Mental transformation abilities in patients with unilateral and bilateral vestibular loss

Abstract

Vestibular information helps to establish a reliable gravitational frame of reference and contributes to the adequate perception of the location of one's own body in space. This information is likely to be required in spatial cognitive tasks. Indeed, previous studies suggest that the processing of vestibular information is involved in mental transformation tasks in healthy participants. In this study, we investigate whether patients with bilateral or unilateral vestibular loss show impaired ability to mentally transform images of bodies and body parts compared to a healthy, age-matched control group. An egocentric and an objectbased mental transformation task were used. Moreover, spatial perception was assessed using a computerized version of the subjective visual vertical and the rod and frame test. Participants with bilateral vestibular loss showed impaired performance in mental transformation, especially in egocentric mental transformation, compared to participants with unilateral vestibular lesions and the control group. Performance of participants with unilateral vestibular lesions and the control group are comparable, and no differences were found between right-and left-sided labyrinthectomized patients. A control task showed no differences between the three groups. The findings from this study substantiate that central vestibular processes are involved in imagined spatial body transformations; but interestingly, only participants with bilateral vestibular loss are affected, whereas unilateral vestibular loss does not lead to a decline in spatial imagery.

Extreme short-term environmental constraints do not update internal models of action as assessed from motor imagery in adults

“…This is corroborated by mental imagery studies conducted on patients with vestibular deficits, who demonstrated impaired ability to mentally transform body images (Grabherr et al, 2011). These authors also demonstrated that a task involving mental transformation of one's own body or body parts becomes more difficult under 0G.…”

Balancing awareness: Vestibular signals modulate visual consciousness in the absence of awareness

“…Whereas these previous studies tested visual and vestibular integration with respect to self-motion and vestibular influences on the processing of consciously perceived visual information, other studies investigated the effects of vestibular stimulation on visual attention (Figliozzi, Guariglia, Silvetti, Siegler, & Doricchi, 2005), bistable visual states (van Elk & Blanke, 2012), and mental rotation (Grabherr et al, 2011;van Elk & Blanke, 2014). Of relevance for vestibular input to visual awareness, it was shown by van Elk & Blanke that the direction of passive self-motion influences the perceived rotation direction of bistable rotating stimuli (that under stationary conditions have 50% of chance to be perceived to be rotating in either direction).…”

“…In addition vestibular stimulation (in the form of caloric stimulation or passive whole body rotations) has been shown to modulate the perception of bistable visual stimuli (Ngo, Liu, Tilley, Pettigrew, & Miller, 2007;van Elk & Blanke, 2012) and the mental rotation of visually presented bodily stimuli (van Elk & Blanke, 2014). Mental transformation of visually presented stimuli is also affected by damage to the vestibular end organs (Grabherr, Cuffel, Guyot, & Mast, 2011) as well as exposure to microgravity (Grabherr et al, 2007) Finally, visual perception is also affected by the observer's position with respect to gravity (Lobmaier & Mast, 2007;Lopez, Bachofner, Mercier, & Blanke, 2009). Collectively, these studies point toward extensive visuo-vestibular interactions for self-motion and visual perception.…”

Difficulties Faced by Patients Suffering from Total Bilateral Vestibular Loss

“…However, it is now well known that the vestibular system plays a role in spatial orientation [8]. Alterations in the concept of right and left can already be observed amongst patients with a unilateral vestibular deficit; the phenomenon is much more marked in the case of a bilateral deficit [9]. Accordingly, patients can be comforted.…”