Differences In Functional Brain Activity Research Articles

Functional Brain Activation in Mild Cognitive Impairment With Defined Small Vessel Disease Burden

AbstractBackgroundVascular dysregulations and changes in functional brain network integrity play a fundamental role in the pathogenesis of dementia. While often identified in individuals with dementia, the role of small vessel disease (SVD) in the development of dementia is not completely understood yet. Previously, structural and functional brain connectivity was shown to be different between individuals with and without cerebral SVD, but a comprehensive measure of SVD has not been used consistently. We aim to analyze functional brain activation differences in mild cognitive impairment (MCI) individuals with defined SVD burden.MethodFunctional brain activation differences were analyzed in MCI individuals with absent or low (n = 34) or high (n = 34) SVD burden using data from the Parelsnoer Institute, a multicenter study involving eight Dutch medical centers. SVD burden was characterized using an ordinal scale ranging from 0 to 4 (Klarenbeek et al., 2013) considering the following markers: lacunes; microbleeds; perivascular spaces in the basal ganglia; white matter hyperintensities based on the Fazekas score. Two groups were identified: the absent or low SVD burden group with a score of 0 or 1 and the high SVD group with a score between 2 and 4. Activation differences were calculated using resting state fMRI data acquired using 3Tesla scanners and analyzed with group‐independent component analysis using the CONN toolbox.ResultActivation of two clusters in the high SVD burden group was lower than in the absent or low SVD group: the cerebellum (p‐FDR >. 001, F = 1.49) and the brainstem (p‐FDR >. 001, F = 2.79). The cerebellar cluster (4541 voxels, +20 ‐74 ‐38) consisted of the left cerebellum crus II, right cerebellum crus II, and left cerebellum lobule VIII. The brainstem cluster (218 voxels, +22 ‐28 +20) involved the right thalamus and the right caudate nucleus.ConclusionBrain activation differences between groups of individuals with MCI and absent or low or high SVD burden were found in the cerebellum and brainstem. These brain areas are mainly responsible for motor, attentional and executive functions, domains which were found in previous studies to be mostly associated with SVD markers.

A Study of Differential Resting-State Brain Functional Activity in Males and Females with Recurrent Depressive Disorder.

In this study, we observed the sex differences in functional brain activity in patients with recurrent depressive disorder (RDE) and assessed the correlation between abnormal functional brain activity changes and clinical symptoms. A total of 40 patients with RDE (19 male and 21 female) and 42 healthy controls (HCs) (20 male and 22 female) met the inclusion criteria. Analysis of images using regional homogeneity (ReHo) and further analysis of the correlation between abnormal brain areas and clinical symptoms of the different sexes with RDE groups were carried out. For the main effects of sex (male vs. female), there were statistically significant differences in ReHo among the four groups in the right middle temporal gyrus, right thalamus, and left posterior cerebellar lobe. For the effects of the sex-by-group interaction, there were statistically significant differences in ReHo among the four groups in the left middle frontal gyrus, left precentral gyrus, and right insula. Post hoc analyses showed that compared with the female RDE group, the male RDE group had decreased ReHo in the left middle frontal gyrus and right insula. In the female RDE group, the ReHo values of the left middle frontal gyrus were positively correlated with the 17-item Hamilton Rating Scale for Depression (HAMD-17) scores. This study provides new insights into the clinical targeting of different sexes for RDE.

Brain Activation During Active Balancing and Its Behavioral Relevance in Younger and Older Adults: A Functional Near-Infrared Spectroscopy (fNIRS) Study.

