Real world navigation independence in the early blind correlates with differential brain activity associated with virtual navigation

Abstract

Navigating is a complex cognitive task that places high demands on spatial abilities, particularly in the absence of sight. Significant advances have been made in identifying the neural correlates associated with various aspects of this skill, however, how the brain is able to navigate in the absence of visual experience remains poorly understood. Furthermore, how neural network activity relates to the wide variability in navigational independence and skill in the blind population is also unknown. Using fMRI, we investigated the neural correlates of audio-based navigation within a large scale, indoor virtual environment in early profoundly blind participants with differing levels of spatial navigation independence (assessed by the Santa Barbara Sense of Direction (SBSoD) scale). Performing path integration tasks in the virtual environment was associated with activation within areas of a core network implicated in navigation. Furthermore, we found a positive relationship between SBSoD scores and activation within right temporal parietal junction (TPJ) during the planning and execution phases of the task. These findings suggest that differential navigational ability in the blind may be related to the utilization of different brain network structures. Further characterization of the factors that influence network activity may have important implications regarding how this skill is taught in the blind community.

Nonvisual spatial navigation fMRI lateralizes mesial temporal lobe epilepsy in a patient with congenital blindness

“…In line with previous research in sighted MTLE patients and congenitally blind individuals without MTLE (Avila et al, 2006;Halko et al, 2014;Janszky et al, 2005;Jokeit et al, 2001;Kupers et al, 2010;Schacher et al, 2006), the present findings clearly show that nonvisual spatial navigation is suitable for mapping mesial temporal regions despite the co-occurrence of MTLE and congenital blindness. The recall of spatial episodic memories was associated with a rightward asymmetry of the mesial temporal lobes, referring to the presence of functional deficits adjacent to the epileptogenic lesion.…”

“…In addition, language-related (inferior frontal and middle temporal gyri, pre-SMA, cerebellum), secondary motor, and visual association (inferior temporal gyrus) areas were activated. Consistent with previous research on spatial cognition and navigation in both sighted and congenitally blind individuals (Cattaneo et al, 2008;Halko et al, 2014;Kupers et al, 2010;Struiksma et al, 2009), this activity pattern strongly suggests that the patient recruited linguistic, motor, and nonvisual sensory sources during spatial navigation.…”

“…Consistently, both animal and human studies provide converging evidence that the ability to represent spatial information and to navigate independently in space is relatively well preserved in light-deprived animals and congenitally blind individuals (Fortin et al, 2008;Kupers, Chebat, Madsen, Paulson, & Ptito, 2010;Save, Cressant, Thinus-Blanc, & Poucet, 1998). In addition, congenitally blind and sighted subjects have recently been shown to recruit a strikingly similar functional network when navigating in space that included mesial temporal regions involved in spatial cognition and memory (Halko, Connors, Sánchez, & Merabet, 2014;Kupers et al, 2010). These findings have led to the suggestion that owing to the adaptive functional reorganization of brain regions mediating nonvisual sensory and verbal modalities, individuals with congenital blindness are able to form spatial representations despite their lack of visual experience (Cattaneo et al, 2008;Struiksma, Noordzij, & Postma, 2009).…”

Rehabilitation program integrating virtual environment to improve orientation and mobility skills for people who are blind

“…Sound-based VEs have been investigated and developed for people who are blind (Halko, Connors, Sánchez, & Merabet, 2014; Gonzalez-Mora, 2003; Seki & Sato, 2011); however, this research showed that successful exploration using only sound requires a very high level of attention. “Haptics,” which refers to sensing and manipulation through touch, is another modality for interacting with a VE that can provide the user with tactile, kinesthetic, and reaction force information about the environment, as well as a means of controlling events in the VE.…”

Self‐reported navigation ability is associated with optic flow‐sensitive regions’ functional connectivity patterns during visual path integration

“…The SBSoD is a widely used self‐report measure of environmental spatial ability that has been shown to correlate with performance on tests of the ability to update one's position and orientation in space (Arnold et al, ; Hegarty et al, ). The SBSoD is increasingly being used as a measure of overall spatial navigation ability—especially in MRI studies (Auger, Mullally, & Maguire, ; Epstein, Higgins, & Thompson‐Schill, ; Halko, Connors, Sánchez, & Merabet, ; Kong et al, ; Sulpizio et al, ; Wegman & Janzen, ). The scale is composed of 15 questions to which participants respond on a Likert‐type scale of 1–7 (strongly agree‐strongly disagree).…”