RESUMEN
In the wild, animals face a highly variable world full of predators. Most predator attacks are unsuccessful, and the prey survives. According to the conventional perspective, the fear responses elicited by predators are acute and transient in nature. However, the long-term, non-lethal effects of predator exposure on prey behavioral stress sequelae, such as anxiety and post-traumatic symptoms, remain poorly understood. Most experiments on animal models of anxiety-related behavior or post-traumatic stress disorder have been carried out using commercial strains of rats and mice. A fundamental question is whether laboratory rodents appropriately express the behavioral responses of wild species in their natural environment; in other words, whether behavioral responses to stress observed in the laboratory can be generalized to natural behavior. To further elucidate the relative contributions of the natural selection pressures influences, this study investigated the bio-behavioral and morphological effects of auditory predator cues (owl territorial calls) in males and females of three wild rodent species in a laboratory set-up: Acomys cahirinus; Gerbillus henleyi; and Gerbillus gerbillus. Our results indicate that owl territorial calls elicited not only "fight or flight" behavioral responses but caused PTSD-like behavioral responses in wild rodents that have never encountered owls in nature and could cause, in some individuals, enduring physiological and morphological responses that parallel those seen in laboratory rodents or traumatized people. In all rodent species, the PTSD phenotype was characterized by a blunting of fecal cortisol metabolite response early after exposure and by a lower hypothalamic orexin-A level and lower total dendritic length and number in the dentate gyrus granule cells eight days after predator exposure. Phenotypically, this refers to a significant functional impairment that could affect reproduction and survival and thus fitness and population dynamics.
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Trastornos por Estrés Postraumático , Humanos , Masculino , Femenino , Ratas , Animales , Trastornos por Estrés Postraumático/metabolismo , Roedores , Ansiedad/etiología , Señales (Psicología) , Neuronas/metabolismo , Modelos Animales de EnfermedadRESUMEN
Sleep figures in numerous ancient texts, for example, Epic of Gilgamesh, and has been a focus for countless mystical and philosophical texts. Even in the present century, sleep remains one of the most complex behaviors whose function still remains to be further explored. Current hypotheses suggest that among other functions, sleep contributes to memory processes. Memory is a core topic of study in post-traumatic stress disorder (PTSD) and other stress-related phenomena. It is widely accepted that sleep plays a major role in the consolidation of newly encoded hippocampus-dependent memories to pre-existing knowledge networks. Conversely, sleep deprivation disrupts consolidation and impairs memory retrieval. Along this line, sleep deprivation following a potentially traumatic event may interfere with the consolidation of event-related memories and, thereby, may reduce long-term post-traumatic stress-related symptoms. This review consolidates clinical and animal studies on the relationships between sleep, sleep deprivation, memory processes, and trauma exposure while introducing new contemporary insights into an ancient African tribal ritual (Àìsùn Oku) and Japanese ceremony ritual (Tsuya). We propose that these findings, focusing specifically on the effects of sleep deprivation in the immediate aftermath of traumatic events, may be explored as a possible therapeutic measure. Along with a summary of the field questions on whether sleep is performed "to remember" or "to forget" we lay the rationale for using sleep deprivation as a clinical tool. A tool that may partially prevent the long-term persistence of these traumatic events' memory and thereby, at least partly, attenuating the development of PTSD.
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Trastornos por Estrés Postraumático , Humanos , Animales , Trastornos por Estrés Postraumático/prevención & control , Privación de Sueño , Conducta Ceremonial , Pueblos del Este de Asia , SueñoRESUMEN
The present study investigates whether predator scent-stress (PSS) shifts the microglia from a quiescent to a chronically activated state and whether morphological alterations in microglial activation differ between individuals displaying resilient vs. vulnerable phenotypes. In addition, we examined the role that GC receptors play during PSS exposure in the impairment of microglial activation and thus in behavioral response. Adult male Sprague Dawley rats were exposed to PSS or sham-PSS for 15 min. Behaviors were assessed with the elevated plus-maze (EPM) and acoustic startle response (ASR) paradigms 7 days later. Localized brain expression of Iba-1 was assessed, visualized, and classified based on their morphology and stereological counted. Hydrocortisone and RU486 were administered systemically 10 min post PSS exposure and behavioral responses were measured on day 7 and hippocampal expression of Ionized calcium-binding adaptor molecule 1 (Iba-1) was subsequently evaluated. Animals whose behavior was extremely disrupted (PTSD-phenotype) selectively displayed excessive expression of Iba-1 with concomitant downregulation in the expression of CX3C chemokine receptor 1 (CX3CR1) in hippocampal structures as compared with rats whose behavior was minimally or partially disrupted. Changes in microglial morphology have also been related only to the PTSD-phenotype group. These data indicate that PSS-induced microglia activation in the hippocampus serves as a critical mechanistic link between the HPA-axis and PSS-induced impairment in behavioral responses.
