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The emotion processing and regulation mechanisms by which dispositional (personality trait) mindfulness exerts its positive effects on mental health remain unclear. Here, we tested, using structural equation modeling, whether the relationship between higher dispositional mindfulness and better mental health is mediated by reduced maladaptive processing of emotional information (e.g., expressive suppression, impoverished emotional experiences, unprocessed emotions, avoidance, externalizing strategies) and associated lower negative affect, enhanced adaptive processing of emotional information (e.g., cognitive reappraisal) and associated higher positive affect, or a combination of these two emotion processing styles. Dispositional mindfulness, mental health, diverse emotional constructs with adaptive and maladaptive dimensions (including range and differentiation of emotional experiences, use of specific emotion regulation strategies, emotion processing deficits, negative affect repair strategies, negative mood regulation expectancies), and positive and negative affect were assessed using self-report measures in a non-clinical sample of 256 adults. The relationship between higher dispositional mindfulness and better mental health was found to be best explained by reduced maladaptive emotion processing styles and associated lower negative affect, rather than by enhanced adaptive emotion processing and higher positive affect. Further research should investigate whether the same mechanisms explain psychological benefits of cultivated mindfulness in people with low dispositional mindfulness and/or with mental health disorders following mindfulness skills training.
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No contemporary unifying framework has been provided for the study of non-ordinary states of consciousness (NSCs) despite increased interest in hypnosis, meditation, and psychedelics. NSCs induce shifts in experiential contents (what appears to the experiencer) and/or structure (how it appears). This can allow the investigation of the plastic and dynamic nature of experience from a multiscale perspective that includes mind, brain, body, and context. We propose a neurophenomenological (NP) approach to the study of NSCs which highlights their role as catalysts of transformation in clinical practice by refining our understanding of the relationships between experiential (subjective) and neural dynamics. We outline the ethical implications of the NP approach for standard conceptions of health and pathology as well as the crucial role of experience-based know-how in NSC-related research and application.
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Alucinógenos , Hipnosis , Meditación , Humanos , Estado de Conciencia , Alucinógenos/farmacología , EncéfaloRESUMEN
The novel coronavirus disease COVID-19 that first emerged in Wuhan, China, in Nov-Dec 2019 has already impacted a significant proportion of the world population. Governments of many countries imposed quarantines and social distancing measures in 2020, many of which remain in place, to mitigate the spread of the SARS-Cov-2 virus causing the COVID-19 disease. The direct impact of COVID-19 on people infected with the virus, their families and the health care workers, as well as the impact of the mitigation measures such as quarantine, social distancing, and self-isolation on the rest of the population have contributed to a global mental health pandemic, including anxiety, depression, panic attacks, posttraumatic stress symptoms, psychosis, addiction, obsessive-compulsive disorder, and suicidality. These effects are present acutely (for example, due to fear of contamination or losing loved ones, effects of quarantine/isolation, withdrawal of community and social services, etc.) and may continue long after the pandemic is over (for example, due to bereavement, unemployment, financial losses, etc). The COVID-19 pandemic has triggered mental health problems in people without previous history of mental illness, as well as worsened the symptoms in those with pre-existing psychiatric diagnosis. Therefore, the global effort is called for to deal with this mental health pandemic secondary to COVID-19 itself to address the emergence of new as well as the exacerbation of the existing mental health issues. Conversely, this global context provides an extraordinary opportunity for studying individual differences in response to and resilience in the face of physical and psychological threat, challenge to "normal" way of life, and long-term uncertainty. In this viewpoint article we outline the particular suitability of mindfulness, its skills and mechanisms, as an approach to the prevention and management of mental health issues, as well as to the promotion of well-being and building the foundations of adaptability and flexibility in dealing with the long-term uncertainty and profound changes to the social, economic, and possibly political systems as this pandemic continues to unfold.
