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1.
Brain Sci ; 12(5)2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35625009

RESUMEN

Musical interventions in therapy have become increasingly relevant for rehabilitation in many clinics. What was long known for physiotherapy training-that the agency of the participant is crucial and moving is much more efficient for rehabilitation success than being moved-has over recent years also been shown to be true for music therapy. Accumulating evidence suggests that active musical interventions are especially efficient at helping rehabilitation success. Here, we review various approaches to active music therapy. Furthermore, we present several components that allow for manipulating musical expressiveness and physical engagement during active musical interventions, applying a technology-based music feedback paradigm. This paper will allow for a transfer of insights to other domains of music-based therapeutic interventions.

2.
Am J Clin Nutr ; 115(5): 1270-1281, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-35021194

RESUMEN

BACKGROUND: The effect of diet on age-related brain atrophy is largely unproven. OBJECTIVES: We aimed to explore the effect of a Mediterranean diet (MED) higher in polyphenols and lower in red/processed meat (Green-MED diet) on age-related brain atrophy. METHODS: This 18-mo clinical trial longitudinally measured brain structure volumes by MRI using hippocampal occupancy score (HOC) and lateral ventricle volume (LVV) expansion score as neurodegeneration markers. Abdominally obese/dyslipidemic participants were randomly assigned to follow 1) healthy dietary guidelines (HDG), 2) MED, or 3) Green-MED diet. All subjects received free gym memberships and physical activity guidance. Both MED groups consumed 28 g walnuts/d (+440 mg/d polyphenols). The Green-MED group consumed green tea (3-4 cups/d) and Mankai (Wolffia-globosa strain, 100 g frozen cubes/d) green shake (+800 mg/d polyphenols). RESULTS: Among 284 participants (88% men; mean age: 51 y; BMI: 31.2 kg/m2; APOE-ε4 genotype = 15.7%), 224 (79%) completed the trial with eligible whole-brain MRIs. The pallidum (-4.2%), third ventricle (+3.9%), and LVV (+2.2%) disclosed the largest volume changes. Compared with younger participants, atrophy was accelerated among those ≥50 y old (HOC change: -1.0% ± 1.4% compared with -0.06% ± 1.1%; 95% CI: 0.6%, 1.3%; P < 0.001; LVV change: 3.2% ± 4.5% compared with 1.3% ± 4.1%; 95% CI: -3.1%, -0.8%; P = 0.001). In subjects ≥ 50 y old, HOC decline and LVV expansion were attenuated in both MED groups, with the best outcomes among Green-MED diet participants, as compared with HDG (HOC: -0.8% ± 1.6% compared with -1.3% ± 1.4%; 95% CI: -1.5%, -0.02%; P = 0.042; LVV: 2.3% ± 4.7% compared with 4.3% ± 4.5%; 95% CI: 0.3%, 5.2%; P = 0.021). Similar patterns were observed among younger subjects. Improved insulin sensitivity over the trial was the parameter most strongly associated with brain atrophy attenuation (P < 0.05). Greater Mankai, green tea, and walnut intake and less red and processed meat were significantly and independently associated with reduced HOC decline (P < 0.05). Elevated urinary concentrations of the polyphenols urolithin-A (r = 0.24; P = 0.013) and tyrosol (r = 0.26; P = 0.007) were significantly associated with lower HOC decline. CONCLUSIONS: A Green-MED (high-polyphenol) diet, rich in Mankai, green tea, and walnuts and low in red/processed meat, is potentially neuroprotective for age-related brain atrophy.This trial was registered at clinicaltrials.gov as NCT03020186.


