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Touching Textures in Different Tasks by a Woman with Congenital Deaf-Blindness

2012; SAGE Publishing; Volume: 106; Issue: 11 Linguagem: Inglês

10.1177/0145482x1210601104

1559-1476

Marleen J. Janssen, Mark Huisman, J.P.M. van Dijk, Wied Ruijssenaars,

Multisensory perception and integration

Little is known about how persons with congenital deaf-blindness use hand movements efficiently for exploring different objects with different textures in different tasks (Miles, 2003). More knowledge in this area would contribute to the adaptations of educational strategies for encouraging touch and tactile exploration. Earlier research (Janssen, Nota, Eling, & Ruijssenaars, 2007) demonstrated that the encoding strategies of Chris, woman with congenital deaf-blindness, were faster than those of hearing and sighted controls in perception and memory task. The purpose for the study presented here was to observe more closely Chris's tactile exploratory procedures when touching objects with microtextures in the different tasks. Lederman and Klatzky (1987, p. 344) defined an exploratory procedure as a stereotyped pattern of hand movements that maximizes the sensory input corresponding to certain property of an object and is considered to have certain characteristics that are invariant and others that are highly typical. They discriminated various exploratory procedures, such as lateral motion and pressure. More experienced participants used tactile exploratory procedures that gathered information more quickly and that captured the more relevant properties of an object (Hughes & Jansson, 1994). Russier (1999) found that persons with congenital blindness were more accurate in the bimanual exploration of two-dimensional line shapes than were persons with late blindness or sighted persons. In uni-manual exploration, differences among the groups were found in using the left hand and the right hand. Other researchers focused more on developmental trend in exploratory procedures during the first years of life, from mouthing to repertoire of more differentiated hand and finger movements and complementary bimanual activities (Bushnell & Bourdreau, 1991). In study with blind children (Schellingerhout, Smitsman, & Van Galen, 1998), posrural constraints were found to determine the use of more fingering and less mouthing of surfaces because of difficulties stabilizing an object while exploring it and difficulties moving the upper body forward for mouthing surface. The study presented here investigated the different tactile exploratory procedures used by woman with congenital deaf-blindness when touching objects with microtextures in three tasks with three types of objects. METHOD Participant and setting The study followed the tenets of the World Medical Association Declaration of Helsinki on Ethical Principles for Medical Research Involving Human Subjects and was approved by the Institutional Review Board of Royal Kentalis in Sint-Michielsgestel, the Netherlands. Informed consent was obtained from Chris, her parents, and her personal caregiver. Chris is 40-year-old woman who is deaf-blind as result of congenital rubella syndrome. She is totally blind (with some light perception) and has profound hearing impairment. Previous psychological examinations revealed no additional disabilities. The study was conducted in quiet room, where Chris sat at table; her intervener (personal caregiver) sat beside her, and the experimenter sat in front of her. Materials The stimuli were obtained from the Tactile Profile (Withagen, Janssen, Vervloed, Ekkens, & Schellingerhout, 2003): rollers (length: 10 centimeters or about 4 inches, diameter: 5 centimeters or about 2 inches) covered with different fabrics of various textures; block houses (5 X 5 X 5 centimeters) with metal caps of different textures; and cards (4 centimeters X 4 centimeters, or about 1.6 inches by 1.6 inches) coated with hard plastic of different textures. The textures of the stimuli were fine. Procedure Instructions were given via Chris's intervener using finger spelling in her hand and natural gestures (such as pointing and other commonly used hand gestures). …