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Positive schizotypy has been shown to predict emergence of schizophrenia-spectrum disorders, with suspiciousness/paranoia regarded a key risk factor. However, magical thinking and unusual perceptual experiences, other aspects of positive schizotypy, are associated with creativity. We investigated whether suspiciousness attenuates the relationship of magical thinking and unusual experiences with creative experience, and explored the interaction of dispositional mindfulness with positive schizotypy and creative experience. 342 (256 females) healthy adults (mean age: 25.9; SD 8.4) completed online self-report measures of schizotypy, creative experience, and dispositional mindfulness. Moderation analysis showed that suspiciousness attenuated the positive relationship of magical thinking (b = -0.29, p = .03) and unusual perceptual experiences (b = -0.23, p = .01) with an aspect of creative experience related to positive affect - power/pleasure. This effect was not present for 4 other aspects of creative experience. Multiple linear regressions revealed higher dispositional mindfulness to interact with aspects of positive schizotypy associated with heightened creative experience of power/pleasure (b = 0.06, p = .03), clarity/preparation (b = 0.03, p = .004), and differing levels of anxiety associated with creative engagement (b = -0.06, p = .003; b = 0.03, p = .047). Higher dispositional mindfulness was also associated with lower suspiciousness (rs = -0.33, p < .001). The study highlights the importance of considering the role of suspiciousness/paranoia when investigating the relationship between positive schizotypy and creativity. The findings provide support for the application of mindfulness-based interventions for mitigating psychosis-risk associated with suspiciousness, whilst supporting the otherwise favourable association of positive schizotypy with creativity.
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Atención Plena , Trastorno de la Personalidad Esquizotípica , Adulto , Creatividad , Femenino , Humanos , Personalidad , PensamientoRESUMEN
To get additional insight into the phenotype of attentional problems, we examined to what extent genetic and environmental factors explain covariation between lack of dispositional mindfulness and attention-deficit/hyperactivity disorder (ADHD) traits in youth, and explored the incremental validity of these constructs in predicting life satisfaction. We used data from a UK population-representative sample of adolescent twins (N = 1092 pairs) on lack of dispositional mindfulness [Mindful Attention Awareness Scale (MAAS)], ADHD traits [Conners' Parent Rating Scale-Revised (CPRS-R): inattentive (INATT) and hyperactivity/impulsivity (HYP/IMP) symptom dimensions] and life satisfaction (Students' Life Satisfaction Scale). Twin model fitting analyses were conducted. Phenotypic correlations (rp) between MAAS and CPRS-R (INATT: rp = 0.18, HYP/IMP: rp = 0.13) were small, but significant and largely explained by shared genes for INATT (% rp INATT-MAAS due to genes: 93%, genetic correlation rA = 0.37) and HYP/IMP (% rp HYP/IMP-MAAS due to genes: 81%; genetic correlation rA = 0.21) with no significant contribution of environmental factors. MAAS, INATT and HYP/IMP significantly and independently predicted life satisfaction. Lack of dispositional mindfulness, assessed as self-reported perceived lapses of attention (MAAS), taps into an aspect of attentional functioning that is phenotypically and genetically distinct from parent-rated ADHD traits. The clinically relevant incremental validity of both scales implicates that MAAS could be used to explore the underlying mechanisms of an aspect of attentional functioning that uniquely affects life satisfaction and is not captured by DSM-based ADHD scales. Further future research could identify if lack of dispositional mindfulness and high ADHD traits can be targeted by different therapeutic approaches resulting in different effects on life satisfaction.