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Reflejo de Sobresalto , Trastornos por Estrés Postraumático , Animales , Conducta Animal , Modelos Animales de Enfermedad , Masculino , Aprendizaje por Laberinto , Microglía/metabolismo , Ratas , Ratas Sprague-Dawley , Reflejo de Sobresalto/fisiología , Trastornos por Estrés Postraumático/metabolismo , Estrés Psicológico/metabolismoRESUMEN
MDMA (3,4-methylenedioxymethamphetamine), a synthetic ring-substituted amphetamine, combined with psychotherapy has demonstrated efficacy for the treatment of chronic posttraumatic stress disorder (PTSD) patients. This controlled prospective study aimed to assess the bio-behavioral underpinnings of MDMA in a translational model of PTSD. Rats exposed to predator-scent stress (PSS) were subjected to a trauma-cue at day 7 shortly after single-dose MDMA injection (5 mg/kg). The elevated plus maze and acoustic startle response tests were assessed on day 14 and served for classification into behavioral response groups. Freezing response to a further trauma-reminder was assessed on Day 15. The morphological characteristics of the dentate gyrus (DG) and basolateral amygdala (BLA) were subsequently examined. Hypothalamic-pituitary-adrenal axis and 5-hydroxytryptamine involvement were evaluated using: (1) corticosterone measurements at 2 h and 4 h after MDMA treatment, (2) Lewis strain rats with blunted HPA-response and (3) pharmacological receptor-blockade. MDMA treatment was effective in attenuating stress behavioral responses only when paired with memory reactivation by a trauma-cue. The effects of the treatment on behavior were associated with a commensurate normalization of the dendritic cytoarchitecture of DG and BLA neurons. Pretreatment with RU486, Ketanserin, or Pindolol prevented the above improvement in anxiety-like behavioral responses. MDMA treatment paired with memory reactivation reduced the prevalence rate of PTSD-phenotype 14 days later and normalized the cytoarchitecture changes induced by PSS (in dendritic complexities) compared to saline control. MDMA treatment paired with a trauma-cue may modify or update the original traumatic memory trace through reconsolidation processes. These anxiolytic-like effects seem to involve the HPA axis and 5-HT systems.
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Ansiolíticos , N-Metil-3,4-metilenodioxianfetamina , Trastornos por Estrés Postraumático , Animales , Ansiolíticos/uso terapéutico , Señales (Psicología) , Modelos Animales de Enfermedad , Sistema Hipotálamo-Hipofisario , N-Metil-3,4-metilenodioxianfetamina/uso terapéutico , Sistema Hipófiso-Suprarrenal , Estudios Prospectivos , Ratas , Ratas Endogámicas Lew , Reflejo de Sobresalto , Trastornos por Estrés Postraumático/tratamiento farmacológico , Trastornos por Estrés Postraumático/prevención & controlRESUMEN
Exposure to high ambient temperature is a stressor that influences both biological and behavioral functions and has been previously shown to have an extensive impact on brain structure and function. Physiological, cellular and behavioral responses to heat-stress (HS) (40-41 °C, 2 h) were evaluated in adult male Sprague-Dawley rats. The effect of HS exposure before predator-scent stress (PSS) exposure (i.e., HS preconditioning) was examined. Finally, a possible mechanism of HS-preconditioning to PSS was investigated. Immunohistochemical analyses of chosen cellular markers were performed in the hippocampus and in the hypothalamic paraventricular nucleus (PVN). Plasma corticosterone levels were evaluated, and the behavioral assessment included the elevated plus-maze (EPM) and the acoustic startle response (ASR) paradigms. Endogenous levels of heat shock protein (HSP)-70 were manipulated using an amino acid (L-glutamine) and a pharmacological agent (Doxazosin). A single exposure to an acute HS resulted in decreased body mass (BM), increased body temperature and increased corticosterone levels. Additionally, extensive cellular, but not behavioral changes were noted. HS-preconditioning provided behavioral resiliency to anxiety-like behavior associated with PSS, possibly through the induction of HSP-70. Targeting of HSP-70 is an attractive strategy for stress-related psychopathology treatment.
