Browsing by Author "Horne, Autumn"

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    Investigating the relation between phonological working memory and speech production
    (2021-07-12) Horne, Autumn; Martin, Randi C.
    Fluent speech production requires interaction between the language processing system and many other cognitive systems, including working memory (WM). However, there are still unanswered questions of how exactly language and WM relate. Previous evidence suggests that verbal WM consists of separable semantic and phonological components which have different relations to language processing (Martin, Rapp, & Purcell, 2020). Recent neuropsychological work replicated a previously reported relation between semantic WM and the elaboration of content in utterances and also reported a relationship between the rate of spontaneous narrative production and phonological WM (Martin & Schnur, 2019). The latter finding was unexpected because the default scope of phonological planning has been considered to be quite small, making few demands on phonological WM. In the current work, we tested the hypothesis that the relation between phonological WM and the rate of narrative production is due not to phonological WM capacity per se, but rather a shared phonological retrieval process that affects both the efficiency of retrieval of words in narrative speech and the rate of rehearsal in supporting performance in the phonological WM task. In Experiment 1, we examined the relations between single word production latencies, phonological WM, and rehearsal rate using an individual differences approach. If the phonological retrieval hypothesis is correct, we should find a relationship between single word production latencies and phonological WM performance. Additionally, we should observe a relation between phonological WM and rehearsal rate. The first prediction was confirmed in that phonological WM related naming to picture naming latencies for lower but not higher frequency items. However, rehearsal rate was unrelated to phonological WM performance when rehearsal rate was measured with the speed of repeating a single word, thus arguing against a role for rehearsal in phonological WM performance. To further investigate whether phonological retrieval supports rehearsal in the phonological WM tasks, Experiment 2 tested participants’ single word production and phonological WM using tasks that either do (i.e., standard word recall or matching span) or do not (i.e., speeded WM tasks) allow for rehearsal. We predicted that phonological WM would be related to single word production when the phonological WM task allowed for rehearsal, but not when the task discouraged it. In contrast to these predictions, performance on the standard WM tasks did not relate to picture naming latencies, whereas for two of the speeded tasks, such relations were found, with the relations being stronger for low frequency items. The failure to find a relation of WM performance to speech rate in Experiment 1 and the relation of picture naming latencies to WM in speeded WM tasks in Experiment 2 call into question the role of rehearsal in WM performance. Consequently, these findings suggest that other explanations for the relationship between narrative language production and phonological WM—including general processing speed and output phonological buffer capacity—should be explored.
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    Opportunity Youth Healthcare Pipeline Study
    (Rice University Kinder Institute for Urban Research and United Way of Greater Houston, 2024) Bao, Katharine Yang; Njeh, Joy; Selsberg, Brad; Niznik, Aaron; Horne, Autumn; Potter, Daniel; Rice University Kinder Institute for Urban Research
    The Opportunity Youth Healthcare Pipeline (OYHP) initiative, a collaborative effort by J.P. Morgan Chase, United Way of Greater Houston, Memorial Hermann Health System, and several community-based organizations, seeks to connect youth with career opportunities in the health care sector in the Houston region. In partnership with the United Way, the Kinder Institute for Urban Research conducted an in-depth study to explore the operational dynamics, challenges, opportunities, and successes of the implementation of the program. Drawing on insights from participants, program staff, and stakeholders, the study highlights the need for enhanced program awareness, clearer communication channels, tailored support initiatives to better serve Opportunity Youth (OY), and training programs that meet the evolving needs and expectations of the job market.
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    Student Enrollment and Mobility During the COVID-19 Pandemic
    (Rice University Kinder Institute for Urban Research) Pham, Annie; Thomas, Tori; Hood, Stacey; Horne, Autumn
    The Houston Education Research Consortium (HERC) examined patterns of student mobility, specifically students changing schools or school districts, in Houston-area school districts during the COVID-19 pandemic. Furthermore, this brief examined whether and how student mobility networks in Houston-area school districts changed during the pandemic.
