Projects

• Tinnitus

How is an auditory conscious percept generated

A fundamental concept in psychology and philosophy of the mind is the notion of perception: the act of interpreting and organizing a sensory stimulus to produce a meaningful experience of the world and of oneself. A stimulus produces an effect on the different sensory receptors, inducing sensation. Further processing of this sensory stimulation generates an internal representation of the outer and inner world called a percept. Since the first days of psychology, two challenging questions have existed: how is sensory information encoded and, in particular, how is this represented information transformed into the individual awareness of a conscious percept? The auditory system is relatively simple in comparison to the somatosensory and visual system and also uses the thalamus as a sensory gate in contrast to the olfactory system. Understanding the brain mechanisms involved in the simplest forms of auditory conscious perception, such as noise and tones is a crucial start for gaining knowledge about auditory consciousness specifically and consciousness at large. Hearing is performed primarily by the auditory system. It has been shown that activity in the auditory cortex is necessary, but not sufficient for auditory consciousness. In order to perceive an auditory stimulus consciously different brain networks need to be co-activated. In this project we try to map and disentangle these different brain networks, most likely working simultaneously in parallel, and determine their exact function related to consciousness by including three populations, one without auditory consciousness (people with deafness), one with normal auditory consciousness and one with too much auditory conscious percepts (phantom sounds). Auditory stimulus presentation just below, at and above hearing threshold will be analyzed using different neuroimaging and neuromodulation techniques. This research project fundamentally contributes to understanding the neurobiological mechanisms involved in auditory conscious perception. Secondly, it contributes to a new approach in neuroscience by introducing network science technology in consciousness research and thirdly, it might help in the development of new diagnostic tools and treatments for patients with auditory disorders.

A blinded randomized pilot study assessing vagus nerve stimulation paried with tones for tinnitus vs. unparied tones

This is a Phase II pilot study designed to provide information on the efficacy and safety of vagus nerve stimulation (VNS) paired with tones for the treatment of tinnitus. The clinical study is proposed to serve as primary support for the design and implementation of a pivotal study for US market approval; it is expected to give efficacy and safety information.

• Pain

The neural correlates of neuropathic pain

Since several decades ago chronic pain understanding has become in one of the most intriguing challenges for health professionals (rheumatologists, psychologists, physiotherapists, anaesthesiologists, pharmacologists, etc). Different reasons are behind that traditionally poor knowledge about the etiology, mechanisms and treatment of chronic pain. Pain has been very often considered as a peripheral entity in which peripheral causes, such as inflammation and structural joint damage, have been only explored. Thus, difficulties to explain painful symptomatology associated to chronic pain patients, such as the great discordance between pain complaints or severity and their supposed peripheral causes, have lead to the development of investigations to advance in the knowledge of pain mechanisms in chronic pain diseases (p.e., non-inflammatory conditions), such as it occurs in fibromyalgia. Fibromyalgia is a poorly understood chronic pain condition in which the patients experience pain in the four quadrants of their body. The pain is continuously present, but can aggravate during ‘flair ups’. There are no abnormal findings on physical or technical examinations. Besides the pain, patients suffer from a variety of associated symptoms. Mood disorders, headaches, sleep disorders, fatigue and gastro-intestinal complaints are a few examples of the associated symptoms. With project we try to have a better understanding of the underlying neural mechanism.

The neural correlates of fibromyalgia

As fibromyalgia lacks a generally accepted pathophysiology, a myriad of treatments have been proposed, none of which that have a high success rate. The European League against Rheumatism and the American Pain Society formulated recommendations and evidence-based guidelines for its treatment. Treatment consists of pharmacological and non-pharmacological approaches. The implementation of antidepressant therapy and novel treatment strategies with pregabaline and duloxetine may expand the therapeutic options. Occipital nerve stimulation (ONS) is being successfully used as a surgical treatment for primary headache syndromes, however there are no placebo controlled studies. Recently, ONS was performed in patients who met criteria for fibromyalgia, presenting with co-morbid headache disorder. In this specific study, which lacked placebo control as well, it was noted that not only headaches, but also the widespread bodily pain improved. Furthermore, associated mood and fatigue scales improved. The principle mechanism of peripheral nerve stimulation (PNS), including ONS, in the treatment of pain is based on the gate control theory. The aim is to perform a double-blind placebo controlled crossover study using ONS for the treatment of fibromyalgia.

• Addiction

Common brain mechanisms in obesity and alcohol addiction

In collaboration with the University of Otago we are looking whether obesity and alcohol addiction excessive consumption of food or alcohol induces similar neuroadaptive responses in brain reward circuitries. Here, we try to find evidence suggesting that obesity and alcohol addiction may share common systems-level mechanisms.

Lab for Auditory & Integrative Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas © 2014