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Corticosterona , Reflejo de Sobresalto , Animales , Proteínas HSP70 de Choque Térmico , Masculino , Ratas , Ratas Sprague-Dawley , Reflejo de Sobresalto/fisiología , Estrés Psicológico/metabolismoRESUMEN
Background and Objectives: Mild cognitive impairment (MCI) is often a precursor of dementia, and in particular of Alzheimer's Disease (AD) which is the most common cause of dementia. Individuals with amnestic MCI are several-fold more likely to develop AD than the general population. Therefore, MCI comprises a well-detectable, early stage time-point for therapeutic intervention and strategic prevention. Based on common electroencephalographical (EEG) pattern changes seen in individuals with MCI, we postulated that EEG-based neurofeedback could help improve the memory performance of patients with MCI. Memory performance is of particular importance in these patients, since memory decline is the most prominent symptom in most patients with MCI, and is the most predictive symptom for cognitive deterioration and the development of AD. Methods: In order to improve the memory performance of patients with MCI we used a system of EEG-based neurofeedback in an attempt to reverse alterations of the EEG that are known to be common in patients with MCI. Our protocol comprised the provision of positive feedback in order to enhance the activity level of the upper alpha band. Participants were divided to two groups receiving either neurofeedback training to enhance the upper alpha frequency (Experimental group) or random feedbacks (Sham group) Results: We witnessed a significant improvement in memory performance in subjects in the experimental group compared to those in the sham group. This improvement was maintained for at least 1 month. Conclusions: Neurofeedback may be a promising and affordable novel approach for treating the decline in memory witnessed in patients with MCI.
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Previously, we found that basal corticosterone pulsatility significantly impacts the vulnerability for developing post-traumatic stress disorder (PTSD). Rats that exhibited PTSD-phenotype were characterized by blunted basal corticosterone pulsatility amplitude and a blunted corticosterone response to a stressor. This study sought to identify the mechanisms underlining both the loss of pulsatility and differences in downstream responses. Serial blood samples were collected manually via jugular vein cannula at 10-min intervals to evaluate suppression of corticosterone following methylprednisolone administration. The rats were exposed to predator scent stress (PSS) after 24 h, and behavioral responses were assessed 7 days post-exposure for retrospective classification into behavioral response groups. Brains were harvested for measurements of the glucocorticoid receptor, mineralocorticoid receptor, FK506-binding protein-51 and arginine vasopressin in specific brain regions to assess changes in hypothalamus-pituitary-adrenal axis (HPA) regulating factors. Methylprednisolone produced greater suppression of corticosterone in the PTSD-phenotype group. During the suppression, the PTSD-phenotype rats showed a significantly more pronounced pulsatile activity. In addition, the PTSD-phenotype group showed distinct changes in the ventral and dorsal CA1, dentate gyrus as well as in the paraventricular nucleus and supra-optic nucleus. These results demonstrate a pre-trauma vulnerability state that is characterized by an over-reactivity of the HPA and changes in its regulating factors.
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Encéfalo/metabolismo , Corticosterona/sangre , Distrés Psicológico , Trastornos por Estrés Postraumático/genética , Animales , Arginina Vasopresina/sangre , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Modelos Animales de Enfermedad , Humanos , Metilprednisolona/farmacología , Sistema Hipófiso-Suprarrenal/metabolismo , Ratas , Receptores de Glucocorticoides/sangre , Receptores de Mineralocorticoides/sangre , Trastornos por Estrés Postraumático/sangre , Trastornos por Estrés Postraumático/patología , Trastornos por Estrés Postraumático/psicología , Proteínas de Unión a Tacrolimus/sangreRESUMEN
Endocannabinoids play a role in adaptation to stress and regulate the release of glucocorticoids in stressed and unstressed conditions. We recently found that basal corticosterone pulsatility may significantly impact the vulnerability for developing post-traumatic-stress-disorder (PTSD), suggesting that the endocannabinoid system may contribute to its development. To examine this, we exposed rats to predator scent stress (PSS). Behavioral reactions were recorded seven days post-PSS. Cerebrospinal fluid (CSF) was collected from anesthetized rats shortly after PSS exposure to determine the levels of 2-arachidonoyl glycerol (2-AG) and anandamide (AEA). To correlate between endocannabinoids and corticosterone levels, rats were placed in metabolic cages for urine collection. To assess the levels of endocannabinoids in specific brain regions, rats' brains were harvested one day after behavioral analysis for staining and fluorescence quantification. Moreover, 2-AG was elevated in the CSF of PTSD-phenotype rats as compared with other groups and was inversely correlated with corticosterone urinary secretion. Eight days post-PSS exposure, hippocampal and hypothalamic 2-AG levels and hippocampal AEA levels were significantly more reduced in the PTSD-phenotype group compared to other groups. We posit that maladaptation to stress, which is propagated by an abnormal activation of endocannabinoids, mediates the subsequent stress-induced behavioral disruption, which, later, reduces neuronal the expression of endocannabinoids, contributing to PTSD symptomology.
