This article provides an overview of an ongoing program of research designed to investigate the effectiveness of haptic
cuing to redirect a user's visual spatial attention under various conditions using a visual change detection paradigm.
Participants visually inspected displays consisting of rectangular horizontal and vertical elements in order to try and
detect an orientation change in one of the elements. Prior to performing the visual task on each trial, the participants
were tapped on the back from one of four locations by a vibrotactile stimulator. The validity of the haptic cues (i.e., the
probability that the tactor location coincided with the quadrant where the visual target occurred) was varied. Response
time was recorded and eye-position monitored with an eyetracker. Under conditions where the validity of the haptic cue
was high (i.e., when the cue predicted the likely target quadrant), initial saccades predominantly went to the cued
quadrant and response times were significantly faster as compared to the baseline condition where no haptic cuing was
provided. When the cue validity was low (i.e., when the cue provided no information with regard to the quadrant in
which the visual target might occur), however, the participants were able to ignore haptic cuing as instructed.
Furthermore, a spotlight effect was observed in that the response time increased as the visual target moved away from
the center of the cued quadrant. These results have implications for the designers of multimodal (or multisensory)
interfaces where a user can benefit from haptic attentional cues in order to detect and/or process the information from a
small region within a large and complex visual display.
Usage of 3D data and models is receiving a growing interest for several applications, like training, museum displays, multimodal interfaces, aid for impaired people. In such a framework the need will soon raise to protect 3D data from misuse. Among the technologies that can be used to this aim, digital watermarking has a prominent role, due to its versatility and non-obtrusiveness. A basic requirement of any watermarking scheme is that the embedded code is invisible, or non-perceivable, by the end user of the data. This requirement also holds for 3D objects, it is then necessary that the human ability of perceiving a signal
hidden in a 3D object is studied. In this paper we present a preliminary analysis aiming at comparing the perceptibility of the hidden signal when the 3D model is sensed through different
senses, namely vision (through common rendering techniques and subsequent display on a monitor) and touch (through a haptic interface). Specifically our investigation aimed at assessing
whether ensuring watermark invisibility is sufficient to ensure that the watermark presence can not be felt haptically. The answer stemming from our preliminary analysis seems to be a clear no, even if further studies will be necessary before a definitive answer can be given.