Matching Items (20)

128216-Thumbnail Image.png

Partially overlapping sensorimotor networks underlie speech praxis and verbal short-term memory: evidence from apraxia of speech following acute stroke

Description

We tested the hypothesis that motor planning and programming of speech articulation and verbal short-term memory (vSTM) depend on partially overlapping networks of neural regions. We evaluated this proposal by

We tested the hypothesis that motor planning and programming of speech articulation and verbal short-term memory (vSTM) depend on partially overlapping networks of neural regions. We evaluated this proposal by testing 76 individuals with acute ischemic stroke for impairment in motor planning of speech articulation (apraxia of speech, AOS) and vSTM in the first day of stroke, before the opportunity for recovery or reorganization of structure-function relationships. We also evaluated areas of both infarct and low blood flow that might have contributed to AOS or impaired vSTM in each person. We found that AOS was associated with tissue dysfunction in motor-related areas (posterior primary motor cortex, pars opercularis; premotor cortex, insula) and sensory-related areas (primary somatosensory cortex, secondary somatosensory cortex, parietal operculum/auditory cortex); while impaired vSTM was associated with primarily motor-related areas (pars opercularis and pars triangularis, premotor cortex, and primary motor cortex). These results are consistent with the hypothesis, also supported by functional imaging data, that both speech praxis and vSTM rely on partially overlapping networks of brain regions.

Contributors

Agent

Created

Date Created
  • 2014-08-25

128594-Thumbnail Image.png

Functional MRI preprocessing in lesioned brains: manual versus automated region of interest analysis

Description

Functional magnetic resonance imaging (fMRI) has significant potential in the study and treatment of neurological disorders and stroke. Region of interest (ROI) analysis in such studies allows for testing of

Functional magnetic resonance imaging (fMRI) has significant potential in the study and treatment of neurological disorders and stroke. Region of interest (ROI) analysis in such studies allows for testing of strong a priori clinical hypotheses with improved statistical power. A commonly used automated approach to ROI analysis is to spatially normalize each participant’s structural brain image to a template brain image and define ROIs using an atlas. However, in studies of individuals with structural brain lesions, such as stroke, the gold standard approach may be to manually hand-draw ROIs on each participant’s non-normalized structural brain image. Automated approaches to ROI analysis are faster and more standardized, yet are susceptible to preprocessing error (e.g., normalization error) that can be greater in lesioned brains. The manual approach to ROI analysis has high demand for time and expertise, but may provide a more accurate estimate of brain response. In this study, commonly used automated and manual approaches to ROI analysis were directly compared by reanalyzing data from a previously published hypothesis-driven cognitive fMRI study, involving individuals with stroke. The ROI evaluated is the pars opercularis of the inferior frontal gyrus. Significant differences were identified in task-related effect size and percent-activated voxels in this ROI between the automated and manual approaches to ROI analysis. Task interactions, however, were consistent across ROI analysis approaches. These findings support the use of automated approaches to ROI analysis in studies of lesioned brains, provided they employ a task interaction design.

Contributors

Agent

Created

Date Created
  • 2015-09-25

128584-Thumbnail Image.png

The relationship between the neural computations for speech and music perception is context-dependent: an activation likelihood estimate study

Description

The relationship between the neurobiology of speech and music has been investigated for more than a century. There remains no widespread agreement regarding how (or to what extent) music perception

The relationship between the neurobiology of speech and music has been investigated for more than a century. There remains no widespread agreement regarding how (or to what extent) music perception utilizes the neural circuitry that is engaged in speech processing, particularly at the cortical level. Prominent models such as Patel's Shared Syntactic Integration Resource Hypothesis (SSIRH) and Koelsch's neurocognitive model of music perception suggest a high degree of overlap, particularly in the frontal lobe, but also perhaps more distinct representations in the temporal lobe with hemispheric asymmetries. The present meta-analysis study used activation likelihood estimate analyses to identify the brain regions consistently activated for music as compared to speech across the functional neuroimaging (fMRI and PET) literature. Eighty music and 91 speech neuroimaging studies of healthy adult control subjects were analyzed. Peak activations reported in the music and speech studies were divided into four paradigm categories: passive listening, discrimination tasks, error/anomaly detection tasks and memory-related tasks. We then compared activation likelihood estimates within each category for music vs. speech, and each music condition with passive listening. We found that listening to music and to speech preferentially activate distinct temporo-parietal bilateral cortical networks. We also found music and speech to have shared resources in the left pars opercularis but speech-specific resources in the left pars triangularis. The extent to which music recruited speech-activated frontal resources was modulated by task. While there are certainly limitations to meta-analysis techniques particularly regarding sensitivity, this work suggests that the extent of shared resources between speech and music may be task-dependent and highlights the need to consider how task effects may be affecting conclusions regarding the neurobiology of speech and music.

