Temporal order and tactile patterns

Abstract

Temporal order judgments (TOJs) were obtained for tactile stimuli presented to subjects' fingerpads. In one set of measurements, pairs of spatial patterns were presented successively to a single fingerpad (same-site condition), to two fingers on the same hand (ipsilateral condition), or to two fingers on opposite hands (bilateral condition). The subjects were instructed to report which one of the two patterns was presented first. TOJs were more accurate in the same-site condition than in either the ipsilateral or the bilateral conditions. In the ipsilateral and bilateral conditions, performance improved when judging which one of two locations received a stimulus first, although performance levels were still lower than in the same-site condition. Increasing the size of the pattern set from which the two patterns to be judged were drawn had only a slight effect on same-site performance and no effect on ipsilateral/bilateral performance; however, changing the nature of the patterns had a considerable effect on same-site performance and a smaller effect on ipsilateral/bilateral performance. Introducing an intensity imbalance between members of the pair of stimuli also had a large effect on same-site TOJs: a less intense stimulus tended to be judged as being presented first. In the bilateral condition, however, there was a small effect in the reverse direction: more intense stimuli tended to be judged as being presented first. The intensity imbalance had no effect in the ipsilateral condition. The results suggest that different mechanisms are responsible for TOJs for patterns presented to the same-site and to separate sites and, furthermore, that separate sites may constitute separate channels for spatial information.

Aging and tactile temporal order

“…Second, the requirement that subjects be able to both identify the patterns and judge the order in which they were delivered likely increases the cognitive complexity of the task, which, in turn, may reveal greater differences due to age. Results from earlier studies indicate that the localization task is less demanding: The thresholds for this task (Sherrick, 1970) are considerably shorter than the thresholds for patterns when, in the latter case, subjects had to both identify the patterns and report them in the correct temporal order (Craig & Xu, 1990). In addition, one of the tasks in the present study required the subjects to correctly report the order of four patterns, adding an additional cognitive load.…”

“…This appeared to be the case for many of the younger subjects. For that reason, and because 75% correct has been used in previous studies of temporal order with patterned stimuli (Craig & Xu, 1990), we also calculated 75% thresholds for the 2-ID.B condition (see Table 2). Again, the older subjects showed significantly longer SOAs (Z 6.04, p .001).…”

“…Most frequently, the focus of these studies has been on the accuracy of reporting which of two locations on the skin was stimulated first (e.g., Hirsh & Sherrick, 1961;Marks et al, 1982;Sherrick, 1970;Shore, Gray, Spry, & Spence, 2005;Shore, Spry, & Spence, 2002). In a few studies, subjects were required to judge the order of stimuli presented to the same or different locations on the basis of the nature of the stimuli rather than the location (Craig & Xu, 1990;Yuan, Reed, & Durlach, 2005). In the present study, measurements were made both of subjects' ability to judge which of two locations was stimulated first and also the order in which patterns were presented.…”

A brief taxonomy of tactile illusions and demonstrations that can be done in a hardware store

“…This was tested using one finger, two fingers of the same hand, or fingers of two hands [16]. But recently, Yamamoto and Kitazawa revealed that the judgement of the temporal ordering of taps in the bilateral condition was reversed from the mere fact of crossing one's arms, and furthermore found that the effect could be cancelled when holding sticks that crossed to 'undo' the crossing of the arms!…”

The effects of complexity on the perception of vibrotactile patterns presented to separate fingers

“…but not when pairs are presented to separate fingers (Craig & Xu, 1990). Finally, temporal masking declines when pairs of patterns are presented to separate fingers instead of a single finger (Craig, 1983).…”