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Endocannabinoides/metabolismo , Sistema Hipotálamo-Hipofisario/fisiología , Sistema Hipófiso-Suprarrenal/patología , Trastornos por Estrés Postraumático/patología , Estrés Psicológico/complicaciones , Estrés Psicológico/metabolismo , Animales , Conducta Animal , Corticosterona/orina , Endocannabinoides/líquido cefalorraquídeo , Masculino , Fenotipo , Ratas Sprague-Dawley , Trastornos por Estrés Postraumático/orina , Estrés Psicológico/orinaRESUMEN
Neurofeedback has begun to attract the attention and scrutiny of the scientific and medical mainstream. Here, neurofeedback researchers present a consensus-derived checklist that aims to improve the reporting and experimental design standards in the field.
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Lista de Verificación/métodos , Neurorretroalimentación/métodos , Adulto , Consenso , Femenino , Humanos , Masculino , Persona de Mediana Edad , Revisión de la Investigación por Pares , Proyectos de Investigación/normas , Participación de los InteresadosRESUMEN
Given the interest in improving executive functions, the present study examines a promising combination of two training techniques: neurofeedback training (NFT) and working memory training (WMT). NFT targeted increasing the amplitude of individual's upper Alpha frequency band at the parietal midline scalp location (Pz), and WMT consisted of an established computerized protocol with working memory updating and set-shifting components. Healthy participants (n = 140) were randomly allocated to five combinations of training, including visual search training used as an active control training for the WMT; all five groups were compared to a sixth silent control group receiving no training. All groups were evaluated before and after training for resting-state electroencephalogram (EEG) and behavioral executive function measures. The participants in the silent control group were unaware of this procedure, and received one of the training protocols only after study has ended. Results demonstrated significant improvement in the practice tasks in all training groups including non-specific influence of NFT on resting-state EEG spectral topography. There was only a near transfer effect (improvement in working memory task) for WMT, which remained significant in the delayed post-test (after 1 month), in comparison to silent control group but not in comparison to active control training group. The NFT + WMT combined group showed improved mental rotation ability both in the post-training and in the follow-up evaluations. This improvement, however, did not differ significantly from that in the silent control group. We conclude that the current training protocols, including their combination, have very limited influence on the executive functions that were assessed in this study.
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Función Ejecutiva/fisiología , Voluntarios Sanos/psicología , Aprendizaje/fisiología , Memoria a Corto Plazo/fisiología , Neurorretroalimentación/fisiología , Adulto , Electroencefalografía , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: Negative symptoms of schizophrenia show limited response to both typical and atypical antipsychotics. Repetitive transcranial magnetic stimulation applied over the prefrontal cortex (PFC) has been proposed as an adjuvant to pharmacological treatment of negative symptoms in schizophrenia, but whether the improvements obtained are specific to negative symptoms or attributable to antidepressant effects is still unclear. OBJECTIVE: The aim of the present study is to determine to which extent the improvements in negative symptoms of schizophrenia obtained after high-frequency stimulation of the bilateral PFC using deep TMS (dTMS) are attributable to antidepressant effects. METHODS: Repetitive dTMS was administered to the PFC in a cohort of 16 patients with schizophrenia under successful pharmacological control of positive symptoms and predominant negative symptoms. Patients were treated using high-frequency (18 Hz) bilateral stimulation applied over the lateral PFC bilaterally using Brainsway H-2 coil. The effects of dTMS on negative symptoms were measured using the Scale for the Assessment of Negative Symptoms and the Positive and Negative Syndrome Scales. We then compared the improvements in negative symptoms obtained in patients showing depressive symptoms (≥7 points) with those found in patients without depression (>7 points), as determined by the Calgary Scale for Depression. RESULTS: Repetitive dTMS treatment induced significant improvements in negative symptoms as assessed using both Scale for the Assessment of Negative Symptoms and Positive and Negative Syndrome Scales. Comparison of the improvements obtained in patients with or without depression at the beginning of treatment revealed similar improvements in negative symptoms, irrespective of subjacent depression. CONCLUSIONS: Our data suggest that the beneficial effects of high frequency dTMS of the PFC cannot be attributed solely to its antidepressant effects.
