Indian Journal of Otology

: 2018  |  Volume : 24  |  Issue : 3  |  Page : 157--161

The role of parental hearing status in theory of mind after cochlear implant surgery

Kourosh Amraei1, Mohammadparsa Azizi2, Amirali Khoshkhabar3, H Soori4,  
1 Department of Psychology, Faculty of Humanistic Sciences, Lorestan University, Khorramabad, Iran
2 Department of Psychology, Faculty Humanities and Social Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
3 Department of Psychology and Education of Exceptional Children, Faculty of Psychology and Education, University of Tehran, Tehran, Iran
4 Department of Psychology, Payame noor University, Tehran, Iran

Correspondence Address:
Dr. Kourosh Amraei
Department of Psychology, Faculty of Humanistic Sciences, Lorestan University, Khorramabad


Introduction: Theory of mind (ToM), or the understanding of others' thoughts and feelings and their behavioral consequences, has been extensively studied in hearing typically developing preschool children over several decades, including research demonstrating the influence of ToM on preschool children's social lives. Hearing impairment is common type of sensory loss in children. Literature indicates that children with hearing impairment deficit in social, cognitive, and communicate skills. Aim: This study performed to compare ToM of cochlear-implanted first- and second-generation deaf children. Methodology: This research is causal comparative. All 15 deaf children with deaf parent selected from Baqiyatallah Cochlear Implant (CI) Center. Hence, 15 cochlear-implanted children paired with them by purposive sampling. Results: Findings showed that t-test (t = −4.52, P < 0.01) was statistically significant. According to t-test, the second-generation children was significantly higher than the first-generation children in ToM. Conclusion: We can assume that the second-generation children were joined with their family in sign language, lead to the use of primary experience before of implant. So, it is recommended to use the sign language before cochlear implantation.

How to cite this article:
Amraei K, Azizi M, Khoshkhabar A, Soori H. The role of parental hearing status in theory of mind after cochlear implant surgery.Indian J Otol 2018;24:157-161

How to cite this URL:
Amraei K, Azizi M, Khoshkhabar A, Soori H. The role of parental hearing status in theory of mind after cochlear implant surgery. Indian J Otol [serial online] 2018 [cited 2019 May 26 ];24:157-161
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Theory of mind (ToM) has become an important theoretical construct and the topic of considerable research effort. ToM describes one approach to a larger topic: Everyday or folk psychology – the construal of persons as psychological beings, interactors, and selves. The phrase, ToM, emphasizes that everyday psychology involves seeing oneself and others in terms of mental states – the desires, emotions, beliefs, intentions, and other inner experiences that result in and are manifested in human action.[1] In other sentence, the ability to understand that two people might interpret the exact same event in different, yet equally plausible, ways is a foundational milestone in children's social–cognitive development. Although children come to understand that individuals can hold false beliefs (FBs) about an object or an event by 4 or 5 years, they do not seem to understand that individuals actively interpret and construct their own beliefs about an event, and that each of these interpretations can potentially be a true belief, until about 6 or 7 years.[2]

The use of a cochlear implant (CI) does not restore hearing to a normal level, but it enables a different course of development of cognitive, speech, and language function than would have been possible without the CI.[3],[4],[5] The development of CI to restore stimulation to the inner ear has revolutionized treatment for most deaf children. Factors affecting the outcome of pediatric CI have been the subject of many researches. Distinguishing such factors is valuable as it enables researchers to develop more sophisticated CI candidacy criteria and also to develop more effective intervention programs to facilitate the auditory, speech, and language development of implantees.[6]

There are different factors that effect on output of CI, for example, their diagnosis (i.e., cause of hearing impairment), age at onset of hearing impairment, age at implantation,[7],[8] type of implant (i.e., number of active electrodes, type of processor[4]), and anatomical aspects of the cochlea.[9]

