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1.
Gerontol Geriatr Educ ; 44(2): 185-195, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36189977

RESUMEN

Despite the growing prevalence of dementia, few models of training for health professional students on this topic have been formally evaluated or widely disseminated. The Dementia Friends (DF) initiative is part of a global movement to improve the way people think, act, and talk about dementia. The impact of these sessions on the dementia-related knowledge and attitudes of health professional trainees has not been adequately assessed. Health professional students (medicine n = 70, physical therapy n = 30, pharmacy n = 28) participated in one-hour DF information sessions, offered in-person or via videoconference. The Dementia Attitudes Scale (DAS), a validated 20-item questionnaire, was administered before and after each session. Pre- and post-session DAS scores were compared using a paired t-test. Students' dementia-friendly action plans were analyzed qualitatively. Of 128 students, 102 (80%) completed both the pre- and post-DAS. The mean DAS score increased significantly from 105.8 (12.3) to 120.8 (10.5) following the DF sessions (p < .001). Students' dementia-friendly action plans included improving communication, promoting quality of life, and learning more about dementia. The DF information session model significantly increased the knowledge and positive attitudes of health professional students toward those living with dementia. Further use and study of this model is appropriate.


Asunto(s)
Demencia , Geriatría , Estudiantes de Enfermería , Humanos , Calidad de Vida , Amigos , Geriatría/educación , Encuestas y Cuestionarios
2.
J Sports Sci Med ; 20(4): 594-617, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-35321131

RESUMEN

The prevalence of inter-limb strength differences is well documented in the literature however, there are inconsistencies related to measurement and reporting, and the normative values and effects associated with inter-limb asymmetry. Therefore, the aims of this systematic review were to: 1) assess the appropriateness of existing indices for the calculation of asymmetry, 2) interrogate the evidence basis for literature reported thresholds used to define asymmetry and 3) summarise normative levels of inter-limb strength asymmetry and their effects on injury and performance. To conduct this systematic review, scientific databases (PubMed, Scopus, SPORTDiscus and Web of Science) were searched and a total of 3,594 articles were retrieved and assessed for eligibility and article quality. The robustness of each identified asymmetry index was assessed, and the evidence-basis of the identified asymmetry thresholds was appraised retrospectively using the references provided. Fifty-three articles were included in this review. Only four of the twelve identified indices were unaffected by the limitations associated with selecting a reference limb. Eighteen articles applied a threshold to original research to identify "abnormal" asymmetry, fifteen of which utilised a threshold between 10-15%, yet this threshold was not always supported by appropriate evidence. Asymmetry scores ranged between and within populations from approximate symmetry to asymmetries larger than 15%. When reporting the effects of strength asymmetries, increased injury risk and detriments to performance were often associated with larger asymmetry, however the evidence was inconsistent. Limitations of asymmetry indices should be recognised, particularly those that require selection of a reference limb. Failure to reference the origin of the evidence for an asymmetry threshold reinforces doubt over the use of arbitrary thresholds, such as 10-15%. Therefore, an individual approach to defining asymmetry may be necessary to refine robust calculation methods and to establish appropriate thresholds across various samples and methodologies that enable appropriate conclusions to be drawn.


Asunto(s)
Extremidad Inferior , Humanos , Estudios Retrospectivos
3.
Home Healthc Now ; 37(1): 33-35, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30608465

RESUMEN

Nurses report significant gaps in communication among patients discharged from the hospital with home healthcare (HHC) services. The aim of this pilot study was to quantify the contents of HHC admission packets used to guide nurses' first home visit after hospital discharge. We evaluated 20 randomly selected charts of older adults admitted to HHC after a hospitalization for heart failure. Admission packets contained nearly 50 pages of material, which frequently included duplicate documents printed from the hospital-based electronic health record (EHR). Despite the plethora of documents, most packets omitted key information, such as patients' cognitive and functional status, and even discharge summaries, which would be relevant and actionable for HHC nurses. Moreover, admission packets contained multiple, often discordant, EHR-generated medication lists, which makes reconciliation challenging for nurses and puts vulnerable patients at risk for adverse drug events. Overall, there is an urgent need to improve health information exchange between hospitals and HHC agencies, which will simultaneously promote nurse efficiency and patient safety.


