidate is the ventromedial pFC (VMPFC). VMPFC has been associated with both self- and other-perception as well as motivated self-perception. Does this function extend to meta-perceptions? The current study examined neural activity while participants made meta-perceptive interpretations in various social scenarios. A drift-diffusion model was used to test whether the VMPFC is associated with two processes involved in interpreting meta-perceptions in a self-flattering manner: the extent to which the interpretation process involves the preferential accumulation of evidence in favor of a self-flattering interpretation versus the extent to which the interpretation process begins with an expectation that favors a self-flattering outcome. Increased VMPFC activity was associated with the extent to which people preferentially accumulate information when interpreting meta-perceptions under ambiguous conditions and marginally associated with self-flattering meta-perceptions. Together, the present findings illuminate the neural underpinnings of a social cognitive process that has received little attention to date: how we make meaning of others' minds when we think those minds are pointed at us.


Asunto(s)
Mapeo Encefálico , Encéfalo/fisiología , Corteza Cerebral/fisiología , Motivación/fisiología , Autoimagen , Percepción Social , Adulto , Análisis de Varianza , Encéfalo/diagnóstico por imagen , Corteza Cerebral/diagnóstico por imagen , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Modelos Neurológicos , Oxígeno/sangre , Adulto Joven
3.
J Trauma Stress ; 29(1): 33-40, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26748991

RESUMEN

Posttraumatic stress disorder (PTSD) has been linked to deficits in response inhibition, and neuroimaging research suggests this may be due to differences in prefrontal cortex recruitment. The current study examined relationships between PTSD from intimate partner violence (IPV) and neural responses during inhibition. There were 10 women with PTSD from IPV and 12 female control subjects without trauma history who completed the stop signal task during functional magnetic resonance imaging. Linear mixed models were used to investigate group differences in activation (stop-nonstop and hard-easy trials). Those with PTSD exhibited greater differential activation to stop-nonstop trials in the right dorsolateral prefrontal cortex and the anterior insula and less differential activation in several default mode regions (d = 1.12-1.22). Subjects with PTSD exhibited less differential activation to hard-easy trials in the lateral frontal and the anterior insula regions (driven by less activation to hard trials) and several default mode regions (i.e., medial prefrontal cortex, posterior cingulate; driven by greater activation to easy trials; d = 1.23-1.76). PTSD was associated with difficulties disengaging default mode regions during cognitive tasks with relatively low cognitive demand, as well as difficulties modulating executive control and salience processing regions with increasing cognitive demand. Together, these results suggest that PTSD may relate to decreased neural flexibility during inhibition.


Asunto(s)
Encéfalo/fisiopatología , Emociones/fisiología , Función Ejecutiva , Violencia de Pareja/psicología , Corteza Prefrontal/fisiopatología , Trastornos por Estrés Postraumático/fisiopatología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Imagen por Resonancia Magnética , Psicofisiología , Trastornos por Estrés Postraumático/diagnóstico por imagen , Trastornos por Estrés Postraumático/psicología
4.
Br J Psychiatry ; 206(3): 206-15, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25573399

RESUMEN

BACKGROUND: Although evidence exists for abnormal brain function across various anxiety disorders, direct comparison of neural function across diagnoses is needed to elicit abnormalities common across disorders and those distinct to a particular diagnosis. AIMS: To delineate common and distinct abnormalities within generalised anxiety (GAD), panic and social anxiety disorder (SAD) during affective processing. METHOD: Fifty-nine adults (15 with GAD, 15 with panic disorder, 14 with SAD, and 15 healthy controls) underwent functional magnetic resonance imaging while completing a facial emotion matching task with fearful, angry and happy faces. RESULTS: Greater differential right amygdala activation to matching fearful v. happy facial expressions related to greater negative affectivity (i.e. trait anxiety) and was heightened across all anxiety disorder groups compared with controls. Collapsing across emotional face types, participants with panic disorder uniquely displayed greater posterior insula activation. CONCLUSIONS: These preliminary results highlight a common neural basis for clinical anxiety in these diagnoses and also suggest the presence of disorder-specific dysfunction.


