Effects of auditory and visual interference control on visuospatial working memory in children with ADHD

Thitiya Wangkawan; Cynthia Lai; Peeraya Munkhetvit; Trevor Yung; Supaporn Chinchai

doi:10.4103/jmedsci.jmedsci_10_20

ORIGINAL ARTICLE

Year : 2021 | Volume : 41 | Issue : 6 | Page : 265-272

Effects of auditory and visual interference control on visuospatial working memory in children with ADHD

Thitiya Wangkawan¹, Cynthia Lai², Peeraya Munkhetvit¹, Trevor Yung³, Supaporn Chinchai¹
¹ Department of Occupational Therapy, Chiang Mai University, Chiang Mai, Thailand
² Department of Rehabilitation Sciences, The Hong Kong Polytechnic University; Department of Rehabilitation Sciences, Applied Cognitive Neuroscience Laboratory, The Hong Kong Polytechnic University; University Research Facility in Behavioral and Systems Neuroscience, The Hong Kong Polytechnic University, Hong Kong, China
³ Department of Rehabilitation Sciences, The Hong Kong Polytechnic University; Department of Rehabilitation Sciences, Applied Cognitive Neuroscience Laboratory, The Hong Kong Polytechnic University, Hong Kong, China

Date of Submission	13-Jan-2020
Date of Decision	30-Oct-2020
Date of Acceptance	04-Apr-2021
Date of Web Publication	24-May-2021

Correspondence Address:
Dr. Supaporn Chinchai
Department of Occupational Therapy, Chiang Mai University
Thailand

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jmedsci.jmedsci_10_20

Abstract

Background: Interference control is the cognitive control needed to prevent interference due to competition of relevant and irrelevant information that closely related to working memory. The aim of this study was to examine the effects of auditory and visual interference control on visuospatial working memory of children with ADHD. Methods: The participants included thirty children with ADHD and thirty normal control children aged 7–12 years old. All children took the computerized test of visuospatial working memory assessment. The test comprised the N-back and running Memory tasks divided into three conditions: noninterference, auditory interference, and visual interference in three levels of difficulty. Results: The results revealed that there was a significant difference in N-back with auditory interference (t = 2.13, P = 0.04) and N-back with visual interference task (t = 2.48, P = 0.02) between normal control children and children with ADHD. However, there was no significant difference in N-back with noninterference task (t = 1.61, P = 0.11) between normal control children and children with ADHD. There was a significant difference in running memory with noninterference (t = 5.34, P ≤ 0.001), running memory with auditory interference (t = 6.23, P ≤ 0.001), and running memory with visual interference task (t = 5.86, P ≤ 0.001) between normal control children and children with ADHD. In addition, the comparison of the mean score revealed that children with ADHD had poorer performance of interference control on visuospatial working memory tasks than normal control children in overall tasks. Conclusion: Children with ADHD exhibited inefficient control over themselves, especially in the interference condition tasks in which they performed more error responses when interacting in the tasks. The present study supports the evidence-based mechanisms of auditory and visual interference control in visuospatial working memory of children with ADHD.

Keywords: Visuospatial working memory assessment, visuospatial working memory, interference control, N-back task, running memory task

How to cite this article:
Wangkawan T, Lai C, Munkhetvit P, Yung T, Chinchai S. Effects of auditory and visual interference control on visuospatial working memory in children with ADHD. J Med Sci 2021;41:265-72

How to cite this URL:
Wangkawan T, Lai C, Munkhetvit P, Yung T, Chinchai S. Effects of auditory and visual interference control on visuospatial working memory in children with ADHD. J Med Sci [serial online] 2021 [cited 2023 Sep 28];41:265-72. Available from: https://www.jmedscindmc.com/text.asp?2021/41/6/265/316668

