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1.
Mol Psychiatry ; 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38951625

RESUMEN

Previous investigations have revealed performance deficits and altered neural processes during working-memory (WM) tasks in major depressive disorder (MDD). While most of these studies used task-based functional magnetic resonance imaging (fMRI), there is an increasing interest in resting-state fMRI to characterize aberrant network dynamics involved in this and other MDD-associated symptoms. It has been proposed that activity during the resting-state represents characteristics of brain-wide functional organization, which could be highly relevant for the efficient execution of cognitive tasks. However, the dynamics linking resting-state properties and task-evoked activity remain poorly understood. Therefore, the present study investigated the association between spontaneous activity as indicated by the amplitude of low frequency fluctuations (ALFF) at rest and activity during an emotional n-back task. 60 patients diagnosed with an acute MDD episode, and 52 healthy controls underwent the fMRI scanning procedure. Within both groups, positive correlations between spontaneous activity at rest and task-activation were found in core regions of the central-executive network (CEN), whereas spontaneous activity correlated negatively with task-deactivation in regions of the default mode network (DMN). Compared to healthy controls, patients showed a decreased rest-task correlation in the left prefrontal cortex (CEN) and an increased negative correlation in the precuneus/posterior cingulate cortex (DMN). Interestingly, no significant group-differences within those regions were found solely at rest or during the task. The results underpin the potential value and importance of resting-state markers for the understanding of dysfunctional network dynamics and neural substrates of cognitive processing.

2.
Transl Psychiatry ; 14(1): 258, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890270

RESUMEN

Neuroimaging studies have identified the anterior cingulate cortex (ACC) as one of the major targets of ketamine in the human brain, which may be related to ketamine's antidepressant (AD) mechanisms of action. However, due to different methodological approaches, different investigated populations, and varying measurement timepoints, results are not consistent, and the functional significance of the observed brain changes remains a matter of open debate. Inhibition of glutamate release during acute ketamine administration by lamotrigine provides the opportunity to gain additional insight into the functional significance of ketamine-induced brain changes. Furthermore, the assessment of trait negative emotionality holds promise to link findings in healthy participants to potential AD mechanisms of ketamine. In this double-blind, placebo-controlled, randomized, single dose, parallel-group study, we collected resting-state fMRI data before, during, and 24 h after ketamine administration in a sample of 75 healthy male and female participants who were randomly allocated to one of three treatment conditions (ketamine, ketamine with lamotrigine pre- treatment, placebo). Spontaneous brain activity was extracted from two ventral and one dorsal subregions of the ACC. Our results showed activity decreases during the administration of ketamine in all three ACC subregions. However, only in the ventral subregions of the ACC this effect was attenuated by lamotrigine. 24 h after administration, ACC activity returned to baseline levels, but group differences were observed between the lamotrigine and the ketamine group. Trait negative emotionality was closely linked to activity changes in the subgenual ACC after ketamine administration. These results contribute to an understanding of the functional significance of ketamine effects in different subregions of the ACC by combining an approach to modulate glutamate release with the assessment of multiple timepoints and associations with trait negative emotionality in healthy participants.


Asunto(s)
Emociones , Giro del Cíngulo , Ketamina , Lamotrigina , Imagen por Resonancia Magnética , Humanos , Ketamina/farmacología , Ketamina/administración & dosificación , Lamotrigina/farmacología , Lamotrigina/administración & dosificación , Giro del Cíngulo/efectos de los fármacos , Giro del Cíngulo/diagnóstico por imagen , Giro del Cíngulo/metabolismo , Masculino , Femenino , Método Doble Ciego , Adulto , Emociones/efectos de los fármacos , Adulto Joven , Antidepresivos/farmacología , Antidepresivos/administración & dosificación , Antagonistas de Aminoácidos Excitadores/farmacología , Antagonistas de Aminoácidos Excitadores/administración & dosificación
3.
J Affect Disord ; 358: 283-291, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38387672