Asunto(s)
Amígdala del Cerebelo/fisiopatología , Trastornos de Ansiedad/fisiopatología , Encéfalo/fisiopatología , Corteza Cerebral/fisiopatología , Expresión Facial , Trastorno de Pánico/fisiopatología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Adulto Joven
5.
Proc Natl Acad Sci U S A ; 109(17): 6479-83, 2012 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-22493264

RESUMEN

Individuals are willing to sacrifice their own resources to promote equality in groups. These costly choices promote equality and are associated with behavior that supports cooperation in humans, but little is known about the brain processes involved. We use functional MRI to study egalitarian preferences based on behavior observed in the "random income game." In this game, subjects decide whether to pay a cost to alter group members' randomly allocated incomes. We specifically examine whether egalitarian behavior is associated with neural activity in the ventromedial prefrontal cortex and the insular cortex, two regions that have been shown to be related to social preferences. Consistent with previous studies, we find significant activation in both regions; however, only the insular cortex activations are significantly associated with measures of revealed and expressed egalitarian preferences elicited outside the scanner. These results are consistent with the notion that brain mechanisms involved in experiencing the emotional states of others underlie egalitarian behavior in humans.


Asunto(s)
Altruismo , Corteza Prefrontal/fisiología , Justicia Social , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino
6.
Behav Brain Sci ; 38: e93, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26787104

RESUMEN

The PASTOR framework needs to be reconciled with existing research on positive illusions, which finds that positive appraisals of stressors have a short shelf life as a mechanism of resilience, do not draw on costly executive functioning, and rely on neural networks that are distinct from those found in studies of experimentally instructed reappraisal or value.


Asunto(s)
Cognición , Humanos
7.
Neuroimage ; 59(3): 2850-9, 2012 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-21982930

RESUMEN

Sensation seeking has been linked to increased risk taking and is therefore crucial in influencing behavioral outcomes of risk-taking behavior. Using functional magnetic resonance imaging (fMRI), the neural underpinnings of risk appraisal were studied in a large subject sample (n=188), stratified according to thrill and adventure seeking (TAS) ratings. As defined by a median split of the sample, low and high TAS groups were compared on a simple decision-making task completed during fMRI. The task was designed such that risk (i.e., magnitude of outcome) and gains (i.e., direction of outcome) could be mapped independently. Behavioral analysis indicated that high TAS individuals are more sensitive to rewards but less discriminating between risk with and without punishment and that low TAS individuals are less sensitive to rewards but quite sensitive to receiving punishments in risky situations. Imaging results on the group differences for the interaction between level of risk and level of gain showed differences in the right superior frontal gyrus (BA6), left insula (BA21), right nucleus accumbens, left lentiform nucleus, and left precuneus (BA7). The presented data suggest a neural model of risk processing in sensation seeking individuals such that the positive response to reward outweighs the impact of equivalent loss. This imbalance in approach/avoidance is evident in differences in the underlying neural substrates in TAS individuals and leads to greater risk behavior in the face of potential loss.


Asunto(s)
Conducta Exploratoria/fisiología , Procesos Mentales/fisiología , Conducta/fisiología , Corteza Cerebral/fisiología , Cuerpo Estriado/fisiología , Toma de Decisiones , Impulso (Psicología) , Entropía , Femenino , Lóbulo Frontal/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Oxígeno/sangre , Pruebas de Personalidad , Castigo , Recompensa , Asunción de Riesgos , Adulto Joven
8.
Neuroimage ; 59(2): 1879-87, 2012 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-21920442