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Depresión/terapia , Esquizofrenia/terapia , Estimulación Magnética Transcraneal , Adulto , Chile , Femenino , Humanos , Masculino , Corteza Prefrontal , Estudios Retrospectivos , Esquizofrenia/tratamiento farmacológicoRESUMEN
OBJECTIVE: Dissociation refers to a disintegration between psychological elements; common manifestations are embodied in "absorption and imaginative involvement," a propensity for being immersed in a stimulus while oblivious to the environment, and acting without awareness. Trait dissociation was hypothesized to relate to lower EEG signal connectivity, but studies on healthy populations are scarce. The present study set out to examine whether dissociative absorption in a nonclinical sample would be associated with decreased intrahemispheric coherence. METHOD: In 84 healthy Israeli soldiers (49% females; Mage = 22.24, SD = 2.64), resting-state electroencephalography (rsEEG) was recorded for a period of 3 min with eyes closed and 3 min with eyes open. RESULTS: Decreased coherence was related to high dissociative absorption in the long (frontal-occipital) range, and in one of the pairs of the short range (central-parietal). The effects emerged mostly in the left hemisphere, in both eyes-open and eyes-closed conditions, and for a range of spectral bands, although long-range effects were more pronounced in slow-wave bands (theta and delta). CONCLUSIONS: Dissociative absorption is manifested in segregated cortical activity, supporting the notion that it may represent less integrated mental functioning. The findings contribute to our understanding of the neural correlates of consciousness and personality.
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Concienciación/fisiología , Corteza Cerebral/fisiología , Electroencefalografía , Personalidad/fisiología , Adulto , Amnesia/fisiopatología , Despersonalización/fisiopatología , Trastornos Disociativos/fisiopatología , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Adulto JovenRESUMEN
Mild cognitive impairment (MCI) is a syndrome characterized by a decrease in cognitive abilities, while daily function is maintained. This condition, which is associated with an increased risk for the development of Alzheimer's disease, has no known definitive treatment at present. In this open-label pilot study we explored the possible benefits of neurofeedback for subjects with MCI. Eleven participants diagnosed with MCI were trained to increase the power of their individual upper alpha band of the electroencephalogram (EEG) signal over the central parietal region. This was achieved using an EEG-based neurofeedback training protocol. Training comprised ten 30-min sessions delivered over 5 weeks. Cognitive and electroencephalographic assessments were conducted before and after training and at 30 days following the last training session. A dose-dependent increase in peak alpha frequency was observed throughout the period of training. Memory performance also improved significantly following training, and this improvement was maintained at 30-day follow-up, while peak alpha frequency returned to baseline at this evaluation. Our findings suggest that neurofeedback may improve memory performance in subjects with mild cognitive impairment, and this benefit may be maintained beyond the training period.
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Ondas Encefálicas , Disfunción Cognitiva/terapia , Memoria/fisiología , Neurorretroalimentación , Anciano , Electroencefalografía , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Proyectos PilotoRESUMEN
OBJECTIVE: Studies have shown that transcranial direct current stimulation (tDCS) has immediate effects on brain activity. The aim of this study was to investigate the potential use of tDCS to regulate obsession-induced anxiety immediately after symptom provocation in patients with refractory obsessive-compulsive disorder (OCD). METHODS: Twelve patients with refractory OCD received cathode, anode, and sham transcranial direct current stimulation over the medial prefrontal cortex conjugant to pharmacological treatment in a crossover design. Before and after the DC stimulation, patients graded the intensity of their anxiety after a short exposure to a provoking stimulus using the visual analogue scale. Clinical questionnaires assessing symptoms severity were also applied before each stimulation mode. RESULTS: We found a statistically significant decrease in the severity of the obsession-induced anxiety (decreased visual analogue scale) as a result of cathode tDCS in comparison with the anode and sham stimulation. Reduction in obsession-induced anxiety was consistent, yet short lasting, and was independent of symptom severity. CONCLUSIONS: Cathode tDCS could be potentially used to regulate obsession-induced anxiety in refractory OCD patients. Further studies are warranted to confirm our results as well as to determine whether tDCS can achieve prolonged benefits in OCD and be of aid in behavioral treatments based on exposure.