Introduction

Working memory refers to a system that temporarily holds and manipulates data when performing a multitude of information^[1] and cognitive tasks such as comprehension, learning, and reasoning.^[2] The four aspects of working memory comprised a phonological loop, a visuospatial sketchpad, a central executive, and an episodic buffer.^[3] Achievement in class and the acquisition of language and academic skills (e.g., reading decoding, reading comprehension, mathematics, and written expression) are greatly influenced by the decent working memory functioning.^[4] Visuospatial sketchpad or visuospatial working memory, in particular, is the significant part of working memory that involves the necessary cognitive capability of encoding, maintaining, manipulating, and retrieving data in the visual space to accomplish the current behavior.^[5] The visuospatial sketchpad is in charge of storing immediate visual and spatial information (e.g., memory for objects and their position). In addition, it serves a vital function when reading, since it allows readers to perform visual encoding of printed letters and words but at the same time keeping a visuospatial frame of reference, enabling them to go back and forth when reading.^[2] Visuospatial working memory combines visuospatial information stored in both immediate and remote working memories. In academic learning, visuospatial working memory is significant for preschoolers because their mathematic mental model is chiefly visuospatial, rather than verbal and abstract. Young children rely on a visual mental model before they learn symbolic and verbal mathematic images.^[6]

Interference control seems to be a crucial factor in how working memory and high levels of cognitive efficiency are linked to each other.^[7] It refers to the cognitive control needed to prevent interference due to competition of relevant and irrelevant stimuli or stimulus characteristics.^[8] Interference control involves both the capability of intentionally inhibiting the processing of unrelated data and the capability of inhibiting automatic response tendencies for performing an action under greater control.^[9] Jonides and Nee^[10] concluded that providing working memory was vital to normal cognitive functioning; thus, proactive interference had a significant role in determining whether working memory would be successful or not. Baddeley^[2] has suggested that working memory is conceived as a cognitive function with limited capacity; hence, at any moment, only a certain amount of information is available for temporary storage and manipulation. Therefore, the efficiency of this memory system relies on interference control mechanisms that are responsible for the constant removal of information that has become irrelevant to release the system to update and process new relevant information.^[2]

The interference control and working memory are the higher-order cognitive skills which are the essential parts of the executive function.^[11] Several studies have been reported the strong relationship between interference control and working memory. They concluded that the interference control involves the need to inhibit and suppress irrelevant information for restricted access in working memory.^{[2],[7],[12],[13],[14],[15],[16],[17]} For example, Baddeley's theory^[2] proposed that the capacity of the working memory system is based on interference control mechanisms, which ensure that irrelevant information is continually removed from the system to enable the update and processing of relevant information. Garon et al.^[13] suggested that the complex response inhibition needs significant working memory by demanding an arbitrary rule to be taken into account and/or requiring the participants to avoid one reaction (prepotent or not) and provide an alternative reaction.

Further evidence supports that interference control is related to working memory. For example, Cansino et al.^[17] conducted a study to investigate how interference control affected visuospatial working memory. The result showed that the access and deletion functions were independent interference control mechanisms. The individuals who had higher memory accuracy rates were also more efficient in controlling irrelevant memory representations. In fact, the ability to control interference from external and internal irrelevant information is essential to accomplish several cognitive goals. This is because human cognition has limited capability of processing the vast amount of information continuously exposed to, from both the external world and internal thoughts and memories.^[17] Thus, interference control tends to play an important part in the association between working memory and greater cognitive efficiency.^[18]

Working memory is related with a wide range of academic performances including reading, language comprehension, and mathematical problem-solving^{[19],[20],[21]} and abilities to complete academic tasks in the classroom such as follow instructions.^[22] Children with ADHD have deficits in working memory,^[23],[24] especially impairments in visuospatial working memory.^[23] Thus, they may struggle with academic learning that places significant demands on working memory^[20] such as oral or written text comprehension.^[25],[26] Martinussen et al.^[23] suggested that poor academic development in children with ADHD may be the result of working memory deficits rather than a direct consequence in lack of attention, which suggests that working memory has essential implication for education of children with ADHD.