Asunto(s)
Dieta Mediterránea , Juglans , Atrofia , Encéfalo/diagnóstico por imagen , Ejercicio Físico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polifenoles/farmacología ,
3.
Sci Rep ; 11(1): 15060, 2021 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-34301974

RESUMEN

Evidence suggests that selective serotonin reuptake inhibitors (SSRIs) reorganize neural networks via a transient window of neuroplasticity. While previous findings support an effect of SSRIs on intrinsic functional connectivity, little is known regarding the influence of SSRI-administration on connectivity during sequence motor learning. To investigate this, we administered 20 mg escitalopram or placebo for 1-week to 60 healthy female participants undergoing concurrent functional magnetic resonance imaging and sequence motor training in a double-blind randomized controlled design. We assessed task-modulated functional connectivity with a psycho-physiological interaction (PPI) analysis in the thalamus, putamen, cerebellum, dorsal premotor, primary motor, supplementary motor, and dorsolateral prefrontal cortices. Comparing an implicit sequence learning condition to a control learning condition, we observed decreased connectivity between the thalamus and bilateral motor regions after 7 days of escitalopram intake. Additionally, we observed a negative correlation between plasma escitalopram levels and PPI connectivity changes, with higher escitalopram levels being associated with greater thalamo-cortico decreases. Our results suggest that escitalopram enhances network-level processing efficiency during sequence motor learning, despite no changes in behaviour. Future studies in more diverse samples, however, with quantitative imaging of neurochemical markers of excitation and inhibition, are necessary to further assess neural responses to escitalopram.


Asunto(s)
Citalopram/administración & dosificación , Aprendizaje/efectos de los fármacos , Plasticidad Neuronal/efectos de los fármacos , Inhibidores Selectivos de la Recaptación de Serotonina/administración & dosificación , Adulto , Cerebelo/diagnóstico por imagen , Cerebelo/efectos de los fármacos , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neuronas Motoras/efectos de los fármacos , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/efectos de los fármacos , Putamen/diagnóstico por imagen , Putamen/efectos de los fármacos , Tálamo/diagnóstico por imagen , Tálamo/efectos de los fármacos , Adulto Joven
4.
J Psychiatry Neurosci ; 46(3): E319-E327, 2021 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-33904667

RESUMEN

Background: Selective serotonin reuptake inhibitors (SSRIs) show acute effects on the neural processes associated with negative affective bias in healthy people and people with depression. However, whether and how SSRIs also affect reward and punishment processing on a similarly rapid time scale remains unclear. Methods: We investigated the effects of an acute and clinically relevant dose (20 mg) of the SSRI escitalopram on brain response during reward and punishment processing in 19 healthy participants. In a doubleblind, placebo-controlled study using functional MRI, participants performed a well-established monetary reward task at 3 time points: at baseline; after receiving placebo or escitalopram; and after receiving placebo or escitalopram following an 8-week washout period. Results: Acute escitalopram administration reduced blood-oxygen-level-dependent (BOLD) response during punishment feedback in the right thalamus (family-wise error corrected [FWE] p = 0.013 at peak level) and the right caudate head (pFWE = 0.011 at peak level) compared to placebo. We did not detect any significant BOLD changes during reward feedback. Limitations: We included only healthy participants, so interpretation of findings are limited to the healthy human brain and require future testing in patient populations. The paradigm we used was based on monetary stimuli, and results may not be generalizable to other forms of reward. Conclusion: Our findings extend theories of rapid SSRI action on the neural processing of rewarding and aversive stimuli and suggest a specific and acute effect of escitalopram in the punishment neurocircuitry.


Asunto(s)
Núcleo Caudado/efectos de los fármacos , Escitalopram/administración & dosificación , Escitalopram/farmacología , Neuronas/efectos de los fármacos , Castigo , Recompensa , Tálamo/efectos de los fármacos , Adulto , Núcleo Caudado/citología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Inhibidores Selectivos de la Recaptación de Serotonina/administración & dosificación , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Tálamo/citología , Adulto Joven
5.
J Physiol ; 599(9): 2435-2451, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-31696938