RESUMEN

Individuals with high anxiety show heightened neural activation in affective processing regions, including the amygdala and insula. Activations have been shown to be correlated with anxiety severity, but although anxiety is a heterogeneous state, prior studies have not systematically disentangled whether neural activity in affective processing circuitry is uniquely related to specific domains of anxiety. Forty-five young adults were tested on an emotional face processing task during functional magnetic resonance imaging. Participants completed the Social Interactional Anxiety Scale, Anxiety Sensitivity Index, and Spielberger Trait Anxiety Inventory. Using a robust multiple regression approach, we examined the effects of social anxiety, anxiety sensitivity, and trait anxiety (which overlapped with depressive symptoms, and can therefore be considered a measure of negative affectivity) on activation in insula, amygdala, and medial prefrontal cortex, in response to emotional faces. Adjusting for negative affectivity and anxiety sensitivity, social anxiety was associated with activity in left amygdala, right insula, and subgenual anterior cingulate across all emotional faces. When comparing negative and positive faces directly, greater negative affectivity was uniquely associated with less activity to positive faces in left amygdala, left anterior insula, and dorsal anterior cingulate. The current findings support the hypothesis that hyperactivity in brain areas during general emotional face processing is predominantly a function of social anxiety. In comparison, hypoactivity to positively valenced faces was predominantly associated with negative affectivity. Implications for the understanding of emotion processing in anxiety are discussed.


Asunto(s)
Afecto , Ansiedad/fisiopatología , Encéfalo/fisiopatología , Inteligencia Emocional , Emociones , Expresión Facial , Red Nerviosa/fisiopatología , Alienación Social , Adolescente , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Adulto Joven
9.
Ann Clin Transl Neurol ; 8(1): 95-110, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33247623

RESUMEN

OBJECTIVE: MAPT mutations typically cause behavioral variant frontotemporal dementia with or without parkinsonism. Previous studies have shown that symptomatic MAPT mutation carriers have frontotemporal atrophy, yet studies have shown mixed results as to whether presymptomatic carriers have low gray matter volumes. To elucidate whether presymptomatic carriers have lower structural brain volumes within regions atrophied during the symptomatic phase, we studied a large cohort of MAPT mutation carriers using a voxelwise approach. METHODS: We studied 22 symptomatic carriers (age 54.7 ± 9.1, 13 female) and 43 presymptomatic carriers (age 39.2 ± 10.4, 21 female). Symptomatic carriers' clinical syndromes included: behavioral variant frontotemporal dementia (18), an amnestic dementia syndrome (2), Parkinson's disease (1), and mild cognitive impairment (1). We performed voxel-based morphometry on T1 images and assessed brain volumetrics by clinical subgroup, age, and mutation subtype. RESULTS: Symptomatic carriers showed gray matter atrophy in bilateral frontotemporal cortex, insula, and striatum, and white matter atrophy in bilateral corpus callosum and uncinate fasciculus. Approximately 20% of presymptomatic carriers had low gray matter volumes in bilateral hippocampus, amygdala, and lateral temporal cortex. Within these regions, low gray matter volumes emerged in a subset of presymptomatic carriers as early as their thirties. Low white matter volumes arose infrequently among presymptomatic carriers. INTERPRETATION: A subset of presymptomatic MAPT mutation carriers showed low volumes in mesial temporal lobe, the region ubiquitously atrophied in all symptomatic carriers. With each decade of age, an increasing percentage of presymptomatic carriers showed low mesial temporal volume, suggestive of early neurodegeneration.


Asunto(s)
Encéfalo/patología , Demencia Frontotemporal/genética , Demencia Frontotemporal/patología , Proteínas tau/genética , Adulto , Anciano , Femenino , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Mutación
10.
Neuroimage Clin ; 22: 101751, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30921613