RESUMEN

BACKGROUND: Both ruminative thought processes and adverse childhood experiences (ACEs) are well-established risk factors for the emergence and maintenance of depression. However, the neurobiological mechanisms underlying these associations remain poorly understood. METHODS: We examined resting-state functional magnetic resonance imaging data (3 T Tim Trio MR scanner; Siemens, Erlangen) of 44 individuals diagnosed with an acute depressive episode. Specifically, we focused on investigating functional brain activity and connectivity within and between three large-scale neural networks associated with processes affected in depression: the default mode network (DMN), the salience network (SN), and the central executive network (CEN). Correlational and regression-based analyses were performed. RESULTS: Our regions of interest analyses revealed that region-specific spontaneous neural activity in the anterior DMN was associated with self-reported trait rumination, specifically, the pregenual anterior cingulate cortex (pgACC). Furthermore, using a liberal statistical threshold, we found that spontaneous neural activity of the ventromedial prefrontal cortex and the pgACC were associated with depression symptom severity. Neither spontaneous neural activity in the SN and CEN nor functional connectivity within and across the investigated networks was associated with depression severity or rumination. Furthermore, there was no association between ACEs and brain activity and connectivity. LIMITATIONS: Lack of a formal control group or low-risk group for comparison. CONCLUSIONS: Overall, our results indicate network-specific changes in spontaneous brain activity, that are linked to both depression severity and rumination. Findings underscore the crucial role of the pgACC in depression and contribute to a dimensional and symptom-based understanding of depression-related network imbalances.


Asunto(s)
Experiencias Adversas de la Infancia , Imagen por Resonancia Magnética , Rumiación Cognitiva , Humanos , Femenino , Masculino , Rumiación Cognitiva/fisiología , Adulto , Red en Modo Predeterminado/fisiopatología , Red en Modo Predeterminado/diagnóstico por imagen , Giro del Cíngulo/fisiopatología , Giro del Cíngulo/diagnóstico por imagen , Corteza Prefrontal/fisiopatología , Corteza Prefrontal/diagnóstico por imagen , Encéfalo/fisiopatología , Encéfalo/diagnóstico por imagen , Persona de Mediana Edad , Red Nerviosa/fisiopatología , Red Nerviosa/diagnóstico por imagen , Trastorno Depresivo Mayor/fisiopatología , Trastorno Depresivo Mayor/diagnóstico por imagen , Adulto Joven , Descanso/fisiología , Mapeo Encefálico , Depresión/fisiopatología , Conectoma
4.
Clin Psychol Psychother ; 30(5): 1170-1178, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37291938

RESUMEN

Childhood emotional maltreatment (CEM) is a risk factor for the pathogenesis of depressive disorders. However, it is not clear whether CEM is more strongly related to specific symptoms of depression and whether specific traits or cognitive states may mediate the association between CEM and depressive symptoms. In our cross-sectional study, including 72 patients with a current depressive episode, we investigated if CEM is specifically related to cognitive symptoms of depression. In addition, we evaluated whether CEM also influences the extent of rumination and hopelessness in adult depression. Using multiple regression analyses, we tested if CEM and rumination could predict cognitive symptoms and hopelessness. A structural equation model (SEM) was used to examine if rumination mediates the relationship between CEM and cognitive symptoms. Correlational analyses revealed that CEM was related to cognitive symptoms, rumination, and hopelessness. The regression analyses showed that only rumination was a significant predictor for cognitive symptoms and hopelessness, whereas CEM could not significantly predict the two constructs. SEM revealed that the association between CEM and cognitive symptoms in adult depression was mediated by rumination. Our results thereby suggest that CEM is a risk factor particularly for the development of cognitive symptoms as well as rumination and hopelessness in adult depression. However, the influence on cognitive symptomatology seems to be indirectly regulated by rumination. These findings may contribute to a better understanding of processes that promote depression, as well as provide guidance for more targeted treatment options.


Asunto(s)
Depresión , Emociones , Adulto , Humanos , Depresión/psicología , Estudios Transversales , Afecto , Cognición
5.
Neuropsychopharmacology ; 48(12): 1735-1741, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37231079

