Residual Sensory Capacities of the Deaf: A Signal Detection Analysis of a Visual Discrimination Task

Abstract

This experiment compared the visual sensory sensitivity of deaf and hearing subjects in a signal detection paradigm. Subjects (ns = 6) were required to give forced-choice responses to a brightness discrimination task under three stimulus probability conditions (0.25, 0.50, and 0.75). A total of 1,800 trials were given to each subject and utilized to construct isosensitivity functions and d' and Beta, indices for sensory sensitivity and response bias, respectively. The results showed that no enhanced sensory sensitivity is present for these deaf children and questions the classical sensory compensation hypothesis. Furthermore, the deaf subjects responded in a relatively bias-free manner to variations in stimulus probability.

Crossmodal reorganization in the early deaf switches sensory, but not behavioral roles of auditory cortex

“…However, with the accumulation of studies examining such compensatory effects following early sensory loss, it is becoming evident that not all features of the replacement sensory modalities are equally represented. For example, early-deaf subjects exhibit supranormal abilities for visual localization (10) and visual motion detection (11,12), but not visual brightness discrimination (13), contrast sensitivity (14), visual shape detection (15), grating acuity, vernier acuity, orientation discrimination, motion direction, or velocity discrimination (11). Thus, rather than a generalized overall improvement, it seems that only specific features of the replacement modality are affected by crossmodal plasticity.…”

Sensibilidade ao contraste de crianças surdas e ouvintes para grades senoidais em condições mesópicas

“…Isto porque os estudos foram realizados com pressupostos teóricos e metodológicos tão diferentes que inviabilizam qualquer comparação. Os mesmos vão desde aqueles que não encontraram alterações sensoriais com o paradigma da detecção de sinais (Bross, 1979a(Bross, , 1979bBross & Sauerwein, 1980) e a FSC em adultos , até aqueles que encontraram melhoras (Bavelier & Neville, 2002;Bosworth & Dobkins, 1999Neville & Lawson, 1987;Proksch & Bavelier, 2002;Sladen, Tharpe, Ashmead, Grantham, & Chun, 2005) ou prejuízos em tarefas envolvendo atenção visual (Erden et al, 2004;Stivalet et al, 1998).…”

“…Enquanto outras, relacionando busca visual e atenção, mostram que os participantes surdos apresentam prejuízos no processamento visual comparados aos ouvintes (Erden, Otman, & Tunay, 2004;Stivalet, Moreno, Richard, Barraud, & Raphel, 1998). Já trabalhos que compararam o desempenho sensorial de crianças e adultos surdos e ouvintes, utilizando o paradigma da detecção de sinais (Bross, 1979a(Bross, , 1979bBross & Sauerwein, 1980), não encontraram alterações na resposta sensorial entre os participantes com e sem surdez. Em termos gerais, há pelo menos duas hipóteses: a primeira defende que apenas alguns aspectos da visão são modificados em função da surdez (Bavelier et al, 2006) e a segunda defende que as contradições entre os estudos estão relacionadas às diferentes metodologias e critérios de amostragem das pesquisas (Bavelier et al, 2006;Rettenbach, Diller, & Sireteanu, 1999;Stevens & Neville, 2006).…”

Electrophysiological evidence for altered visual, but not auditory, selective attention in adolescent cochlear implant users

“…Deaf individuals (with and without a CI) have been shown to have some enhanced visual skills that are likely the result of both cross-modal plasticity between the visual and auditory system, as well as changes in visual attention [14]. Typically, no differences have been found between hearing and non-hearing groups' in visual acuity, as measured in lowlevel perceptual tasks that alter contrast sensitivity, motion velocity and sensitivity, brightness and the temporal resolution of stimuli [15][16][17][18][19]. But more consistent betweenPage 5 of 37 A c c e p t e d M a n u s c r i p t group differences have been observed under conditions of selective attention and/or processing of peripherally located and salient items [20][21][22].…”