Age-related deterioration of balance control is widely regarded as an important phenomenon influencing quality of life and longevity, such that a more comprehensive understanding of the neural mechanisms underlying this process is warranted. Specifically, previous studies have reported that older adults typically show higher neural activity during balancing as compared to younger counterparts, but the implications of this finding on balance performance remain largely unclear. Using functional near-infrared spectroscopy (fNIRS), differences in the cortical control of balance between healthy younger (n = 27) and older (n = 35) adults were explored. More specifically, the association between cortical functional activity and balance performance across and within age groups was investigated. To this end, we measured hemodynamic responses (i.e., changes in oxygenated and deoxygenated hemoglobin) while participants balanced on an unstable device. As criterion variables for brain-behavior-correlations, we also assessed postural sway while standing on a free-swinging platform and while balancing on wobble boards with different levels of difficulty. We found that older compared to younger participants had higher activity in prefrontal and lower activity in postcentral regions. Subsequent robust regression analyses revealed that lower prefrontal brain activity was related to improved balance performance across age groups, indicating that higher activity of the prefrontal cortex during balancing reflects neural inefficiency. We also present evidence supporting that age serves as a moderator in the relationship between brain activity and balance, i.e., cortical hemodynamics generally appears to be a more important predictor of balance performance in the older than in the younger. Strikingly, we found that age differences in balance performance are mediated by balancing-induced activation of the superior frontal gyrus, thus suggesting that differential activation of this region reflects a mechanism involved in the aging process of the neural control of balance. Our study suggests that differences in functional brain activity between age groups are not a mere by-product of aging, but instead of direct behavioral relevance for balance performance. Potential implications of these findings in terms of early detection of fall-prone individuals and intervention strategies targeting balance and healthy aging are discussed.

Late combination shows that MEG adds to MRI in classifying MCI versus controls

Early detection of Alzheimer's disease (AD) is essential for developing effective treatments. Neuroimaging techniques like Magnetic Resonance Imaging (MRI) have the potential to detect brain changes before symptoms emerge. Structural MRI can detect atrophy related to AD, but it is possible that functional changes are observed even earlier. We therefore examined the potential of Magnetoencephalography (MEG) to detect differences in functional brain activity in people with Mild Cognitive Impairment (MCI) – a state at risk of early AD. We introduce a framework for multimodal combination to ask whether MEG data from a resting-state provides complementary information beyond structural MRI data in the classification of MCI versus controls. More specifically, we used multi-kernel learning of support vector machines to classify 163 MCI cases versus 144 healthy elderly controls from the BioFIND dataset. When using the covariance of planar gradiometer data in the low Gamma range (30–48 Hz), we found that adding a MEG kernel improved classification accuracy above kernels that captured several potential confounds (e.g., age, education, time-of-day, head motion). However, accuracy using MEG alone (68%) was worse than MRI alone (71%). When simply concatenating (normalized) features from MEG and MRI into one kernel (Early combination), there was no advantage of combining MEG with MRI versus MRI alone. When combining kernels of modality-specific features (Intermediate combination), there was an improvement in multimodal classification to 74%. The biggest multimodal improvement however occurred when we combined kernels from the predictions of modality-specific classifiers (Late combination), which achieved 77% accuracy (a reliable improvement in terms of permutation testing). We also explored other MEG features, such as the variance versus covariance of magnetometer versus planar gradiometer data within each of 6 frequency bands (delta, theta, alpha, beta, low gamma, or high gamma), and found that they generally provided complementary information for classification above MRI. We conclude that MEG can improve on the MRI-based classification of MCI.

Sex-Based Differences in Functional Brain Activity During Working Memory in Survivors of Pediatric Acute Lymphoblastic Leukemia.

BackgroundLong-term survivors of pediatric acute lymphoblastic leukemia are at elevated risk for neurocognitive deficits and corresponding brain dysfunction. This study examined sex-based differences in functional neuroimaging outcomes in acute lymphoblastic leukemia survivors treated with chemotherapy alone.MethodsFunctional magnetic resonance imaging (fMRI) and neurocognitive testing were obtained in 123 survivors (46% male; median [min-max] age = 14.2 years [8.3-26.5 years]; time since diagnosis = 7.7 years [5.1-12.5 years]) treated on the St. Jude Total XV treatment protocol. Participants performed the n-back working memory task in a 3 T scanner. Functional neuroimaging data were processed (realigned, slice time corrected, normalized, smoothed) and analyzed using statistical parametric mapping with contrasts for 1-back and 2-back conditions, which reflect varying degrees of working memory and task load. Group-level fMRI contrasts were stratified by sex and adjusted for age and methotrexate exposure. Statistical tests were 2-sided (P < .05 statistical significance threshold).ResultsRelative to males, female survivors exhibited less activation (ie, reduced blood oxygen dependent–level signals) in the right parietal operculum, supramarginal gyrus and inferior occipital gyrus, and bilateral superior frontal medial gyrus during increased working memory load (family-wise error–corrected P = .004 to .008, adjusting for age and methotrexate dose). Female survivors were slower to correctly respond to the 2-back condition than males (P < .05), though there were no differences in overall accuracy. Performance accuracy was negatively correlated with fMRI activity in female survivors (Pearson’s r = −0.39 to −0.29, P = .001 to .02), but not in males.ConclusionsThese results suggest the working memory network is more impaired in female survivors than male survivors, which may contribute to ongoing functional deficits.