RESUMEN

There is intriguing evidence suggesting that ketamine might have distinct acute and delayed neurofunctional effects, as its acute administration transiently induces schizophrenia-like symptoms, while antidepressant effects slowly emerge and are most pronounced 24 h after administration. Studies attempting to characterize ketamine's mechanism of action by using blood oxygen level dependent (BOLD) imaging have yielded inconsistent results regarding implicated brain regions and direction of effects. This may be due to intrinsic properties of the BOLD contrast, while cerebral blood flow (CBF), as measured with arterial spin labeling, is a single physiological marker more directly related to neural activity. As effects of acute ketamine challenge are sensitive to modulation by pretreatment with lamotrigine, which inhibits glutamate release, a combination of these approaches should be particularly suited to offer novel insights. In total, 75 healthy participants were investigated in a double blind, placebo-controlled, randomized, parallel-group study and underwent two scanning sessions (acute/post 24 h.). Acute ketamine administration was associated with higher perfusion in interior frontal gyrus (IFG) and dorsolateral prefrontal cortex (DLPFC), but no other investigated brain region. Inhibition of glutamate release by pretreatment with lamotrigine abolished ketamine's effect on perfusion. At the delayed time point, pretreatment with lamotrigine was associated with lower perfusion in IFG. These findings underscore the idea that regionally selective patterns of CBF changes reflect proximate effects of modulated glutamate release on neuronal activity. Furthermore, region- specific sustained effects indicate both a swift restoration of disturbed homeostasis in DLPFC as well changes occurring beyond the immediate effects on glutamate signaling in IFG.


Asunto(s)
Ketamina , Humanos , Lamotrigina/farmacología , Encéfalo/diagnóstico por imagen , Anticonvulsivantes/farmacología , Glutamatos , Circulación Cerebrovascular
6.
Neuropsychobiology ; 82(2): 91-103, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36731434

RESUMEN

INTRODUCTION: Cognition and emotion are fundamentally integrated in the brain and mutually contribute to behavior. The relation between working memory (WM) and emotion is particularly suited to investigate cognition-emotion interaction since WM is an essential component of many higher cognitive functions. Ketamine affects not only WM but also has a profound impact on emotional processing. Effects of acute ketamine challenge are sensitive to modulation by pretreatment with lamotrigine, which inhibits glutamate release. Accordingly, a combination of these approaches should be particularly suited to investigate cognition-emotion interaction. METHODS: Seventy five healthy subjects were investigated in a double-blind, placebo-controlled, randomized, single-dose, parallel-group study with three treatment conditions. All subjects underwent two scanning sessions (acute/post 24 h). RESULTS: Compared to placebo, acute ketamine administration induced significant dissociative, psychotomimetic, and cognitive effects, as well as an increase in neural activity during WM for positive stimuli. Inhibition of glutamate release by pretreatment with lamotrigine did not influence ketamine's subjective effects, but significantly attenuated its impact on emotional WM and associated neural activity. There was no effect on these measures 24 h after ketamine administration. CONCLUSION: Our results demonstrate differential acute effects of modulated glutamate release and a swift restoration of disturbed neurobehavioral homeostasis in healthy subjects.


Asunto(s)
Ketamina , Humanos , Ketamina/farmacología , Ketamina/uso terapéutico , Lamotrigina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Encéfalo , Emociones/fisiología , Cognición , Anticonvulsivantes/farmacología , Ácido Glutámico
7.
Sci Rep ; 13(1): 1954, 2023 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-36732349

RESUMEN

Taste may be the first sense that emerged in evolution. Taste is also a very important sense since it signals potential beneficial or dangerous effects of foods. Given this fundamental role of taste in our lives, it is not surprising that taste also affects our psychological perception and thinking. For example, previous research demonstrated remarkable psychological effects of sweet taste experiences, suggesting that sweetness may be a source domain for prosocial functioning. Recent research reports that briefly experiencing sweet taste made participants more helpful in their intentions and behavior. The current study aims to test this hypothesis and to examine the neural underpinnings of this effect by using an fMRI approach. Participants were asked to taste sweet, salty, and neutral taste while lying in the fMRI scanner. Subsequently their prosocial behavior was tested by playing the dictator game, a measure of prosocial behavior. Results showed that sweet taste was associated with an increase in prosocial behavior compared with previously experiencing salty taste but did not affect control stimuli ratings. FMRI results revealed a modulation of the dorsal anterior cingulate cortex associated with this sweetness effect. This brain area is known to play a central role for monitoring conflicts and decisions and has been directly linked to selfish and prosocial economic decisions. The results demonstrate that sweet taste has complex psychological effects including positive and socially desirable outcomes. We discuss the results with other studies on psychological sweetness effects and suggest possible implications of these findings.