Asunto(s)
Continuidad de la Atención al Paciente/organización & administración , Intercambio de Información en Salud/estadística & datos numéricos , Servicios de Atención de Salud a Domicilio/organización & administración , Conciliación de Medicamentos/organización & administración , Enfermeros de Salud Comunitaria/organización & administración , Alta del Paciente/estadística & datos numéricos , Anciano , Femenino , Humanos , Proyectos Piloto
4.
Geriatr Nurs ; 40(3): 277-283, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30503605

RESUMEN

Despite patient safety initiatives to improve care transitions, prior research largely neglects to elicit feedback from home health nurses regarding health information exchange. The goal of this quality improvement study was to identify opportunities to facilitate information transfer during hospital-to-home-health-care transitions for older adults with heart failure. We conducted focus groups with 19 nurses employed by a single healthcare system using two commercially available electronic health record (EHR) vendors. We analyzed interview transcripts following an immersion/crystallization approach to identify themes. Average participants were females in their mid-fifties with 15 years of home health experience. Nurses reported challenges with hospital-to-home-health-care information exchange, specifically: 1) poor medication management, 2) ineffective communication, 3) technology issues, and 4) patient factors. Nurses identified several opportunities for improvement, including discordant EHR-generated medication lists, which may be amenable to technological solutions. Local quality improvement efforts should incorporate nurses' suggestions and leverage existing best practices.


Asunto(s)
Registros Electrónicos de Salud/normas , Intercambio de Información en Salud , Servicios de Atención de Salud a Domicilio/organización & administración , Enfermeros de Salud Comunitaria/organización & administración , Femenino , Grupos Focales , Insuficiencia Cardíaca/enfermería , Hospitales , Humanos , Conciliación de Medicamentos/organización & administración , Persona de Mediana Edad , Enfermeros de Salud Comunitaria/estadística & datos numéricos , Alta del Paciente , Transferencia de Pacientes , Mejoramiento de la Calidad
5.
Neuroimage Clin ; 8: 429-39, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26106568

RESUMEN

Motor speech disorders, including apraxia of speech (AOS), account for over 50% of the communication disorders following stroke. Given its prevalence and impact, and the need to understand its neural mechanisms, we used resting state functional MRI to examine functional connectivity within a network of regions previously hypothesized as being associated with AOS (bilateral anterior insula (aINS), inferior frontal gyrus (IFG), and ventral premotor cortex (PM)) in a group of 32 left hemisphere stroke patients and 18 healthy, age-matched controls. Two expert clinicians rated severity of AOS, dysarthria and nonverbal oral apraxia of the patients. Fifteen individuals were categorized as AOS and 17 were AOS-absent. Comparison of connectivity in patients with and without AOS demonstrated that AOS patients had reduced connectivity between bilateral PM, and this reduction correlated with the severity of AOS impairment. In addition, AOS patients had negative connectivity between the left PM and right aINS and this effect decreased with increasing severity of non-verbal oral apraxia. These results highlight left PM involvement in AOS, begin to differentiate its neural mechanisms from those of other motor impairments following stroke, and help inform us of the neural mechanisms driving differences in speech motor planning and programming impairment following stroke.


Asunto(s)
Apraxias/fisiopatología , Corteza Cerebral/fisiopatología , Conectoma/métodos , Red Nerviosa/fisiopatología , Accidente Cerebrovascular/fisiopatología , Anciano , Apraxias/etiología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/complicaciones
6.
Hum Brain Mapp ; 36(5): 1951-62, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25627959

RESUMEN

Over 90 percent of patients with Parkinson's disease experience speech-motor impairment, namely, hypokinetic dysarthria characterized by reduced pitch and loudness. Resting-state functional connectivity analysis of blood oxygen level-dependent functional magnetic resonance imaging is a useful measure of intrinsic neural functioning. We utilized resting-state functional connectivity modeling to analyze the intrinsic connectivity in patients with Parkinson's disease within a vocalization network defined by a previous meta-analysis of speech (Brown et al., 2009). Functional connectivity of this network was assessed in 56 patients with Parkinson's disease and 56 gender-, age-, and movement-matched healthy controls. We also had item 5 and 18 of the UPDRS, and the PDQ-39 Communication subscale available for correlation with the voice network connectivity strength in patients. The within-group analyses of connectivity patterns demonstrated a lack of subcortical-cortical connectivity in patients with Parkinson's disease. At the cortical level, we found robust (homotopic) interhemispheric connectivity but only inconsistent evidence for many intrahemispheric connections. When directly contrasted to the control group, we found a significant reduction of connections between the left thalamus and putamen, and cortical motor areas, as well as reduced right superior temporal gyrus connectivity. Furthermore, most symptom measures correlated with right putamen, left cerebellum, left superior temporal gyrus, right premotor, and left Rolandic operculum connectivity in the voice network. The results reflect the importance of (right) subcortical nodes and the superior temporal gyrus in Parkinson's disease, enhancing our understanding of the neurobiological underpinnings of vocalization impairment in Parkinson's disease.