Working memory impairment is fundamental in children with ADHD since working memory deficiency and children with ADHD are related to certain impairments in executive skills.^[27] Particularly, inhibition, which functions as executive processing, serves a vital function for working memory processing through the suppression and deactivation of irrelevant data on the current task.^[28] Various studies indicated that children with ADHD encounter difficulties with interference control problems. For example, Tannock et al.^[29] reported that children with ADHD had sensitivity to interference during the Stroop Color–Word task, which was the result of irrelevant controlled deficit and rapid responses. They also showed increased error rates in rapid stimulus presentation rate and hearing warning proceeding stimuli task.^[30] Furthermore, Crone et al.^[31] showed that, compared with normal control children, children with ADHD performed more slowly in congruent flanker task compared with a condition without flankers. Cornoldi et al.^[32] also confirmed that children with ADHD who had inattention or impulsivity symptoms gave fewer accurate responses and more errors in comparison with the control group. In the present study, we have applied and included the auditory and visual interference in N-back and running memory task of visuospatial working memory assessment. Furthermore, the present study highlighted auditory function and visual interference control on visuospatial working memory performance though the use of the N-back and running memory task which had never been investigated elsewhere.

The present study aimed to examine the effects of auditory and visual interference control on visuospatial working memory of children with ADHD. The minor objective of this study is to make comparisons of how ADHD children perform the auditory interference, visual interference, and noninterference control on visuospatial working memory. We would like to determine the effect of auditory and visual interference on visuospatial working memory performance of children with ADHD using the computerized test of visuospatial working memory assessment. Furthermore, this study investigated the hypothesis that whether interference could affect to visuospatial working memory of children with ADHD and how their performance between different interference. To examine this effect, we compared the performance of children with ADHD with normal control children.

Procedure

Participants

The participants included thirty children with ADHD and thirty normal control children aged between 7 and 12 years old who were recruited from Chiang Mai, Thailand. Sixty children were selected using purposive sampling with aged-matched control design. The research study was approved by the ethics committee, Faculty of Associated Medical Sciences, Chiang Mai University, Thailand. Project number: AMSEC-60EX-031, ethics clearance number: 001/2561, approved date: 3rd January 2018. The parents of the children were contacted for their consent in conducting this study. The informed consent form from the parents and assent from the participants were obtained in research process for their agreement to participate in the research. The participants had normal general cognitive function, as determined by a clinician's judgment based on the Test of Nonverbal Intelligence, Fourth Edition.^[33] They had no visual and physical impairments, were able to understand instructions, and were willing to participate in the study. Children with ADHD had received a diagnosis of ADHD by a psychiatrist.

Materials and Methods

The materials of this study included the computerized laboratory paradigm of the visuospatial working memory assessment^[34] as follows.

The computerized test

The computerized test of the visuospatial working memory assessment^[34] was used in the experiment method to examine the auditory and visual interference control of children. The assessment was developed to examine the visuospatial working memory performance and interference control on visuospatial working memory of children. The visuospatial working memory assessment had psychometric properties in content validity (IOC = 1.0 in overall items), internal consistency (α = 0.88), test–retest reliability (ICC = 0.88–0.99), concurrent validity (r = 0.30-0.71), and construct validity (t = 2.13–6.23). In the current research, the visuospatial working memory assessment was a computerized test which comprised N-back and running memory task. All the N-back and running memory tasks administered during the individual sessions were presented on a 14-inch screen laptop with conventional input peripherals (mouse). The assessment included interference with three test experiments: noninterference, auditory interference, and visual interference. The sequencing of the assessment starts from noninterference, auditory interference, and visual interference conditions as following which the total time of all experiments of N-back and running memory task lasting about 1 h. The child could be resting during the assessment if he/she feels uncomfortable.

N-back task

In the N-back task [Figure 1],^[34] the child was presented the continuous stimuli of the 9 × 9 grid on the computer screen. The stimuli were presented on a computer screen at a viewing distance of about 50 cm. Each stimulus was presented for 2000 ms in sequential order (30–50 stimuli). The participant was requested to click on the red button if the stimulus showed the red cross as same as position like n (1, 2, 3) stimulus previously. In N-back with auditory interference task is appear sound ding while each stimulus appears. The yellow cross is the visual interference in N-back with visual interference task. The assessment including three levels of tests; 1-Back, 2-Back and 3-Back task. The task consisted of 10 trials in each condition. The participant participated in this session lasting about 30 min.