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Ansiedad/terapia , Trastorno Obsesivo Compulsivo/terapia , Estimulación Transcraneal de Corriente Directa/métodos , Adulto , Ansiedad/etiología , Ansiedad/psicología , Estudios Cruzados , Resistencia a Medicamentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastorno Obsesivo Compulsivo/complicaciones , Trastorno Obsesivo Compulsivo/psicología , Proyectos Piloto , Escalas de Valoración Psiquiátrica , Resultado del Tratamiento , Adulto JovenRESUMEN
Resting-state electroencephalogram (rsEEG) has been found to be associated with psychopathology, intelligence, problem solving, academic performance and is sometimes used as a supportive physiological indicator of enhancement in cognitive training interventions (e.g. neurofeedback, working memory training). In the current study, we measured rsEEG spectral power measures (relative power, between-band ratios and asymmetry) in one hundred sixty five young adults who were also tested on a battery of executive function (EF). We specifically focused on upper Alpha, Theta and Beta frequency bands given their putative role in EF. Our indices enabled finding correlations since they had decent-to-excellent internal and retest reliability and very little range restriction relative to a nation-wide representative large sample. Nonetheless, Bayesian statistical inference indicated support for the null hypothesis concerning lack of monotonic correlation between EF and rsEEG spectral power measures. Therefore, we conclude that, contrary to the quite common interpretation, these rsEEG spectral power measures do not indicate individual differences in the measured EF abilities.
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Encéfalo/fisiología , Electroencefalografía , Función Ejecutiva , Adulto , Teorema de Bayes , Función Ejecutiva/fisiología , Femenino , Humanos , Masculino , Descanso , Procesamiento de Señales Asistido por Computador , Adulto JovenRESUMEN
We report reduced repetitive behaviors similar to obsessive compulsive disorder and improved emotional recognition and cognitive abilities in two young patients diagnosed with high-functioning Autism as a result of deep transcranial magnetic stimulation (dTMS). The patients received daily high-frequency (5 Hz) dTMS with HAUT-coil over the medial prefrontal cortex for a period of 5-6 weeks. A computerized cognitive battery, tasks for testing emotional recognition, and clinical questionnaires were used to measure the effects of treatment. TMS might have modulated networks related to metalizing abilities and self-referential processes since both patients reported improved sociability and communication skills.
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Síndrome de Asperger/psicología , Cognición , Trastorno Obsesivo Compulsivo/complicaciones , Estimulación Magnética Transcraneal , Adulto , Síndrome de Asperger/complicaciones , Síndrome de Asperger/terapia , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Corteza Prefrontal/fisiopatologíaRESUMEN
Task control is an executive control mechanism that facilitates goal-directed task selection by suppressing irrelevant automatic "stimulus-driven" behaviors. In the current study, we test the hypothesis that less efficient task control in individuals diagnosed with obsessive-compulsive disorder (OCD) is associated with OCD symptoms, and specifically, with the inability to inhibit unwanted behaviors in OCD. Thirty-five healthy controls, 30 participants with OCD, and 26 participants with generalized anxiety disorder (GAD) completed the object-interference (OI) task to measure task control, the stop-signal task to measure response inhibition, and the arrow-flanker task to evaluate executive abilities not contingent upon task control. OCD patients, but not GAD patients or healthy controls, exhibited impaired performance on the OI task. The deficit in task control, but not in response inhibition, correlated with OCD symptom severity. We suggest that reduced task control may be one of the neurocognitive processes that underlie the inability to inhibit unwanted behaviors in OCD.