RESUMEN

KEY POINTS: Two groups of inexperienced brain-computer interface users underwent a purely mental EEG-BCI session that rapidly impacted on their brain. Modulations in structural and functional MRI were found after only 1 h of BCI training. Two different types of BCI (based on motor imagery or visually evoked potentials) were employed and analyses showed that the brain plastic changes are spatially specific for the respective neurofeedback. This spatial specificity promises tailored therapeutic interventions (e.g. for stroke patients). ABSTRACT: A brain-computer-interface (BCI) allows humans to control computational devices using only neural signals. However, it is still an open question, whether performing BCI also impacts on the brain itself, i.e. whether brain plasticity is induced. Here, we show rapid and spatially specific signs of brain plasticity measured with functional and structural MRI after only 1 h of purely mental BCI training in BCI-naive subjects. We employed two BCI approaches with neurofeedback based on (i) modulations of EEG rhythms by motor imagery (MI-BCI) or (ii) event-related potentials elicited by visually targeting flashing letters (ERP-BCI). Before and after the BCI session we performed structural and functional MRI. For both BCI approaches we found increased T1-weighted MR signal in the grey matter of the respective target brain regions, such as occipital/parietal areas after ERP-BCI and precuneus and sensorimotor regions after MI-BCI. The latter also showed increased functional connectivity and higher task-evoked BOLD activity in the same areas. Our results demonstrate for the first time that BCI by means of targeted neurofeedback rapidly impacts on MRI measures of brain structure and function. The spatial specificity of BCI-induced brain plasticity promises therapeutic interventions tailored to individual functional deficits, for example in patients after stroke.


Asunto(s)
Interfaces Cerebro-Computador , Neurorretroalimentación , Encéfalo/diagnóstico por imagen , Electroencefalografía , Humanos , Imaginación , Plasticidad Neuronal
6.
Neuroimage ; 199: 680-690, 2019 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31173902

RESUMEN

Acute stress triggers a broad psychophysiological response that is adaptive if rapidly activated and terminated. While the brain controls the stress response, it is strongly affected by it. Previous research of stress effects on brain activation and connectivity has mainly focused on pre-defined brain regions or networks, potentially missing changes in the rest of the brain. We here investigated how both stress reactivity and stress recovery are reflected in whole-brain network topology and how changes in functional connectivity relate to other stress measures. Healthy young males (n = 67) completed the Trier Social Stress Test or a control task. From 60 min before until 105 min after stress onset, blocks of resting-state fMRI were acquired. Subjective, autonomic, and endocrine measures of the stress response were assessed throughout the experiment. Whole-brain network topology was quantified using Eigenvector centrality (EC) mapping, which detects central hubs of a network. Stress influenced subjective affect, autonomic activity, and endocrine measures. EC differences between groups as well as before and after stress exposure were found in the thalamus, due to widespread connectivity changes in the brain. Stress-driven EC increases in the thalamus were significantly correlated with subjective stress ratings and showed non-significant trends for a correlation with heart rate variability and saliva cortisol. Furthermore, increases in thalamic EC and in saliva cortisol persisted until 105 min after stress onset. We conclude that thalamic areas are central for information processing after stress exposure and may provide an interface for the stress response in the rest of the body and in the mind.


Asunto(s)
Corteza Cerebral/fisiopatología , Conectoma , Red Nerviosa/fisiopatología , Estrés Psicológico/fisiopatología , Tálamo/fisiopatología , Adolescente , Adulto , Sistema Nervioso Autónomo/fisiopatología , Corteza Cerebral/diagnóstico por imagen , Humanos , Hidrocortisona/metabolismo , Imagen por Resonancia Magnética , Masculino , Red Nerviosa/diagnóstico por imagen , Estrés Psicológico/diagnóstico por imagen , Estrés Psicológico/metabolismo , Tálamo/diagnóstico por imagen , Adulto Joven
7.
Neurology ; 92(8): e758-e773, 2019 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-30674602

