Language and Neural Recovery from Stroke – Tatiana T. Schnur, Ph.D.

Language and Neural Recovery from Stroke
credit: Tatiana T. Schnur, Ph.D.Neurosurgery Department

A fundamental aspect of our existence is that spoken language is our primary means of communication with others. Unfortunately, the ability to speak is impaired following stroke. It is unclear what drives successful recovery of language production following stroke. The Schnur Lab uses cognitive behavioral testing, quantitative (structural, diffusion tensor imaging, perfusion) and functional neuroimaging (resting state functional connectivity), and statistical modeling to understand how multi-word production and the neural structures that support it change during recovery following by testing participants within 72 hours of stroke (acute stage) and again at 1, 6, and 12 months after stroke. We recruit participants in the acute phase after stroke in collaboration with the three comprehensive stroke centers in the Houston Texas Medical Center (Memorial Hermann Hospital, Houston Methodist Hospital, and Baylor St. Luke’s Hospital). Results from this project will help us gain predictive power to assess what types of brain damage and behavior lead to chronic language loss, thus informing both psychological theories and treatment approaches to language.

Identifying Mechanisms for Frequency Processing - Jeffrey M. Yau, Ph.D.

fMRI Decoding (320x240)
credit: Jeffrey YaufMRI Decoding

Our sensory experience depends on the integration of multisensory information over time and space. Our lab aims to identify principles that unify our senses. We investigate the relationship between the brain and behavior using functional neuroimaging, noninvasive brain stimulation, computational modeling, and psychophysics. One current line of research investigates how we perceive temporal frequency by audition and touch. We use fMRI adaptation and decoding to characterize population neural tuning for auditory and tactile temporal frequency in human cortex. Preliminary results reveal the existence of modality-invariant frequency tuning mechanisms. Specifically, these studies have shown that overlapping areas in perisylvian brain regions, including areas typically thought of as unisensory auditory and somatosensory cortex, are involved in temporal frequency processing for both audition and touch (see Figure). Our research also focuses on developing and refining methods for concurrent TMS-fMRI, which involves delivering noninvasive brain stimulation in the MRI scanner. This technique allows us to selectively perturb neural activity in targeted brain areas while we simultaneously visualize the regional and distributed hemodynamic consequences of this manipulation.

Imaging Biomarkers of Psychiatric Illness - Ramiro Salas Lab

Habenula (320x240)

The Salas lab studies multimodal imaging (structural, resting state functional connectivity, diffusion tensor imaging and reward task) in a large series of psychiatric patients from The Menninger Clinic. These patients present with major depression, substance abuse, bipolar, anxiety, and personality disorders and all possible comorbidities. We use brain imaging and collaborate with labs performing genetics and clinical assessments on the same patients to develop multimodal biomarkers of psychiatric illness. Other projects in the lab include the investigation of the reward and habenular (disappointment) systems in Parkinson's disease, cancer cachexia/anorexia and tobacco and cocaine abuse.

Using Facial Expressions to Communicate - Michael Beauchamp Lab

Beauchamp (320x240)
Using Facial Expressions to Communicate

Humans use facial expressions to communicate. Two of the most important types of facial expressions are mouth movements and eye movements. Yet, we know little about the brain mechanisms for understanding facial expressions. To solve this mystery, Lin Zhu, a BCM M.D./Ph.D. student working in Dr. Michael Beauchamp’s laboratory, is using the 3 tesla scanners in the Center for Advanced MRI.

In her studies, Lin is showing volunteers mouth movements and eye movements and measuring their brain activity with blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI).

Her studies have shown that different parts of the brain, especially the superior temporal sulcus, prefer mouth movements or eye movements. Interestingly, the parts of the brain that respond strongly to mouth movements also respond strongly to listening to stories. This suggests a link between the neural structures that process visual information and those that process auditory information, a phenomenon known as multisensory integration. This knowledge will be very important for helping patients who have trouble communicating, such as children with autism spectrum disorders.

Brain Research Analysis in Neurodevelopment Laboratory

Sentence Comprehension (320x240)
Sentence Comprehension

The Brain Research Analysis in Neurodevelopment (BRAIN) Laboratory, directed by Dr. Jennifer Juranek, investigates the functional and structural neural mechanisms of reading comprehension in typical and struggling readers using a multimodal neuroimaging approach.  The overall purpose of this study is to examine how developmental outcomes of educational interventions are related to aspects of brain organization. Children between the ages of 8-12 years are given reading and executive function tasks while their brains are being scanned in a 3T Siemens MRI scanner. Measures of functional MRI, quantitative structural MRI, and DTI are obtained. The results from this study will assess the impact of educational intervention on the developing brain and the implications might lead to identifying neurobiological markers for reading disabilities.

In addition to this research, the BRAIN laboratory, in collaboration with Drs. Ursula Johnson and Susan Landry, examines the role of parenting practices on brain development in toddlers. For this investigation structural and functional data are collected from children between the ages of 15 and 26 months.  The goal of this investigation is to document the impact of an existing intervention on parenting practices on neurodevelopment during early childhood.  

Hemodynamic Response Function - David Ress Lab

BOLD HRF (320x240)
BOLD HRFs and predicted corresponding CBF and CMRO2

Jung Hwan Kim’s work focuses specifically on studying the vascular response to brief periods of neural activity in human brain. Such response is known as the hemodynamic response function (HRF). He introduced a novel computational model of the transient delivery of oxygen in the brain based on arterial vasodilation by local neural activity in human visual cortex. His hypothesis is based on recent experimental evidences that brief local neural activity induces upstream arterial vasodilation. His model is able to demonstrate how cerebral blood flow and oxygen consumption temporally competes each other to yield observed the HRF. He also measures high spatiotemporal resolution fMRI blood oxygen level-dependent (BOLD) HRF in human cortical and subcortical regions, and he uses his computational model to interpret the measured HRFs to understand the mechanism of neurovascular and neurometabolic coupling.

Investigational Targeted Brain Neuro-Therapeutics - Theodora Dorina Papageorgiou Lab

Real Time fMRI (320x240)
Real Time fMRI

The Investigational Targeted Brain Neuro-therapeutics lab focuses on the neuro-rehabilitation of the following brain impairments as a result of traumatic brain injury, stroke, brain tumor, neurodegenerative disease, and pain syndromes: (i) visual cortical blindness; (iii) lower cranial nerves that affect tongue movement, swallowing, and mastication, and (iii) chronic pain. We use a novel intervention to provide targeted neuro-rehabilitation, called real-time functional MRI neurofeedback to induce reorganization in cortical and subcortical pathways. Patients undergo neurofeedback in real time to upregulate or downregulate the activity of intact cortical and/or subcortical areas in conjunction with the continuous presentation of visual stimuli inside the MRI environment with the goal to restore or reorganize lesioned pathways associated with vision, speech, or pain. The modulation in the Blood-Oxygen-Level-Dependent (BOLD) signal intensity is achieved by feeding" back to the patient the magnitude of mean BOLD signal intensity of his/her intact cortical area during the presentation of a stimulus in real-time. The hypothesis is that such training engages Hebbian mechanisms that modulate the activity of intact cortical areas with the goal to improve performance. The goals of my laboratory are: (i) to examine and understand the neural mechanisms of adaptive plasticity in the design of treatments that will enhance nervous system recovery after a brain insult; (ii) to achieve individualized, and long-term effects via real-time fMRI neurofeedback at targeted cortical and subcortical areas, and; (iii) to optimize rt-fMRI neurofeedback as the "next generation" of noninvasive, brain neurotherapeutics with the long-term goal to use this tool in the clinical setting.