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Biomedical subjects

Gottfried Schlaug

Publications and source records attributed to Gottfried Schlaug.

At least 37 records · Page 2Linked to original sources
PubMed2005

Markedly reduced apparent blood volume on bolus contrast magnetic resonance imaging as a predictor of hemorrhage after thrombolytic therapy for acute ischemic stroke.

BACKGROUND AND PURPOSE: Accurate assessment of the risk of hemorrhage could help to improve patient selection for thrombolytic therapy and reduce hemorrhagic complications, especially for patients with longer or uncertain time after symptom onset. This study sought to define characteristics of hemodynamic magnetic resonance imaging (MRI), which best predict hemorrhage. METHODS: Bolus contrast and diffusion MRI were performed before intravenous tissue plasminogen activator (tPA) therapy in 20 patients presenting with acute stroke symptoms within the first 6 hours after symptom onset. Hemorrhage was assessed on follow-up MRI (n=15) and computed tomography (n=5) scans. RESULTS: Of the 20 patients studied, 5 had detectable hemorrhage on follow-up scans. Blood volume maps demonstrated virtually no signal within much of the hemorrhagic region, indicating contrast did not arrive by the end of the imaging series (80 seconds). Within the hemodynamically abnormal region, a threshold of at least 126 voxels with blood volume <5% of contralateral normal gray matter separated hemorrhagic patients from nonhemorrhagic with a sensitivity of 100% and a specificity of 73% (P<0.01). All subjects with hemorrhage were at least partially reperfused after thrombolysis, whereas most false-positives did not reperfuse (P<0.05). The number of low blood volume voxels within individual patients correlated with the number of voxels with apparent diffusion coefficient values <550x10(-6) mm2/s (P<0.019), another previously proposed predictor of hemorrhage. CONCLUSIONS: Extremely low or completely absent contrast arrival may indicate tissue-at-risk for hemorrhage before tPA treatment and thus may aid in risk-benefit assessments. Occurrence of hemorrhage within at-risk areas may depend on tissue reperfusion.

Adult↗
PubMed2005

How do we modulate our emotions? Parametric fMRI reveals cortical midline structures as regions specifically involved in the processing of emotional valences.

One of the major problems in affective neuroscience of healthy subjects as well as of patients with emotional dysfunctions is to disentangle emotional core functions and non-emotional processes. Emotional valence is considered an emotional key process. The present study employed a parametric functional magnetic resonance imaging (fMRI) study to address this question. Thirteen healthy volunteers were scanned during emotional stimulus processing (International Affective Picture System). The presented pictures covered the entire range of emotional valences. The fMRI data were consecutively subjected to a preliminary categorical (valence-independent) and a detailed parametric analysis, the latter using individual valence ratings as regressor. The parametric analysis revealed a linear valence-dependent modulation of the BOLD signal in the orbito- and dorsomedial prefrontal cortex (OMPFC, DMPFC), medial parietal cortex (MPC), and insula. In addition, we observed that emotional valence exerts its effects predominantly via modulation of signal decreases. We conclude that the psychological concept of emotional valence may be related to neural processing in cortical midline regions.

Adult↗
PubMed2005

Effects of music training on the child's brain and cognitive development.

Research has revealed structural and functional differences in the brains of adult instrumental musicians compared to those of matched nonmusician controls, with intensity/duration of instrumental training and practice being important predictors of these differences. Nevertheless, the differential contributions of nature and nurture to these differences are not yet clear. The musician-nonmusician comparison is an ideal model for examining whether and, if so, where such functional and structural brain plasticity occurs, because musicians acquire and continuously practice a variety of complex motor, auditory, and multimodal skills (e.g., translating visually perceived musical symbols into motor commands while simultaneously monitoring instrumental output and receiving multisensory feedback). Research has also demonstrated that music training in children results in long-term enhancement of visual-spatial, verbal, and mathematical performance. However, the underlying neural bases of such enhancements and whether the intensity and duration of instrumental training or other factors, such as extracurricular activities, attention, motivation, or instructional methods can contribute to or predict these enhancements are yet unknown. Here we report the initial results from our studies examining the brain and cognitive effects of instrumental music training on young children in a longitudinal study and a cross-sectional comparison in older children. Further, we present a comparison of the results in these children's studies with observations from our cross-sectional studies with adults.

Adolescent↗
PubMed2005

The power of listening: auditory-motor interactions in musical training.

We trained musically naive subjects to play a short piano melody by ear in a fully monitored computerized environment and tested their potential to acquire a functional linkage between actions and sounds. Individual notes that were simply acoustic pretraining signals became "physically meaningful" posttraining. In addition, we found preliminary evidence that passive listening to a newly learned musical piece can enhance motor performance in the absence of physical practice.

Adult↗
PubMed2004

Imaging melody and rhythm processing in young children.