RESUMEN

Mutations in progranulin (GRN) cause heterogeneous clinical syndromes, including behavioral variant frontotemporal dementia (bvFTD), primary progressive aphasia (PPA), corticobasal syndrome (CBS) and Alzheimer-type dementia (AD-type dementia). Human studies have shown that presymptomatic GRN carriers feature reduced connectivity in the salience network, a system targeted in bvFTD. Mice with homozygous deletion of GRN, in contrast, show thalamo-cortical hypersynchrony due to aberrant pruning of inhibitory synapses onto thalamo-cortical projection neurons. No studies have systematically explored the intrinsic connectivity networks (ICNs) targeted by the four GRN-associated clinical syndromes, or have forged clear links between human and mouse model findings. We compared 17 preclinical GRN carriers (14 "presymptomatic" clinically normal and three "prodromal" with mild cognitive symptoms) to healthy controls to assess for differences in cognitive testing and gray matter volume. Using task-free fMRI, we assessed connectivity in the salience network, a non-fluent variant primary progressive aphasia network (nfvPPA), the perirolandic network (CBS), and the default mode network (AD-type dementia). GRN carriers and controls showed similar performance on cognitive testing. Although carriers showed little evidence of brain atrophy, markedly enhanced connectivity emerged in all four networks, and thalamo-cortical hyperconnectivity stood out as a unifying feature. Voxelwise assessment of whole brain degree centrality, an unbiased graph theoretical connectivity metric, confirmed thalamic hyperconnectivity. These results show that human GRN disease and the prevailing GRN mouse model share a thalamo-cortical network hypersynchrony phenotype. Longitudinal studies will determine whether this network physiology represents a compensatory response as carriers approach symptom onset, or an early and sustained preclinical manifestation of lifelong progranulin haploinsufficiency.


Asunto(s)
Corteza Cerebral/fisiopatología , Disfunción Cognitiva/fisiopatología , Conectoma/métodos , Demencia Frontotemporal/fisiopatología , Red Nerviosa/fisiopatología , Síntomas Prodrómicos , Progranulinas/genética , Tálamo/fisiopatología , Adulto , Anciano , Corteza Cerebral/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Femenino , Demencia Frontotemporal/diagnóstico por imagen , Heterocigoto , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Red Nerviosa/diagnóstico por imagen , Tálamo/diagnóstico por imagen
11.
PLoS One ; 10(6): e0127010, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26076493

RESUMEN

OBJECTIVE: Approximately 10% of young adults report non-medical use of stimulants (cocaine, amphetamine, methylphenidate), which puts them at risk for the development of dependence. This fMRI study investigates whether subjects at early stages of stimulant use show altered decision making processing. METHODS: 158 occasional stimulants users (OSU) and 50 comparison subjects (CS) performed a "risky gains" decision making task during which they could select safe options (cash in 20 cents) or gamble them for double or nothing in two consecutive gambles (win or lose 40 or 80 cents, "risky decisions"). The primary analysis focused on risky versus safe decisions. Three secondary analyses were conducted: First, a robust regression examined the effect of lifetime exposure to stimulants and marijuana; second, subgroups of OSU with >1000 (n = 42), or <50 lifetime marijuana uses (n = 32), were compared to CS with <50 lifetime uses (n = 46) to examine potential marijuana effects; third, brain activation associated with behavioral adjustment following monetary losses was probed. RESULTS: There were no behavioral differences between groups. OSU showed attenuated activation across risky and safe decisions in prefrontal cortex, insula, and dorsal striatum, exhibited lower anterior cingulate cortex (ACC) and dorsal striatum activation for risky decisions and greater inferior frontal gyrus activation for safe decisions. Those OSU with relatively more stimulant use showed greater dorsal ACC and posterior insula attenuation. In comparison, greater lifetime marijuana use was associated with less neural differentiation between risky and safe decisions. OSU who chose more safe responses after losses exhibited similarities with CS relative to those preferring risky options. DISCUSSION: Individuals at risk for the development of stimulant use disorders presented less differentiated neural processing of risky and safe options. Specifically, OSU show attenuated brain response in regions critical for performance monitoring, reward processing and interoceptive awareness. Marijuana had additive effects by diminishing neural risk differentiation.