Contributors

Agent

Created

Date Created
  • 2015-08-11

134813-Thumbnail Image.png

The effect of scale and familiarity on the perception of music "dissonance"

Description

Music is part of cultures all over the world and is entrenched in our daily lives, and yet little is known about the neural pathways responsible for how we perceive

Music is part of cultures all over the world and is entrenched in our daily lives, and yet little is known about the neural pathways responsible for how we perceive music. The property of "dissonance" is central to our understanding of the emotional meaning in music, and this study is a preliminary step in understanding how this property of music is perceived. Twenty-four participants with normal hearing listened to melodies and ranked their degrees of dissonance. Melodies that are categorized as "dissonant" according to Western music theory were ranked as more "dissonant" to a significant degree across the 9 conditions (3 conditions of scale: Major, Neapolitan Minor, and Oriental; 3 conditions of wrong notes: no wrong notes, diatonic wrong notes, and non-diatonic wrong notes). As expected, the familiar Major scale was identified as more consonant across all wrong note conditions than the other scales. Notably, a significant interaction was found, with diatonic and non-diatonic notes not perceived differently in both of the unfamiliar scales, Neapolitan and Oriental. This study suggests that the context of musical scale does influence how we create expectations of music and perceive dissonance. Future studies are necessary to understand the mechanisms by which scales drive these expectations.

Contributors

Agent

Created

Date Created
  • 2016-12

134926-Thumbnail Image.png

A Functional and Structural MRI Investigation of the Neural Signatures of Dyslexia in Adults

Description

The International Dyslexia Association defines dyslexia as a learning disorder that is characterized by poor spelling, decoding, and word recognition abilities. There is still no known cause of dyslexia, although

The International Dyslexia Association defines dyslexia as a learning disorder that is characterized by poor spelling, decoding, and word recognition abilities. There is still no known cause of dyslexia, although it is a very common disability that affects 1 in 10 people. Previous fMRI and MRI research in dyslexia has explored the neural correlations of hemispheric lateralization and phonemic awareness in dyslexia. The present study investigated the underlying neurobiology of five adults with dyslexia compared to age- and sex-matched control subjects using structural and functional magnetic resonance imaging. All subjects completed a large battery of behavioral tasks as part of a larger study and underwent functional and structural MRI acquisition. This data was collected and preprocessed at the University of Washington. Analyses focused on examining the neural correlates of hemispheric lateralization, letter reversal mistakes, reduced processing speed, and phonemic awareness. There were no significant findings of hemispheric differences between subjects with dyslexia and controls. The subject making the largest amount of letter reversal errors had deactivation in their cerebellum during the fMRI language task. Cerebellar white matter volume and surface area of the premotor cortex was the largest in the individual with the slowest reaction time to tapping. Phonemic decoding efficiency had a high correlation with neural activation in the primary motor cortex during the fMRI motor task (r=0.6). Findings from the present study suggest that brain regions utilized during motor control, such as the cerebellum, premotor cortex, and primary motor cortex, may have a larger role in dyslexia then previously considered. Future studies are needed to further distinguish the role of the cerebellum and other motor regions in relation to motor control and language processing deficits related to dyslexia.