In the adult brain, melody and rhythm processing have been found to show different hemispheric dominance, with the right hemisphere apparently more sensitive to melody and the left hemisphere to rhythm. We used a novel, child-friendly scanning protocol to examine the neural basis of melody and rhythm processing in young children (mean age 6 years 4 months, n=33). FMRI data were acquired using a sparse temporal sampling technique, taking advantage of the natural delay in the cerebrovascular response to neuronal activity. We found that this group of young children showed some differential specialization for melody and rhythm processing, but to a lesser extent than previously reported in adults. These results suggest that hemispheric specialization for musical processing may develop with age.

Acoustic Stimulation↗
PubMed2004

Absolute pitch in blind musicians.

Absolute pitch (AP) is possessed by only a small percentage of musicians (typically < 20%). From a sample of 46 early blind subjects, we identified 21 who had musical training, 12 of whom (57.1%) reported having AP, reflecting markedly increased prevalence compared to sighted musicians, despite the fact that mean age of commencement of musical training was significantly later among blind than sighted AP musicians in our database. MR images acquired in a subset of blind AP musicians revealed greater variability in planum temporale asymmetry compared with the increased left-sided asymmetry previously described in sighted AP musicians. This suggests that neural mechanisms underlying AP in blind musicians could differ from those in sighted musicians.

Adult↗
PubMed2004

The influence of sleep on auditory learning: a behavioral study.

Evidence continues to support a role for sleep in delayed learning without further practice. Here we demonstrate the beneficial influence of sleep on auditory skill learning. Fifty-six subjects were randomly assigned to two groups, trained and tested on a pitch memory task three times across 24 h. The morning group was trained at 09.00 h, retested 12 h later that same day, and again after 12 h sleep. The evening group was trained at 21.00 h, retested 12 h immediately after sleep, and again 12 h later the next day. At retesting, both groups combined showed significant delayed learning only after sleep, but not across equivalent periods of wake, regardless of which came first. These data add to the growing literature describing sleep-dependent learning throughout sensory and motor domains.

Acoustic Stimulation↗
PubMed2004

Safety of latest-generation self-expanding stents in patients with NASCET-ineligible severe symptomatic extracranial internal carotid artery stenosis.

BACKGROUND: Patients with symptomatic extracranial internal carotid artery stenosis (> or =70%) benefit from carotid endarterectomy when compared with medical management. However, independent risk factors can significantly increase the combined stroke and death risk after carotid endarterectomy. Carotid angioplasty and stenting (CAS) is a therapeutic option in patients who are otherwise at high risk or ineligible for carotid endarterectomy. Previous-generation self-expanding stents were hampered by length foreshortening, which limited their application in multifactorial occlusive extracranial internal carotid artery stenosis. METHODS: This is a single-center, prospective, open-label, safety study of CAS with the latest-generation self-expanding stents in patients with extracranial internal carotid artery symptomatic stenosis (> or =70%). All patients included were adjudicated to be ineligible for carotid endarterectomy by a vascular surgeon and/or a neurologist according to the exclusion criteria. Primary adverse events included death and all strokes (ipsilateral and contralateral). Secondary adverse events included transient ischemic attack, myocardial infarction, stent thrombosis, need for reintervention, and presence of hematomas. All adverse events were recorded at 24 hours, 30 days, and 6 months after CAS. RESULTS: Between June 1, 2001, and January 30, 2003, 23 consecutive patients (14 women and 9 men; mean age, 65 years; age range, 48-85 years) underwent 24 extracranial CAS procedures with the latest-generation self-expanding stents. All patients had one or multiple criteria for ineligibility according to the North American Symptomatic Carotid Endarterectomy Trial. Extracranial CAS was successful in all patients, with average residual stenosis of less than 20%. One patient (4%) experienced a stroke by the 30-day periprocedure examination. The total number of primary adverse events at 6 months after CAS was 2 strokes (9%), 1 of which was contralateral to the stent placement; there were no deaths. Twenty-two patients were asymptomatic at 6 months, with a modified Rankin scale score of 1 or less. Of the 2 patients who had a stroke, 1 had a follow-up modified Rankin scale score of 3. CONCLUSION: Extracranial CAS with the latest-generation self-expanding stents is a valid alternative treatment in high-risk or North American Symptomatic Carotid Endarterectomy Trial-ineligible patients.

Aged↗
PubMed2004

Reciprocal modulation and attenuation in the prefrontal cortex: an fMRI study on emotional-cognitive interaction.