Asunto(s)
Encéfalo/fisiopatología , Estimulantes del Sistema Nervioso Central/efectos adversos , Imagen por Resonancia Magnética , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/fisiopatología , Adolescente , Adulto , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Neuroimagen , Fenotipo , Factores de Riesgo , Asunción de Riesgos , Evaluación de Síntomas , Adulto Joven
12.
Soc Cogn Affect Neurosci ; 9(9): 1379-87, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23934417

RESUMEN

Computerized attention modification is a relatively new and empirically validated treatment approach for different types of anxiety disorders. However, its neural basis and processes involved are poorly understood. This study examined the effect of a one-time application of an attention modification program (AMP) on neural substrates underlying emotion processing in individuals with high social anxiety. Fourteen individuals with elevated social anxiety symptoms completed an emotional face processing task during functional magnetic resonance imaging before and after AMP, and were subsequently exposed to a laboratory stressor. Results revealed the following: First, there was attenuated activation from pre- to post-AMP in the bilateral amygdala, bilateral insula and subgenual anterior cingulate cortex. Second, post-AMP, individuals exhibited increased activation in several regions of the prefrontal cortex (PFC). Third, those individuals with greater enhancement of ventromedial PFC activation after AMP showed diminished attentional allocation for threat and attenuated anxiety reactivity to the stressor. We conclude that AMP exerts effects that are similar to those previously reported for standard anxiolytics; however, it also appears to foster deployment of top-down brain processes aimed to regulate anxiety.


Asunto(s)
Ansiedad/patología , Ansiedad/rehabilitación , Atención/fisiología , Mapeo Encefálico , Emociones/fisiología , Terapia Asistida por Computador/instrumentación , Adolescente , Análisis de Varianza , Ansiedad/fisiopatología , Encéfalo/irrigación sanguínea , Encéfalo/patología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Oxígeno/sangre , Reconocimiento Visual de Modelos , Estimulación Luminosa , Escalas de Valoración Psiquiátrica , Adulto Joven
13.
J Affect Disord ; 169: 76-85, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25171782

RESUMEN

BACKGROUND: The neural processes underlying the benefits of cognitive behavioral treatment (CBT) for generalized anxiety disorder (GAD) are not well understood. METHODS: Twenty-one (n=21) adults with a principal diagnosis of GAD and eleven (n=11) non-anxious healthy controls (HC) underwent functional magnetic resonance imaging while completing a facial emotion processing task. Responses to threat-related emotionality (i.e., the contrast of fear and angry vs. happy faces) were assessed at pretreatment and again following 10 sessions of CBT in the GAD group and a comparable waiting period in the HC group. RESULTS: At pretreatment, GAD participants displayed blunted responses in the amygdala, insula, and anterior cingulate to the happy face-processing comparison condition, and greater amygdalo-insular connectivity. CBT was associated with attenuated amygdalar and subgenual anterior cingulate activation to fear/angry faces and heightened insular responses to the happy face comparison condition, but had no apparent effects on connectivity. Pre-treatment abnormalities and treatment-related changes were not associated with symptoms of worry. LIMITATIONS: There was no active control condition (e.g., treatment waitlist) for comparison of treatment effects. CONCLUSIONS: Taken together, these results provide evidence for a dual-process psychotherapeutic model of neural systems changes in GAD in which cingulo-amygdalar reactivity to threat-cues is attenuated while insular responses to positive facial emotions are potentiated. Future work is needed to determine the clinical implications of these changes and their specificity to CBT.


Asunto(s)
Trastornos de Ansiedad/terapia , Terapia Cognitivo-Conductual , Giro del Cíngulo/fisiopatología , Adulto , Amígdala del Cerebelo/fisiopatología , Ira , Trastornos de Ansiedad/fisiopatología , Estudios de Casos y Controles , Cognición , Señales (Psicología) , Emociones , Expresión Facial , Miedo , Femenino , Felicidad , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto Joven
14.
Soc Cogn Affect Neurosci ; 9(2): 225-31, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23171614

