RESUMEN
This study evaluates electroencephalography (EEG) and positron emission tomography (PET) in the same subjects. Fourteen murderers were assessed by using both PET (while they were performing the continuous performance task) and EEG during a resting state. EEG revealed significant increases in slow-wave activity in the temporal, but not frontal, lobe in murderers, in contrast to prior PET findings that showed reduced prefrontal, but not temporal, glucose metabolism. Results suggest that resting EEG shows empirical utility distinct from PET activation findings.
Asunto(s)
Nivel de Alerta/fisiología , Glucemia/metabolismo , Electroencefalografía , Homicidio , Lóbulo Temporal/fisiopatología , Tomografía Computarizada de Emisión , Adulto , Ritmo beta , Mapeo Encefálico , Ritmo Delta , Femenino , Lóbulo Frontal/fisiopatología , Humanos , Defensa por Insania , Masculino , Pruebas Neuropsicológicas , Desempeño Psicomotor/fisiología , Valores de Referencia , Ritmo TetaRESUMEN
A significant gap in the psychopathy literature is the lack of studies comparing "successful," nonconvicted psychopaths with "unsuccessful," convicted psychopaths. This study tested the hypothesis that successful psychopaths show increased autonomic stress reactivity and better neuropsychological function compared with unsuccessful psychopaths. A total of 26 controls, 16 unsuccessful psychopaths, and 13 successful psychopaths were assessed on psychophysiological measures recorded during an emotional manipulation, the Wisconsin Card Sorting Test (WCST), Wechsler Memory Scale--Revised subtests, and childhood stressors. Compared with controls, unsuccessful psychopaths showed reduced cardiovascular stress reactivity. In contrast, successful psychopaths showed heightened reactivity, better WCST performance, and more parental absence than unsuccessful psychopaths and controls. The implications of these findings and the generalizability of existing psychopathy research are discussed.
Asunto(s)
Trastorno de Personalidad Antisocial/psicología , Cognición , Crimen/psicología , Respuesta Galvánica de la Piel , Frecuencia Cardíaca , Estrés Psicológico/fisiopatología , Adulto , Sistema Nervioso Autónomo/fisiopatología , Estudios de Casos y Controles , Humanos , Masculino , Pruebas Neuropsicológicas , Escalas de Valoración PsiquiátricaRESUMEN
Research suggests that those with antisocial tendencies are larger than controls, but studies have not assessed this association in antisocial personality disorder (APD) or its hypothesized sub-types (i.e. adolescence-limited, late-onset). Height, weight, body mass index, bulk, and psychosocial adversity were assessed in 44 controls, nine adolescent-limited antisocials, 21 APDs, and 13 late-onset antisocials from the community. Adult antisocial individuals, regardless of age of onset, were significantly taller and had greater body bulk than controls. Although groups tended to differ on weight, they did not differ on body mass index. In addition, APDs and adolescent-limited individuals reported greater psychosocial adversity than the other groups. Adversity did not account for height or bulk differences. Results suggest prior findings on height and bulk may apply to APD and support differentiating adolescent-limited and life-course persistent subgroups.
Asunto(s)
Trastorno de Personalidad Antisocial/diagnóstico , Estatura , Peso Corporal , Adolescente , Adulto , Antropometría , Trastorno de Personalidad Antisocial/epidemiología , Índice de Masa Corporal , Trastorno de la Conducta/epidemiología , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: Major damage to gray and white matter in the prefrontal cortex and autonomic deficits have been found to result in pseudopsychopathic personality in patients with neurological disorders, but it is not known whether people with antisocial personality disorder (APD) in the community who do not have discernable brain trauma also have subtle prefrontal deficits. METHODS: Prefrontal gray and white matter volumes were assessed using structural magnetic resonance imaging in 21 community volunteers with APD (APD group) and in 2 control groups, comprising 34 healthy subjects (control group), 26 subjects with substance dependence (substance-dependent group), and 21 psychiatric controls. Autonomic activity (skin conductance and heart rate) was also assessed during a social stressor in which participants gave a videotaped speech on their faults. RESULTS: The APD group showed an 11.0% reduction in prefrontal gray matter volume in the absence of ostensible brain lesions and reduced autonomic activity during the stressor. These deficits predicted group membership independent of psychosocial risk factors. CONCLUSIONS: To our knowledge, these findings provide the first evidence for a structural brain deficit in APD. This prefrontal structural deficit may underlie the low arousal, poor fear conditioning, lack of conscience, and decision-making deficits that have been found to characterize antisocial, psychopathic behavior.