Asunto(s)
Encéfalo/fisiopatología , Enfermedad de Parkinson/fisiopatología , Voz , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Actividad Motora/fisiología , Vías Nerviosas/fisiopatología , Descanso , Índice de Severidad de la Enfermedad , Voz/fisiología
7.
Hum Brain Mapp ; 35(7): 3499-516, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25050431

RESUMEN

Cortico-basal ganglia connections are involved in a range of behaviors within motor, cognitive, and emotional domains; however, the whole-brain functional connections of individual nuclei are poorly understood in humans. The first aim of this study was to characterize and compare the connectivity of the subthalamic nucleus (STN) and globus pallidus pars interna (GPi) using meta-analytic connectivity modeling. Structure-based activation likelihood estimation meta-analyses were performed for STN and GPi seeds using archived functional imaging coordinates from the BrainMap database. Both regions coactivated with caudate, putamen, thalamus, STN, GPi, and GPe, SMA, IFG, and insula. Contrast analyses also revealed coactivation differences within SMA, IFG, insula, and premotor cortex. The second aim of this study was to examine the degree of overlap between the connectivity maps derived for STN and GPi and a functional activation map representing the speech network. To do this, we examined the intersection of coactivation maps and their respective contrasts (STN > GPi and GPi > STN) with a coordinate-based meta-analysis of speech function. In conjunction with the speech map, both STN and GPi coactivation maps revealed overlap in the anterior insula with GPi map additionally showing overlap in the supplementary motor area (SMA). Among cortical regions activated by speech tasks, STN was found to have stronger connectivity than GPi with regions involved in cognitive linguistic processes (pre-SMA, dorsal anterior insula, and inferior frontal gyrus), while GPi demonstrated stronger connectivity to regions involved in motor speech processes (middle insula, SMA, and premotor cortex).


Asunto(s)
Mapeo Encefálico , Globo Pálido/fisiología , Vías Nerviosas/fisiología , Habla/fisiología , Núcleo Subtalámico/fisiología , Bases de Datos Factuales/estadística & datos numéricos , Lateralidad Funcional , Humanos , Funciones de Verosimilitud
8.
J Acoust Soc Am ; 135(5): 3036-44, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24815283

RESUMEN

Previous research has shown that vocal errors can be simulated using a pitch perturbation technique. Two types of responses are observed when subjects are asked to ignore changes in pitch during a steady vowel production, a compensatory response countering the direction of the perceived change in pitch and a following response in the same direction as the pitch perturbation. The present study investigated the nature of these responses by asking subjects to volitionally change their voice fundamental frequency either in the opposite direction ("opposing" group) or the same direction ("following" group) as the pitch shifts (±100 cents, 1000 ms) presented during the speaker's production of an /a/ vowel. Results showed that voluntary responses that followed the stimulus directions had significantly shorter latencies (150 ms) than opposing responses (360 ms). In addition, prior to the slower voluntary opposing responses, there were short latency involuntary responses that followed the stimulus direction. These following responses may involve mechanisms of imitation or vocal shadowing of acoustical stimuli when subjects are predisposed to respond to a change in frequency of a sound. The slower opposing responses may represent a control strategy that requires monitoring and correcting for errors between the feedback signal and the intended vocal goal.