Everyday and clinical experience demonstrate strong interactions between emotions and cognitions. Nevertheless the neural correlates underlying emotional-cognitive interaction remain unclear. Using event-related fMRI, we investigated BOLD-signal increases and decreases in medial and lateral prefrontal cortical regions during emotional and non-emotional judgment of photographs taken from the International Affective Picture System (IAPS). Emotional and non-emotional judgment conditions were compared to each other as well as with baseline allowing for distinction between relative signal changes (comparison between conditions) and true signal changes (referring to baseline). We have found that: (1) both emotional and non-emotional judgment of IAPS pictures were characterized by signal increases in ventrally and dorsally located lateral prefrontal cortical areas and concurrent signal decreases in ventro- and dorsomedial prefrontal cortex; (2) direct comparison between emotional and non-emotional judgment showed relative signal increases in ventro- and dorsomedial prefrontal cortex, and in contrast, relative signal increases were detected in ventrally and dorsally located lateral prefrontal cortical areas when comparing non-emotional to emotional judgment; and (3) as shown in separate comparisons with baseline, these relative signal changes were due to smaller signal decreases in ventro- and dorsomedial prefrontal cortex and smaller signal increases in ventrally and dorsally located lateral prefrontal cortical areas during emotional judgment. Therefore, the emotional load of a cognitive task lead to both less deactivation of medial prefrontal regions and, at the same time, less activation of lateral prefrontal regions. Analogous patterns of reciprocal modulation and attenuation have previously been described for other cortical regions such as visual and auditory areas. Reciprocal modulation and attenuation in medial and lateral prefrontal cortex might constitute the neurophysiologic basis for emotional-cognitive interaction as observed in both healthy and psychiatric subjects.

Adult↗
PubMed2003

The effect of musicianship on pitch memory in performance matched groups.

We compared brain activation patterns between musicians and non-musicians (matched in performance score) while they performed a pitch memory task (using a sparse temporal sampling fMRI method). Both groups showed bilateral activation of the superior temporal, supramarginal, posterior middle and inferior frontal gyrus, and superior parietal lobe. Musicians showed more right temporal and supramarginal gyrus activation while non-musicians had more right primary and left secondary auditory cortex activation. Since both groups' performance were matched, these results probably indicate processing differences between groups that are possibly related to musical training. Non-musicians rely more on brain regions important for pitch discrimination while musicians prefer to use brain regions specialized in short-term memory and recall to perform well in this pitch memory task.

Acoustic Stimulation↗
PubMed2003

Brain structures differ between musicians and non-musicians.

From an early age, musicians learn complex motor and auditory skills (e.g., the translation of visually perceived musical symbols into motor commands with simultaneous auditory monitoring of output), which they practice extensively from childhood throughout their entire careers. Using a voxel-by-voxel morphometric technique, we found gray matter volume differences in motor, auditory, and visual-spatial brain regions when comparing professional musicians (keyboard players) with a matched group of amateur musicians and non-musicians. Although some of these multiregional differences could be attributable to innate predisposition, we believe they may represent structural adaptations in response to long-term skill acquisition and the repetitive rehearsal of those skills. This hypothesis is supported by the strong association we found between structural differences, musician status, and practice intensity, as well as the wealth of supporting animal data showing structural changes in response to long-term motor training. However, only future experiments can determine the relative contribution of predisposition and practice.

Adolescent↗
PubMed2003

The effects of gender on the neural substrates of pitch memory.

Imaging studies have indicated that males and females differ anatomically in brain regions thought to underlie language functions. Functional studies have corroborated this difference by showing gender differences in terms of language processing with females relying on less lateralized processing strategies than males. Gender differences in musical functions might show similar differences in functional asymmetries, although no detailed study has been performed. The current study employed a pitch memory task while acquiring functional magnetic resonance images to investigate possible differences in hemispheric processing between males and females. Gender differences were found in the time course of activation (during the first four imaging time points after the end of the auditory stimulus-"perceptual phase"-and the subsequent three imaging time points after the end of the auditory stimulus-"memory phase") in both anterior and posterior perisylvian regions. Male subjects had greater lateralized activations (left > right) in anterior and posterior perisylvian regions during the "perceptual" as well as during the "memory" phase. There was a trend for males to have more cerebellar activation than females. Females showed more prominently posterior cingulate/retrosplenial cortex activation compared to males. Although activation patterns differed, there was no difference in the behavioral performance between both genders. These data indicate that similar to language studies, males rely more on left lateralized hemispheric processing even for basic pitch tasks.

Acoustic Stimulation↗
PubMed2003

Corpus callosum: musician and gender effects.

Previously we found that musicians have significantly larger anterior corpus callosum (CC). In the current study, we intended to replicate and extend our previous results using a new and larger sample of gender-matched subjects (56 right-handed professional musicians and 56 age- and handedness-matched controls). We found a significant gender x musicianship interaction for anterior and posterior CC size; male musicians had a larger anterior CC than non-musicians, while females did not show a significant effect of musicianship. The lack of a significant effect in females may be due to a tendency for a more symmetric brain organization and a disproportionately high representation of absolute pitch (AP) musicians among females. Although a direct causal effect between musicianship and alterations in the midsagittal CC size cannot be established, it is likely that the early commencement and continuous practice of bimanual motor training serves as an external trigger that can influence midsagittal CC size through changes in the actual callosal fiber composition and in the degree of myelinization, which will have implications for interhemispheric connectivity.

