and fingers plausible (Klatzky - PDF document

a1 1975; J M Loomis, R L Klatzky. S and fingers plausible (Klatzky a1 1989), then one expect touch the integration sensory processing, there are ciated with higher-level processing. noncontiguous regions two fingers Although the two fingers one hand to be subjects seem take full capacity when (Lappin factors involve working Because tactual perception normally more upon sequential exploration than in the same information, the depends more memory and integration that coherent perception on sampled infor- these factors performance, as touch must at a disadvantage. picture perception faring badly in the compar- picture perception that line often use perspective) that have less touch than are the studies. Torii a1 (reviewed in a1 adventitiously blind, and blind observers. in which another, and depict simple groups in 1989; Lederman et a1 have also congenitally blind poorly in that previous visual experience facilitates those employing pictorial conventions, it would be incorrect it is to interpret pictorial conventions sensed tactually by employing visual imagery mediate recognition a1 evaluate this possibility is and tactual in terms this possibility, present study also sought be attributable limited field ined this recognize pictures tactually spatial information available as possible two fingers. subjects scanned a computer-driven an electronic over a over the in the moved, a displayed within a rectangular display screen. Thus, the saw what behind a stationary to the were blurred spatial detail 170 J M Loomis, R L Klatzky, intersubject agreement. For all drawings their largest sion (width, or diagonal) a rectangle facsimiles of the pictures figure 1 were created by xeroxing special heat-sensitive paper and copies through a Stereo Copy has been to produce tactile maps resulting raised pictures had lines unifor~lr mm), uniform the paper surface (0.2 mm), and were dimensions as original line drawings. preserved in During the a wooden dimensions; this frame allowed tactual workspace. Subjects in raised pictures distal pad the outstretched finger, while subjects in juxtaposed distal the outstretched index and middle finger hand. Subjects were instructed keep the finger(s) the frame ensure that pads were less even drawing; tilting produce contact to promote closer equivalence constraints, lateral motions the hand effected mostly while radial and away body were In the stages we the contact area finger using fingerprinting; this order to match stimula- tactual condition. Referring average contact W,) authors and fourth person the average 16.1 mm; is actually subjects were be representative average full (a) (b) middle fingers right hand from above rectangular contact areas were specified and widths the relative 0,. simulate the tactual contact areas. position were specified L,, W,, so that to the the tactual contact areas 172 J M Loomis, R L Klatzky, S J Lederman 14.2%, simulated one-finger covered virtually average finger pad in the touch the two-finger wide field x pixels were juxtaposed without any gap. one-finger and two-finger in size the software only permitted widths that were (Loomis In contrast, their relative vertical positions were subject to relative position distal and index and middle fingers; simulated middle finger a number visual simulation the observer the tactual blurred so as to mimic any picture detail resulting spatial resolution (Loomis To effect between visual and subject's two-point limen using a series discussed above; were experienced then illuminated two monitor that expressed as a 'finger width' the visible From the subject's these would normally large glass the monitor the observer blur) until two points be barely the perceptual equal to that raised pictures, it probably no great very few were filtered out under summarize, the visual conditions that provided same information raised images and the spatial video image, cutaneous information touch condition. Information about the both conditions the kinesthetic information from hand movement, information that Sensory modality size was were assigned domly to wide field different rows I), assessed in a1 the experiment proper, each presented with and the modality after every set (six For example, subject would be presented trials in with vision, counterbalanced across Subjects were that the wedding ring but that the drawings had been rescaled the tactual subjects participated a practice session they received touch trials and vision trials the experiment were allowed their response. they were also 174 J M Loornis, R L Klatzky, S J Lederrnan size by modality interaction (F,,,, = 9.02, p 0.01) as main effects (F,,,, = 15.24, p 0.001), field size (F,,,, = 7.30, p for response (F,,,, = 11.91, p main effects (F,,,, 26.65, p 0.001) and (F,,,, = 16.48,~ Table 1 correct responses six) and modality, recognition accuracy and -0.84 for for touch correlates significantly with latency corresponding correlation for recognition accuracy limited reliability, provide additional some degree similarity between the narrow control condition, pictures in the absence a restricted blur used by any subjects in experiment. Recogni- 10O0/0 the response latency averaging subjects had in in the tactual conditions cannot be due to poor Number of correct average response latencies field condition. latency/s responses latency/s Lightbulb Pencil Envelope Glove Hanger Screw Sweater Key Spoon Clothespin Carrot Comb Knife Sock Glasses Scissors Screwdriver Ashtray Candle Whistle CUP Bowl Hammer Lock 176 J M Loomis, R L Klatzky, in table I, far from pictures employing touch than narrow-field vision. and candle make such conventions and were recognized by and bowl constitute counterexamples. one cannot argue forcefully at a disadvantage conventions, at least would involve the deliberate perspective and occlusion such cues of these to the in the present experiment. result is that increasing senses. Doubling in visual recognition performance, measured latency, but virtually change in tactual recognition performance. in visual that subjects were integrate information the double aperture, necessarily perfectly. the total extent, permitted nearly 80% subjects were using from the arm and hand quite successive images arm/hand resulted in little improvement performance is consistent Lappin and Foulke Lappin index and middle a task attributed to two different that there parallel perceptual a serial process found that spread across two fingers hand, subjects integrate the distributed the pattern. His is thus much information about a to integrate C Craig a lack invariance in the spatiotemporal somatosensory cortex; this make integra- pattern information the somatosensory temporary circumstances where stimulation is invariant abutting). Arguing against this across the fingers is improved somewhat pattern information across the in integrating might be between-finger masking find across-finger integration objects is for one expect such active exploration objects. However, objects should