The effect of task modality and stimulus frequency in paced serial addition tests on functional brain activity.

IntroductionThe paced serial addition test (PSAT) is regularly used to assess cognitive deficits in various neuropsychiatric conditions. Being a complex test, it reflects the status of multiple cognitive domains such as working memory, information processing speed and executive functioning. Two versions of the PSAT exist. One uses auditory stimuli through spoken numbers and is known as the PASAT, while the other one presents patients with visual stimuli and is called PVSAT. The PASAT is considered more frustrating by patients, and hence the visual version is usually preferred. Research has suggested that an interference might exist between patients’ verbal answers and the auditory presentation of stimuli. We therefore removed the verbal response in this study, and aimed to investigate differences in functional brain activity through functional magnetic resonance imaging.MethodsFifteen healthy controls performed the two test versions inside an MRI scanner—switching between stimulus modality (auditory vs. visual) as well as inter-stimulus frequency (3s vs. 2s). We extracted 11 independent components from the data: attentional, visual, auditory, sensorimotor and default mode networks. We then performed statistical analyses of mean network activity within each component, as well as inter-network connectivity of each component pair during the different task types.ResultsUnsurprisingly, we noted an effect of modality on activity in the visual and auditory components. However, we also describe bilateral frontoparietal, anterior cingulate and insular attentional network activity. An effect of frequency was noted only in the sensorimotor network. Effects were found on edges linking visual and auditory regions. Task modality influenced an attentional-sensorimotor connection, while stimulus frequency had an influence on sensorimotor-default mode connections.ConclusionsScanner noise during functional MRI may interfere with brain activation—especially during tasks involving auditory pathways. The question whether to use PVSAT or PASAT for an fMRI study is, therefore, an important one. Specific effects of both modalities should be known to study designers. We conclude that both tests should not be considered interchangeable, as significant changes were brought to light during test performance in different modalities.

Imaging decision about whether to benefit self by harming others: Adolescents with conduct and substance problems, with or without callous-unemotionality, or developing typically

We sought to identify brain activation differences in conduct-problem youth with limited prosocial emotions (LPE) compared to conduct-problem youth without LPE and community adolescents, and to test associations between brain activation and severity of callous-unemotional traits. We utilized a novel task, which asks subjects to repeatedly decide whether to accept offers where they will benefit but a beneficent other will be harmed. Behavior on this task has been previously associated with levels of prosocial emotions and severity of callous-unemotional traits, and is related to empathic concern. During fMRI acquisition, 66 male adolescents (21 conduct-problem patients with LPE, 21 without, and 24 typically-developing controls) played this novel game. Within typically-developing controls, we identified a network engaged during decision involving bilateral insula, and inferior parietal and medial frontal cortices, among other regions. Group comparisons using non-parametric (distribution-free) permutation tests demonstrated LPE patients had lower activation estimates than typically-developing adolescents in right anterior insula. Additional significant group differences emerged with our a priori parametric cluster-wise inference threshold. These results suggest measurable functional brain activation differences in conduct-problem adolescents with LPE compared to typically-developing adolescents. Such differences may underscore differential treatment needs for conduct-problem males with and without LPE.

Urgency urinary incontinence and the interoceptive network: a functional magnetic resonance imaging study