Contributors

Agent

Created

Date Created
  • 2016-12

131285-Thumbnail Image.png

Dyslexia, Creativity, and Neural Adaptation

Description

Objective: A recent electroencephalogram (EEG) study of adults with dyslexia showed that individuals with dyslexia have diminished auditory sensory gating compared to typical controls. Previous studies done involving intoxication and

Objective: A recent electroencephalogram (EEG) study of adults with dyslexia showed that individuals with dyslexia have diminished auditory sensory gating compared to typical controls. Previous studies done involving intoxication and its effect on sensory gating and creativity have shown that there is a positive correlation between creativity (divergent thinking problem solving) and sensory gating deficiency. With previous study findings, the link between dyslexia and sensory gating deficiency and the link between sensory gating deficiency and creativity have been shown, but not the link between dyslexia and creativity. This pilot study aims to address this knowledge gap using event-related potentials.

Methods: Two adults with dyslexia and 4 control adults participated in an auditory gating test using tone pairs. Latencies and Amplitudes for the N100 and P200 responses were recorded and analyzed. Participants were also administered the Abbreviated Torrance Test for Adults (ATTA), a test of creative ability designed to evaluate divergent thinking in individuals. Results were averaged and compared.

Results: The averaged difference in measured N100 amplitudes between tone 1 and tone 2 was significantly larger in the control group compared to the difference observed in the dyslexia group. In particular, one participant with dyslexia who had low scores on a task of rapid word recognition also showed no evidence of gating at the N100 component, whereas the other participant with dyslexia with good word recognition scores showed evidence of intact gating. The averaged difference in measured P200 amplitude between tone 1 and tone 2 was larger in the dyslexia group compared to the control group; however, the difference was small enough to be considered insignificant. The total average ATTA score for the control group was higher than the average of the dyslexia group. This difference in total average was less than one point on a 106-point scale.

Conclusions: Neural sensory gating occurs approximately 100 ms after the onset of a stimulus and is diminished in adults with dyslexia who also have deficits in rapid word recognition. There is a difference in creativity, in terms of divergent thinking, between those with dyslexia and those without (controls scored higher on average); however, the difference is not significant (less than one point). Dyslexia scores were more consistent than controls.

Contributors

Agent

Created

Date Created
  • 2020-05

131230-Thumbnail Image.png

The Post Stroke Journey: A Survey Study of the Effects of Family Support and Psychological Factors on Rehabilitation Goals

Description

Stroke is the fifth most common cause of death in America and a leading cause of long-term adult disability, affecting more than 795,000 people a year ("American Stroke Association: A

Stroke is the fifth most common cause of death in America and a leading cause of long-term adult disability, affecting more than 795,000 people a year ("American Stroke Association: A Division of the American Heart Association"). Many of these individuals experience persistent difficulty with the execution of daily tasks as a direct consequence of a stroke. A key factor in the successful recovery of a stroke survivor is rehabilitation. Rehabilitation sessions can start within two days of the stroke if the patient is in stable condition, and often continues long after their release from the hospital ("American Stroke Association: A Division of the American Heart Association"). The rehabilitation sessions are driven by a team of rehabilitation care professionals which includes, but is not limited to a physical therapist, occupational therapist, and speech-language pathologist. These professionals are available to the stroke survivor as resources to assist in developing and organizing ways to achieve independence as opposed to dependence. Ultimately, a stroke survivor’s family typically provides the most important long-term support during recovery and rehabilitation ("American Stroke Association: A Division of the American Heart Association"). However, there is very little research that focuses on the impact that local family can have on the stroke survivor’s establishment and achievement of goals throughout their recovery and rehabilitation. This study examines this gap in knowledge.

Contributors

Agent

Created

Date Created
  • 2020-05

135887-Thumbnail Image.png

Is Cognitive Control Reliable? When means are not enough

Description

Most theories of cognitive control assume goal-directed behavior takes the form of performance monitor-executive function-action loop. Recent theories focus on how a single performance monitoring mechanism recruits executive function -

Most theories of cognitive control assume goal-directed behavior takes the form of performance monitor-executive function-action loop. Recent theories focus on how a single performance monitoring mechanism recruits executive function - dubbed single-process accounts. Namely, the conflict-monitoring hypothesis proposes that a single performance monitoring mechanism, housed in the anterior cingulate cortex, recruits executive functions for top-down control. This top-down control manifests as trial-to-trial micro adjustments to the speed and accuracy of responses. If these effects are produced by a single performance monitoring mechanism, then the size of these sequential trial-to-trial effects should be correlated across tasks. To this end, we conducted a large-scale (N=125) individual differences experiment to examine whether two sequential effects - the Gratton effect and error-related slowing effect - are correlated across a Simon, Flanker, and Stroop task. We find weak correlations for these effects across tasks which is inconsistent with single-process accounts.

