Investigating Possible Mechanism of Human-Animal Bond in Companion Dogs Using Functional Near-Infrared Spectroscopic (fNIRS) Brain Imaging | HABRI

Investigating Possible Mechanism of Human-Animal Bond in Companion Dogs Using Functional Near-Infrared Spectroscopic (fNIRS) Brain Imaging

Principal Investigator

Niwako Ogata (Purdue University)


Dog ownership is commonly assumed to have a beneficial impact on human physiological and mental health (i.e., “pet effect”); yet the mechanisms underlying this effect of the human-animal bond (HAB) are not well understood from a neuroscience perspective. To maximize the impact of animal-assisted interventions and understand the dynamic nature of human-animal interaction (HAI), such an understanding is critical. We propose to address this knowledge gap using fNIRS, a functional imaging method for brain activity that can be applied in a natural environment non-invasively. Our inter-disciplinary team approach will result in methodologically rigorous evidence regarding the neural correlates of the bond between humans and pet dogs.


  • Aim 1: Probe the neural correlates of the HAB in pet owners using functional near-infrared spectroscopy (fNIRS). We will use fNIRS to detect brain activation of the HAB and examine differential response among human participants experiencing various types of HAB. Brain activation of the HAB will be measured in context of a stress recovery period.
  • Aim 2: Determine the effect of a dog’s familiarity and physical presence on a dog owner’s stress recovery response. We hypothesize that benefits of the pet effect are maximized when a dog is present with a human (i.e., direct contact), and that individuals perceiving a familiar dog—in contrast to an unfamiliar dog—will show a better stress recovery response. Human response will be determined by fNIRS as well as other stress parameters (subjective stress rating, heart rate [HR], and saliva cortisol).
  • Aim 3: Determine if feedback from a dog correlates with a dog owner’s regional brain activation. We hypothesize that the dog’s behavior/emotional response during an interaction correlates with the human’s brain activity. The dog’s feedback when interacting with the human will be determined via video analysis and heart rate variability (HRV) while the human’s brain activation will be determined via fNIRS.


To determine human neural correlates of the pet effect, we will use fNIRS to explore hemodynamic changes in the brain. The study will be conducted in a laboratory setting with healthy adult participants. Thus, to maximize the potential to detect a pet effect, data will be taken in the context of an induced stress recovery period. We will implement a cross-over design that allows us to directly assess similarities and differences between test conditions with each participant serving as their own control. We will induce two types of stress (psychosocial and physiological stress) in study participants using a standard laboratory test and then compare effects during the recovery period. The response to a dog presented in different contexts (e.g., direct vs indirect contact and familiar vs unfamiliar dog) will be compared. Data from validated stress markers and a self-report assessment will also be collected. The dog’s behavioral/emotional responses will be measured to determine the degree to which its response impacts human brain activity.

Expected Results

The project is expected to result in neural correlates of the HAB and potential factors to enhance it (e.g., direct vs. indirect contact, familiar vs unfamiliar dog). It will also result in preliminary data vital for addressing questions regarding the underlying mechanisms of the HAB, particularly pet effects.