RESUMEN

OBJECTIVE: To test whether elevated blood pressure (BP) relates to gray matter (GM) volume (GMV) changes in young adults who had not previously been diagnosed with hypertension (systolic BP [SBP]/diastolic BP [DBP] ≥140/90 mm Hg). METHODS: We associated BP with GMV from structural 3T T1-weighted MRI of 423 healthy adults between 19 and 40 years of age (mean age 27.7 ± 5.3 years, 177 women, SBP/DBP 123.2/73.4 ± 12.2/8.5 mm Hg). Data originated from 4 previously unpublished cross-sectional studies conducted in Leipzig, Germany. We performed voxel-based morphometry on each study separately and combined results in image-based meta-analyses (IBMA) to assess cumulative effects across studies. Resting BP was assigned to 1 of 4 categories: (1) SBP <120 and DBP <80 mm Hg, (2) SBP 120-129 or DBP 80-84 mm Hg, (3) SBP 130-139 or DBP 85-89 mm Hg, (4) SBP ≥140 or DBP ≥90 mm Hg. RESULTS: IBMA yielded the following results: (1) lower regional GMV was correlated with higher peripheral BP; (2) lower GMV was found with higher BP when comparing individuals in subhypertensive categories 3 and 2, respectively, to those in category 1; (3) lower BP-related GMV was found in regions including hippocampus, amygdala, thalamus, frontal, and parietal structures (e.g., precuneus). CONCLUSION: BP ≥120/80 mm Hg was associated with lower GMV in regions that have previously been related to GM decline in older individuals with manifest hypertension. Our study shows that BP-associated GM alterations emerge continuously across the range of BP and earlier in adulthood than previously assumed. This suggests that treating hypertension or maintaining lower BP in early adulthood might be essential for preventing the pathophysiologic cascade of asymptomatic cerebrovascular disease to symptomatic end-organ damage, such as stroke or dementia.


Asunto(s)
Presión Sanguínea , Sustancia Gris/diagnóstico por imagen , Hipertensión/epidemiología , Adulto , Amígdala del Cerebelo/diagnóstico por imagen , Amígdala del Cerebelo/patología , Estudios Transversales , Femenino , Lóbulo Frontal/diagnóstico por imagen , Lóbulo Frontal/patología , Alemania/epidemiología , Sustancia Gris/patología , Hipocampo/diagnóstico por imagen , Hipocampo/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Tamaño de los Órganos , Lóbulo Parietal/diagnóstico por imagen , Lóbulo Parietal/patología , Prehipertensión/epidemiología , Tálamo/diagnóstico por imagen , Tálamo/patología , Adulto Joven
8.
Brain Lang ; 190: 10-15, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30665002

RESUMEN

Musical excerpts have been shown to have the capacity to prime the processing of target words and vice versa, strongly suggesting that music can convey concepts. However, to date no study has investigated an influence of musical semantics on novel word acquisition, thus corroborating evidence for a similarity of underlying semantic processing of music and words behaviourally. The current study investigates whether semantic content of music can assist the acquisition of novel words. Forty novel words and their German translation were visually presented to 26 participants accompanied by either semantically congruent or incongruent music. Semantic congruence between music and words was expected to increase performance in the subsequent forced-choice recognition test. Participants performed significantly better on the retention of novel words presented with semantically congruent music compared to those presented with semantically incongruent music. This provides first evidence that semantic "enrichment" by music during novel word learning can augment novel word acquisition. This finding may lead to novel approaches in foreign language acquisition and language rehabilitation, and further strongly supports the concept that music has a strong capacity to iconically convey meaning.


Asunto(s)
Estimulación Acústica/psicología , Música , Semántica , Aprendizaje Verbal , Estimulación Acústica/métodos , Adulto , Femenino , Voluntarios Sanos , Humanos , Lenguaje , Masculino , Música/psicología , Conducta Verbal , Aprendizaje Verbal/fisiología , Adulto Joven
9.
Neuroimage ; 166: 198-208, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29100939

RESUMEN

Real-time fMRI neurofeedback is a feasible tool to learn the volitional regulation of brain activity. So far, most studies provide continuous feedback information that is presented upon every volume acquisition. Although this maximizes the temporal resolution of feedback information, it may be accompanied by some disadvantages. Participants can be distracted from the regulation task due to (1) the intrinsic delay of the hemodynamic response and associated feedback and (2) limited cognitive resources available to simultaneously evaluate feedback information and stay engaged with the task. Here, we systematically investigate differences between groups presented with different variants of feedback (continuous vs. intermittent) and a control group receiving no feedback on their ability to regulate amygdala activity using positive memories and feelings. In contrast to the feedback groups, no learning effect was observed in the group without any feedback presentation. The group receiving intermittent feedback exhibited better amygdala regulation performance when compared with the group receiving continuous feedback. Behavioural measurements show that these effects were reflected in differences in task engagement. Overall, we not only demonstrate that the presentation of feedback is a prerequisite to learn volitional control of amygdala activity but also that intermittent feedback is superior to continuous feedback presentation.