Asunto(s)
Retroalimentación Psicológica/fisiología , Retroalimentación Sensorial/fisiología , Distorsión de la Percepción/fisiología , Fonación/fisiología , Percepción de la Altura Tonal/fisiología , Adaptación Fisiológica/fisiología , Adulto , Femenino , Humanos , Masculino , Destreza Motora , Fonética , Tiempo de Reacción , Reflejo , Calidad de la Voz , Volición , Adulto Joven
9.
Brain Lang ; 132: 7-13, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24681401

RESUMEN

Voice control is critical to communication. To date, studies have used behavioral, electrophysiological and functional data to investigate the neural correlates of voice control using perturbation tasks, but have yet to examine the interactions of these neural regions. The goal of this study was to use structural equation modeling of functional neuroimaging data to examine network properties of voice with and without perturbation. Results showed that the presence of a pitch shift, which was processed as an error in vocalization, altered connections between right STG and left STG. Other regions that revealed differences in connectivity during error detection and correction included bilateral inferior frontal gyrus, and the primary and pre motor cortices. Results indicated that STG plays a critical role in voice control, specifically, during error detection and correction. Additionally, pitch perturbation elicits changes in the voice network that suggest the right hemisphere is critical to pitch modulation.


Asunto(s)
Corteza Cerebral/fisiología , Retroalimentación Fisiológica/fisiología , Modelos Neurológicos , Discriminación de la Altura Tonal/fisiología , Voz/fisiología , Adulto , Mapeo Encefálico/métodos , Neuroimagen Funcional/métodos , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Corteza Motora/fisiología , Red Nerviosa/fisiología , Percepción de la Altura Tonal/fisiología , Corteza Prefrontal/fisiología , Lóbulo Temporal/fisiología
10.
Front Neurosci ; 8: 46, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24634644

RESUMEN

It is advantageous to study a wide range of vocal abilities in order to fully understand how vocal control measures vary across the full spectrum. Individuals with absolute pitch (AP) are able to assign a verbal label to musical notes and have enhanced abilities in pitch identification without reliance on an external referent. In this study we used dynamic causal modeling (DCM) to model effective connectivity of ERP responses to pitch perturbation in voice auditory feedback in musicians with relative pitch (RP), AP, and non-musician controls. We identified a network compromising left and right hemisphere superior temporal gyrus (STG), primary motor cortex (M1), and premotor cortex (PM). We specified nine models and compared two main factors examining various combinations of STG involvement in feedback pitch error detection/correction process. Our results suggest that modulation of left to right STG connections are important in the identification of self-voice error and sensory motor integration in AP musicians. We also identify reduced connectivity of left hemisphere PM to STG connections in AP and RP groups during the error detection and corrections process relative to non-musicians. We suggest that this suppression may allow for enhanced connectivity relating to pitch identification in the right hemisphere in those with more precise pitch matching abilities. Musicians with enhanced pitch identification abilities likely have an improved auditory error detection and correction system involving connectivity of STG regions. Our findings here also suggest that individuals with AP are more adept at using feedback related to pitch from the right hemisphere.

11.
Neuropsychologia ; 51(8): 1471-80, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23665378

RESUMEN

The integration of auditory feedback with vocal motor output is important for the control of voice fundamental frequency (F0). We used a pitch-shift paradigm where subjects respond to an alteration, or shift, of voice pitch auditory feedback with a reflexive change in F0. We presented varying magnitudes of pitch shifted auditory feedback to subjects during vocalization and passive listening and measured event related potentials (ERPs) to the feedback shifts. Shifts were delivered at +100 and +400 cents (200 ms duration). The ERP data were modeled with dynamic causal modeling (DCM) techniques where the effective connectivity between the superior temporal gyrus (STG), inferior frontal gyrus and premotor areas were tested. We compared three main factors: the effect of intrinsic STG connectivity, STG modulation across hemispheres and the specific effect of hemisphere. A Bayesian model selection procedure was used to make inference about model families. Results suggest that both intrinsic STG and left to right STG connections are important in the identification of self-voice error and sensory motor integration. We identified differences in left-to-right STG connections between 100 cent and 400 cent shift conditions suggesting that self- and non-self-voice error are processed differently in the left and right hemisphere. These results also highlight the potential of DCM modeling of ERP responses to characterize specific network properties of forward models of voice control.


