Neurophysiology and Neuroplasticity Studies

Swallowing is a complex biological function that is controlled by six pairs of cranial nerves and many areas/centers in the brainstem and brain. Disruptions in any of the complex swallowing neural pathways may lead to difficulty swallowing (also known as dysphagia). 

The series of swallowing neurophysiology and neuroplasticity studies conducted by our team aim to help us better understand the underlying central and peripheral neural mechanisms that control this vital human function, in an effort to inform clinical decisions and develop neurophysiologically-driven treatments.

Brain Activity during swallowing

Brain activity during swallowing in healthy young adults

Our early swallowing neurophysiology work focused on providing insights on the underlying neural mechanisms of swallowing function in healthy adults (Malandraki et al. 2009; Malandraki et al. 2010; Malandraki et al. 2011; Paine et al. 2011). Based on this work our team was among the first to identify areas of the brain responsible for different aspects of the swallowing sequence, thus providing insights on functional specificity and further validation for the role of the brain (cortex and subcortex) in swallowing control.

Brain slices

Areas of most significant activation during swallowing (shown in red), during throat clearing (shown in blue), and during tongue tapping (shown in yellow). (Malandraki et al. 2009)

Developmental Neuroplasticity of Swallowing and Speech – CP study

One of our largest current studies (funded by NIH and AACPDM) is focused on examining the neuroplastic adaptations of swallowing and speech in children with unilateral and bilateral brain damage, and specifically in children with cerebral palsy (CP). 

In essence by investigating the behavioral, peripheral, and central neurophysiological profile of these children we have started gaining a better understanding of how the central and the peripheral nervous systems adapt for several functions, such as feeding, swallowing, and speech after early brain lesions. This understanding is imperative in our efforts to develop new and better treatments for feeding, swallowing, and speech for these children who currently remain largely under-treated in these domains. This study is partially supported by the NIH (NIDCD) and the American Academy of Cerebral Palsy and Pedal-with-Pete Foundation.

To learn more about our current studies on developmental neuroplasticity and how to participate (if your child qualifies) please see our study flyer (on the right hand side) or contact us at swallowinglab@purdue.edu.

SMN network in CP

Sensorimotor network at rest of two children with unilateral CP. Our preliminary studies show that children with bilateral sensorimotor resting networks (as shown on the right image) may have more severe clinical signs of dysphagia than children with contralesional sensorimotor resting networks (shown on the left image) (Malandraki et al. 2017, ESSD).

Determining the Relationship between the Aerodigestive and Manual Systems

Eating is typically a social event, but much is still unknown about the coordination between speaking, eating, and breathing. In conjunction with the Purdue Motor Speech Lab, we are investigating the relationship between the swallowing, speech, and manual subsystems in both healthy young and older adults. Our eventual aim is to better understand dysphagia in an environment that mimics a typical meal.

To learn more about this study and how to participate (if you qualify) please see our study flyer (below) or contact us at swallowinglab@purdue.edu or (765) 496-0207.

Determining the Relationship between Swallowing and Voice

Research has shown that the functions of swallowing and voice production (particularly pitch elevation) share anatomical and neurophysiological substrates. In our earlier preliminary research in this area we showed that reduced pitch elevation can be indicative of reduced airway protection in some dysphagia patients (Malandraki et al. 2011). More recently our team revealed that reduced ability to elevate vocal pitch was actually predictive of silent aspiration of small liquid volumes with high sensitivity and moderate specificity in a sample of stroke patients (Rajappa et al. 2017).

Although these findings are promising and have started shedding light into how these cross-system interactions can be utilized, the exact neurophysiological and biomechanical correlates between the two functions are still not very well understood.

Our current study, funded by the Dept of Speech, Language, & Hearing Sciences, investigates this relationship in depth in a sample of healthy young and older adults.

To learn more about this study contact us at swallowinglab@purdue.edu.

Picth elevation fluoro1
Pitch elevation

Students/trainees involved in these studies (now or in the past)

  • Rachel Arkenberg
  • Carey Smith
  • Anny Alvar
  • Anumitha Venkatraman
  • Kara Simon
  • Kausar Abbas
  • Tom Lu
  • Lucia Figueiredo-Mourao
  • Naomi Dreyer
  • Pratik Kashyap
  • Cagla Kantarcigil

Funding provided by:

  • National Institute on Deafness and Other Communication Disorders (NIDCD, NIH) [Early Career R21, PI: Malandraki]
  • American Academy of Cerebral Palsy and Developmental Medicine and Pedal-with-Pete Foundation [PI: Malandraki]
  • Department of Speech, Language, & Hearing Sciences [student grant]
  • Seed MRI fund, College of Health and Human Sciences, Purdue University [PI: Malandraki]
  • Indiana Lions McKinney Outreach Program [student grant]
  • National Institutes of Health / Eunice Kennedy Shriver National Institute of Child Health and Human Development [R01, PI: Friel]