Asunto(s)
Amígdala del Cerebelo/fisiología , Emociones/fisiología , Neuroimagen Funcional/métodos , Aprendizaje/fisiología , Neurorretroalimentación/fisiología , Adulto , Amígdala del Cerebelo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Volición , Adulto Joven
10.
Front Hum Neurosci ; 10: 510, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27803655

RESUMEN

Acupuncture can have instant and sustained effects, however, its mechanisms of action are still unclear. Here, we investigated the sustained effect of acupuncture by evaluating centrality changes in resting-state functional magnetic resonance imaging after manually stimulating the acupuncture point ST36 at the lower leg or two control point locations (CP1 same dermatome, CP2 different dermatome). Data from a previously published experiment evaluating instant BOLD effects and S2-seed-based resting state connectivity was re-analyzed using eigenvector centrality mapping and degree centrality mapping. These data-driven methods might add new insights into sustained acupuncture effects on both global and local inter-region connectivity (centrality) by evaluating the summary of connections of every voxel. We found higher centrality in parahippocampal gyrus and middle temporal gyrus after ST36 stimulation in comparison to the two control points. These regions are positively correlated to major hubs of the default mode network, which might be the primary network affected by chronic pain. The stronger integration of both regions within the whole-brain connectome after stimulation of ST36 might be a potential contributor to pain modulation by acupuncture. These findings highlight centrality mapping as a valuable analysis for future imaging studies investigating clinically relevant outcomes associated with physiological response to acupuncture stimulation. CLINICAL TRIAL REGISTRATION: NCT01079689, ClinicalTrials.gov.

12.
J Cogn Neurosci ; 28(1): 41-54, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26351994

RESUMEN

Complex human behavior is hierarchically organized. Whether or not syntax plays a role in this organization is currently under debate. The present ERP study uses piano performance to isolate syntactic operations in action planning and to demonstrate their priority over nonsyntactic levels of movement selection. Expert pianists were asked to execute chord progressions on a mute keyboard by copying the posture of a performing model hand shown in sequences of photos. We manipulated the final chord of each sequence in terms of Syntax (congruent/incongruent keys) and Manner (conventional/unconventional fingering), as well as the strength of its predictability by varying the length of the Context (five-chord/two-chord progressions). The production of syntactically incongruent compared to congruent chords showed a response delay that was larger in the long compared to the short context. This behavioral effect was accompanied by a centroparietal negativity in the long but not in the short context, suggesting that a syntax-based motor plan was prepared ahead. Conversely, the execution of the unconventional manner was not delayed as a function of Context and elicited an opposite electrophysiological pattern (a posterior positivity). The current data support the hypothesis that motor plans operate at the level of musical syntax and are incrementally translated to lower levels of movement selection.


Asunto(s)
Percepción Auditiva/fisiología , Encéfalo/fisiología , Potenciales Evocados/fisiología , Movimiento , Música , Estimulación Acústica , Adulto , Análisis de Varianza , Electroencefalografía , Femenino , Análisis de Fourier , Humanos , Masculino , Destreza Motora/fisiología , Estimulación Luminosa , Tiempo de Reacción , Adulto Joven
13.
PLoS One ; 10(6): e0129508, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26079870

RESUMEN

In sport events like Olympic Games or World Championships competitive athletes keep pushing the boundaries of human performance. Compared to team sports, high achievements in many athletic disciplines depend solely on the individual's performance. Contrasting previous research looking for expertise-related differences in brain anatomy at the group level, we aim to demonstrate changes in individual top athlete's brain, which would be averaged out in a group analysis. We compared structural magnetic resonance images (MRI) of three professional track-and-field athletes to age-, gender- and education-matched control subjects. To determine brain features specific to these top athletes, we tested for significant deviations in structural grey matter density between each of the three top athletes and a carefully matched control sample. While total brain volumes were comparable between athletes and controls, we show regional grey matter differences in striatum and thalamus. The demonstrated brain anatomy patterns remained stable and were detected after 2 years with Olympic Games in between. We also found differences in the fusiform gyrus in two top long jumpers. We interpret our findings in reward-related areas as correlates of top athletes' persistency to reach top-level skill performance over years.