Asunto(s)
Corteza Auditiva/fisiología , Potenciales Evocados/fisiología , Retroalimentación Sensorial/fisiología , Percepción de la Altura Tonal/fisiología , Voz/fisiología , Adolescente , Mapeo Encefálico , Electroencefalografía , Análisis Factorial , Femenino , Lateralidad Funcional , Humanos , Masculino , Modelos Neurológicos , Vías Nerviosas/fisiología , Dinámicas no Lineales , Psicoacústica , Adulto Joven
12.
J Pain ; 14(7): 663-75, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23685185

RESUMEN

UNLABELLED: The diversity of chronic pain syndromes and the methods employed to study them make integrating experimental findings challenging. This study performed coordinate-based meta-analyses using voxel-based morphometry imaging results to examine gray matter volume (GMV) differences between chronic pain patients and healthy controls. There were 12 clusters where GMV was decreased in patients compared with controls, including many regions thought to be part of the "pain matrix" of regions involved in pain perception, but also including many other regions that are not commonly regarded as pain-processing areas. The right hippocampus and parahippocampal gyrus were the only regions noted to have increased GMV in patients. Functional characterizations were implemented using the BrainMap database to determine which behavioral domains were significantly represented in these regions. The most common behavioral domains associated with these regions were cognitive, affective, and perceptual domains. Because many of these regions are not classically connected with pain and because there was such significance in functionality outside of perception, it is proposed that many of these regions are related to the constellation of comorbidities of chronic pain, such as fatigue and cognitive and emotional impairments. Further research into the mechanisms of GMV changes could provide a perspective on these findings. PERSPECTIVE: Quantitative meta-analyses revealed structural differences between brains of individuals with chronic pain and healthy controls. These differences may be related to comorbidities of chronic pain.


Asunto(s)
Encéfalo/patología , Dolor Crónico/patología , Humanos
13.
J Neuropsychol ; 7(1): 29-44, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22804795

RESUMEN

Tourette syndrome (TS) is a neuro-developmental disorder characterized by the occurrence of motor and vocal tics: involuntary, repetitive, stereotyped behaviours that occur with a limited duration, often typically many times in a single day. Previous studies suggest that children and adolescents with TS may undergo compensatory, neuroplastic changes in brain structure and function that help them gain control over their tics. In the current study we used single-pulse and dual-site paired-pulse transcranial magnetic stimulation (TMS), in conjunction with a manual choice reaction time task that induces high levels of inter-manual conflict, to investigate this conjecture in a group of children and adolescents with TS, but without co-morbid Attention Deficit Hyperactivity Disorder (ADHD). We found that performance on the behavioural response-conflict task did not differ between the adolescents with TS and a group of age-matched typically developing individuals. By contrast, our study demonstrated that cortical excitability, as measured by TMS-induced motor-evoked potentials (MEPs), was significantly reduced in the TS group in the period immediately preceding a finger movement. This effect is interpreted as consistent with previous suggestions that the cortical hyper-excitability that may give rise to tics in TS is actively suppressed by cognitive control mechanisms. Finally, we found no reliable evidence for altered patterns of functional inter-hemispheric connectivity in TS. These results provide evidence for compensatory brain reorganization that may underlie the increased self-regulation mechanisms that have been hypothesized to bring about the control of tics during adolescence.


Asunto(s)
Potenciales Evocados Motores/fisiología , Lateralidad Funcional/fisiología , Movimiento/fisiología , Síndrome de Tourette/fisiopatología , Adolescente , Niño , Electromiografía , Femenino , Mano/inervación , Humanos , Masculino , Tiempo de Reacción/fisiología , Factores de Tiempo , Estimulación Magnética Transcraneal , Adulto Joven
14.
Neurosci Biobehav Rev ; 37(6): 1016-25, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23017869

RESUMEN

Tourette syndrome [TS] is a neurodevelopmental disorder characterised by chronic vocal and motor tics. TS has been associated with dysfunctional cognitive (inhibitory) control of behaviour, however the evidence for this, beyond the occurrence of tics, is scant. Furthermore, in recent studies of uncomplicated TS, it has been shown that adolescents with TS exhibit paradoxically enhanced cognitive control of motor output, consistent with the typical developmental profile of increasing control of tics during adolescence. Here we present arguments, together with new data, that run counter to the widely held view that prefrontal cortex (PFC) is the source of inhibitory task-control signals. Instead, we argue that PFC should be viewed as a source of facilitatory signals that bias competition in brain areas more directly involved in motor execution. Importantly, we argue that in TS, over-activation of PFC may contribute to the hyper-excitability of motor regions and the occurrence of tics; and that compensatory changes, leading to enhanced cognitive control in TS, may primarily be implemented by distributed changes in local cortical excitability.