RESUMEN

Understanding the neural processes that characterize elite performers is a first step to develop a neuroscience model that can be used to improve performance in stressful circumstances. Adventure racers are elite athletes that operate in small teams in the context of environmental and physical extremes. In particular, awareness of team member's emotional status is critical to the team's ability to navigate high-magnitude stressors. Thus, this functional magnetic resonance imaging (fMRI) study examined the hypothesis that adventure racers would show altered emotion processing in brain areas that are important for resilience and social awareness. Elite adventure racers (n = 10) were compared with healthy volunteers (n = 12) while performing a simple emotion face-processing (modified Hariri) task during fMRI. Across three types of emotional faces, adventure racers showed greater activation in right insula, left amygdala and dorsal anterior cingulate. Additionally, compared with healthy controls adventure racers showed attenuated right medial prefrontal cortex activation. These results are consistent with previous studies showing elite performers differentially activate neural substrates underlying interoception. Thus, adventure racers differentially deploy brain resources in an effort to recognize and process the internal sensations associated with emotions in others, which could be advantageous for team-based performance under stress.


Asunto(s)
Atletas , Corteza Cerebral/fisiología , Emociones , Expresión Facial , Reconocimiento Visual de Modelos/fisiología , Corteza Prefrontal/fisiología , Adulto , Encéfalo/fisiología , Mapeo Encefálico , Cara , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Estimulación Luminosa , Competencia Profesional , Percepción Social , Análisis y Desempeño de Tareas
15.
Front Hum Neurosci ; 7: 450, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23935580

RESUMEN

An integration of existing research and newly conducted psychophysiological interaction (PPI) connectivity analyses suggest a new framework for understanding the contribution of midline regions to social cognition. Recent meta-analyses suggest that there are no midline regions that are exclusively associated with self-processing. Whereas medial prefrontal cortex (MPFC) is broadly modulated by self-processing, subdivisions within MPFC are differentially modulated by the evaluation of close others (ventral MPFC: BA 10/32) and the evaluation of other social targets (dorsal MPFC: BA 9/32). The role of DMPFC in social cognition may also be less uniquely social than previously thought; it may be better characterized as a region that indexes certainty about evaluation rather than previously considered social mechanisms (i.e., correction of self-projection). VMPFC, a region often described as an important mediator of socioemotional significance, may instead perform a more cognitive role by reflecting the type of information brought to bear on evaluations of people we know well. Furthermore, the new framework moves beyond MPFC and hypothesizes that two other midline regions, ventral anterior cingulate cortex (VACC: BA 25) and medial orbitofrontal cortex (MOFC: BA 11), aid motivational influences on social cognition. Despite the central role of motivation in psychological models of self-perception, neural models have largely ignored the topic. Positive connectivity between VACC and MOFC may mediate bottom-up sensitivity to information based on its potential for helping us evaluate ourselves or others the way we want. As connectivity becomes more positive with striatum and less positive with middle frontal gyrus (BA 9/44), MOFC mediates top-down motivational influences by adjusting the standards we bring to bear on evaluations of ourselves and other people.

16.
PLoS One ; 8(2): e52970, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23418419

RESUMEN

Liberals and conservatives exhibit different cognitive styles and converging lines of evidence suggest that biology influences differences in their political attitudes and beliefs. In particular, a recent study of young adults suggests that liberals and conservatives have significantly different brain structure, with liberals showing increased gray matter volume in the anterior cingulate cortex, and conservatives showing increased gray matter volume in the in the amygdala. Here, we explore differences in brain function in liberals and conservatives by matching publicly-available voter records to 82 subjects who performed a risk-taking task during functional imaging. Although the risk-taking behavior of Democrats (liberals) and Republicans (conservatives) did not differ, their brain activity did. Democrats showed significantly greater activity in the left insula, while Republicans showed significantly greater activity in the right amygdala. In fact, a two parameter model of partisanship based on amygdala and insula activations yields a better fitting model of partisanship than a well-established model based on parental socialization of party identification long thought to be one of the core findings of political science. These results suggest that liberals and conservatives engage different cognitive processes when they think about risk, and they support recent evidence that conservatives show greater sensitivity to threatening stimuli.