Asunto(s)
Altruismo , Gusto , Humanos , Disgeusia , Percepción del Gusto , Encéfalo/diagnóstico por imagen , Preferencias Alimentarias/psicología
8.
Eur Arch Psychiatry Clin Neurosci ; 273(7): 1489-1499, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36715751

RESUMEN

Electroconvulsive therapy (ECT) is one of the most effective treatments for treatment-resistant depression. However, the underlying mechanisms of action are not yet fully understood. The investigation of depression-specific networks using resting-state fMRI and the relation to differential symptom improvement might be an innovative approach providing new insights into the underlying processes. In this naturalistic study, we investigated the relationship between changes in resting-state functional connectivity (rsFC) and symptom improvement after ECT in 21 patients with treatment-resistant depression. We investigated rsFC before and after ECT and focused our analyses on FC changes directly related to symptom reduction and on FC at baseline to identify neural targets that might predict individual clinical responses to ECT. Additional analyses were performed to identify the direct relationship between rsFC change and symptom dimensions such as sadness, negative thoughts, detachment, and neurovegetative symptoms. An increase in rsFC between the left amygdala and left dorsolateral prefrontal cortex (DLPFC) after ECT was related to overall symptom reduction (Bonferroni-corrected p = 0.033) as well as to a reduction in specific symptoms such as sadness (r = 0.524, uncorrected p = 0.014), negative thoughts (r = 0.700, Bonferroni-corrected p = 0.002) and detachment (r = 0.663, p = 0.004), but not in neurovegetative symptoms. Furthermore, high baseline rsFC between the left amygdala and the right frontal pole (FP) predicted treatment outcome (uncorrected p = 0.039). We conclude that changes in FC in regions of the limbic-prefrontal network are associated with symptom improvement, particularly in affective and cognitive dimensions. Frontal-limbic connectivity has the potential to predict symptom improvement after ECT. Further research combining functional imaging biomarkers and a symptom-based approach might be promising.


Asunto(s)
Trastorno Depresivo Mayor , Terapia Electroconvulsiva , Humanos , Terapia Electroconvulsiva/métodos , Depresión/diagnóstico por imagen , Depresión/terapia , Trastorno Depresivo Mayor/terapia , Amígdala del Cerebelo/diagnóstico por imagen , Corteza Prefrontal/diagnóstico por imagen , Imagen por Resonancia Magnética
9.
Neuropsychopharmacology ; 48(3): 560-566, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36456814

RESUMEN

While placebo effects are well-known, research in the last decade revealed intriguing effects that placebos may have beneficial effects even when given without deception. At first glance, this seems paradoxical, but several studies have reported improvements in pain, depression, or anxiety. However, it still remains unclear whether these results represent objective biological effects or simply a bias in response and what neural underpinnings are associated with the open-label placebo effects. In two studies, we address this gap by demonstrating that open-label placebos reduce self-reported emotional distress when viewing highly arousing negative pictures. This reduced emotional distress was associated with an activation of brain areas known to modulate affective states such as the periaqueductal gray, the bilateral anterior hippocampi, and the anterior cingulate cortex. We did not find any prefrontal brain activation. Furthermore, brain activation was not associated with expectation of effects. In contrast, we found that brain responses were linked to general belief in placebos. The results demonstrate that the neural mechanisms of open-label placebo effects are partly identical to the neurobiological underpinnings of conventional placebos, but our study also highlights important differences with respect to a missing engagement of prefrontal brain regions, suggesting that expectation of effects may play a less prominent role in open-label placebos.


Asunto(s)
Efecto Placebo , Distrés Psicológico , Humanos , Dolor , Ansiedad/tratamiento farmacológico , Trastornos de Ansiedad
10.
Int J Neuropsychopharmacol ; 26(1): 20-31, 2023 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-36173403

RESUMEN

BACKGROUND: Electroconvulsive therapy (ECT) is an effective treatment for patients suffering from depression. Yet the exact neurobiological mechanisms underlying the efficacy of ECT and indicators of who might respond best to it remain to be elucidated. Identifying neural markers that can inform about an individual's response to ECT would enable more optimal treatment strategies and increase clinical efficacy. METHODS: Twenty-one acutely depressed inpatients completed an emotional working memory task during functional magnetic resonance imaging before and after receiving treatment with ECT. Neural activity was assessed in 5 key regions associated with the pathophysiology of depression: bilateral dorsolateral prefrontal cortex and pregenual, subgenual, and dorsal anterior cingulate cortex. Associations between brain activation and clinical improvement, as reflected by Montgomery-Åsberg Depression Rating Scale scores, were computed using linear regression models, t tests, and Pearson correlational analyses. RESULTS: Significant neurobiological prognostic markers or changes in neural activity from pre- to post ECT did not emerge. CONCLUSIONS: We could not confirm normalization effects and did not find significant neural markers related to treatment response. These results demonstrate that the search for reliable and clinically useful biomarkers for ECT treatment remains in its initial stages and still faces challenges.