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    The white matter correlates of domain-specific working memory and language processing
    (2022-11-21) Horne, Autumn; Martin, Randi C
    Prior neuropsychological evidence suggests separable, domain-specific working memory (WM) buffers for maintaining phonological (i.e., speech sound) and semantic (i.e., meaning) information. The phonological and semantic WM buffers can be damaged separately from each other, having distinct effects on both language comprehension and production. The phonological WM buffer’s proposed location is the left supramarginal gyrus (SMG), whereas semantic WM has been related to the left inferior frontal gyrus (IFG), middle frontal gyrus (MFG), and angular gyrus (AG). However, less is known about the white matter correlates of phonological and semantic WM and any corresponding relationships to multiword language processing. Here, I report 1) the white matter correlates of phonological and semantic WM, 2) the white matter correlates of multiword language production and comprehension, and 3) evidence that semantic WM can mediate the relation between tract integrity and language processing. These analyses focus on the left hemisphere as there is strong evidence for the involvement of left hemisphere regions in verbal WM and language processing. I also present exploratory analyses of the relations between right hemisphere tracts and both WM and language processing to address the possibility that WM and/or language function reorganizes to the right hemisphere after left hemisphere brain damage. Participants were 45 individuals with left hemisphere brain damage. Each participant was tested on a battery of single word processing, phonological WM, semantic WM, sentence comprehension, and narrative production tasks. T1 and diffusion weighted scans were also obtained for each participant. Virtual dissections were performed for each participants’ arcuate fasciculus (AF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), middle longitudinal fasciculus (MLF), and uncinate fasciculus (UF). These tracts were chosen because they have terminations in regions that have previously been identified as potential domain-specific WM buffers: the SMG for phonological WM and the IFG, MFG, and AG for semantic WM. In chapter 2, to test the relation between white matter tract integrity and domain-specific working memory, I took a multiple regression approach which allowed us to control for both single word processing and gray matter damage to the regions where each tract terminates. I predicted that the indirect pathway of the left AF would support phonological WM while the left IFOF, ILF, MLF, UF, and direct pathway of the AF would support semantic WM. Further, because semantic WM is critical for multiword language processing, it was predicted that tracts supporting semantic WM should also support multiword language production and comprehension. In line with the predictions, the left ILF, left MLF, left IFOF, and left direct segment of the AF were related to semantic WM performance. Relationships between semantic WM and right ILF and right IFOF integrity were also observed. Phonological WM was related to both the left ILF and MLF. In chapter 3, I used a multiple regression approach to investigate the relation between tract integrity and language processing while controlling for single word processing and gray matter damage. I found that the left AF, IFOF, ILF, and right IFOF were related to language comprehension while the left IFOF and ILF were related to language production. The right IFOF was also related to language comprehension. Further, I used mediation analysis to investigate whether semantic WM fully or partially mediates the relation between left IFOF and left ILF tract integrity and multiple aspects of multiword language processing. Additionally, phonological WM mediated the relation between left ILF integrity and language comprehension. The results of this work inform our understanding of the white matter correlates of both WM and language processing, especially semantic WM, and the neural basis of the relation between semantic WM and language processing, which no previous work has investigated. From a theoretical perspective, this work is also important for adjudicating between alternative buffer theories of verbal WM and should inform future research on neuroplasticity, particularly how the right hemisphere may support cognitive processing after left hemisphere brain damage
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    White Matter Correlates of Domain-Specific Working Memory
    (MDPI, 2023) Horne, Autumn; Ding, Junhua; Schnur, Tatiana T.; Martin, Randi C.
    Prior evidence suggests domain-specific working memory (WM) buffers for maintaining phonological (i.e., speech sound) and semantic (i.e., meaning) information. The phonological WM buffer’s proposed location is in the left supramarginal gyrus (SMG), whereas semantic WM has been related to the left inferior frontal gyrus (IFG), the middle frontal gyrus (MFG), and the angular gyrus (AG). However, less is known about the white matter correlates of phonological and semantic WM. We tested 45 individuals with left hemisphere brain damage on single word processing, phonological WM, and semantic WM tasks and obtained T1 and diffusion weighted neuroimaging. Virtual dissections were performed for each participants’ arcuate fasciculus (AF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), middle longitudinal fasciculus (MLF), and uncinate fasciculus (UF), which connect the proposed domain-specific WM buffers with perceptual or processing regions. The results showed that the left ILF, MLF, IFOF, and the direct segment of the AF were related to semantic WM performance. Phonological WM was related to both the left ILF and the MLF. This work informs our understanding of the white matter correlates of WM, especially semantic WM, which has not previously been investigated. In addition, this work helps to adjudicate between theories of verbal WM, providing some evidence for separate pathways supporting phonological and semantic WM.