Image Processing Reference
In-Depth Information
characterized yet, there is strong evidence on the integration and sharing of
perceptual information since the very early sensory processing stages [
42
,
43
]
and on the bounding effects of cognitive, emotional, and personality factors [
10
].
The presence of a given modality can distort or modulate (either intensifying or
attenuating) the perception in other modality. Cross-modal interaction processes—
as for example, synesthesia—underline the relative importance of the different
sensory modalities presented (see [
43
] and citations thereof). This phenomenon
has been widely analyzed, from an empirical perspective, in terms of the relative
influence of vision and sound on task-related performance [
44
-
48
]. Findings reveal
the potential of vision to alter the perception of speech and spatial location of audio
sources and the influence of audio on vision in terms of temporal resolution,
intensity, quality, structure, and interpretation of visual motion events. Concerning
other modalities, a form of synesthesia—defined as “crossmodal transfer”—has
been reported between vision and touch. The phenomenon is characterized by the
appearance of a perceptual illusion in one modality induced by a correlated
stimulus on other sensory modality (e.g., illusion of physical resistance induced
by the manipulation of a virtual object in a mediated environment) [
49
]. Interest-
ingly (although not surprisingly), this cross-modal illusion was found correlated
with the sensation of spatial and sensory presence in the displayed environment. In
[
41
], participants reacted faster (i.e., lower simple detection times were measured)
to auditory and haptic stimulus than to visual stimulus when only one of them was
presented (unimodal condition). In coherence, the bimodal auditory-haptic combi-
nation resulted in even faster reactions in comparison to those reported for each
unimodal component and for the other two bimodal combinations (visual-haptic
and visual-auditory). These results suggest a highly relevant influence of auditory
and haptic stimuli on processing times at the initial perceptual stage, which
according to the authors allows users more time in the consequent cognitive stages,
enabling them better integration and filling in of missing information. Similarly, the
authors in [
50
] found that haptic feedback can led to an improved task performance
and feeling of “sense of togetherness” in shared VEs.
The majority of these empirical findings support the “modality appropriateness”
hypothesis, which argues that
the modality that is most appropriate or reliable with
respect to a given task dominates the perception in the context of that task
[
51
]. However, this and other approaches still require further elaboration to better
explain complex effects as the wide variety of responses to inter-sensory divergent
events reported in literature.
2.3 The Influence of Immersion
The effectiveness of a mediated environment to evoke cognitive and emotional
reactions in a similar way to non-mediated experiences is heavily conditioned by
the consistency between the displayed environment and an equivalent real envi-
ronment as regards to the user experience [
52
,
53
]. Two main components