Asunto(s)
Terapia Electroconvulsiva , Humanos , Terapia Electroconvulsiva/métodos , Resultado del Tratamiento , Giro del Cíngulo/diagnóstico por imagen , Emociones , Imagen por Resonancia Magnética
12.
J Psychiatr Res ; 156: 639-646, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36375231

RESUMEN

Intranasal (IN) and intravenous (IV) applications of ketamine have been proven effective for the treatment of depression, but direct comparative trials or meta-analyses on whether both differ in their antidepressant efficacy are lacking. We aimed to meta-analytically compare the short-term efficacy of a single dose of IV and IN ketamine in adult patients with major depressive disorder (MDD) and included double-blind, randomized controlled trials published until February 2022 in our analyses. The main outcome was a response 24 h after the administration of a single dose of ketamine. A random-effects model was used to calculate odds ratios and confidence intervals. Differences in efficacy between intranasal and intravenous application were statistically assessed by calculating a z-test. A total of eleven studies, comprising 1340 patients, were included. Results showed, that while both IN and IV ketamine were associated with increased response rates, efficacy did not differ significantly between these routes. Heterogeneity and funnel plot asymmetry was found in the intranasal sample only. The results of the present meta-analysis corroborate the efficacy of both IN and IV application of ketamine for the treatment of MDD but suggest no difference between both routes of administration. Accordingly, future large-scale trials as well as direct comparative trials are needed to further investigate this question.


Asunto(s)
Trastorno Depresivo Mayor , Ketamina , Humanos , Administración Intranasal , Trastorno Depresivo Mayor/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto
13.
Int J Neuropsychopharmacol ; 25(12): 1003-1013, 2022 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-35948274

RESUMEN

BACKGROUND: Growing evidence underscores the utility of ketamine as an effective and rapid-acting treatment option for major depressive disorder (MDD). However, clinical outcomes vary between patients. Predicting successful response may enable personalized treatment decisions and increase clinical efficacy. METHODS: We here explored the potential of pregenual anterior cingulate cortex (pgACC) activity to predict antidepressant effects of ketamine in relation to ketamine-induced changes in glutamatergic metabolism. Prior to a single i.v. infusion of ketamine, 24 patients with MDD underwent functional magnetic resonance imaging during an emotional picture-viewing task and magnetic resonance spectroscopy. Changes in depressive symptoms were evaluated using the Beck Depression Inventory measured 24 hours pre- and post-intervention. A subsample of 17 patients underwent a follow-up magnetic resonance spectroscopy scan. RESULTS: Antidepressant efficacy of ketamine was predicted by pgACC activity during emotional stimulation. In addition, pgACC activity was associated with glutamate increase 24 hours after the ketamine infusion, which was in turn related to better clinical outcome. CONCLUSIONS: Our results add to the growing literature implicating a key role of the pgACC in mediating antidepressant effects and highlighting its potential as a multimodal neuroimaging biomarker of early treatment response to ketamine.


Asunto(s)
Trastorno Depresivo Mayor , Ketamina , Humanos , Giro del Cíngulo/metabolismo , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/tratamiento farmacológico , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Ácido Glutámico/metabolismo , Imagen por Resonancia Magnética , Biomarcadores/metabolismo
14.
Eur Arch Psychiatry Clin Neurosci ; 272(8): 1421-1435, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35781841

RESUMEN

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder, characterized by core symptoms of inattention, hyperactivity and impulsivity. Comorbid depression is commonly observed in ADHD-patients. Psychostimulants are recommended as first-line treatment for ADHD. Aberrant long-range temporal correlations (LRTCs) of neuronal activities in resting-state are known to be associated with disorganized thinking and concentrating difficulties (typical in ADHD) and with maladaptive thinking (typical in depression). It has yet to be examined whether (1) LRTC occur in ADHD-patients, and if so, (2) whether LRTC might be a competent biomarker in ADHD comorbid with current depression and (3) how depression affects psychostimulant therapy of ADHD symptoms. The present study registered and compared LRTCs in different EEG frequency bands in 85 adults with ADHD between groups with (n = 28) and without (n = 57) additional depressive symptoms at baseline. Treatment-related changes in ADHD, depressive symptoms and LRTC were investigated in the whole population and within each group. Our results revealed significant LRTCs existed in all investigated frequency bands. There were, however, no significant LRTC-differences between ADHD-patients with and without depressive symptoms at baseline and no LRTC-changes following treatment. However, depressed ADHD patients did seem to benefit more from the therapy with psychostimulant based on self-report.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Adulto , Humanos , Trastorno por Déficit de Atención con Hiperactividad/complicaciones , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Depresión/epidemiología , Comorbilidad , Descanso , Electroencefalografía
15.
Sci Rep ; 12(1): 12024, 2022 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-35835782

