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Monitoring Intraventricular Hemorrhage In Preterm Infants, Lilian Mn Kebaya

Electronic Thesis and Dissertation Repository

Germinal Matrix-Intraventricular hemorrhage (GMH-IVH) remains a significant cause of adverse neurodevelopmental outcomes in preterm infants. Current management options for GMH-IVH rely on serial 2-dimensional cranial ultrasound (2D cUS) ventricular measurements and clinical signs. A need exists for reliable biomarkers to aid in the early detection of posthemorrhagic ventricular dilatation (PHVD) and cerebral palsy (CP). We incorporated 3-dimensional cranial US (3D cUS) and functional infrared spectroscopy (fNIRS) to monitor ventricle volumes (VV) and spontaneous functional connectivity (sFC) in preterm infants with GMH-IVH. Infants with severe GMH-IVH who underwent cerebrospinal fluid diversion showed larger VV, which correlated with decreased sFC. Our findings …

Data-Driven Neuroanatomical Subtypes In Various Stages Of Schizophrenia: Linking Cortical Thickness, Glutamate, And Language Functioning, Liangbing Liang

Electronic Thesis and Dissertation Repository

The considerable variation in the spatial distribution of cortical thickness changes has been used to parse heterogeneity in schizophrenia. We aimed to recover a ‘cortical impoverishment’ subgroup with widespread cortical thinning. We applied hierarchical cluster analysis to cortical thickness data of three datasets in different stages of psychosis and studied the cognitive, functional, neurochemical, language and symptom profiles of the observed subgroups. Our consensus-based clustering procedure consistently produced a subgroup characterized by significantly lower cortical thickness. This ‘cortical impoverishment’ subgroup was associated with a higher symptom burden in a clinically stable sample and higher glutamate levels with language impairments in …

Postexercise Executive Function Benefits And Cerebral Blood Flow: In The Lab And At Home, Benjamin Tari

Electronic Thesis and Dissertation Repository

A single bout of aerobic exercise improves executive function; however, the mechanism, or mechanisms, supporting this improvement remain unclear. One candidate mechanism is an exercise-mediated increase in cerebral blood flow (CBF) that enhances the efficiency of executive-related frontoparietal networks. To evaluate the link between exercise, CBF and executive function, three separate experiments were conducted. In the first study, separate 10-min sessions of moderate-to-heavy-intensity aerobic exercise, and a hypercapnic environment (i.e., 5% CO₂) were implemented. The hypercapnic condition was included because it increases CBF independent of the metabolic demands of exercise. The second study investigated whether exercise intensity-specific changes …

Long Term Outcomes After Norse: Treatment With Vagus Nerve Stimulation, Poul H. Espino, Jorge G. Burneo, Gaby Moscol, Teneille Gofton, Keith Macdougall, Ana Suller-Marti

Brain and Mind Institute Researchers' Publications

New-onset refractory status epilepticus (NORSE) is associated with high mortality, therapy resistant epilepsy (TRE) and poor cognitive and functional outcomes. Some patients develop multifocal TRE, for whom surgery with a curative intention, is not an option. In these patients, Vagus Nerve Stimulation (VNS) is performed as a palliative treatment. We report the long-term outcomes regarding seizure frequency, functional and cognitive outcome, and effectiveness of VNS in two patients with TRE as a consequence of NORSE. In the first patient with cryptogenic NORSE, VNS implantation occurred during the acute stage, probably contributing to the cessation of her status epilepticus. However, in …

No Statistical Learning Advantage In Children Over Adults: Evidence From Behaviour And Neural Entrainment., Christine N Moreau, Marc F. Joanisse, Jerrica Mulgrew, Laura J. Batterink

Brain and Mind Institute Researchers' Publications

Explicit recognition measures of statistical learning (SL) suggest that children and adults have similar linguistic SL abilities. However, explicit tasks recruit additional cognitive processes that are not directly relevant for SL and may thus underestimate children's true SL capacities. In contrast, implicit tasks and neural measures of SL should be less influenced by explicit, higher-level cognitive abilities and thus may be better suited to capturing developmental differences in SL. Here, we assessed SL to six minutes of an artificial language in English-speaking children (n = 56, 24 females, M = 9.98 years) and adults (n = 44; 31 females, M …

Exploring The Structural And Functional Effects Of Pediatric Hydrocephalus On The Hippocampus, Lili Meng

Undergraduate Student Research Internships Conference

Hydrocephalus is one of the most common pediatric neurological problems that requires brain surgery in children. Pediatric hydrocephalus is characterized as an abnormal cerebrospinal fluid (CSF) buildup in the brain’s ventricles due to ineffective CSF reabsorption. When this fluid builds up in these cavities, it increases intracranial pressure and has a direct mass effect on the surrounding brain tissue and structures. Ultimately, various functions are affected including—but not limited to—vision, learning, memory, motor control, and hearing. Despite current literature suggesting that hydrocephalus may be associated with reduced hippocampal volume among rats and human adults, findings remain limited in the human …

In-Vitro Validation Of Intratumoral Modulation Therapy For Glioblastoma, Abdulla Elsaleh

Undergraduate Student Research Internships Conference

Intratumoral modulation therapy (IMT) is a novel electrotherapy used to treat brain cancer tumours using electric fields applied directly to the tumours through implanted electrodes. Previous research has validated IMT's effectiveness and provided computer-simulated optimizations for IMT electric fields. This work validates these computer optimizations in-vitro, using a PCB construct to deliver electric fields, and bioluminescence imaging to assess cell viability.

