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Tactile stimulator array.
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Tactile pattern recognition was studied by presenting pairs of alphabetic shapes in rapid succession at the same anatomical
location, the subject being required on each trial to identify bath of the patterns. Experimental variables were the duration
of each stimulus and the time between stimuli. Three aspects of the observed interaction were (1) an...
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The Japanese macaque (Macaca fuscata) exhibits a species-specific communication sound called the “coo call” to locate group members and maintain within-group contact. Monkeys have been demonstrated to be capable of discriminating between individuals based only on their voices, but there is still debate regarding how the fundamental frequencies (F0)...
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... However, when the SOA was relatively long (> 200 ms) backward masking became negligible whereas forward masking remained visible for SOAs up to 1200 ms. This is consistent with the results reported by Bliss et al. (1966). However, Gescheider, Bolanowski and Verrillo [99] did not find any differences and Weisenberger [100] reported more forward masking than backward masking for relatively short ISIs. ...
... However, Gescheider, Bolanowski and Verrillo [99] did not find any differences and Weisenberger [100] reported more forward masking than backward masking for relatively short ISIs. The difference between the above mentioned studies might be due to the difference between signal detection [99,100] and pattern recognition [98,101]. It is possible that different processes are involved in detecting simple vibrotactile signals and in recognising complex patterns of stimulation. ...
... Some theories on masking are discussed briefly. Bliss et al. [101] described masking with a model consisting of three intervals: ...
This report describes the state-of-the-art of touch-based displays in military environments: neurophysiology, psychophysics, perceptual and human factors issues, hardware and integration issues and lessons learned, and future directions. The document gives an overview of NATO activities and is useful for both end users and designers.
... Although the body surface clearly offers a potentially important alternative means of conveying information to an interface operator, several fundamental questions concerning the limitations and/or advantages of utilizing tactile information displays have yet to be addressed empirically [6,10]. These include questions related to the kinds of information that are best conveyed by touch, how many tactile sources of information can be perceived at any one time [11,12], and how well people can detect changes to ongoing patterns of tactile stimulation [13][14][15]. In the present study, we explored the ability of normal adult human observers to perceive changes to simple sequentially-presented tactile patterns consisting of between 1-3 vibrotactile stimuli distributed over the body surface. ...
Interest in the use of tactile information displays has grown rapidly in recent years. However, relatively little research has been conducted to explore any cognitive and/or attentional limitations that may be inherent when using the body as a receptor surface for the transmission of information. In the present study, participants attempted to detect changes to tactile patterns presented sequentially on the body surface. The patterns consisted of 1-3 vibrotactile stimuli presented for 200 ms with a blank interstimulus interval of 800 ms. The pattern of tactile stimulation was repeatedly changed (alternating between two different patterns) on 50% of the trials, while no change occurred on the remaining trials. The results showed that participants often failed to detect the changes to the consecutively-presented tactile patterns. This finding may reflect a tactile equivalent of the phenomenon of change blindness reported in previous visual studies. The implications of these finding for human tactile interface design are discussed.
... In two other paradigms, the subject is required to identify one of the two patterns and ignore the other. If the two patterns are presented to the same site, this is typically considered a temporal masking paradigm (Bliss, Crane, Link, & Townsend, 1966; Craig, 1982b Craig, , 1983 Craig, , 1985 Craig & Evans, 1987; Evans & Craig, 1986; Schindler & Knapp, 1976). Ifthe patterns are presented to separate sites, the task becomes one of selective attention (Evans & Craig, 1991 Evans, Craig, & Rinker, 1992; Rinker & Craig, 1994). ...
When two tactile patterns, a target and a nontarget pattern, are presented in close temporal proximity to the same location, the nontarget pattern may interfere with the identification of the target. A series of experiments examined the extent to which the interference in target identification results from masking (interference in the representation of the target at an early stage of processing) or from response competition. A response competition view of pattern perception holds that both the target and nontarget are fully processed to the level of evoking responses. Interference is produced when subjects select the nontarget rather than the target. This view was tested with a paradigm developed in studies of selective attention. Pairs of tactile patterns were presented to subjects' left index fingerpads. The amount of interference produced by a nontarget that is physically different from a target depends on whether the nontarget is associated with the same response as the target or a different response. The amount of masking also depends on the set of target and nontarget patterns that are used. The results support the conclusion that subjects have available a representation of both the target and the nontarget and that a substantial portion of the interference previously attributed to masking may be due to response competition.
... On the other hand, it is just as probable that transient masking and other spatiotemporal interactions also contribute to the difficulty of tactile recognition when the entire display is modulated in time as well as in space; precisely this view has been taken by Craig in interpreting some recent masking effects he observed in letter recognition studies using the Optacon in the "Times-Square" mode (Craig, Note 1). Previously, too, the various forms of spatiotemporal interaction have certainly been of major concern to those concerned with the perception of patterns using multiple stimulator arrays (Bliss, Crane, Link, & Townsend, 1966; Gilson, 1969b; Hill & Bliss, 1968). Realizing that these other masking effects may be present, we nevertheless think that our finding of a spatial masking effect and its interpretation are useful in understanding other tactile phenomena. ...