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Función Ejecutiva/fisiología , Inhibición Psicológica , Trastorno Obsesivo Compulsivo/psicología , Adolescente , Adulto , Trastornos de Ansiedad/psicología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
BACKGROUND: Patients diagnosed with Alzheimer disease (AD) show severe cognitive deficits. Decline in memory, language, and executive function have repeatedly been reported. Although AD affects 60% to 80% of demented elderly patients, there is currently no cure and limited treatment alternatives. OBJECTIVES: The aim of the study was to evaluate the feasibility of stimulating prefrontal cortex (PFC) with deep transcranial magnetic stimulation (dTMS) to ameliorate cognitive deficits in patients suffering from AD. METHODS: Eleven patients (6 males; mean [SD] age, 76 [7] years) in moderate to severe stages of AD received dTMS over the PFC for 20 sessions. Computerized battery (Mindstreams [MS]) and neuropsychological testing (Addenbrooke Cognitive Examination [ACE]) were used to assess cognitive performance before and after treatment. RESULTS: Compared with baseline, 60% of patients performed better on the MS battery and 77% of patients performed better on the ACE testing at the end of dTMS treatment. None of the patients performed worse on both tests at the end of treatment. The DTMS effects on the group mean in ACE and MS approached significance (P = 0.065 and P = 0.086, respectively). A dTMS-induced improvement in the ACE was significant (P = 0.001) on patients in more progressed stage (n = 6). Change in ACE negatively correlated with score at baseline. CONCLUSIONS: In sum, the current report of this novel technique indicates that deep stimulation might lead to preservation and even improvement of cognitive functions, at least during the time of treatment. Further examinations should report of long-term effects of this technique.
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Enfermedad de Alzheimer/psicología , Enfermedad de Alzheimer/terapia , Estimulación Magnética Transcraneal/métodos , Anciano , Anciano de 80 o más Años , Cognición , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/psicología , Trastornos del Conocimiento/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Corteza Prefrontal , Resultado del TratamientoRESUMEN
BACKGROUND: Optimizing performance of aviators while minimizing risks arising from the exposure to extreme environment, both external and internal, is one of the principles guiding the Israeli Air Force. Young cadets in particular are considered an "at risk" population due to the fact that they have no experience in flight in the first stages of training and are therefore subjects for investigation. METHODS: In this study, we investigated the cognitive performance of young cadet pilots across different hours of the day. 39 cadets were randomly divided into 3 groups: morning, late afternoon, and late evening groups and then tested on a cognitive battery that contained both simple performance measures but also complex measures like dual-tasking and mental rotation test. RESULTS: The analysis indicated a significant effect of 'time of day' on the participants' accuracy [F (2, 32) = 3.4, p < 0.05]. In a post hoc pairwise t-tests, we found a near significant (p = 0.52) increase in participants' accuracy and a significant increase [F (2, 32) = 4.5, p < 0.05] in participants' reaction time in the late evening group as compared to the morning group. We also found a differential effect of dual tasking on accuracy in the different daytimes [F (2, 33) = 5.6, p < 0.01]. In a post hoc analysis, we found that accuracy in the 1-back task deteriorates from single task condition to the dual task condition only in the morning group (p < 0.05), but not in the late evening or late-afternoon group. CONCLUSIONS: This 'trade-off' behavior, slowing down in order to perform better, in the late evening group may be a result of a voluntary control mechanism (top-down processes) activated at night, in this group. The combination of feeling fatigue, along with the understanding that complex tasks are more resource consuming, caused the cadets to check and double-check before answering, whereas in the morning group, they felt alert and vital, and acted more reactively, ended in an impulsive manner that caused to inaccurate performance.
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INTRODUCTION: The Beer Sheva Mental Health Center is the second largest mental health hospital in Israel and provides acute and chronic in-patient services for the entire population of the Southern District of Israel, from Ashdod to Eilat (about 1.2 million people) from adolescence to the elderly. The outpatient services include a variety of regional specialty services such as bipolar, eating disorders, anxiety, neuromodulation, gender-oriented, attention deficit hyperactivity disorder, sleep, dual diagnosis, geronto-psychiatry and post-traumatic stress disorder clinics and various rehabilitation day-care services. The emergency department provides 24 hour services with a 30-bed intensive care ward alongside it. The center offers up to date bio-psycho-social treatment and rehabilitation care, provided by academically-approved clinical social workers, psychologists, nursing staff and psychiatrists, all of whom are involved in under-graduate Mental Health Education (affiliated to Ben-Gurion University) and post-graduate Residency Training Programs (for each of the above disciplines). Despite the routine workload vis-a-vis patients and families and the busy teaching schedule, the center regards research as a lynch-pin of health care provision. In this issue of "Harefuah", clinical research and study reports by physicians, psychologists, clinical social workers and basic scientists from the Mental Health Center are presented. The manuscripts relate to quantitative and qualitative studies with patients and animal models, therapeutic approaches and scientific theories, which represent a sample of the ongoing clinical research activities.