Research of visual attention networks in deaf individuals: a systematic review.

The impact of deafness on visual attention has been widely discussed in previous research. It has been noted that deficiencies and strengths of previous research can be attributed to temporal or spatial aspects of attention, as well as variations in development and clinical characteristics. Visual attention is categorized into three networks: orienting (exogenous and endogenous), alerting (phasic and tonic), and executive control. This study aims to contribute new neuroscientific evidence supporting this hypothesis. This paper presents a systematic review of the international literature from the past 15 years focused on visual attention in the deaf population. The final review included 24 articles. The function of the orienting network is found to be enhanced in deaf adults and children, primarily observed in native signers without cochlear implants, while endogenous orienting is observed only in the context of gaze cues in children, with no differences found in adults. Results regarding alerting and executive function vary depending on clinical characteristics and paradigms used. Implications for future research on visual attention in the deaf population are discussed.

Executive functions in deaf and hearing children: The mediating role of language skills in inhibitory control.

This study aimed to analyze one of the critical components of inhibitory control-the ability to suppress interference-in deaf and hearing children and to investigate the mediating role of language skills in this central component of executive functions. To this end, a cross-sectional study was carried out with 40 deaf children with and without cochlear implants (CIs) and 21 hearing children age 7-10 years. The ability to suppress interference was assessed with the children's version of the Attentional Network Test (child-ANT), and language skills were assessed with a computerized version of the Carolina Picture Vocabulary Test (CPVT), a receptive vocabulary test. As a measure of control of nonverbal cognitive abilities, we used the Test of Nonverbal Intelligence (TONI-2). The results showed that deaf children had lower nonverbal IQ than hearing children. In addition, deaf children, compared with hearing children and regardless of whether they used CIs, showed a lower range of receptive vocabulary and a poorer ability to suppress the interference of distractors in the child-ANT. Linear regression mediation analyses revealed that this more significant interference effect was mediated by receptive vocabulary level and not by hearing deprivation. These results are consistent with the hypothesis that language is one of the critical factors in the development of executive functions.

Inattention, Impulsivity, and Hyperactivity in Deaf Children Are Not Due to Deficits in Inhibitory Control, but May Reflect an Adaptive Strategy.

The present study had two main aims: (1) to determine whether deaf children show higher rates of key behaviors of ADHD (inattentive, hyperactive, and impulsive behaviors) and of Conduct Disorder-CD-(disruptive, aggressive, or antisocial behaviors) than hearing children, also examining whether the frequency of these behaviors in deaf children varied based on cochlear implant (CI) use, type of school (regular vs. specific for deaf) and level of receptive vocabulary; and (2) to determine whether any behavioral differences between deaf and hearing children could be explained by deficits in inhibitory control. We measured behaviors associated with ADHD and CD in 34 deaf and hearing children aged 9-10 years old, using the revised Spanish version of the Conners scale. We then assessed inhibitory control ability using a computerized Stroop task and a short version of the Attention Network Test for children. To obtain a measure of the level of receptive vocabulary of the deaf children we used a Spanish version of the Carolina Picture Vocabulary Test for Deaf and hearing-impaired children. Deaf children showed significantly higher rates of behaviors associated with ADHD and CD, and over 85% of cases detected with high risk of ADHD-inattentive type in the entire present sample were deaf children. Further, in the group of deaf children a negative correlation was found between receptive vocabulary and frequency of disruptive, aggressive, or antisocial behaviors associated with CD. However, inhibitory control scores did not differ between deaf and hearing children. Our results suggested that the ADHD-related behaviors seen in deaf children were not associated with a deficit in inhibitory control, at least in the interference suppression subcomponent. An alternative explanation could be that these behaviors are reflecting an adaptive strategy that permits deaf children to access information from their environment which is not available to them via audition.