Examining the neurovisceral integration model through fNIRS

The neurovisceral integration model (NVM) proposes that an organisms ability to flexibly adapt to their environment is related to biological flexibility within the central autonomic network. One important aspect of this flexibility is behavioral inhibition (Thayer and Friedman, 2002). During a behavioral inhibition task, the central autonomic network (CAN), which is comprised of a series of feedback loops, must be able to integrate information and react to these inputs flexibly to facilitate optimal performance. The functioning of the CAN is shown to be associated with respiratory sinus arrhythmia (RSA), as the vagus nerve is part of this feedback system. While the NVM has been examined through neural imaging and RSA, only a few studies have examined these measures simultaneously during the neuroimaging procedure. Furthermore, these studies were done at rest or used tasks that were not targeted at processes associated with the NVM, such as behavior inhibition and cognitive flexibility. For this reason, the present study assessed RSA and neural activation in the prefrontal cortex simultaneously while subjects completed a behavior inhibition task. Using a series of go/no-go tasks, RSA and functional near-infrared spectroscopy (fNIRS) were collected to investigate the relationship between prefrontal activation and vagal activity at rest and during behavioral inhibition.

There are three primary aims of this study. First, examine prefrontal activation during various inhibition tasks through fNIRS. Second, evaluate the NVM during a cognitive task using simultaneous fNIRS and RSA analysis. Third, relate task performance, imaging, and RSA measures during behavioral inhibition to deficits in flexible everyday responding, as indicated by self-report measures of behavior. Doing so will elucidate the connection with prefrontal activation and RSA as proposed by the NVM model and determine whether neural and RSA metrics can be related to broader symptoms of inflexibility.