Asunto(s)
Atletas , Encéfalo/anatomía & histología , Neuroanatomía/métodos , Atletismo/fisiología , Adulto , Rendimiento Atlético/fisiología , Cuerpo Estriado/anatomía & histología , Sustancia Gris/anatomía & histología , Humanos , Imagen por Resonancia Magnética , Masculino , Músculo Esquelético/fisiología , Resistencia Física/fisiología , Esfuerzo Físico/fisiología , Tálamo/anatomía & histología
14.
Front Hum Neurosci ; 9: 74, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25741269

RESUMEN

Acupuncture can be regarded as a complex somatosensory stimulation. Here, we evaluate whether the point locations chosen for a somatosensory stimulation with acupuncture needles differently change the brain activity in healthy volunteers. We used EEG, event-related fMRI, and resting-state functional connectivity fMRI to assess neural responses to standardized needle stimulation of the acupuncture point ST36 (lower leg) and two control point locations (CP1 same dermatome, CP2 different dermatome). Cerebral responses were expected to differ for stimulation in two different dermatomes (CP2 different from ST36 and CP1), or stimulation at the acupuncture point vs. the control points. For EEG, mu rhythm power increased for ST36 compared to CP1 or CP2, but not when comparing the two control points. The fMRI analysis found more pronounced insula and S2 (secondary somatosensory cortex) activation, as well as precuneus deactivation during ST36 stimulation. The S2 seed-based functional connectivity analysis revealed increased connectivity to right precuneus for both comparisons, ST36 vs. CP1 and ST36 vs. CP2, however in different regions. Our results suggest that stimulation at acupuncture points may modulate somatosensory and saliency processing regions more readily than stimulation at non-acupuncture point locations. Also, our findings suggest potential modulation of pain perception due to acupuncture stimulation.

15.
J Neurosci ; 33(40): 15868-78, 2013 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-24089493

RESUMEN

Perceptual learning requires the generalization of categorical perceptual sensitivity from trained to untrained items. For degraded speech, perceptual learning modulates activation in a left-lateralized network, including inferior frontal gyrus (IFG) and inferior parietal cortex (IPC). Here we demonstrate that facilitatory anodal transcranial direct current stimulation (tDCS(anodal)) can induce perceptual learning in healthy humans. In a sham-controlled, parallel design study, 36 volunteers were allocated to the three following intervention groups: tDCS(anodal) over left IFG, IPC, or sham. Participants decided on the match between an acoustically degraded and an undegraded written word by forced same-different choice. Acoustic degradation varied in four noise-vocoding levels (2, 3, 4, and 6 bands). Participants were trained to discriminate between minimal (/Tisch/-FISCH) and identical word pairs (/Tisch/-TISCH) over a period of 3 d, and tDCS(anodal) was applied during the first 20 min of training. Perceptual sensitivity (d') for trained word pairs, and an equal number of untrained word pairs, was tested before and after training. Increases in d' indicate perceptual learning for untrained word pairs, and a combination of item-specific and perceptual learning for trained word pairs. Most notably for the lowest intelligibility level, perceptual learning occurred only when tDCS(anodal) was applied over left IFG. For trained pairs, improved d' was seen on all intelligibility levels regardless of tDCS intervention. Over left IPC, tDCS(anodal) did not modulate learning but instead introduced a response bias during training. Volunteers were more likely to respond "same," potentially indicating enhanced perceptual fusion of degraded auditory with undegraded written input. Our results supply first evidence that neural facilitation of higher-order language areas can induce perceptual learning of severely degraded speech.


