Haptically Induced Illusory Self-motion and the Influence of Context of Motion

Abstract

Abstract. The ability of haptic stimuli to augment visually and auditorily induced self-motion illusions has in part been investigated. However, haptically induced illusory self-motion in environments deprived of explicit motion cues remain unexplored. In this paper we present an experiment performed with the intention of investigating how different virtual environments -contexts of motion -influences self-motion illusions induced through haptic stimulation of the feet. A concurrent goal was to determine whether horizontal self-motion illusions can be induced through stimulation of the supporting areas of the feet. The experiment was based on the a within-subjects design and included four conditions, each representing one context of motion: an elevator, a train compartment, a bathroom, and a completely dark environment. The audiohaptic stimuli was identical across all conditions. The participants' sensation of movement was assessed by means of existing measures of illusory self-motion, namely, reported self-motion illusion per stimulus type, illusion compellingness, intensity and onset time. Finally the participants were also asked to estimate the experienced direction of movement. While the data obtained from all measures did not yield significant differences, the experiment did provide interesting indications. If motion is simulated through implicit motion cues, then the perceived context does influence the magnitude of displacement and the direction of movement of self-motion illusions as well as whether the illusion is experienced in the first place. Finally, the experiment confirmed that haptically induced illusory self-motion in the horizontal plane is indeed possible.

A Systematic Review and Meta-Analysis on The Use of Tactile Stimulation in Vection Research

“…Most of the reviewed articles in this paper presented the definition of vection as an illusory perception of self-motion that is visually induced (Amemiya et al, 2016;Farkhatdinov et al, 2013;Kitazaki et al, 2019Kitazaki et al, , 2016Lind et al, 2016;Nilsson et al, 2012;Nordahl et al, 2012;Riecke et al, 2009;Väljamäe et al, 2009), which would align with the first definition of vection as described by Palmisano et al (2015). For example, Amemiya et al (2016) defined vection as a phenomenon "…the illusory perception of actual self-motion rather than the sensation of simply watching a moving world … and is strongly induced when the peripheral visual field is stimulated."…”

Future challenges for vection research: definitions, functional significance, measures, and neural bases

“…Given that there is no inherent visual connotation in the Latin root of the word, it is perhaps no surprise that ‘vection’ is now increasingly being used to also refer to illusory self-motions induced by stimulating the non-visual self-motion senses . These non-visual illusions of self-motion (where the observer is typically either seated in darkness or blindfolded) include: (1) Auditory vection – illusory self-motion induced by moving the observer’s acoustic surround ( Dodge, 1923 ; Lackner, 1977 ; Sakamoto et al, 2004 ; Riecke et al, 2008 ; Keshavarz et al, 2014 ; see Väljamäe, 2009 for a review); (2) Haptokinetic vection – illusory self-motion produced by applying tactile motion stimulation to large areas of the observer’s body ( Dichgans and Brandt, 1978 ; Nilsson et al, 2012 ; Nordahl et al, 2012 ; Murata et al, 2014 ); (3) Arthrokinetic vection – illusory self-motion induced by passively rotating the observer’s limb/s ( Brandt et al, 1977 ; Howard et al, 1998 ); and (4) Biomechanical vection – illusory self-motion generated when a standing/seated subject repeatedly steps on a treadmill ( Bles, 1981 ; Riecke et al, 2011 ). Interestingly, while illusions of self-motion can also be induced by caloric (e.g., Fasold et al, 2002 ) and direct galvanic stimulation (e.g., Cress et al, 1997 ; Lepecq et al, 2006 ), such vestibular illusions are rarely referred to as vestibular vection (see below for one notable exception) 2 .…”

Vibrotactile inputs to the feet can modulate vection

“…Vibrations of 50 Hz applied to the feet, together with visual and auditory stimuli, was used to generate vertical illusory self-motion [9]. Similar studies investigated the influence of the feet vibration on the strength of the illusion according to different visual and auditory contexts [8].…”