Treatment of urgency urinary incontinence has focused on pharmacologically treating detrusor overactivity. Recent recognition that altered perception of internal stimuli (interoception) plays arole in urgency urinary incontinence suggests that exploration of abnormalities of brain function in this disorder could lead to better understanding of urgency incontinence and its treatment. We sought to: (1) evaluate the relationship between bladder filling, perceived urgency, and activation at brain sites within theinteroceptive network in urgency urinary incontinence; (2) identify coactivation of other brain networks that could affect interoception during bladder filling in urgency incontinence; and (3) demonstrate interaction between these sites prior to bladder filling by evaluating their resting-state connectivity. We performed an observational cohort study using functional magnetic resonance imaging to compare brain function in 53 women with urgency urinary incontinence and 20 controls. Whole-brain voxelwise analyses of covariance were performed to examine differences in functional brain activation between groups during a task consisting of bladder filling, hold (static volume), and withdrawal phases. The task was performed at 3 previously established levels of baseline bladder volume, the highest exceeding strong desire to void volume. All women continuously rated their urge on a 0- to 10-point Likert scale throughout the task and a mixed measures analysis of variance was used to test for differences in urge ratings. Empirically derived regions of interest from analysis of activation during the task were used as seeds for examining group differences in resting-state functional connectivity. In both urgency urinary incontinent participants and controls, changes in urge ratings were greatest during bladder filling initiated from a high baseline bladder volume and urgency incontinent participants' rating changes were greater than controls. During this bladder-filling phase urgency incontinent participant's activation of the interoceptive network was greater than controls, including in the left insula and the anterior andmiddle cingulate cortex. Urgency incontinent participant's activation was also greater than controls at sites in the ventral attention network and posterior default mode network. Urgency incontinent participant's connectivity was greater than controls between a middle cingulate seed point and the dorsal attention network, a "top-down" attentional network. Control connectivity was greater between the midcingulate seed point and the ventral attention network, a "bottom-up" attentional network. Increasing urge was associated with greater urgency incontinent participant than control activation of the interoceptive network and activation in networks that are determinants of self-awareness (default mode network) and of response to unexpected external stimuli (ventral attention network). Differences in connectivity between interoceptive networks and opposing attentional networks (ventral attention network vsdorsal attention network) were present even before bladder filling (in the resting state). These findings are strong evidence for a central nervous system component of urgency urinary incontinence that could be mediated by brain-directed therapies.

Speech acquisition predicts regions of enhanced cortical response to auditory stimulation in autism spectrum individuals

A continuum of phenotypes makes up the autism spectrum (AS). In particular, individuals show large differences in language acquisition, ranging from precocious speech to severe speech onset delay. However, the neurological origin of this heterogeneity remains unknown. Here, we sought to determine whether AS individuals differing in speech acquisition show different cortical responses to auditory stimulation and morphometric brain differences. Whole-brain activity following exposure to non-social sounds was investigated. Individuals in the AS were classified according to the presence or absence of Speech Onset Delay (AS-SOD and AS-NoSOD, respectively) and were compared with IQ-matched typically developing individuals (TYP). AS-NoSOD participants displayed greater task-related activity than TYP in the inferior frontal gyrus and peri-auditory middle and superior temporal gyri, which are associated with language processing. Conversely, the AS-SOD group only showed enhanced activity in the vicinity of the auditory cortex. We detected no differences in brain structure between groups. This is the first study to demonstrate the existence of differences in functional brain activity between AS individuals divided according to their pattern of speech development. These findings support the Trigger-threshold-target model and indicate that the occurrence of speech onset delay in AS individuals depends on the location of cortical functional reallocation, which favors perception in AS-SOD and language in AS-NoSOD.

Neuroimaging explanations of age-related differences in task performance

Advancing age affects both cognitive performance and functional brain activity and interpretation of these effects has led to a variety of conceptual research models without always explicitly linking the two effects. However, to best understand the multifaceted effects of advancing age, age differences in functional brain activity need to be explicitly tied to the cognitive task performance. This work hypothesized that age-related differences in task performance are partially explained by age-related differences in functional brain activity and formally tested these causal relationships. Functional MRI data was from groups of young and old adults engaged in an executive task-switching experiment. Analyses were voxel-wise testing of moderated-mediation and simple mediation statistical path models to determine whether age group, brain activity and their interaction explained task performance in regions demonstrating an effect of age group. Results identified brain regions whose age-related differences in functional brain activity significantly explained age-related differences in task performance. In all identified locations, significant moderated-mediation relationships resulted from increasing brain activity predicting worse (slower) task performance in older but not younger adults. Findings suggest that advancing age links task performance to the level of brain activity. The overall message of this work is that in order to understand the role of functional brain activity on cognitive performance, analysis methods should respect theoretical relationships. Namely, that age affects brain activity and brain activity is related to task performance.