Contributors

Agent

Created

Date Created
  • 2015-12

135399-Thumbnail Image.png

The neurobiology of sentence comprehension: an fMRI study of late American Sign Language acquisition

Description

Language acquisition is a phenomenon we all experience, and though it is well studied many questions remain regarding the neural bases of language. Whether a hearing speaker or Deaf signer,

Language acquisition is a phenomenon we all experience, and though it is well studied many questions remain regarding the neural bases of language. Whether a hearing speaker or Deaf signer, spoken and signed language acquisition (with eventual proficiency) develop similarly and share common neural networks. While signed language and spoken language engage completely different sensory modalities (visual-manual versus the more common auditory-oromotor) both languages share grammatical structures and contain syntactic intricacies innate to all languages. Thus, studies of multi-modal bilingualism (e.g. a native English speaker learning American Sign Language) can lead to a better understanding of the neurobiology of second language acquisition, and of language more broadly. For example, can the well-developed visual-spatial processing networks in English speakers support grammatical processing in sign language, as it relies heavily on location and movement? The present study furthers the understanding of the neural correlates of second language acquisition by studying late L2 normal hearing learners of American Sign Language (ASL). Twenty English speaking ASU students enrolled in advanced American Sign Language coursework participated in our functional Magnetic Resonance Imaging (fMRI) study. The aim was to identify the brain networks engaged in syntactic processing of ASL sentences in late L2 ASL learners. While many studies have addressed the neurobiology of acquiring a second spoken language, no previous study to our knowledge has examined the brain networks supporting syntactic processing in bimodal bilinguals. We examined the brain networks engaged while perceiving ASL sentences compared to ASL word lists, as well as written English sentences and word lists. We hypothesized that our findings in late bimodal bilinguals would largely coincide with the unimodal bilingual literature, but with a few notable differences including additional attention networks being engaged by ASL processing. Our results suggest that there is a high degree of overlap in sentence processing networks for ASL and English. There also are important differences in regards to the recruitment of speech comprehension, visual-spatial and domain-general brain networks. Our findings suggest that well-known sentence comprehension and syntactic processing regions for spoken languages are flexible and modality-independent.

Contributors

Agent

Created

Date Created
  • 2016-05

148374-Thumbnail Image.png

The effect of corpus callosum agenesis on the communication between cerebral hemispheres

Description

Agenesis of the corpus callosum is the lack of the development of the corpus callosum. This condition can lead to impairments in language processing, epilepsy, and emotion and social functioning,

Agenesis of the corpus callosum is the lack of the development of the corpus callosum. This condition can lead to impairments in language processing, epilepsy, and emotion and social functioning, but many individuals with this condition do not show any of these impairments. The present study investigated the connectivity of language and sensorimotor networks within an individual with agenesis of the corpus callosum using resting-state fMRI. The individual’s results were compared to those of neurotypical control subjects. It was hypothesized that the overall interhemispheric functional connectivity would be less than that of a control group in bilateral language networks, but the intrahemispheric connectivity, particularly within the sensorimotor network, would show greater functional connectivity. The results revealed significantly weaker functional connectivity in the individual with agenesis of the corpus callosum within the right ventral stream compared to the control group. There were no other significant inter or intrahemispheric differences in the functional connectivity of the language and sensorimotor networks. These findings lead us to conclude that the right hemisphere’s ventral stream perhaps relies upon connections with the left hemisphere’s language networks to maintain its typical functionality. The results of this study support the idea that, in the case of corpus callosum agenesis, the right language network may contribute differently to language processes than in neurotypical controls.

Contributors

Agent

Created

Date Created
  • 2021-05