On the other hand, studies of both individuals and groups of profoundly deaf children have shown positive effects from the use of CIs on speech perception,[10],[11],[12],[13] speech production[3],[13],[14],[15],[16] and language development,[10],[17] social skill,[13],[18] and quality of life.[19] Cognitive abilities have also been implicated as influencing language development after cochlear implantation,[20] but this finding has not been universal.[21]

The certain atypical groups, such as deaf children[22] and autism[23] children from hearing families are often substantially delayed, routinely continuing to fail throughout middle childhood and the early teens. Parental hearing is one of the important factors in the cognitive and language development of deaf children. Deaf children born in deaf families have been found to outperform those from hearing families in terms of intelligence and related abilities.[24] In the other hand, deaf children born in hearing families not only in oral language, but also they have a delay in sign language.[6],[25] Such second-generation deaf children, who learn sign language from their parents as their native language from birth and are hence termed “native signers,” perform better in intelligence tests than their deaf peers with hearing parents.[26],[27],[28] They also show significantly better performance of “theory of mind” tasks in comparison with deaf children from hearing families.[22],[29],[30],[31],[32] One view holds that, for deaf children of hearing parents (i.e., nonnative signers), restricted social and conversational experience during early childhood in a hearing, nonsigning family delays the development of preschool ToM concepts.[33] Furthermore, they show better development of a second, verbal language, and of reading skills, compared with the first-generation deaf children.[34]

Comparisons of the ToM of deaf children raised in deaf families versus those raised in hearing families have been published. However, CI outcomes in these two groups of deaf children have not been compared and do remain this results after CL. This retrospective study investigated the relationship between parental hearing status and CI outcomes in their deaf children. We compared the ToM of deaf children with deaf parents versus those with hearing parents, after CI.

 Materials and Methods

The study group comprised 15 cochlear-implanted deaf children with deaf parents. This group had the opportunity to acquire Persian sign language from their parents. An equal number of deaf children with normal-hearing parents were selected by matched sampling as a control group. Participants were matched based on onset and severity of deafness, duration of deafness, age at CI, duration of CI, gender, and implant model. All participants with syndromic deafness and additional disability were excluded from the study. Demographic features of the participants are given in [Table 1]. Participants were selected from prelingually deaf children who underwent CI between 2 and 103 months of age, in the Baqiyatallah Hospital CI Center. All participants had been diagnosed with profound, bilateral, sensorineural hearing loss, within their 1st year of life.{Table 1}

Theory of mind functioning was measured by False belief task.

False belief

Children's FB understanding was measured using unexpected location (UL) and unexpected content (UC) tasks. From the earliest research, however, a central focus has been on children's understanding of belief, especially FB. Why? Mental-state understanding requires realizing that such states may reflect reality and may be manifest in overt behavior, but are nonetheless internal and mental, and thus distinct from real-world events, situations, or behaviors. A child's understanding that a person has a FB – one whose content contradicts reality – provides compelling evidence for appreciating this distinction between mind and world.[1] The UL and UC tasks were designed to measure children's ability to identify the beliefs of a naive other as well as their own initial beliefs regarding the location of an object and the content of a tangible object. The UL task was modeled after the traditional “Sally–Anne” task. One of two characters hides an object and leaves the room. The remaining character moves the hidden object to a different location. The naive character who left the room returns. The child is then asked where the naive character will look for the object. The UL task was presented to the child using a story format with accompanying pictures on a laptop computer. Then, the child was asked the FB question (e.g., When Tom went into the kitchen, where would he look for the cake?). Thus, the child was also asked two memory control questions relating to the original location of the object (e.g., Where did Tom put the cake?) and the new location of the object (e.g., Where is the cake now?). Virtually, all children provided correct answers. Two versions of the FB task were presented at each time point. The UC task involved tangible objects. In this task, the child was shown an M and M bag and asked what he or she thought was in the bag. The child was then shown the true contents of the bag (e.g., paperclips) and asked to identify the contents. The experimenter then placed the contents back into the bag and asked the child about his or her own original belief (e.g., When you first saw this bag all closed up like this, what you thought was inside the bag?). The correct identification of one's own belief (i.e., M and Ms) received one point. Next, a naïve puppet was presented, and the child was asked about the puppet's beliefs (e.g., Big Bird has never looked inside of this bag before; what does Big Bird think is inside the bag?). The correct identification of a naïve puppet's belief (i.e., M and Ms) received one point. Four additional stories with the same format were used at times 2 and 3, two stories each time. After each FB question, children were tested on whether they remember the actual contents. Children who answered the FB question correctly also correctly answered the memory control questions.[35]