Differences in Functional Brain Activation and Hippocampal Volume Among Amnestic Mild Cognitive Impairment Subtypes

Patients with amnestic mild cognitive impairment (aMCI) often display deficits in episodic memory. Amnestic MCI is now recognized as a prodromal form of Alzheimer's disease. Various aMCI clinical subtypes have been identified as ingle-domain (SD) or multi-domain (MD). The various subtypes represent heterogeneous syndrome indicating the probability of progression to AD, impaired cognitive domains and so on. To examine the characteristics of brain regions of aMCI subtypes is likely to be important for early diagnosis and prediction to AD. This study investigated brain functional activation and hippocampal atrophy during a visually complex scene encoding in 20 individuals with aMCI-SD, 14 individuals with aMCI-MD and 25 healthy controls. During the encoding task, aMCI-MD patients had reduced activation in right superior medial frontal, right inferior and middle temporal, right middle occipital and left inferior frontal regions compared to controls. The different active brain regions between aMCI-MD and aMCI-SD patients are the right middle occipital and left middle cingulum regions. The aMCI-MD group had significantly lower left hippocampus volumes compared to the aMCI-SD group and controls, but there was no difference between aMCI-SD patients and the control group in terms of left hippocampus atrophy. The findings provide evidence that aMCI may represent a heterogeneous group. The aMCI-MD patients displayed more severe hippocampcal atrophy and fMRI activation changes than aMCI-SD. The aMCIMD may represent a more advanced prodromal stage of AD.

Persistent Differences in Patterns of Brain Activation after Sports-Related Concussion: A Longitudinal Functional Magnetic Resonance Imaging Study

Avoiding recurrent injury in sports-related concussion (SRC) requires understanding the neural mechanisms involved during the time of recovery after injury. The decision for return-to-play is one of the most difficult responsibilities facing the physician, and so far this decision has been based primarily on neurological examination, symptom checklists, and neuropsychological (NP) testing. Functional magnetic resonance imaging (fMRI) may be an additional, more objective tool to assess the severity and recovery of function after concussion. The purpose of this study was to define neural correlates of SRC during the 2 months after injury in varsity contact sport athletes who suffered a SRC. All athletes were scanned as they performed an n-back task, for n=1, 2, 3. Subjects were scanned within 72 hours (session one), at 2 weeks (session two), and 2 months (session three) post-injury. Compared with age and sex matched normal controls, concussed subjects demonstrated persistent, significantly increased activation for the 2 minus 1 n-back contrast in bilateral dorsolateral prefrontal cortex (DLPFC) in all three sessions and in the inferior parietal lobe in session one and two (α≤0.01 corrected). Measures of task performance revealed no significant differences between concussed versus control groups at any of the three time points with respect to any of the three n-back tasks. These findings suggest that functional brain activation differences persist at 2 months after injury in concussed athletes, despite the fact that their performance on a standard working memory task is comparable to normal controls and normalization of clinical and NP test results. These results might indicate a delay between neural and behaviorally assessed recovery after SRC.

Neurobiological underpinnings of shame and guilt: a pilot fMRI study

In this study, a functional magnetic resonance imaging paradigm originally employed by Takahashi et al. was adapted to look for emotion-specific differences in functional brain activity within a healthy German sample (N = 14), using shame- and guilt-related stimuli and neutral stimuli. Activations were found for both of these emotions in the temporal lobe (shame condition: anterior cingulate cortex, parahippocampal gyrus; guilt condition: fusiform gyrus, middle temporal gyrus). Specific activations were found for shame in the frontal lobe (medial and inferior frontal gyrus), and for guilt in the amygdala and insula. This is consistent with Takahashi et al.'s results obtained for a Japanese sample (using Japanese stimuli), which showed activations in the fusiform gyrus, hippocampus, middle occipital gyrus and parahippocampal gyrus. During the imagination of shame, frontal and temporal areas (e.g. middle frontal gyrus and parahippocampal gyrus) were responsive regardless of gender. In the guilt condition, women only activate temporal regions, whereas men showed additional frontal and occipital activation as well as a responsive amygdala. The results suggest that shame and guilt share some neural networks, as well as having individual areas of activation. It can be concluded that frontal, temporal and limbic areas play a prominent role in the generation of moral feelings.