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Trastorno por Déficit de Atención con Hiperactividad/genética , Enfermedades en Gemelos/genética , Atención Plena/métodos , Adolescente , Atención , Exposición a Riesgos Ambientales , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: This study examined the effects of cultivated (i.e. developed through training) and dispositional (trait) mindfulness on smooth pursuit (SPEM) and antisaccade (AS) tasks known to engage the fronto-parietal network implicated in attentional and motion detection processes, and the fronto-striatal network implicated in cognitive control, respectively. METHODS: Sixty healthy men (19-59years), of whom 30 were experienced mindfulness practitioners and 30 meditation-naïve, underwent infrared oculographic assessment of SPEM and AS performance. Trait mindfulness was assessed using the self-report Five Facet Mindfulness Questionnaire (FFMQ). RESULTS: Meditators, relative to meditation-naïve individuals, made significantly fewer catch-up and anticipatory saccades during the SPEM task, and had significantly lower intra-individual variability in gain and spatial error during the AS task. No SPEM or AS measure correlated significantly with FFMQ scores in meditation-naïve individuals. CONCLUSIONS: Cultivated, but not dispositional, mindfulness is associated with improved attention and sensorimotor control as indexed by SPEM and AS tasks.
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Atención/fisiología , Función Ejecutiva/fisiología , Meditación , Atención Plena , Seguimiento Ocular Uniforme/fisiología , Movimientos Sacádicos/fisiología , Percepción Visual/fisiología , Adulto , Medidas del Movimiento Ocular , Humanos , Individualidad , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Despite growing evidence for demonstrated efficacy of mindfulness in various disorders, there is a continuous concern about the relationship between mindfulness practice and psychosis. As schizotypy is part of the psychosis spectrum, we examined the relationship between long-term mindfulness practice and schizotypy in two independent studies. Study 1 included 24 experienced mindfulness practitioners (19 males) from the Buddhist tradition (meditators) and 24 meditation-naïve individuals (all males). Study 2 consisted of 28 meditators and 28 meditation-naïve individuals (all males). All participants completed the Schizotypal Personality Questionnaire (Raine, 1991), a self-report scale containing 9 subscales (ideas of reference, excessive social anxiety, magical thinking, unusual perceptual experiences, odd/eccentric behavior, no close friends, odd speech, constricted affect, suspiciousness). Participants of study 2 also completed the Five-Facet Mindfulness Questionnaire which assesses observing (Observe), describing (Describe), acting with awareness (Awareness), non-judging of (Non-judgment) and non-reactivity to inner experience (Non-reactivity) facets of trait mindfulness. In both studies, meditators scored significantly lower on suspiciousness and higher on magical thinking compared to meditation-naïve individuals and showed a trend towards lower scores on excessive social anxiety. Excessive social anxiety correlated negatively with Awareness and Non-judgment; and suspiciousness with Awareness, Non-judgment and Non-reactivity facets across both groups. The two groups did not differ in their total schizotypy score. We conclude that mindfulness practice is not associated with an overall increase in schizotypal traits. Instead, the pattern suggests that mindfulness meditation, particularly with an emphasis on the Awareness, Non-judgment and Non-reactivity aspects, may help to reduce suspiciousness and excessive social anxiety.
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[This corrects the article DOI: 10.1371/journal.pone.0123512.].
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BACKGROUND: Mindfulness as a mode of sustained and receptive attention promotes openness to each incoming stimulus, even if repetitive and/or aversive. Mindful attention has been shown to attenuate sensory habituation in expert meditators; however, others were not able to replicate this effect. The present study used acoustic startle reflex to investigate the effect of mindfulness practice intensity on sensory habituation. METHODS: Auditory Startle Response (ASR) to 36 startling probes (12 trials x 3 block with 40 ms inter-block intervals), was measured using electromyography (EMG) in three groups of participants (N = 12/group): meditation-naïve, moderate practice, and intensive practice. RESULTS: Intensive practice group showed attenuated startle habituation as evidenced by significantly less habituation over the entire experiment relative to the meditation-naïve and moderate practice groups. Furthermore, there was a significant linear effect showing between-block habituation in meditation-naïve and moderate practice groups, but not in the intensive practice group. However, the Block x Group interaction between the intensive practice and the meditation-naive groups was not significant. Moderate practice group was not significantly different from the meditation-naïve in the overall measure of habituation, but showed significantly stronger habituation than both meditation-naïve and intensive practice groups in Block 1. Greater practice intensity was significantly correlated with slower overall habituation and habituation rate in Blocks 2 and 3 in the intensive, but not in the moderate, practice group. CONCLUSIONS: The study provides tentative evidence that intensive mindfulness practice attenuates acoustic startle habituation as measured by EMG, but the effect is modest.Moderate practice, on the other hand, appears to enhance habituation, suggesting the effect of mindfulness practice on startle habituation might be non-linear [corrected] . Better understanding of the effect of mindful attention on startle habituation may shed new light on sensory information processing capacity of the human brain and its potential for de-automatisation of hard-wired processes.
