Our Approach
Our lab uses classic non-invasive integrative physiological methods, reimagines old methods, and pioneers new methods to probe neurovascular coupling as a critical link between cerebrovascular function and cognitive function. In our lab, we define neurovascular coupling as the change in cerebral blood flow, cortical oxygenation and neural excitation that occurs with the change in metabolic demand instigated by manipulating cognitive load. Cognitive load is altered with mental tasks, physical tasks, or both (dual tasks).
Our Methods
Large Artery Stiffness and Central Hemodynamic Pulsatility
A person is only as old as their arteries. We assess vascular aging with gold standard methods such as carotid-femoral pulse wave velocity (aortic stiffness), ultrasonography (carotid stiffness), and pulse contour analysis of pressure waveforms (wave reflections, augmentation index, reservoir pressure). Additionally, we are exploring use of shear wave elastography to measure viscoelastic tissue properties of the carotid artery as a novel measure of carotid artery stiffness.
Cerebral Hemodynamics
Hemodynamics is the study of blood pressure and blood flow. To assess cerebral hemodynamics, we use transcranial Doppler to evaluate cerebral blood velocity. Measurement of cerebral blood velocity during cognitive tasks and acute changes in blood pressure with mental tasks (Stroop task) or physical tasks (sit to stand) is used to assess neurovascular coupling and cerebral autoregulation, respectively. We also utilize rheoencephalography to obtain intracranial impedance waveforms and are exploring novel ways of analyzing these waveforms with harmonic distortion to understand brain physiology. Finally, we are piloting ultrasound-based methods that combine speckle tracking and tissue Doppler imaging to assess brain tissue pulsations that are produced with each heartbeat.
Cortical Oxygenation and Neural Activity
Electroencephalography (EEG) is used to assess spontaneous neural oscillations caused by fluctuations in neuronal excitability. In addition to obtaining information across different frequency bands (delta, theta, alpha, beta, gamma), we are exploring different approaches to measuring functional connectivity (how different parts of the brain interact and exchange information). EEG can be combined with functional near-infrared spectroscopy (fNIRS) to assess regional cortical tissue oxygenation changes that occur with concomitant neural activation.
Cognitive Function and Sensorimotor Integration
Cognitive function is assessed using a variety of methods including such platforms as NIH Toolbox along with customized continuous performance tasks to assess cognitive control. Cognitive tasks can be combined with gait tasks and balance tasks (measured on a force platform to obtain center of mass postural sway metrics) to increase cognitive load (dual tasks). Additionally, we are exploring use of virtual reality to perform novel tests of sensorimotor integration.
General Fitness Measures
Aside from all of the fancy measures of vascular function and brain function, we also have access to some neat tools to assess general health and fitness. Our lab adjoins the Applied Physiology (AP) Strength Lab. The Strength Lab has a full assortment of Olympic weights, kettlebells, lifting blocks, a power rack, dumbbells, resistance bands, and one small yellow multi-purpose traffic cone. The AP Strength Lab also houses a Cosmed BodPod and Styku 3D Body Scanner for the assessment of body composition (body fat, muscle, and estimates of bone density). Additionally, the lab has a Wattbike which can be used to perform tests of anaerobic power and submaximal tests of aerobic capacity. Contact us to learn more.
Publications - Hot Off The Press
1. Wakeham DJ, Pierce GL, Heffernan KS. Effect of Acute Resistance Exercise on Central Pulsatile Hemodynamics and Large Artery Stiffness: Part I. Pulse, In Press. Pulse 2025;13:31–44 (DOI:10.1159/000543313)
2. Wakeham DJ, Pierce GL, Heffernan KS. Effect of Resistance Exercise Training on Central Pulsatile Hemodynamics and Large Artery Stiffness: Part II. Pulse, In Press. Pulse 2025;13:45–61 (DOI:10.1159/000543314)
Presentations
1. Williams P, Martin, K, Quackenbush J, Greenberg J, Hudson C, Gallegos R, Brignoli H, Heffernan K. Blood Pressure and Aortic Stiffness in Young Adults with Previous ACL Injury. Greater NY Regional Chapter of the American College of Sports Medicine Annual Conference, 2024.
2. Kuo J, Cassette J, Chen KH, Armstrong M, Heffernan K. Carotid Artery Viscoelasticity Following Acute Exercise: Insight from Shear Wave Elastography. MARC American College of Sports Medicine Annual Conference, 2024. *Research Award Finalist
3. Williams P, Martin, K, Quackenbush J, Greenberg J, Hudson C, Gallegos R, Brignoli H, Heffernan K. Superficial Femoral Artery Reactivity in Young Adults with Previous ACL Injury. MARC American College of Sports Medicine Annual Conference, 2024. *Research Award Finalist
4. Bjalme-Evans M, Wani D, Heffernan K, Quinn L. Using fNIRS to explore neural correlates of the clinical progression of Parkinson Disease during the miniBESTest: A protocol for a pilot feasibility study. The Society for functional Near Infrared Spectroscopy Conference, 2024.
5. Williams P, Armstrong M, Pierce G, and Heffernan KS. The effect of acute moderate intensity exercise on arterial reservoir and excess pressure in young adults. Scientific Conference of the North American Artery Society, 2024.
6. Heffernan K. Resistance Exercise and Arterial Stiffness: Something Old, Something New, Something Borrowed and Something Blue, Past-President Lecture at the MARC American College of Sports Medicine Annual Conference, 2024.
7. Heffernan K. Vascular aging and lifestyle medicine: will resistance exercise ever go out of (life)style? Invited Lecture at the Greater NY Regional Chapter of the American College of Sports Medicine Annual Conference, 2024.