Asunto(s)
Amígdala del Cerebelo/fisiología , Corteza Cerebral/fisiología , Toma de Decisiones/fisiología , Política , Adulto , Actitud , Femenino , Humanos , Juicio/fisiología , Imagen por Resonancia Magnética , Masculino , Asunción de Riesgos
17.
J Affect Disord ; 146(3): 426-32, 2013 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-22910447

RESUMEN

BACKGROUND: Exposure to psychological stress during combat can lead to posttraumatic stress disorder (PTSD). Anticipation of aversive events is often associated with an intense emotional state in individuals with PTSD. Both the valence (i.e., positive or negative) of the anticipated event and the degree of temporal predictability (i.e., one's ability to predict when an event will occur) have profound effects on an individual's emotional experience. This investigation tested the hypothesis that individuals with combat-related PTSD would show increased activation in the insula and related emotion-processing circuitry when anticipating emotionally significant events such as portrayed in combat-related images, and this heighted response within the insula would be particularly enhanced during temporal unpredictability. METHODS: About 15 male veterans with PTSD and 15 male veterans with combat-exposure but no current or lifetime history of PTSD (combat exposed controls/CEC) performed a temporal unpredictability anticipation task of unpleasant (combat-related) and pleasant images during fMRI. RESULTS: As expected, greater activation in the bilateral anterior insulae was observed in the PTSD versus the CEC subjects during anticipation of combat-related images when the anticipatory period was of uncertain duration (p<0.05). Furthermore, activation in the right anterior insula was related to greater perceived threat in the CEC group (ρ=0.619). LIMITATIONS: The current study looks only at combat-related PTSD in a modest preliminary sized sample. CONCLUSIONS: These findings suggest that an excessive anticipatory reaction in individuals with PTSD to temporally unpredictable aversive stimulus may relate to greater perceived threat. These findings are concordant with psychological models of PTSD that focus on the association of PTSD with the experience of decreased predictability and control.


Asunto(s)
Anticipación Psicológica/fisiología , Corteza Cerebral/fisiología , Trastornos de Combate/fisiopatología , Trastornos por Estrés Postraumático/fisiopatología , Veteranos/psicología , Adulto , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Factores de Tiempo , Veteranos/estadística & datos numéricos , Adulto Joven
18.
Psychiatry Res ; 211(2): 93-103, 2013 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-23154098

RESUMEN

Childhood maltreatment (CM) is a strong risk factor for development of posttraumatic stress disorder (PTSD) upon adult exposure to extreme adverse events. However, the neural underpinnings of this relationship are not well understood. Here, we test the hypothesis that severity of CM history is positively correlated with emotion-processing limbic and prefrontal brain activation/connectivity and negatively correlated with prefrontal gray matter volumes in women with PTSD due to intimate-partner violence (IPV-PTSD). Thirty-three women with IPV-PTSD underwent structural and functional magnetic resonance imaging while completing a facial emotion processing task. Multivariate regressions examined the relationship of CM to patterns of activation, connectivity, and gray matter volumes. CM severity was: (a) positively correlated with ventral ACC activation while processing angry faces; (b) negatively correlated with dorsal ACC and insula activation while processing fear and angry faces, arising from positive correlations with the shape-matching baseline; (c) positively correlated with limbic-prefrontal connectivity while processing fear faces but negatively correlated with amygdalo-insular connectivity while processing fear and angry; and (d) negatively correlated with prefrontal gray matter volumes. These results suggest CM exposure may account for variability in limbic/prefrontal brain function and prefrontal structure in adulthood PTSD and offer one potential mechanism through which CM confers risk to future development of PTSD.