Differences in Brain Activation Between Tremor- and Nontremor-Dominant Parkinson Disease

OBJECTIVE To compare differences in functional brain activity between tremor- and nontremor-dominant subtypes of Parkinson disease (PD) using functional magnetic resonance imaging. DESIGN In our study, patients with tremor-dominant PD and those with nontremor-dominant PD performed a grip task, and the results obtained were compared using voxelwise analysis. Areas of the brain that were significantly different were then examined using a region-of-interest analysis to compare these patients with healthy controls. Voxel-based morphometry was used to determine macroscopic differences in gray and white matter volume between patient groups. SETTING University-affiliated research institution. PARTICIPANTS A total of 20 drug-naive patients with PD (10 with tremor-dominant PD and 10 with nontremor-dominant PD) and a total of 20 healthy controls. MAIN OUTCOME MEASURES Blood oxygenation level-dependent activation and percent signal change. RESULTS Robust findings across both voxelwise and region-of-interest analyses showed that, compared with patients with tremor-dominant PD, patients with nontremor-dominant PD had reduced activation in the ipsilateral dorsolateral prefrontal cortex, the globus pallidus interna, and the globus pallidus externa. Region-of-interest analyses confirmed that patients with nontremor-dominant PD had reduced activity in the ipsilateral dorsolateral prefrontal cortex, the globus pallidus interna, and the globus pallidus externa compared with patients with tremor-dominant PD and healthy controls. Patients with tremor-dominant PD had increased activity in the contralateral dorsolateral prefrontal cortex compared with patients with nontremor-dominant PD and healthy controls. These results could not be explained by differences in gray or white matter volume. CONCLUSIONS Reduced brain activity occurs in the prefrontal cortex and globus pallidus of patients with nontremor-dominant PD compared with both patients with tremor-dominant PD and healthy controls, which suggests that functional magnetic resonance imaging is a promising technique to understand differences in brain activation between subtypes of PD.

Functional Brain Activation Differences in School-Age Children With Speech Sound Errors: Speech and Print Processing

To examine neural response to spoken and printed language in children with speech sound errors (SSE). Functional magnetic resonance imaging was used to compare processing of auditorily and visually presented words and pseudowords in 17 children with SSE, ages 8;6[years;months] through 10;10, with 17 matched controls. When processing spoken words and pseudowords, the SSE group showed less activation than typically speaking controls in left middle temporal gyrus. They also showed greater activation than controls in several cortical and subcortical regions (e.g., left superior temporal gyrus, globus pallidus, insula, fusiform, and bilateral parietal regions). In response to printed words and pseudowords, children with SSE had greater activation than controls in regions including bilateral fusiform and anterior cingulate. Some differences were found in both speech and print processing that that may be associated with children with SSE failing to show common patterns of task-induced deactivation and/or attentional resource allocation. Compared with controls, children with SSE appear to rely more on several dorsal speech perception regions and less on ventral speech perception regions. When processing print, numerous regions were observed to be activated more for the SSE group than for controls.

Local brain atrophy accounts for functional activity differences in normal aging

Functional brain imaging studies of normal aging typically show age-related under- and overactivations during episodic memory tasks. Older individuals also undergo nonuniform gray matter volume (GMv) loss. Thus, age differences in functional brain activity could at least in part result from local atrophy. We conducted a series of voxel-based blood oxygen level-dependent (BOLD)-GMv analyses to highlight whether age-related under- and overrecruitment was accounted for by GMv changes. Occipital GMv loss accounted for underrecruitment at encoding. Efficiency reduction of sensory-perceptual mechanisms underpinned by these areas may partly be due to local atrophy. At retrieval, local GMv loss accounted for age-related overactivation of left dorsolateral prefrontal cortex, but not of left dorsomedial prefrontal cortex. Local atrophy also accounted for age-related overactivation in left lateral parietal cortex. Activity in these frontoparietal regions correlated with performance in the older group. Atrophy in the overrecruited regions was modest in comparison with other regions as shown by a between-group voxel-based morphometry comparison. Collectively, these findings link age-related structural differences to age-related functional under- as well as overrecruitment.