Asunto(s)
Lóbulo Frontal/fisiología , Percepción del Habla/fisiología , Habla/fisiología , Aprendizaje Verbal/fisiología , Estimulación Acústica , Adulto , Estimulación Eléctrica , Femenino , Humanos , Lenguaje , Masculino
16.
Eur J Neurosci ; 38(7): 3099-105, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23859464

RESUMEN

Helmholtz himself speculated about a role of the cochlea in the perception of musical dissonance. Here we indirectly investigated this issue, assessing the valence judgment of musical stimuli with variable consonance/dissonance and presented diotically (exactly the same dissonant signal was presented to both ears) or dichotically (a consonant signal was presented to each ear--both consonant signals were rhythmically identical but differed by a semitone in pitch). Differences in brain organisation underlying inter-subject differences in the percept of dichotically presented dissonance were determined with voxel-based morphometry. Behavioral results showed that diotic dissonant stimuli were perceived as more unpleasant than dichotically presented dissonance, indicating that interactions within the cochlea modulated the valence percept during dissonance. However, the behavioral data also suggested that the dissonance percept did not depend crucially on the cochlea, but also occurred as a result of binaural integration when listening to dichotic dissonance. These results also showed substantial between-participant variations in the valence response to dichotic dissonance. These differences were in a voxel-based morphometry analysis related to differences in gray matter density in the inferior colliculus, which strongly substantiated a key role of the inferior colliculus in consonance/dissonance representation in humans.


Asunto(s)
Percepción Auditiva , Colículos Inferiores/anatomía & histología , Música , Estimulación Acústica , Adulto , Femenino , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética , Masculino , Adulto Joven
17.
Diabetes Care ; 36(7): 1933-40, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23462665

RESUMEN

OBJECTIVE: Glucagon-like peptide-1 receptor agonists such as exenatide are known to influence neural activity in the hypothalamus of animals and to reduce energy intake. In humans, however, significant weight loss has been observed in only a subgroup of patients. Why only some individuals respond with weight loss and others do not remains unclear. In this functional magnetic resonance imaging (fMRI) study, we investigated differences in hypothalamic connectivity between "responders" (reduction in energy intake after exenatide infusion) and "nonresponders." RESEARCH DESIGN AND METHODS: We performed a randomized, double-blinded, placebo-controlled, cross-over fMRI study with intravenous administration of exenatide in obese male volunteers. During brain scanning with continuous exenatide or placebo administration, participants rated food and nonfood images. After each scanning session, energy intake was measured using an ad libitum buffet. Functional hypothalamic connectivity was assessed by eigenvector centrality mapping, a measure of connectedness throughout the brain. RESULTS: Responders showed significantly higher connectedness of the hypothalamus, which was specific for the food pictures condition, in the exenatide condition compared with placebo. Nonresponders did not show any significant exenatide-induced changes in hypothalamic connectedness. CONCLUSIONS: Our results demonstrate a central hypothalamic effect of peripherally administered exenatide that occurred only in the group that showed an exenatide-dependent anorexigenic effect. These findings indicate that the hypothalamic response seems to be the crucial factor for the effect of exenatide on energy intake.


Asunto(s)
Ingestión de Energía/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Péptidos/farmacología , Ponzoñas/farmacología , Adulto , Algoritmos , Glucemia/metabolismo , Estudios Cruzados , Método Doble Ciego , Exenatida , Humanos , Insulina/sangre , Imagen por Resonancia Magnética , Masculino , Adulto Joven
18.
J Neurol Neurosurg Psychiatry ; 83(8): 776-84, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22696587

RESUMEN

OBJECTIVE: Vascular lesions of the posterolateral thalamus typically result in a somatosensory syndrome in which some patients develop central neuropathic post-stroke pain (CPSP). Damage to the spinothalamic tract terminus is assumed to be a prerequisite for thalamic CPSP. At the nuclear level, it remains a matter of debate whether the ventral posterolateral nucleus (VPL) or the posterior portion of the ventral medial nucleus (VMpo) constitutes the decisive lesion site. The hypothesis of the study was that lesion location in thalamic CPSP patients differs from that in thalamic stroke patients without pain, and the aim was to identify whether this difference comprises the VPL and/or the VMpo. DESIGN: 30 patients with chronic thalamic stroke and a persistent contralateral somatosensory syndrome were examined. CPSP patients (n=18) were compared with non-pain control patients. By coregistration of a digitised thalamic atlas with T1 weighted MR images, lesion clusters were allocated to the thalamic nuclei. RESULTS: VPL was affected in both groups, but CPSP lesion clusters comprised the more posterior, inferior and lateral parts of the VPL compared with controls. Additional partial involvement of the VMpo was seen in only three pain patients. In three other pain patients, lesions involved neither the VPL nor the VMpo, but mainly affected the anterior pulvinar. CONCLUSION: This study specifies the role of the VPL in thalamic CPSP and shows that the posterolateratal and inferior parts in particular are critically lesioned in pain patients. In this thalamic subregion, afferents of the spinothalamic tract are known to terminate. In contrast, the data do not support a pivotal impact of the VMpo on thalamic CPSP.