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Habituación Psicofisiológica , Meditación , Atención Plena , Práctica Psicológica , Adulto , Atención , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reflejo de SobresaltoRESUMEN
BACKGROUND: Mindfulness-based therapies have been shown to be effective in treating depression and reducing cognitive biases. Anxiety sensitivity is one cognitive bias that may play a role in the association between mindfulness and depressive symptoms. It refers to an enhanced sensitivity toward symptoms of anxiety, with a belief that these are harmful. Currently, little is known about the mechanisms underpinning the association between mindfulness, depression, and anxiety sensitivity. The aim of this study was to examine the role of genetic and environmental factors in trait mindfulness, and its genetic and environmental overlap with depressive symptoms and anxiety sensitivity. METHODS: Over 2,100 16-year-old twins from a population-based study rated their mindfulness, depressive symptoms, and anxiety sensitivity. RESULTS: Twin modeling analyses revealed that mindfulness is 32% heritable and 66% due to nonshared environmental factors, with no significant influence of shared environment. Genetic influences explained over half of the moderate phenotypic associations between low mindfulness, depressive symptoms, and anxiety sensitivity. About two-thirds of genetic influences and almost all nonshared environmental influences on mindfulness were independent of depression and anxiety sensitivity. CONCLUSIONS: This is the first study to show that both genes and environment play an important role in the etiology of mindfulness in adolescence. Future research should identify the specific environmental factors that influence trait mindfulness during development to inform targeted treatment and resilience interventions. Shared genetic liability underpinning the co-occurrence of low mindfulness, depression, and anxiety sensitivity suggests that the biological pathways shared between these traits should also be examined.
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Ansiedad , Depresión , Enfermedades en Gemelos , Ambiente , Interacción Gen-Ambiente , Atención Plena , Adolescente , Ansiedad/epidemiología , Ansiedad/etiología , Ansiedad/genética , Depresión/epidemiología , Depresión/etiología , Depresión/genética , Enfermedades en Gemelos/etiología , Inglaterra/epidemiología , Femenino , Humanos , Masculino , Atención Plena/estadística & datos numéricos , Gales/epidemiologíaRESUMEN
We examined whether monaural prepulses produce more prepulse inhibition (PPI) because they might be more attention capturing (unambiguous to locate) than binaural prepulses. Monaural and binaural PPI was tested under normal and verbal and visuospatial attention manipulation conditions in 55 healthy men, including 29 meditators. Attention manipulations abolished monaural PPI superiority, similarly in meditators and meditation-naïve individuals, and this was most strongly evident for right ear PPI under visuospatial attention manipulation. Meditators performed better than meditation-naïve individuals on attention tasks (verbal: more targets detected; visuospatial: faster reaction time). Spatial attention processes contribute to monaural PPI, particularly with the right ear. Better attentional performance, with similar attentional modulation of PPI, may indicate a stronger attentional capacity in meditators, relative to meditation-naïve individuals.