Functional brain activation differences in stuttering identified with a rapid fMRI sequence

The purpose of this study was to investigate whether brain activity related to the presence of stuttering can be identified with rapid functional MRI (fMRI) sequences that involved overt and covert speech processing tasks. The long-term goal is to develop sensitive fMRI approaches with developmentally appropriate tasks to identify deviant speech motor and auditory brain activity in children who stutter closer to the age at which recovery from stuttering is documented. Rapid sequences may be preferred for individuals or populations who do not tolerate long scanning sessions. In this report, we document the application of a picture naming and phoneme monitoring task in 3 min fMRI sequences with adults who stutter (AWS). If relevant brain differences are found in AWS with these approaches that conform to previous reports, then these approaches can be extended to younger populations. Pairwise contrasts of brain BOLD activity between AWS and normally fluent adults indicated the AWS showed higher BOLD activity in the right inferior frontal gyrus (IFG), right temporal lobe and sensorimotor cortices during picture naming and higher activity in the right IFG during phoneme monitoring. The right lateralized pattern of BOLD activity together with higher activity in sensorimotor cortices is consistent with previous reports, which indicates rapid fMRI sequences can be considered for investigating stuttering in younger participants. Educational objectives: The reader will learn about and be able to describe the: (1) use of functional MRI to study persistent developmental stuttering; (2) differences in brain activation between persons who stutter and normally fluent speakers; and (3) potential benefit of time efficient fMRI sequences combined with a range of speech processing tasks for investigating stuttering in younger populations.

Expertise-related deactivation of the right temporoparietal junction during musical improvisation

Musical training has been associated with structural changes in the brain as well as functional differences in brain activity when musicians are compared to nonmusicians on both perceptual and motor tasks. Previous neuroimaging comparisons of musicians and nonmusicians in the motor domain have used tasks involving prelearned motor sequences or synchronization with an auditorily presented sequence during the experiment. Here we use functional magnetic resonance imaging (fMRI) to examine expertise-related differences in brain activity between musicians and nonmusicians during improvisation – the generation of novel musical–motor sequences – using a paradigm that we previously used in musicians alone. Despite behaviorally matched performance, the two groups showed significant differences in functional brain activity during improvisation. Specifically, musicians deactivated the right temporoparietal junction (rTPJ) during melodic improvisation, while nonmusicians showed no change in activity in this region. The rTPJ is thought to be part of a ventral attentional network for bottom-up stimulus-driven processing, and it has been postulated that deactivation of this region occurs in order to inhibit attentional shifts toward task-irrelevant stimuli during top-down, goal-driven behavior. We propose that the musicians' deactivation of the rTPJ during melodic improvisation may represent a training-induced shift toward inhibition of stimulus-driven attention, allowing for a more goal-directed performance state that aids in creative thought.

Differences in Functional Brain Activation during Working Memory between Children with Prenatal Methamphetamine Exposure and those with Prenatal Alcohol Exposure

Differences in Functional Brain Activation during Working Memory between Children with Prenatal Methamphetamine Exposure and those with Prenatal Alcohol Exposure

Sex differences in functional brain activation during noxious visceral stimulation in rats

Studies in healthy human subjects and patients with irritable bowel syndrome suggest sex differences in cerebral nociceptive processing. Here we examine sex differences in functional brain activation in the rat during colorectal distention (CRD), a preclinical model of acute visceral pain. [14C]-iodoantipyrine was injected intravenously in awake, non-restrained female rats during 60- or 0-mmHg CRD while electromyographic abdominal activity (EMG) and pain behavior were recorded. Regional cerebral blood flow-related tissue radioactivity was analyzed by statistical parametric mapping from autoradiographic images of three-dimensionally reconstructed brains. Sex differences were addressed by comparing the current data with our previously published data collected from male rats. While sex differences in EMG and pain scores were modest, significant differences were noted in functional brain activation. Females showed widespread changes in limbic (amygdala, hypothalamus) and paralimbic structures (ventral striatum, nucleus accumbens, raphe), while males demonstrated broad cortical changes. Sex differences were apparent in the homeostatic afferent network (parabrachial nucleus, thalamus, insular and dorsal anterior cingulate cortices), in an emotional–arousal network (amygdala, locus coeruleus complex), and in cortical areas modulating these networks (prefrontal cortex). Greater activation of the ventromedial prefrontal cortex and broader limbic/paralimbic changes in females suggest greater engagement of affective mechanisms during visceral pain. Greater cortical activation in males is consistent with the concept of greater cortical inhibitory effects on limbic structures in males, which may relate to differences in attentional and cognitive attribution to visceral stimuli. These findings show remarkable similarities to reported sex differences in brain responses to visceral stimuli in humans.