Asunto(s)
Accidente Cerebrovascular/patología , Enfermedades Talámicas/patología , Tálamo/patología , Adulto , Anciano , Anciano de 80 o más Años , Cefalea/etiología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neuroimagen , Estudios Prospectivos , Trastornos Somatosensoriales/etiología , Trastornos Somatosensoriales/patología , Accidente Cerebrovascular/complicaciones , Enfermedades Talámicas/complicaciones , Núcleos Talámicos Ventrales/patología
19.
Hum Brain Mapp ; 30(4): 1168-87, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18465747

RESUMEN

Similar to the posterior alpha rhythm, pericentral (Rolandic) EEG rhythms in the alpha and beta frequency range are referred to as "idle rhythms" indicating a "resting state" of the respective system. The precise function of these rhythms is not clear. We used simultaneous EEG-fMRI during a bimanual motor task to localize brain areas involved in Rolandic alpha and beta EEG rhythms. The identification of these rhythms in the MR environment was achieved by a blind source separation algorithm. Rhythm "strength", i.e. spectral power determined by wavelet analysis, inversely correlated most strongly with the fMRI-BOLD signal in the postcentral cortex for the Rolandic alpha (mu) rhythm and in the precentral cortex for the Rolandic beta rhythm. FMRI correlates of Rolandic alpha and beta rhythms were distinct from those associated with the posterior "classical" alpha rhythm, which correlated inversely with the BOLD signal in the occipital cortex. An inverse correlation with the BOLD signal in the respective sensory area seems to be a general feature of "idle rhythms".


Asunto(s)
Ritmo alfa , Ritmo beta , Corteza Motora/irrigación sanguínea , Corteza Motora/fisiología , Corteza Somatosensorial/irrigación sanguínea , Corteza Somatosensorial/fisiología , Estimulación Acústica , Adulto , Algoritmos , Mapeo Encefálico , Señales (Psicología) , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Oxígeno/sangre , Desempeño Psicomotor/fisiología , Tiempo de Reacción , Reproducibilidad de los Resultados , Estadística como Asunto , Análisis y Desempeño de Tareas , Factores de Tiempo , Adulto Joven
20.
Neuroimage ; 42(2): 483-90, 2008 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-18586526

RESUMEN

Functional magnetic resonance imaging (fMRI) measures neural activity indirectly via its slow vascular/metabolic consequences. At a temporal resolution on the order of seconds, fMRI does not reveal the real 'language of neurons', spelt out by fast electrical discharges ('spikes') which occur on a time scale of milliseconds. In animal studies, these limitations have been addressed by adding invasive electrode measurements to fMRI. Here, we propose to circumvent this 'inverse problem of fMRI' by deriving a noninvasive spike measure from recordings of ultrafast electroencephalography (EEG) signals during fMRI. We demonstrate how in response to median nerve stimulation 600 Hz oscillatory EEG signals can be measured reliably during fMRI. These high-frequency bursts (HFBs) are supposed to reflect population spikes in the thalamus and the somatosensory cortex, respectively. We show that distinct fMRI activations in these two generator structures can be attributed to spontaneous HFB fluctuations. Thus, our approach allowed the noninvasive identification of neural processes along the thalamocortical pathway unfolding at a millisecond time scale.


Asunto(s)
Potenciales de Acción/fisiología , Relojes Biológicos/fisiología , Corteza Cerebral/fisiología , Electroencefalografía/métodos , Imagen por Resonancia Magnética/métodos , Tálamo/fisiología , Adulto , Femenino , Humanos , Masculino , Adulto Joven
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