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Atención/fisiología , Percepción Auditiva/fisiología , Meditación , Inhibición Prepulso/fisiología , Desempeño Psicomotor/fisiología , Percepción Espacial/fisiología , Estimulación Acústica/métodos , Adulto , Humanos , Masculino , Persona de Mediana EdadRESUMEN
In the present state of healthcare, usual medical care is generally given to the already diseased person, while the key link-personal health monitoring underlain by predictive, preventive, and personalised medicine (PPPM) techniques that are being intensively elaborated worldwide-is simply missing. It is this link, based on the recognition of subclinical conditions, prediction, and further preventive measures, that is capable of regulating morbidity and diminishing the rates of disability among able-bodied population, thus significantly cutting the traditionally high costs of treating the already diseased people. To achieve the above-mentioned goal-the elaboration of the PPPM concept and its practical implementation-it is necessary to create a fundamentally new strategy based upon the subclinical recognition of the signs-bioindicators of cryptic abnormalities long before the disease clinically manifests itself. The implementation of PPPM programme requires an adjusted technology for the proper interpretation of diagnostic data, which would allow for the current 'physician-patient' model to be gradually replaced by a novel model, 'medical advisor-healthy men-at-risk'. This is the reason for an additional need in organising combinatorial scientific, clinical, training and educational projects in the area of PPPM to elicit the content of this new branch of medicine.
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BACKGROUND: Prepulse inhibition (PPI) of the startle response refers to the ability of a weak prestimulus to transiently inhibit the response to a closely following strong sensory stimulus. PPI provides an operational index of sensorimotor gating and is reduced, on average, in people with schizophrenia, relative to healthy people. Given the variable response to Cognitive Behaviour Therapy for psychosis (CBTp) and positive associations between pre-therapy brain and cognitive functions and CBT outcome across disorders, we examined whether pre-therapy level of PPI is associated with clinical outcome following CBTp. METHOD: Fifty-six outpatients stable on medication with at least one distressing symptom of schizophrenia and willing to receive CBTp in addition to their usual treatment were assessed on acoustic PPI. Subsequently, 28 patients received CBTp (CBTp+treatment-as-usual, 23 completers) for 6-8months and 28 continued with their treatment-as-usual (TAU-alone, 17 completers). Symptoms were assessed (blindly) at entry and follow-up. RESULTS: The CBTp+TAU and TAU-alone groups did not differ demographically, clinically or in PPI at baseline. The CBTp+TAU group showed improved symptoms relative to the TAU-alone group, which showed no change, at follow-up. Pre-therapy PPI level correlated positively with post-CBTp symptom improvement. CONCLUSIONS: Relatively intact sensorimotor gating is associated with a good clinical response following a 6-8months course of NICE compliant CBTp in schizophrenia. Pharmacological or psychological interventions capable of improving PPI may enhance the effectiveness of CBTp in people with schizophrenia, particularly in those who fail to show clinical improvement with currently available antipsychotic drugs and adjunctive CBTp.
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Terapia Cognitivo-Conductual/métodos , Trastornos Psicóticos/rehabilitación , Filtrado Sensorial/fisiología , Estimulación Acústica , Adulto , Análisis de Varianza , Antipsicóticos/uso terapéutico , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Trastornos Psicóticos/tratamiento farmacológico , Filtrado Sensorial/efectos de los fármacos , Resultado del TratamientoRESUMEN
Previous small-sample studies have shown altered frontotemporal activity in schizophrenia patients with auditory hallucinations and impaired monitoring of self-generated speech. We examined a large cohort of patients with schizophrenia (n = 63) and a representative group of healthy controls (n = 20) to disentangle performance, illness, and symptom-related effects in functional magnetic resonance imaging-detected brain abnormalities during monitoring of self- and externally generated speech in schizophrenia. Our results revealed activation of the thalamus (medial geniculate nucleus, MGN) and frontotemporal regions with accurate monitoring across all participants. Less activation of the thalamus (MGN, pulvinar) and superior-middle temporal and inferior frontal gyri occurred in poorly performing patients (1 standard deviation below controls' mean; n = 36), relative to the combined group of controls and well-performing patients. In patients, (1) greater deactivation of the ventral striatum and hypothalamus to own voice, combined with nonsignificant activation of the same regions to others' voice, associated positively with negative symptoms (blunted affect, emotional withdrawal, poor rapport, passive social avoidance) regardless of performance and (2) exaggerated activation of the right superior-middle temporal gyrus during undistorted, relative to distorted, feedback associated with both positive symptoms (hallucinations, persecution) and poor performance. A further thalamic abnormality characterized schizophrenia patients regardless of performance and symptoms. We conclude that hypoactivation of a neural network comprised of the thalamus and frontotemporal regions underlies impaired speech monitoring in schizophrenia. Positive symptoms and poor monitoring share a common activation abnormality in the right superior temporal gyrus during processing of degraded speech. Altered striatal and hypothalamic modulation to own and others' voice characterizes emotionally withdrawn and socially avoidant patients.
