Transfer of the curvature aftereffect in dynamic touch

Abstract

a b s t r a c tA haptic curvature aftereffect is a phenomenon in which the perception of a curved shape is systematically altered by previous contact to curvature. In the present study, the existence and intermanual transfer of curvature aftereffects for dynamic touch were investigated. Dynamic touch is characterized by motion contact between a finger and a stimulus. A distinction was made between active and passive contact of the finger on the stimulus surface. We demonstrated the occurrence of a dynamic curvature aftereffect and found a complete intermanual transfer of this aftereffect, which suggests that dynamically obtained curvature information is represented at a high level. In contrast, statically perceived curvature information is mainly processed at a level that is connected to a single hand, as previous studies indicated. Similar transfer effects were found for active and passive dynamic touch, but a stronger aftereffect was obtained when the test surface was actively touched. We conclude that the representation of object information depends on the exploration mode that is used to acquire information.

Human perception of shape from touch

“…Strength of the after-effect is defined as follows: 100 % Â (PSE after adaptation to a convex stimulus minus PSE after adaptation to a concave stimulus)/(convex minus concave adaptation curvature). Data from various studies combined and reanalysed: (a) Same hand or finger conditions: hand static [9,12], hand dynamic [12], five fingers static [12], one finger static [18], one finger active [16]; (b) Transfer to other hand or finger: hand static [12], finger static [18], finger active [16], finger passive [16]; (c) Different conditions with the same hand or finger: hand dynamic-static and hand static-dynamic [12], finger active-passive and finger passive-dynamic [16]; (d ) From hand to fingers and vice versa [12]. The numbers in the bars indicate the number of subjects that participated in an experiment.…”

“…The data of four studies of haptic after-effects will be presented, compared and discussed [9,12,16,18]. As these studies have large parts of their procedures in common, these will be described together.…”

Intra- and Intermanual Curvature Aftereffect Can Be Obtained via Tool-Touch

“…This phenomenon was later examined by Vogels et al [19], who found a curvature aftereffect when observers explored curved surface under whole-hand, direct-touch static conditions. Indeed, haptic aftereffects have been observed in various touch exploration modes, both static [19], [20] and dynamic [21].…”

“…Further, van der Horst et al also found that the curvature aftereffect transferred between hands during both passive [20] and active [21] modes of exploration, suggesting that curvature information may also be represented at a stage in the somatosensory cortex shared by the fingers of both hands, involving several levels of neural processing. In addition, a larger aftereffect in active exploration compared to passive exploration suggests the importance of selfinduced movement [21], which in turn suggests that representation depends on the exploration mode.…”

“…In addition, a larger aftereffect in active exploration compared to passive exploration suggests the importance of selfinduced movement [21], which in turn suggests that representation depends on the exploration mode.…”