Figure 1: Example of 2-Back task

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Running memory task

In the running memory task [Figure 2],^[34], the child was presented the 9 × 9 grid on the computer screen. The stimuli were presented on a computer screen at about 50 cm of a view distance. The grid showed which appeared a red dot in any space for 2000 ms (4–8 times) and then disappear. After a red dot stop, the computer screen showed blank grid. Then, the participant was requested to remember and click on the last 1, last 2, or last 3 of position that red dot appears. In running memory with auditory interference task is appear sound ding while each stimulus appears. The yellow dot is the visual interference in running memory with visual interference task. The assessment including three levels of tests; 1 Last Running Memory, 2 Last Running Memory and 3 Last Running Memory tasks. The task consisted of 10 trials in each condition. The participant participated in this session lasting about 30 min.

Figure 2: Example of 2 Last Running Memory task

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Results

The results were presented in three conditions of N-back and running memory tasks, which included noninterference, auditory interference, and visual interference as shown in [Table 1] and [Table 2], respectively. To investigate the effect of auditory and visual interference control of children with ADHD, the analysis included 2 factors: the experiment tasks and grouping of children. Thirty children with ADHD and thirty normal control children were examined all the tasks to analyze the effect of interference control on visuospatial working memory.

Table 1: Normal distribution analysis of mean total score of normal control children and children with attention deficit hyperactivity disorder

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Table 2: Statistical analysis of known-group method by independent sample t-test (n=60)

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[Table 1] illustrates the normal distribution analysis of the mean total score of normal control children and children with ADHD. The results revealed that the mean total score of normal control children and children with ADHD has a normal distribution. The parametric test is used for conducting statistically significant tests in the testing of hypothesis, which is independent samples t-test as shown in [Table 2].

The independent samples t-test was conducted to compare visuospatial working memory performance between normal control children and children with ADHD as demonstrated in [Table 2]. The results revealed that there was a significant difference between normal control children and ADHD children except the N-back with noninterference task. There was a significant difference in N-back with auditory interference and N-back with visual interference task between normal control children and children with ADHD; t (59) = 2.13 and 2.48 and P = 0.04 and 0.02, respectively. In contrast, there was no significant difference in N-back task between normal control children and children with ADHD group; t (59) = 1.61 and P = 0.11. Furthermore, there was a significant difference in running memory, running memory with auditory interference, and running memory with visual interference task between normal control children and children with ADHD; t (59) = 5.34, 6.23, and 5.86 and P < 0.001, < 0.001, and < 0.001, respectively.

The results revealed a significant difference between normal control children and children with ADHD especially in interference tasks. This suggests that children with ADHD performed more error responses in interference conditions of N-back and running memory task compared with normal control children. Thus, the interference control deficit is the core problem of children with ADHD as they had some difficulties in the control and suppress of the irrelevant information in interference tasks.

Discussion

The current study aimed to examine the effects of auditory and visual interference control on visuospatial working memory of children with ADHD who were 7–12 years old. The computerized test of visuospatial working memory assessment was used to examine the auditory and visual interference control in children with ADHD and normal control children. The assessment comprised N-back and running memory tasks, which included auditory and visual interference in the tasks.

The results of the present study presented that the auditory and visual interference affected visuospatial working memory of children with ADHD. They had some difficulties in controlling irrelevant information in the interference condition tasks. Children with ADHD performed more error responses in the interference condition compared with noninterference conditions. They showed significantly lower visuospatial working memory performance in interference conditions. The finding suggested that the visuospatial working memory was affected by auditory and visual interference in both of N-back and running memory tasks.

Furthermore, the results revealed that the N-back and running memory tasks of computerized test showed a significant difference between normal control children and children with ADHD except the N-back with noninterference task as shown in [Table 2]. This finding indicated that children with ADHD had the same level of visuospatial working memory ability in N-back with noninterference task as normal control group, because the N-back with noninterference task was the first level of N-Back task which was noninterference experiment and children could easily complete the task compared to interference conditions. The result suggested that children with ADHD could sustain their visuospatial working memory in the mechanism of noninterference as they were able to use ample resources for manipulating information in the experiment without interference.

