Temporal masking of multidimensional tactual stimuli

Abstract

Experiments were performed to examine the temporal masking properties of multidimensional tactual stimulation patterns delivered to the left index finger. The stimuli consisted of fixed-frequency sinusoidal motions in the kinesthetic (2 or 4 Hz), midfrequency (30 Hz), and cutaneous (300 Hz) frequency ranges. Seven stimuli composed of one, two, or three spectral components were constructed at each of two signal durations (125 or 250 ms). Subjects identified target signals under three different masking paradigms: forward masking, backward masking, and sandwiched masking (in which the target is presented between two maskers). Target identification was studied as a function of interstimulus interval (ISI) in the range 0 to 640 ms. For both signal durations, percent-correct scores increased with ISI for each of the three masking paradigms. Scores with forward and backward masking were similar and significantly higher than scores obtained with sandwiched masking. Analyses of error trials revealed that subjects showed a tendency to respond, more often than chance, with the masker, the composite of the masker and target, or the combination of the target and a component of the masker. The current results are compared to those obtained in previous studies of tactual recognition masking with brief cutaneous spatial patterns. The results are also discussed in terms of estimates of information transfer (IT) and IT rate, are compared to previous studies with multidimensional tactual signals, and are related to research on the development of tactual aids for the deaf.

Different Effects of Adding White Noise on Cognitive Performance of Sub-, Normal and Super-Attentive School Children

“…It has been shown that if the masker was predictable ADHD participants behave less impulsively [64] and exhibit improved signal detection [65]. Masking effects have been shown in both the visual [66] and tactile modalities [67]. In both SR and in masking, task irrelevant (meaningless) stimulation in different modalities increases the signal-to-noise ratio and thus improves performance on various tasks.…”

Designing haptic icons to support collaborative turn-taking

“…To formalize this step, there is a critical need for the haptics and HCI communities to jointly map the large space of haptic stimulus and icon design, and support it with heuristics, such as those gleanable from (van Erp, 2002;Swindells et al, 2005;Brown et al, 2006a, b;Luk et al, 2006), as well as prototyping tools (e.g., Enriquez and MacLean, 2003;Swindells et al, 2006) and perceptual foundations (in the manner of Tan et al, 1999Tan et al, , 2003MacLean, 2004, 2007;Pasquero, 2006;Dixon et al, 2007;.…”

Tactual display of consonant voicing as a supplement to lipreading

“…The specific scheme for the presentation of the EOA cue was designed to optimize the tactual delivery of EOA information: ͑1͒ the two modulated envelopes were presented to two different fingers with the assumption that the amount of cross-finger masking is less than that of same-finger masking ͑Verrillo et al, 1983͒ and ͑2͒ the two amplitude envelopes were modulated by two different frequencies with the belief that the farther the distance between the two modulating frequencies the less the amount of masking between them ͑Ge-scheider et Tan et al, 2003͒. The selection of the two modulating frequencies of 50 and 250 Hz for the low-and high-pass bands, respectively, was based on the following criteria: ͑1͒ The two modulating envelopes have the same order as the two frequency regions from which the envelopes are extracted, i.e., the carrier with higher frequency was modulated by the amplitude envelope from the higher frequency band, while the carrier with lower frequency was modulated by the amplitude envelope from the lower frequency band; ͑2͒ the two frequencies are perceptually distinct ͑see Tan, 1996͒; and ͑3͒ in general, the duration of the amplitude envelope signals exceeds 20 ms, allowing each modulating envelope to contain at least one cycle.…”