Where is straight ahead to a patient with unilateral vestibular loss?

Saj̈, Arnaud; Honoré, Jacques; Bernard-Demanze, Laurence; Devèze, Arnaud; Magnan, Jacques; Borel, Liliane

doi:10.1016/j.cortex.2012.05.019

Cited by 27 publications

(30 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, it has been shown that vestibular signals are necessary for the accurate representation of body pointing direction, as shown by changes in the visual localization of subjective straight ahead (SSA), which indicates the location of the body mid-sagittal plane. Previous studies have revealed a SSA deviation in the acute [27], [28] and chronic stages several years after unilateral vestibular loss [29]. However, it remains unclear whether changes in the representation of the external world interact with the representation of body pointing direction.…”

Section: Introductionmentioning

confidence: 96%

Unilateral Vestibular Loss Impairs External Space Representation

et al. 2014

Self Cite

View full text Add to dashboard Cite

The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation), and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

show abstract

Section: Introductionmentioning

confidence: 96%

Unilateral Vestibular Loss Impairs External Space Representation

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…This would allow to compare the consequence of left vs. right UVF as there is an ipsilateral dominance of the vestibulo-thalamo-cortical pathways, and an overall right hemisphere dominance for vestibular information processing in right-handed participants [84,85]. Left and right UVF impact differently visuo-spatial tasks, with a stronger impact of left UVF on the perceived straight-ahead [86], and a stronger impact of right UVF on visual vertical perception [87]. Interestingly, out-of-body experiences have been related to the right temporo-parietal junction [7,11], an important region of the cortical vestibular network [88,89].…”

Section: Discussionmentioning

confidence: 99%

Anchoring the Self to the Body in Bilateral Vestibular Failure

Deroualle

Toupet²,

Nechel

et al. 2017

PLoS ONE

View full text Add to dashboard Cite

Recent findings suggest that vestibular information plays a significant role in anchoring the self to the body. Out-of-body experiences of neurological origin are frequently associated with vestibular sensations, and galvanic vestibular stimulation in healthy participants anchors the self to the body. Here, we provide the first objective measures of anchoring the self to the body in chronic bilateral vestibular failure (BVF). We compared 23 patients with idiopathic BVF to 23 healthy participants in a series of experiments addressing several aspects of visuo-spatial perspective taking and embodiment. In Experiment 1, participants were involved in a virtual “dot-counting task” from their own perspective or the perspective of a distant avatar, to measure implicit and explicit perspective taking, respectively. In both groups, response times increased similarly when the avatar’s and participant’s viewpoint differed, for both implicit and explicit perspective taking. In Experiment 2, participants named ambiguous letters (such as “b” or “q”) traced on their forehead that could be perceived from an internal or external perspective. The frequency of perceiving ambiguous letters from an internal perspective was similar in both groups. In Experiment 3, participants completed a questionnaire measuring the experienced self/body and self/environment “closeness”. Both groups reported a similar embodied experience. Altogether, our data show that idiopathic BVF does not change implicit and explicit perspective taking nor subjective anchoring of the self to the body. Our negative findings offer insight into the multisensory mechanisms of embodiment. Only acute peripheral vestibular disorders and neurological disorders in vestibular brain areas (characterized by strong multisensory conflicts) may evoke disembodied experiences.

show abstract

“…The deviations of SSA under these conditions are mainly due to the post-training effect, which is very different from the mechanisms leading to the deviation of SSA in our present study. Second, patients with lateralized lesion of the peripheral nervous system or visual cortices also show the deviations of SSA, such as unilateral pathologic pain (Sumitani et al, 2007; Reinersmann et al, 2012), left vestibular loss (Saj et al, 2013) and homonymous hemianopia (Ferber and Karnath, 1999; Rousseaux et al, 2013) or quadrantanopia (Kuhn et al, 2010). Third, damage in cortical regions, in particular the parietal cortex, results in the symptom of hemispatial neglect and the ipsilesional deviation of SSA (Karnath, 1994; Farne et al, 1998; Ferber and Karnath, 1999; Schindler and Kerkhoff, 2004; Richard et al, 2004a,b, 2005; Saj et al, 2006; Rousseaux et al, 2013).…”

Section: Discussionmentioning

confidence: 99%

“…These findings reveal that the processing of egocentric information is asymmetrically distributed between the two hemispheres, with the right hemisphere playing a more dominant role. However, studies of SSA in healthy subjects showed controversial results (Jeannerod and Biguer, 1989; Karnath et al, 1994, 2002; Chokron and Imbert, 1995; McCourt et al, 1997; Vallar et al, 1999; Richard et al, 2004a,b; Saj et al, 2006, 2013; Sumitani et al, 2007; Reinersmann et al, 2012; Rousseaux et al, 2013). …”

Section: Introductionmentioning

confidence: 99%

“…In the former task, since the location of SSA was influenced by the pointing hand (left versus right) and the starting position of the hand (Jeannerod and Biguer, 1989; Chokron and Imbert, 1995; McCourt et al, 1997), the results were diverse among the studies. On the other hand, in the visual straight ahead task, only a few studies reported a slight leftward deviation of SSA in healthy right-handed subjects (Sumitani et al, 2007; Reinersmann et al, 2012), while others reported the overlap of SSA with the body mid-sagittal plane (Karnath et al, 1994, 2002; Vallar et al, 1999; Richard et al, 2004a,b; Saj et al, 2006, 2013; Rousseaux et al, 2013). The controversies among previous studies confounded the understanding of the processing of egocentric judgment in the brain.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Leftward Deviation and Asymmetric Speed of Egocentric Judgment between Left and Right Visual Fields

Zhou

Wang

et al. 2017

Front. Neurosci.

View full text Add to dashboard Cite

The egocentric reference frame is essential for body orientation and spatial localization of external objects. Recent neuroimaging and lesion studies have revealed that the right hemisphere of humans may play a more dominant role in processing egocentric information than the left hemisphere. However, previous studies of egocentric discrimination mainly focused on assessing the accuracy of egocentric judgment, leaving its timing unexplored. In addition, most previous studies never monitored the subjects' eye position during the experiments, so the influence of eye position on egocentric judgment could not be excluded. In the present study, we systematically assessed the processing of egocentric information in healthy human subjects by measuring the location of their visual subjective straight ahead (SSA) and their manual reaction time (RT) during fixation (monitored by eye tracker). In an egocentric discrimination task, subjects were required to judge the position of a visual cue relative to the subjective mid-sagittal plane and respond as quickly as possible. We found that the SSA of all subjects deviated to the left side of the body mid-sagittal plane. In addition, all subjects but one showed the longest RT at the location closest to the SSA; and in population, the RTs in the left visual field (VF) were longer than that in the right VF. These results might be due to the right hemisphere's dominant role in processing egocentric information, and its more prominent representation of the ipsilateral VF than that of the left hemisphere.

show abstract

Where is straight ahead to a patient with unilateral vestibular loss?

Cited by 27 publications

References 60 publications

Unilateral Vestibular Loss Impairs External Space Representation

Unilateral Vestibular Loss Impairs External Space Representation

Anchoring the Self to the Body in Bilateral Vestibular Failure

Leftward Deviation and Asymmetric Speed of Egocentric Judgment between Left and Right Visual Fields

Contact Info

Product

Resources

About