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Atención/fisiología , Concienciación/fisiología , Encéfalo/fisiopatología , Alucinaciones/fisiopatología , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Consumo de Oxígeno/fisiología , Esquizofrenia/fisiopatología , Lenguaje del Esquizofrénico , Psicología del Esquizofrénico , Percepción del Habla/fisiología , Conducta Verbal/fisiología , Adulto , Mapeo Encefálico , Estudios de Cohortes , Cuerpo Estriado/fisiopatología , Femenino , Lóbulo Frontal/fisiopatología , Cuerpos Geniculados/fisiopatología , Alucinaciones/psicología , Humanos , Hipotálamo/fisiopatología , Masculino , Persona de Mediana Edad , Red Nerviosa/fisiopatología , Distorsión de la Percepción/fisiología , Pulvinar/fisiopatología , Acústica del Lenguaje , Lóbulo Temporal/fisiopatología , Adulto JovenRESUMEN
Prepulse inhibition (PPI) of the startle response, a cross-species measure of sensorimotor gating, provides a valuable tool to study the known inability of a large proportion of individuals with schizophrenia to effectively screen out irrelevant sensory input. The cortico-striato-pallido-thalamic circuitry is thought to be responsible for modulation of PPI in experimental animals. The involvement of this circuitry in human PPI is supported by observations of deficient PPI in a number of neuropsychiatric disorders that are characterised by abnormalities at some level in this circuitry, and findings of recent functional neuroimaging studies in healthy participants. The current study sought to investigate the structural neural correlates of PPI in a sample of 42 stable male outpatients with schizophrenia. Participants underwent magnetic resonance imaging (MRI) at 1.5T and were assessed (off-line) on acoustic PPI using electromyographic recordings of the orbicularis oculi muscle beneath the right eye. Optimised volumetric voxel-based morphometry implemented in SPM2 was used to investigate the relationship of PPI (prepulse onset-to-pulse onset interval 120msec) to regional grey matter (GM) volumes. Significant positive correlations were obtained between PPI and GM volume in the dorsolateral prefrontal, middle frontal and the orbital/medial prefrontal cortices. Our findings are consistent with (a) previous suggestions of susceptibility of PPI to cognitive processes controlled in a 'top down' manner by the cortex and (b) the hypothesis that compromised neural resources in the frontal cortex contribute to reduced PPI in schizophrenia.