RESUMEN

Sensory processing sensitivity is described as a personality trait associated with a high sensitivity to environmental and social stimuli. It has been assumed that about 15-20% of the total population can be described as highly sensitive. The concept states that those individuals represent a higher sensitivity to subtle stimuli, thereby exhibiting a different somatic sensation. Here we aim to test the assumption that the brain's sensory perception is different in individuals with high sensory processing sensitivity. We used a German version of the Highly Sensitive Person scale to measure sensory processing sensitivity. Furthermore, we assessed the Big Five personality dimensions and trait empathy (using IRI). To test the hypothesis that the brain's handling of sensory information is different in individuals with high sensory-processing sensitivity, we scanned participant's brain activity with functional magnetic resonance imaging (fMRI) while they were touched by an experimenter's hand. Results showed positive correlations of sensory processing sensitivity with neuroticism, openness, and empathy. Introversion was not a significant predictor. Neuroimaging data demonstrated that sensory processing sensitivity (controlled for associated personality dimensions) was not related to primary or secondary somatosensory BOLD responses, but positively associated with BOLD activity in left posterior insular cortex. Based on these results we conclude that sensory processing sensitivity seems to represent insula-mediated affective touch. We discuss these results with previous studies reporting an engagement of the insula in individuals with high sensory processing sensitivity.


Asunto(s)
Percepción del Tacto , Tacto , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Mapeo Encefálico , Emociones/fisiología , Humanos , Imagen por Resonancia Magnética , Corteza Somatosensorial/diagnóstico por imagen , Corteza Somatosensorial/fisiología , Tacto/fisiología , Percepción del Tacto/fisiología
16.
Brain Sci ; 12(5)2022 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-35625027

RESUMEN

Many concepts of the human personality are based on assumptions about underlying physiological processes. The most prominent example is probably the concept of extraversion introduced by H.J. Eysenck decades ago. However, more recent approaches also propose that personality traits may be reflected by physiological processes. For example, empathic personality dimensions have been linked to tactile perception, suggesting that individuals with higher tactile sensitivity are also more empathetic to the sensations of others. Another recent example is the concept of sensory processing sensitivity, which has been linked to enhanced primary sensory processing. However, the exact relationship between tactile abilities and personality is still unclear, thus the current study aims to test whether different personality dimensions affect the performance in a tactile acuity task. Tactile abilities of healthy participants were tested with tactile 2-point-thresholds on the hands. Personality dimensions were examined with respect to empathy, sensory processing sensitivity, and the Big Five. Results revealed that empathy, but not sensory processing sensitivity, was associated with tactile performance. We conclude that the ability to feel with someone else seems to be linked to the perception of our own body. Thus, the sense of touch may play an important role for empathy. We discuss explanations of these results and highlight possible implications of our findings.

17.
Eur Arch Psychiatry Clin Neurosci ; 272(4): 703-714, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35020021

RESUMEN

Ketamine exerts its rapid antidepressant effects via modulation of the glutamatergic system. While numerous imaging studies have investigated the effects of ketamine on a functional macroscopic brain level, it remains unclear how altered glutamate metabolism and changes in brain function are linked. To shed light on this topic we here conducted a multimodal imaging study in healthy volunteers (N = 23) using resting state fMRI and proton (1H) magnetic resonance spectroscopy (MRS) to investigate linkage between metabolic and functional brain changes induced by ketamine. Subjects were investigated before and during an intravenous ketamine infusion. The MRS voxel was placed in the pregenual anterior cingulate cortex (pgACC), as this region has been repeatedly shown to be involved in ketamine's effects. Our results showed functional connectivity changes from the pgACC to the right frontal pole and anterior mid cingulate cortex (aMCC). Absolute glutamate and glutamine concentrations in the pgACC did not differ significantly from baseline. However, we found that stronger pgACC activation during ketamine was linked to lower glutamine concentration in this region. Furthermore, reduced functional connectivity between pgACC and aMCC was related to increased pgACC activation and reduced glutamine. Our results thereby demonstrate how multimodal investigations in a single brain region could help to advance our understanding of the association between metabolic and functional changes.