We found electric field strength to correlate with cell viability, and found that rotating (phase-shifted) electric fields did not produce significant improvements in IMT efficacy. Future work will investigate different IMT frequencies and other parameters, while providing biological replicates …

Auditory Sensory Filtering And Development In Children With Autism Spectrum Disorder, Hiruthika Ravi, Ala Seif, Ryan A. Stevenson

Undergraduate Student Research Internships Conference

Sensory filtering is the process of separating and distilling relevant sensory information from irrelevant, which in turn greatly reduces the quantity of sensory information that is fully processed and leads to significant increases in efficiency. Atypical sensory filtering can result in sensory hypo- or hypersensitivity — atypical sensory filtering and hypo/hypersensitivity have been observed in people with autism. Atypical sensory filtering contributes to canonical symptoms in Autism.

Sensory filtering can be measured in a few different ways, one of which is the Acoustic Startle Response (ASR). ASR is a reflexively produced muscular reaction to sudden auditory stimuli.

Our study aims …

An Open Access Resource For Functional Brain Connectivity From Fully Awake Marmosets, David J. Schaeffer, L Martyn Klassen, Yuki Hori, Xiaoguang Tian, Diego Szczupak, Cecil Chern-Chyi Yen, Justine C. Cléry, Kyle M. Gilbert, Joseph S. Gati, Ravi S. Menon, Cirong Liu, Stefan Everling, Afonso C. Silva

Brain and Mind Institute Researchers' Publications

The common marmoset (Callithrix jacchus) is quickly gaining traction as a premier neuroscientific model. However, considerable progress is still needed in understanding the functional and structural organization of the marmoset brain to rival that documented in longstanding preclinical model species, like mice, rats, and Old World primates. To accelerate such progress, we present the Marmoset Functional Brain Connectivity Resource (marmosetbrainconnectome.org), currently consisting of over 70 h of resting-state fMRI (RS-fMRI) data acquired at 500 µm isotropic resolution from 31 fully awake marmosets in a common stereotactic space. Three-dimensional functional connectivity (FC) maps for every cortical and subcortical gray matter voxel …

Neural Activity During Story Listening Is Synchronized Across Individuals Despite Acoustic Masking., Vanessa C Irsik, Ingrid Johnsrude, Björn Herrmann

Brain and Mind Institute Researchers' Publications

Older people with hearing problems often experience difficulties understanding speech in the presence of background sound. As a result, they may disengage in social situations, which has been associated with negative psychosocial health outcomes. Measuring listening (dis)engagement during challenging listening situations has received little attention thus far. We recruit young, normal-hearing human adults (both sexes) and investigate how speech intelligibility and engagement during naturalistic story listening is affected by the level of acoustic masking (12-talker babble) at different signal-to-noise ratios (SNRs). In Experiment 1, we observed that word-report scores were above 80% for all but the lowest SNR (-3 dB …

Learning Words Without Trying: Daily Second Language Podcasts Support Word Form Learning In Adults, Elise Alexander, Stephen C. Van Hedger, Laura Batterink

Brain and Mind Institute Researchers' Publications

Spoken language contains overlapping patterns across different levels, from syllables to words to phrases. The discovery of these structures may be partially supported by statistical learning (SL), the unguided, automatic extraction of regularities from the environment through passive exposure. SL supports word learning in artificial language experiments, but few studies have examined whether it scales up to support natural language learning in adult second language learners. Here, adult English speakers (n = 70) listened to daily podcasts in either Italian or English for two weeks while going about their normal routines. To measure word knowledge, participants provided familiarity ratings of …

Completing The Puzzle: Why Studies In Non-Human Primates Are Needed To Better Understand The Effects Of Non-Invasive Brain Stimulation, Sebastian J. Lehmann, Brian D. Corneil

Brain and Mind Institute Researchers' Publications

Brain stimulation is a core method in neuroscience. Numerous non-invasive brain stimulation (NIBS) techniques are currently in use in basic and clinical research, and recent advances promise the ability to non-invasively access deep brain structures. While encouraging, there is a surprising gap in our understanding of precisely how NIBS perturbs neural activity throughout an interconnected network, and how such perturbed neural activity ultimately links to behaviour. In this review, we will consider why non-human primate (NHP) models of NIBS are ideally situated to address this gap in knowledge, and why the oculomotor network that moves our line of sight offers …

A Neural Signature Of Regularity In Sound Is Reduced In Older Adults, Björn Herrmann, Burkhard Maess, Ingrid S. Johnsrude

Brain and Mind Institute Researchers' Publications

Sensitivity to repetitions in sound amplitude and frequency is crucial for sound perception. As with other aspects of sound processing, sensitivity to such patterns may change with age, and may help explain some age-related changes in hearing such as segregating speech from background sound. We recorded magnetoencephalography to characterize differences in the processing of sound patterns between younger and older adults. We presented tone sequences that either contained a pattern (made of a repeated set of tones) or did not contain a pattern. We show that auditory cortex in older, compared to younger, adults is hyperresponsive to sound onsets, but …