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Corteza Cerebral/fisiopatología , Habituación Psicofisiológica/fisiología , Reflejo de Sobresalto/fisiología , Esquizofrenia/fisiopatología , Estimulación Acústica/métodos , Adulto , Parpadeo/fisiología , Corteza Cerebral/patología , Dominancia Cerebral/fisiología , Electromiografía/métodos , Músculos Faciales/fisiología , Lóbulo Frontal/patología , Lóbulo Frontal/fisiopatología , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Corteza Prefrontal/patología , Corteza Prefrontal/fisiopatología , Tiempo de Reacción/fisiología , Estadística como AsuntoRESUMEN
A key feature of schizophrenia is the inability to screen out irrelevant sensory input. Prepulse inhibition (PPI) of the startle response, a cross-species measure of sensorimotor gating, provides a valuable opportunity to study this feature. PPI is reliably impaired in schizophrenia. Animal models of disrupted PPI have proved valuable for the evaluation of antipsychotic substances. The cortico-striato-pallido-thalamic circuitry is primarily responsible for modulation of PPI in animals. We examined PPI and its brain correlates, using functional magnetic resonance imaging (fMRI), in men with schizophrenia treated with typical or atypical antipsychotics. Thirty men with schizophrenia on stable doses of typical antipsychotics (n=10), risperidone (n=10) or olanzapine (n=10; 9 with usable fMRI data) and 12 healthy men underwent psychophysiological testing and fMRI during a tactile PPI paradigm. The results showed reduced PPI of the eye-blink startle response in patients compared with healthy controls. Within the patient group, those on typical antipsychotics showed significantly impaired PPI but risperidone- or olanzapine-treated patients showed a milder (non-significant) deficit. Increased activity in the striatum, thalamus, insula, hippocampal, temporal, inferior frontal and inferior parietal regions occurred in association with PPI in controls. Patients treated with risperidone or olanzapine, but not with typical antipsychotics, showed significant activation in PPI-relevant regions. Our findings provide preliminary evidence that atypical antipsychotics positively influence PPI and partially restore associated brain functions in schizophrenia. Imaging data buttress the validity of PPI as a useful animal model of schizophrenia.
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Antipsicóticos/uso terapéutico , Atención/efectos de los fármacos , Mapeo Encefálico/métodos , Encéfalo/efectos de los fármacos , Imagen por Resonancia Magnética , Reflejo de Sobresalto/efectos de los fármacos , Esquizofrenia/tratamiento farmacológico , Estimulación Acústica , Adulto , Antipsicóticos/farmacología , Benzodiazepinas/uso terapéutico , Parpadeo/efectos de los fármacos , Encéfalo/fisiopatología , Habituación Psicofisiológica/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Olanzapina , Tiempo de Reacción/efectos de los fármacos , Risperidona/uso terapéutico , Esquizofrenia/fisiopatología , Tacto , Resultado del TratamientoRESUMEN
Neural regions modulating prepulse inhibition (PPI) of the startle response, an operational measure of sensorimotor gating, are well established from animal studies using surgical and pharmacological procedures. The limbic and cortico-pallido-striato-thalamic circuitry is thought to be responsible for modulation of PPI in the rat. The involvement of this circuitry in human PPI is suggested by observations of deficient PPI in a number of neuropsychiatric disorders characterized by abnormalities at some level in this circuitry and recent functional neuroimaging studies in humans. The current study sought to investigate structural neural correlates of PPI in a sample of twenty-four right-handed, healthy subjects (10 men, 14 women). Subjects underwent magnetic resonance imaging (MRI) at 1.5 T and were assessed (off-line) on acoustic PPI using electromyographic recordings of the orbicularis oculi muscle beneath the right eye. Optimized volumetric voxel-based morphometry (VBM) implemented in SPM99 was used to investigate the relationship of PPI (prepulse onset-to-pulse onset interval 120 ms) to regional grey matter volumes, covarying for sex. Significant positive correlations were obtained between PPI and grey matter volume in the hippocampus extending to parahippocampal gyrus, basal ganglia including parts of putamen, globus pallidus, and nucleus accumbens, superior temporal gyrus, thalamus, and inferior frontal gyrus. These findings identify the relationship between PPI and grey matter availability on a highly spatially localized scale in brain regions shown to be activated in recent functional neuroimaging studies in association with PPI in healthy humans and demonstrate the validity of structural neuroimaging methods in delineating the neural mechanisms underlying human PPI.