Asunto(s)
Giro del Cíngulo , Ketamina , Ácido Glutámico/metabolismo , Glutamina/metabolismo , Giro del Cíngulo/metabolismo , Humanos , Ketamina/farmacología , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética
18.
World J Biol Psychiatry ; 23(8): 643-652, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34985394

RESUMEN

Ketamine is a promising treatment option for patients with Major Depressive Disorder (MDD) and has become an important research tool to investigate antidepressant mechanisms of action. However, imaging studies attempting to characterise ketamine's mechanism of action using blood oxygen level-dependent signal (BOLD) imaging have yielded inconsistent results- at least partly due to intrinsic properties of the BOLD contrast, which measures a complex signal related to neural activity. To circumvent the limitations associated with the BOLD signal, we used arterial spin labelling (ASL) as an unambiguous marker of neuronal activity-related changes in cerebral blood flow (CBF). We measured CBF in 21 MDD patients at baseline and 24 h after receiving a single intravenous infusion of subanesthetic ketamine and examined relationships with clinical outcomes. Our findings demonstrate that increase in thalamus perfusion 24 h after ketamine administration is associated with greater improvement of depressive symptoms. Furthermore, lower thalamus perfusion at baseline is associated both with larger increases in perfusion 24 h after ketamine administration and with stronger reduction of depressive symptoms. These findings indicate that ASL is not only a useful tool to broaden our understanding of ketamine's mechanism of action but might also have the potential to inform treatment decisions based on CBF-defined regional disruptions.


Asunto(s)
Trastorno Depresivo Mayor , Ketamina , Humanos , Ketamina/efectos adversos , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/tratamiento farmacológico , Antidepresivos/farmacología , Antidepresivos/uso terapéutico , Tálamo/diagnóstico por imagen , Circulación Cerebrovascular , Marcadores de Spin
19.
Soc Cogn Affect Neurosci ; 17(5): 437-446, 2022 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-34746947

RESUMEN

Giving and receiving touch are some of the most important social stimuli we exchange in daily life. By touching someone, we can communicate various types of information. Previous studies have also demonstrated that interpersonal touch may affect our altruistic behavior. A classic study showed that customers give bigger tips when they are lightly touched by a waitress, which has been called the Midas touch effect. Numerous studies reported similar effects of touch on different kinds of helping or prosocial behaviors. Here, we aim to examine the neural underpinnings of this effect by employing a functional magnetic resonance imaging approach. While lying in the scanner, participants played different rounds of the dictator game, a measure of prosocial behavior. Before each round, participants were touched (or not touched in the control condition) by an experimenter. We found that touching the hand increased the likeliness to behave prosocial (but not the general liking of control stimuli), thereby confirming the Midas touch effect. The effect was predicted by activity in the primary somatosensory cortex, indicating that the somatosensory cortex here plays a causal role in prosocial behavior. We conclude that the tactile modality in social life may be much more important than previously thought.


Asunto(s)
Altruismo , Tacto , Humanos , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Corteza Somatosensorial/diagnóstico por imagen
20.
Brain Sci ; 11(8)2021 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-34439703

RESUMEN

In the present study, we investigated the effects of a four-week working memory (WM) and attention training program using commercial brain training (Synaptikon GmbH, Berlin). Sixty young healthy adults were assigned to the experimental and active control training programs. The training was conducted in a naturalistic home-based setting, while the pre- and post-examinations were conducted in a controlled laboratory setting. Transfer effects to an untrained WM task and to an untrained episodic memory task were examined. Furthermore, possible influences of personality, i.e., the five-factor model (FFM) traits and need for cognition (NFC), on training outcomes were examined. Additionally, the direct relationship between improvement in single trained tasks and improvement in the transfer tasks was investigated. Our results showed that both training groups significantly increased performance in the WM task, but only the WM training group increased their performance in the episodic memory transfer task. One of the training tasks, a visuospatial WM task, was particularly associated with improvement in the episodic memory task. Neuroticism and conscientiousness showed differential effects on the improvement in training and transfer tasks. It needs to be further examined whether these effects represent training effects or, for example, retest/practice or motivation effects.

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