In a letter recognition task in which the letters were presented temporally across two columns of a vibrotactile array, the
masking effects of added columns of steady vibrotactile stimulation were investigated. The primary variable studied was the
spatial separation between the masking columns and the letter-carrying columns. The results indicate a spatially dependent
masking effect which is independent of the tactile masking associated with mask onset. A comparable masking effect was obtained
with visual letter recognition using the same relative stimulus configurations viewed under conditions of optical blurring.
An interpretation of the tactile masking is offered in terms of the limited spatial resolution of the cutaneous sense.
... The palmar sides of the fingers were suspended about 1/8 in. above the airjet stimulators in the same apparatus described previously (Bliss, Crane, Mansfield & Townsend, 1966). The Ss' arms were supported from wrist to elbow, permitting the hands to be suspended in this manner for extended periods without fatigue. ...
... Thus, the fraction of positions perceived varies with the position in the Ss' response schedule. This result is in agreement with the results reported by Bliss, Crane, Mansfield and Townsend (1966) for simultaneous point stimuli, and by Bliss, Crane, Link and Townsend (1966) for sequential patterned stimuli. (4) There was not enough evidence to show that the interaction between SOl and SSP was significant; the data indicate that the probabilities for each S are a linear sum of these two independent terms. ...
... (4) There was not enough evidence to show that the interaction between SOl and SSP was significant; the data indicate that the probabilities for each S are a linear sum of these two independent terms. This result is in contrast with the results of Bliss, Crane, Link and Townsend (1966), in which a greater percentage of first-response errors was obtained with patterned tactile stimuli for short interstimulus ...
Either two or three brief (10 msec) airjet stimuli were sequentially presented to any of the 24 interjoint regions of the
fingers (thumbs excluded). The stimulus onset interval (SOI) ranged from zero (simultaneous presentation) through 200 msec.
The S’s task in one part of the experiment was to report the positions stimulated in the order that the stimuli were presented;
in a second part it was to rate the apparent motion produced by the stimulus sequence. While the ability of Ss to spatially
localize the stimuli was a constant independent of SOI, their ability to temporally order the stimuli depended strongly on
SOI. With two stimuli, these sequential errors decayed exponentially with SOI with a time constant of 26 msec. With three
stimuli, however, both the sequential errors and equivalent temporal Urnen were more than twice as large as with two stimuli,
indicating that the three-stimulus task is considerably more difficult than the two, and that the same simple temporal resolution
model does not explain both cases. A model with a constant rate of information uptake, however, can explain both of these
cases.
... However, when the SOA was relatively long (> 200 ms) backward masking became negligible whereas forward masking remained visible for SOAs up to 1200 ms. This is consistent with the results reported by Bliss et al. (1966). However, Gescheider, Bolanowski and Verrillo [99] did not find any differences and Weisenberger [100] reported more forward masking than backward masking for relatively short ISIs. ...
... However, Gescheider, Bolanowski and Verrillo [99] did not find any differences and Weisenberger [100] reported more forward masking than backward masking for relatively short ISIs. The difference between the above mentioned studies might be due to the difference between signal detection [99,100] and pattern recognition [98,101]. It is possible that different processes are involved in detecting simple vibrotactile signals and in recognising complex patterns of stimulation. ...
... Some theories on masking are discussed briefly. Bliss et al. [101] described masking with a model consisting of three intervals: ...
In this chapter, we are concerned with what our touch receptors and the associated central nervous structures do. Our description begins with the anatomical and physiological characteristics of the touch receptors followed by a comprehensive psychophysical overview of touch sensation and perception. The conditions under which touch sensations and perception arise and the rules that govern them will also be described.
The standard braille code symbols are very difficult to discriminate tactually, and the braille alphabet code is difficult to learn. It is possible to design alphabet code symbols which are significantly easier to discriminate and learn. Tests of an improved code called C5 are described, which show that its symbols can be perceived accurately when formed by a braille printer.
Based on a review of the literature on reading, including the details of its information processing aspects and the role of the sensory register, short-term memory, and long-term memory, it is concluded that both visual and tactile reading involve the same basic processes. Taking into account what is known about visual reading and the results of recent experiments on the sense of touch, it is suggested that certain simplifications in the braille code and changes in the mode of presentation (dynamic-rhythmic rather than spatial) would considerably improve the efficiency of braille reading.
This document describes the hardware developed to realize a shape memory alloy (SMA) tactile stimulator. A 5x6 30 element array has been developed to provide tactile stimulation to the human operator of a remotely controlled robotic system. The work verifies that a tactile stimulator can be packaged in finger-pad size arrays and that computer control is feasible. Actuation profiles and design techniques are discussed.
The purpose of this report is to describe the development of a framework to enable classification, evaluation, and comparison of multimodal display research, based on task demands, display characteristics, research design, and individual differences. In this report, we describe the process by which a bibliographic database was developed and organized. First, the framework was specified, which then guided the identification and review of research and theory-based articles that were included in the bibliography. The results of the overall effort, the multimodal framework and article tracking sheet, bibliographic database, and searchable multimodal database make substantial and valuable contributions to the accumulation and interpretation of multimodal research. References collected in this effort are listed in the appendix.