Asunto(s)
Trastornos del Conocimiento/etiología , Inhibición Psicológica , Trastornos del Movimiento/etiología , Corteza Prefrontal/fisiopatología , Síndrome de Tourette , Adolescente , Análisis de Varianza , Niño , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Oxígeno/sangre , Corteza Prefrontal/irrigación sanguínea , Tiempo de Reacción/fisiología , Síndrome de Tourette/complicaciones , Síndrome de Tourette/patología , Síndrome de Tourette/psicología
15.
Neuroimage ; 61(1): 314-22, 2012 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-22406500

RESUMEN

Auditory feedback is important for the control of voice fundamental frequency (F0). In the present study we used neuroimaging to identify regions of the brain responsible for sensory control of the voice. We used a pitch-shift paradigm where subjects respond to an alteration, or shift, of voice pitch auditory feedback with a reflexive change in F0. To determine the neural substrates involved in these audio-vocal responses, subjects underwent fMRI scanning while vocalizing with or without pitch-shifted feedback. The comparison of shifted and unshifted vocalization revealed activation bilaterally in the superior temporal gyrus (STG) in response to the pitch shifted feedback. We hypothesize that the STG activity is related to error detection by auditory error cells located in the superior temporal cortex and efference copy mechanisms whereby this region is responsible for the coding of a mismatch between actual and predicted voice F0.


Asunto(s)
Sensación/fisiología , Voz/fisiología , Estimulación Acústica , Adulto , Algoritmos , Corteza Auditiva/fisiología , Mapeo Encefálico , Corteza Cerebral/fisiología , Interpretación Estadística de Datos , Retroalimentación Sensorial , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Músculos Laríngeos/inervación , Músculos Laríngeos/fisiología , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/fisiología , Oxígeno/sangre , Percepción de la Altura Tonal/fisiología , Lóbulo Temporal/fisiología , Adulto Joven
16.
Curr Biol ; 21(7): 580-5, 2011 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-21439830

RESUMEN

Children with neurological disorders may follow unique developmental trajectories whereby they undergo compensatory neuroplastic changes in brain structure and function that help them gain control over their symptoms. We used behavioral and brain imaging techniques to investigate this conjecture in children with Tourette syndrome (TS). Using a behavioral task that induces high levels of intermanual conflict, we show that individuals with TS exhibit enhanced control of motor output. Then, using structural (diffusion-weighted imaging) brain imaging techniques, we demonstrate widespread differences in the white matter (WM) microstructure of the TS brain that include alterations in the corpus callosum and forceps minor (FM) WM that significantly predict tic severity in TS. Most importantly, we show that task performance for the TS group (but not for controls) is strongly predicted by the WM microstructure of the FM pathways that lead to the prefrontal cortex and by the functional magnetic resonance imaging blood oxygen level-dependent response in prefrontal areas connected by these tracts. These results provide evidence for compensatory brain reorganization that may underlie the increased self-regulation mechanisms that have been hypothesized to bring about the control of tics during adolescence.


Asunto(s)
Encéfalo/fisiopatología , Encéfalo/ultraestructura , Plasticidad Neuronal , Neuronas/metabolismo , Síndrome de Tourette/patología , Síndrome de Tourette/fisiopatología , Adolescente , Encéfalo/metabolismo , Mapeo Encefálico , Niño , Cuerpo Calloso/fisiopatología , Cuerpo Calloso/ultraestructura , Imagen de Difusión por Resonancia Magnética , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Actividad Motora , Tics
17.
Q J Exp Psychol (Hove) ; 64(5): 839-54, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21213193