Adolescent↗
PubMed2003

Ipsilateral motor cortex activation on functional magnetic resonance imaging during unilateral hand movements is related to interhemispheric interactions.

Distal, unilateral hand movements can be associated with activation of both sensorimotor cortices on functional MRI. The neurophysiological significance of the ipsilateral activation remains unclear. We examined 10 healthy right-handed subjects with and without activation of the ipsilateral sensorimotor area during unilateral index-finger movements, to examine ipsilateral, uncrossed-descending pathways and interhemispheric interaction between bilateral motor areas, using transcranial magnetic stimulation (TMS). No subject showed ipsilateral activation during right hand movement. Five subjects showed ipsilateral sensorimotor cortical activation during left hand movement (IpsiLM1). In these subjects, paired-pulse TMS revealed a significant interhemispheric inhibition of the left motor cortex by the right hemisphere that was not present in the 5 subjects without IpsiLM1. Neither ipsilateral MEPs nor ipsilateral silent periods were evoked by TMS in any subjects. Our observation suggests that IpsiLM1 is not associated with the presence of ipsilateral uncrossed-descending projections. Instead, IpsiLM1 may reveal an enhanced interhemispheric inhibition from the right hemisphere upon the left to suppress superfluous, excessive activation.

Adult↗
PubMed2003

Functional anatomy of pitch memory--an fMRI study with sparse temporal sampling.

Auditory functional magnetic resonance imaging tasks are challenging since the MR scanner noise can interfere with the auditory stimulation. To avoid this interference a sparse temporal sampling method with a long repetition time (TR = 17 s) was used to explore the functional anatomy of pitch memory. Eighteen right-handed subjects listened to a sequence of sine-wave tones (4.6 s total duration) and were asked to make a decision (depending on a visual prompt) whether the last or second to last tone was the same or different as the first tone. An alternating button press condition served as a control. Sets of 24 axial slices were acquired with a variable delay time (between 0 and 6 s) between the end of the auditory stimulation and the MR acquisition. Individual imaging time points were combined into three clusters (0-2, 3-4, and 5-6 s after the end of the auditory stimulation) for the analysis. The analysis showed a dynamic activation pattern over time which involved the superior temporal gyrus, supramarginal gyrus, posterior dorsolateral frontal regions, superior parietal regions, and dorsolateral cerebellar regions bilaterally as well as the left inferior frontal gyrus. By regressing the performance score in the pitch memory task with task-related MR signal changes, the supramarginal gyrus (left>right) and the dorsolateral cerebellum (lobules V and VI, left>right) were significantly correlated with good task performance. The SMG and the dorsolateral cerebellum may play a critical role in short-term storage of pitch information and the continuous pitch discrimination necessary for performing this pitch memory task.

Adolescent↗
PubMed2003

Cerebellar volume of musicians.

There is evidence that the cerebellum is involved in motor learning and cognitive function in humans. Animal experiments have found structural changes in the cerebellum in response to long-term motor skill activity. We investigated whether professional keyboard players, who learn specialized motor skills early in life and practice them intensely throughout life, have larger cerebellar volumes than matched non-musicians by analyzing high-resolution T(1)-weighted MR images from a large prospectively acquired database (n = 120). Significantly greater absolute (P = 0.018) and relative (P = 0.006) cerebellar volume but not total brain volume was found in male musicians compared to male non-musicians. Lifelong intensity of practice correlated with relative cerebellar volume in the male musician group (r = 0.595, P = 0.001). In the female group, there was no significant difference noted in volume measurements between musicians and non-musicians. The significant main effect for gender on relative cerebellar volume (F = 10.41, P < 0.01), with females having a larger relative cerebellar volume, may mask the effect of musicianship in the female group. We propose that the significantly greater cerebellar volume in male musicians and the positive correlation between relative cerebellar volume and lifelong intensity of practice represents structural adaptation to long-term motor and cognitive functional demands in the human cerebellum.

Adult↗
PubMed2003

Musicians differ from nonmusicians in brain activation despite performance matching.

Brain activation patterns in a group of musicians and a group of nonmusicians (matched in performance score to the musician group) were compared during a pitch memory task using a sparse-temporal sampling functional magnetic resonance imaging experiment. Both groups showed bilateral activaton (left more than right) of the superior temporal gyrus, supramarginal gyrus, posterior middle and inferior frontal gyrus, and superior parietal lobe. Musicians showed greater right posterior temporal and supramarginal activation, whereas nonmusicians had greater activation of the left secondary auditory cortex.

Adolescent↗