Descriptive characteristics (mean and standard deviation) have been showed for both of first and second generation. First and second generation have difference in ToM [Table 2] and [Figure 1]. T-test use to examine of difference between group.{Table 2}{Figure 1}

The assumption of normality is for all variable in ToM. It means, ToM variable fallow of normal curve, and skewness showed no significant. Hence, Levene's test was used to equality of error variances assumption, that, the results indicate which variances of the populations which from different samples are drawn are equal [Table 3].{Table 3}

The results of t-test show that there is difference between groups in the depended variable (t = −4.52, P < 0.01). t-test shows that the second-generation deaf children acquire higher score than the first-generation deaf children in ToM score. Therefore, it can be said which deaf children with deaf parent have better ToM than deaf children with hearing parent. The role of parent status in children's ToM is important. Deaf children, that have equal sing language with their parent, shows better performance [Table 4].{Table 4}


This study aimed to compare the ToM of the first-generation deaf children versus second-generation deaf children with hearing parents. Our findings indicated that the deaf children with deaf parents outperformed those with hearing parents as regards CI outcomes. This difference in ToM occurred even though all our participants were homogeneous regarding the onset and severity of deafness, duration of deafness, age at CI, duration of CI, gender, and implant model.

Earlier studies have indicated that deaf children with deaf parents perform better than deaf children with hearing parents in intelligence tests, ToM tasks, second language development, reading skills, reaction time, and left hemisphere maturation.[3],[6],[12],[15],[19],[22],[24],[25],[26],[33],[34],[36],[37],[38],[39],[40]

While the results of the numerous studies summarized above are combined with the findings of the current study, the resulting evidence indicates that deaf children with deaf parents have enhanced communication abilities compared with their peers with hearing parents. This could be related to the earlier onset of communication between deaf children and deaf parents. Deaf parents deal better with the early learning needs of their deaf children, compared with hearing parents.[26],[41] In addition, learning the visio-spatial grammar of sign language improves the visual and spatial skills of deaf children.[42] Exposure to visual communication promotes strategies begins at birth in deaf families: Deaf parents communicate with their deaf child through gestures and signs immediately after birth. Deaf children do not have access to adequate auditory information before CI; therefore, the visual part of communication is critical for them. Deaf parents develop communication with their deaf children using eye contact, facial expression, body language, speech reading, and sign language in particular. Deaf parents of deaf children can sustain communication in a visual mode, waiting for their child's visual attention to be drawn, in order to communicate. This communication practice is not a natural habit for hearing parents, because they use an aural–visual mode of communication.[43] Therefore, deaf children with deaf parents acquire language in a natural way.

In addition, earlier studies indicate that the age of first language acquisition can be a determining factor in the success of both the first and second language acquisition. Early acquisition of sign language as the child's first language supports later learning of a spoken language.[44],[45] Entry into a community of fluently signing peers and teachers in primary school can subsequently assist the development of ToM understanding, although on a delayed timetable. The fact that natively signing deaf children with deaf parents (a 5% minority of children born deaf) develop ToM on the same early timetable as hearing children is consistent with this theory.[33],[40]


These study findings confirm that the second-generation deaf children exceed deaf children of hearing parents in terms of CI performance. We may conclude that encouraging deaf children to communicate in sign language at a very early age, before CI, improves their ability to learn spoken language and cognitive ability after CI.

We recommend for future studies to compare greater numbers of deaf children with deaf parents versus deaf children with hearing parents, when assessing CI outcomes, and use of longitudinal study.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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