Validation of the Tactual Span in individuals with congenital and acquired blindness

Abstract

Neuropsychological assessment tools for individuals with blindness are relatively scarce. In the current study, we assessed the validity of the Tactual Span, a task aimed at evaluating tactile working memory. During the task, the fingers of both hands are touched in specific sequences of ascending difficulty, which participants are asked to repeat in exact and reverse order. Twelve participants with congenital blindness and 13 with acquired blindness were examined alongside 18 sighted controls, matched to the experimental group with respect to age and education. Participants performed the Tactual Span and three additional tasks assessing working memory in the auditory modality, as well as a Semantic Fluency test. Results showed that the Tactual Span was significantly correlated with most of the other working memory measures, in all groups, but not with the Semantic Fluency test. In addition, the congenital and acquired blindness groups performed similarly to one another and better than sighted controls on most working memory tasks, but not on the Semantic Fluency test. Findings suggest that the Tactual Span is a feasible task for measuring tactile working memory in individuals with congenital and acquired blindness. Therefore, it can expand the cognitive assessment toolbox of professionals working with blind individuals and increase the strength of conclusions drawn from cognitive assessments in educational and vocational settings.

Deductive Reasoning and Working Memory Skills in Individuals with Blindness

“…Research on deductive reasoning and working memory in people who are blind does not clearly support either of these [13][14][15]. For instance, in terms of working memory tested via the auditory modality, certain studies indicate better performance by people who are blind [16][17][18][19], while others find they perform equally well compared to sighted controls [20][21][22]. Working memory can also be tested via the tactile modality, and here too there exist inconsistencies in the literature, as certain studies show superior or equal performance by people with blindness compared to sighted controls [17,[22][23][24], while others show deficiencies [22,[25][26][27].…”

“…For instance, in terms of working memory tested via the auditory modality, certain studies indicate better performance by people who are blind [16][17][18][19], while others find they perform equally well compared to sighted controls [20][21][22]. Working memory can also be tested via the tactile modality, and here too there exist inconsistencies in the literature, as certain studies show superior or equal performance by people with blindness compared to sighted controls [17,[22][23][24], while others show deficiencies [22,[25][26][27]. In terms of deductive reasoning, the same contradictions exist since certain findings indicate that blind individuals perform worst on deductive reasoning tasks compared to sighted controls [28][29][30], yet others indicate that they perform equally well or better than controls [31][32][33][34][35].…”

Working memory in intact modalities among individuals with sensory deprivation

“…The study sample comprised 56 Hebrew-speaking adults with no history of developmental, psychiatric, or neurological disorders, who were allocated to three groups according to their sensory status. A blindness group included 14 participants (7 men; mean age = 37.35, SD = 11.6; mean years of education = 15.85, SD = 3.39), 12 with congenital blindness and two who became blind at the age of 2 years (previously presented in Heled and Oshri, 2021 ). A deafness group included 20 participants (9 men; mean age = 32.55, SD = 11.72; mean years of education = 13.9, SD = 2.73) with congenital hearing loss greater than 80dB (previously presented in Heled and Ohayon, 2021 ) skilled in sign language.…”

“…Studies have shown inconsistent results regarding WM ability in the intact senses of individuals with blindness or deafness. In relation to blindness and the auditory modality, some indicate better ( Dormal et al., 2016 ; Heled and Oshri, 2021 ; Pigeon and Marin-Lamellet, 2015 ; Withagen et al., 2013 ) and others equal performance compared to controls ( Park et al., 2011 ; Rokem and Ahissar, 2009 ; Vecchi et al., 2004 ). However, tactile WM has been shown to be superior and equal to controls ( Cohen et al., 2010 ; Heled and Oshri, 2021 ; Occelli et al., 2017 ; Vecchi et al., 2004 ), but also worse ( Aleman et al., 2001 ; Cornoldi et al., 1991 ; Vecchi, 1998 ; Vecchi et al., 2004 ).…”