Asunto(s)
Trastorno de Personalidad Antisocial/diagnóstico , Enfermedades del Sistema Nervioso Autónomo/diagnóstico , Encéfalo/anatomía & histología , Imagen por Resonancia Magnética , Corteza Prefrontal/anatomía & histología , Adulto , Alcoholismo/diagnóstico , Alcoholismo/epidemiología , Trastorno de Personalidad Antisocial/epidemiología , Enfermedades del Sistema Nervioso Autónomo/epidemiología , Comorbilidad , Respuesta Galvánica de la Piel/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Trastornos Mentales/diagnóstico , Trastornos Mentales/epidemiología , Inventario de Personalidad/estadística & datos numéricos , Factores de Riesgo , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/epidemiologíaRESUMEN
There appear to be no brain imaging studies investigating which brain mechanisms subserve affective, impulsive violence versus planned, predatory violence. It was hypothesized that affectively violent offenders would have lower prefrontal activity, higher subcortical activity, and reduced prefrontal/subcortical ratios relative to controls, while predatory violent offenders would show relatively normal brain functioning. Glucose metabolism was assessed using positron emission tomography in 41 comparisons, 15 predatory murderers, and nine affective murderers in left and right hemisphere prefrontal (medial and lateral) and subcortical (amygdala, midbrain, hippocampus, and thalamus) regions. Affective murderers relative to comparisons had lower left and right prefrontal functioning, higher right hemisphere subcortical functioning, and lower right hemisphere prefrontal/subcortical ratios. In contrast, predatory murderers had prefrontal functioning that was more equivalent to comparisons, while also having excessively high right subcortical activity. Results support the hypothesis that emotional, unplanned impulsive murderers are less able to regulate and control aggressive impulses generated from subcortical structures due to deficient prefrontal regulation. It is hypothesized that excessive subcortical activity predisposes to aggressive behaviour, but that while predatory murderers have sufficiently good prefrontal functioning to regulate these aggressive impulses, the affective murderers lack such prefrontal control over emotion regulation.
Asunto(s)
Afecto/fisiología , Trastornos Disruptivos, del Control de Impulso y de la Conducta/metabolismo , Trastornos Disruptivos, del Control de Impulso y de la Conducta/psicología , Homicidio/psicología , Sistema Límbico/metabolismo , Mesencéfalo/metabolismo , Corteza Prefrontal/metabolismo , Tálamo/metabolismo , Tomografía Computarizada de Emisión , Química Encefálica , Estudios de Casos y Controles , Psicología Criminal , Trastornos Disruptivos, del Control de Impulso y de la Conducta/diagnóstico por imagen , Psiquiatría Forense , Glucosa/metabolismo , Humanos , Competencia Mental , Conducta Predatoria , Método Simple CiegoRESUMEN
Murderers pleading not guilty by reason of insanity (NGRI) are thought to have brain dysfunction, but there have been no previous studies reporting direct measures of both cortical and subcortical brain functioning in this specific group. Positron emission tomography brain imaging using a continuous performance challenge task was conducted on 41 murderers pleading not guilty by reason of insanity and 41 age- and sex-matched controls. Murderers were characterized by reduced glucose metabolism in the prefrontal cortex, superior parietal gyrus, left angular gyrus, and the corpus callosum, while abnormal asymmetries of activity (left hemisphere lower than right) were also found in the amygdala, thalamus, and medial temporal lobe. These preliminary findings provide initial indications of a network of abnormal cortical and subcortical brain processes that may predispose to violence in murderers pleading NGRI.
Asunto(s)
Corteza Cerebral/irrigación sanguínea , Circulación Cerebrovascular/fisiología , Homicidio , Adulto , Química Encefálica , Corteza Cerebral/anatomía & histología , Femenino , Glucosa/metabolismo , Humanos , Masculino , Técnicas Estereotáxicas , Tomografía Computarizada de EmisiónRESUMEN
Positron emission tomography using [18F]deoxyglucose (FDG) as a marker of regional brain metabolism was used to investigate the neural substrate of stuttering. Four patients with severe developmental stuttering were studied while reading aloud to another person (stuttering condition) and while reading aloud in unison with someone else (non-stuttering condition). The patients were also compared with four normal controls reading aloud by themselves. In the stuttering condition, significant decreases in regional glucose metabolism in Broca's area, Wernicke's area and frontal pole were seen compared with themselves while not stuttering. These differences were also seen in stuttering condition compared with normal controls. Significantly lower left caudate metabolism was seen in patients during both stuttering and non-stuttering conditions compared with normal controls. A circuit for stuttering is proposed based on these findings.