Asunto(s)
Adultos Sobrevivientes del Maltrato a los Niños/psicología , Sistema Límbico/fisiopatología , Fibras Nerviosas Amielínicas/patología , Corteza Prefrontal/fisiopatología , Trastornos por Estrés Postraumático/patología , Trastornos por Estrés Postraumático/fisiopatología , Adulto , Atrofia/patología , Corteza Cerebral/fisiopatología , Emociones/fisiología , Femenino , Humanos , Persona de Mediana Edad , Vías Nerviosas/patología , Vías Nerviosas/fisiopatología , Neuroimagen , Corteza Prefrontal/patología , Parejas Sexuales/psicología , Trastornos por Estrés Postraumático/psicología , Violencia/psicología
19.
Biol Psychiatry ; 73(3): 235-41, 2013 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-23021534

RESUMEN

BACKGROUND: While stimulant-dependent individuals continue to make risky decisions, in spite of poor outcomes, much less is known about decision-making characteristics of occasional stimulant users (OSU) at risk for developing stimulant dependence. This study examines whether OSU exhibit inefficient learning and execution of reinforced decision-outcome contingencies. METHODS: Occasional stimulant users (n = 161) and stimulant-naïve comparison subjects (CTL) (n = 48) performed a Paper Scissors Rock task during functional magnetic resonance imaging. Selecting a particular option was associated with a predetermined probability of winning, which was altered repeatedly to examine neural and behavioral characteristics of reinforced contingencies. RESULTS: Occasional stimulant users displayed greater anterior insula, inferior frontal gyrus, and dorsal striatum activation than CTL during late trials when contingencies were familiar (as opposed to being learned) in the presence of comparable behavioral performance in both groups. Follow-up analyses demonstrated that during late trials: 1) OSU with high cannabis use displayed greater activation in these brain regions than CTL, whereas OSU with low cannabis use did not differ from the other two groups; and 2) OSU preferring cocaine exhibited greater anterior insula, inferior frontal gyrus, and dorsal striatum activation than CTL and also displayed higher activation in the former two regions than OSU who preferred prescription stimulants. CONCLUSIONS: Occasional stimulant users exhibit inefficient resource allocation during the execution of reinforced contingencies that may be a result of additive effects of cocaine and cannabis use. A critical next step is to establish whether this inefficiency predicts transition to stimulant dependence.


Asunto(s)
Encéfalo/fisiopatología , Toma de Decisiones/fisiología , Aprendizaje/fisiología , Refuerzo en Psicología , Trastornos Relacionados con Sustancias/psicología , Mapeo Encefálico , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Factores de Riesgo , Trastornos Relacionados con Sustancias/fisiopatología , Adulto Joven
20.
Psychiatry Res ; 214(1): 48-55, 2013 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-23916537

RESUMEN

Therapy for combat and accident-related posttraumatic stress disorder (PTSD) has been reported to influence amygdala and anterior cingulate cortex (ACC) response during emotional processing. It is not yet understood how therapy influences different phases of emotional processing, and whether previous findings generalize to other PTSD populations. We hypothesized that cognitive trauma therapy for battered women (CTT-BW) would alter insula, amygdala, and cingulate responses during anticipation and presentation of emotional images. Fourteen female patients with PTSD related to domestic violence completed the Clinician Administered PTSD Scale (CAPS) and functional magnetic resonance imaging (fMRI) before and after CTT-BW. The fMRI task involved cued anticipation followed by presentation of positive versus negative affective images. CTT-BW was associated with decreases in CAPS score, enhanced ACC and decreased anterior insula activation during anticipation, and decreased dorsolateral prefrontal cortex and amygdala response during image presentation (negative-positive). Pre-treatment ACC activation during anticipation and image presentation exhibited positive and negative relationships to treatment response, respectively. Results suggest that CTT-BW enhanced efficiency of neural responses during preparation for upcoming emotional events in a way that reduced the need to recruit prefrontal-amygdala responses during the occurrence of the event. Results also suggest that enhancing ACC function during anticipation may be beneficial for PTSD treatment.


Asunto(s)
Mujeres Maltratadas/psicología , Encéfalo/fisiopatología , Terapia Cognitivo-Conductual/métodos , Violencia Doméstica/psicología , Trastornos por Estrés Postraumático/fisiopatología , Adulto , Atención/fisiología , Emociones/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Pruebas Neuropsicológicas , Trastornos por Estrés Postraumático/psicología , Trastornos por Estrés Postraumático/terapia , Resultado del Tratamiento
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