RESUMEN

The intention to execute a movement can modulate our perception of sensory events, and this modulation is observed ahead of both ocular and upper limb movements. However, theoretical accounts of these effects, and also the empirical data, are often contradictory. Accounts of "active touch", and the premotor theory of attention, have emphasized how movement intention leads to enhanced perceptual processing at the target of a movement, or on the to-be-moved effector. By contrast, recent theories of motor control emphasize how internal "forward" model (FM) estimates may be used to cancel or attenuate sensory signals that arise as a result of self-generated movements. We used behavioural and functional brain imaging (functional magnetic resonance imaging, fMRI) to investigate how perception of a somatosensory stimulus differed according to whether it was delivered to a hand that was about to execute a reaching movement or the alternative, nonmoving, hand. The results of our study demonstrate that a somatosensory stimulus delivered to a hand that is being prepared for movement is perceived to have occurred later than when that same stimulus is delivered to a nonmoving hand. This result indicates that it takes longer for a tactile stimulus to be detected when it is delivered to a moving limb and may correspond to a change in perceptual threshold. Our behavioural results are paralleled by the results of our fMRI study that demonstrated that there were significantly reduced blood-oxygen-level-dependent (BOLD) responses within the parietal operculum and insula following somatosensory stimulation of the hand being prepared for movement, compared to when an identical stimulus was delivered to a nonmoving hand. These findings are consistent with the prediction of FM accounts of motor control that postulate that central sensory suppression of somatosensation accompanies self-generated limb movements, and with previous reports indicating that effects of sensory suppression are observed in higher order somatosensory regions.


Asunto(s)
Intención , Movimiento/fisiología , Corteza Somatosensorial/irrigación sanguínea , Corteza Somatosensorial/fisiología , Percepción del Tacto/fisiología , Adulto , Análisis de Varianza , Mapeo Encefálico , Femenino , Lateralidad Funcional/fisiología , Mano/inervación , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Juicio/fisiología , Imagen por Resonancia Magnética/métodos , Masculino , Oxígeno/sangre , Estimulación Física/métodos , Factores de Tiempo , Adulto Joven
18.
Cogn Neurosci ; 2(3-4): 227-243, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22299020

RESUMEN

Several common neuropsychiatric disorders (e.g., obsessive-compulsive disorder, Tourette syndrome (TS), autistic spectrum disorder) are associated with unpleasant bodily sensations that are perceived as an urge for action. Similarly, many of our everyday behaviors are also characterized by bodily sensations that we experience as urges for action. Where do these urges originate? In this paper, we consider the nature and the functional anatomy of "urges-for-action," both in the context of everyday behaviors such as yawning, swallowing, and micturition, and in relation to clinical disorders in which the urge-for-action is considered pathological and substantially interferes with activities of daily living (e.g., TS). We review previous frameworks for thinking about behavioral urges and demonstrate that there is considerable overlap between the functional anatomy of urges associated with everyday behaviors such as swallowing, yawning, and micturition, and those urges associated with the generation of tics in TS. Specifically, we show that the limbic sensory and motor regions-insula and mid-cingulate cortex-are common to all of these behaviors, and we argue that this "motivation-for-action" network should be considered distinct from an "intentional action" network, associated with regions of premotor and parietal cortex, which may be responsible for the perception of "willed intention" during the execution of goal-directed actions.

19.
Cogn Neurosci ; 2(1): 47-56, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24168423

RESUMEN

The intention to execute a movement can modulate our perception of sensory events; however, theoretical accounts of these effects, and also empirical data, are often contradictory. We investigated how perception of a somatosensory stimulus differed according to whether it was delivered to a limb being prepared for movement or to a nonmoving limb. Our results demonstrate that individuals perceive a somatosensory stimulus delivered to the "moving" limb as occurring significantly later than when an identical stimulus is delivered to a "nonmoving" limb. Furthermore, human brain imaging (fMRI) analyses demonstrate that this modulation is accompanied by a significant decrease in BOLD signal in the right parietal operculum (SII) for stimuli delivered to the moving limb. These results indicate that during movement preparation a network of premotor brain areas may facilitate movement execution by attenuating the processing of behaviorally irrelevant signals within higher-order secondary somatosensory (SII) areas.

20.
Cogn Neurosci ; 2(3-4): 252-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-24168551

RESUMEN

In our article we considered the nature and the functional anatomy of "urges-for-action," both in the context of everyday behaviors such as yawning, swallowing, and micturition, and in relation to clinical disorders in which the urge-for-action is considered pathological (e.g., Tourette syndrome), and we argued for a key role for the insular and cingulate cortices in experiencing the urge-for-action. Here we seek to address some of the key points raised within several of the interesting commentaries on, and challenges to, our paper.

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