In contrast, from the results, there were significant differences between normal control children and ADHDR children in running memory with noninterference task. This implies that children with ADHD were different from normal control children with regard to how they performed visuospatial working memory in the running memory with noninterference task in backward span condition. The finding agrees with prior research in which, to perform in the backward span, the children needed to store and recollect the data, but children with ADHD had impaired visual–spatial storage as well as visual–spatial central executive domains.^[23] According to meta-analyses, children with ADHD were usually accompanied by impaired visual–spatial working memory, especially in the abilities to store and manipulate information, but were not associated with accomplishments in learning. In addition, working memory is deemed to be involved as a pivotal process in children with ADHD, and research has recently emphasized deficits in visual–spatial working memory.^[23],[35]

However, normal control children had greater visuospatial working memory performance than children with ADHD in overall tasks. This finding demonstrated that children with ADHD performed less interference control on visuospatial working memory tasks than normal control children. Children with ADHD failed interference control on visuospatial working memory with irrelevant information of auditory and visual interference experiments. They also exhibited inefficient control over themselves, especially in the interference condition tasks, showed more error responses, and were easily distracted when interacting in the tasks.

The present study supports the previous studies which have reported the relationship between interference control and working memory performance. For example, Cowan^[28] asserted that inhibition was the important executive processing function and played a significant role in working memory processing as it could suppress and deactivate data which were irrelevant to the present task. According to the study, the finding revealed that children with ADHD performed less auditory and visual interference control in visuospatial working memory tasks compared with normal control children. Children with ADHD who showed a deficit in the ability of interference control had some difficulties to control irrelevant information in the interference condition tasks.

In addition, Palladino and Ferrari^[7] found that unsatisfactory levels of working memory performance of people with poor comprehension ability and children with risks of ADHD and LD were associated with lower levels of memory function overall. Low working memory performance was linked to difficulty in inhibitory control that was correlated to poorer control over unrelated information. This research supports the result of the present study that normal control children exhibited greater performance in overall tasks of auditory and visual interference control of visuospatial working memory. The result suggested that poor working memory performance related to the abilities to suppress the relevant and irrelevant information of ADHD group.

The finding of this study showed that auditory and visual interference could affect visuospatial working memory performance in children with ADHD. In interference experimental trials, ADHD group performed lower interference control compared with normal control group. These results support the previous evidence of interference control in children with ADHD. A remarkable finding presented that children with ADHD exhibited more error response in visual interference tasks than auditory interference tasks. They showed less efficient control of visual irrelevant information in visual interference task^[34][Figure 1] and [Figure 2]. This finding supports previous research that children with ADHD performed more poorly in visual tasks than in auditory tasks.^[35],[36]

The results indicate that children with ADHD are more sensitive to visual interference than auditory interference that they difficult to control irrelevant information on visual tasks when they focused the stimulus on the computer screen. Another result from this study revealed that children with ADHD showed different performance in difficulty level as they performed less interference control and increased error rate in more difficult levels. These problems may cause working memory and interference control difficulties to children with ADHD, resulting in failure to suppress and control irrelevant information. The finding indicates that interference control mechanisms depended on working memory load which was the main problem of children with ADHD. In addition, Cansino et al.^[12] studied the influence of interference control on visuospatial working memory. The result showed that although the participants could effectively use the access and deletion function when doing tasks that were lowly, moderately difficult, they could only employ the access functions but did not successfully adopt the deletion function when performing highly difficult tasks.

A great deal of research has reported that children with ADHD face interference control problems and showed poor performance in interference tasks such as more error response and longer reaction time.^[37],[38] Cornoldi et al.^[32] reported that children with ADHD had trouble remembering the final item in the string and demonstrated larger numbers of intrusions during the memorization of items which were out of position. This suggested that children with ADHD were confronted with working memory difficulty due to the lack of ability to suppress information which, at the beginning, needs to be processing deficits. This evidence agrees with the result of the present study that children with ADHD demonstrated less interference control performance, particularly in running memory with interference task. In this task, the subjects needed to update and maintain information of visuospatial position, and they showed difficulty in remembering the reverse of the last span of information.

However, the results of the present study demonstrated that the interference control deficit was the core problem of children with ADHD as they had difficulty in controlling and suppressing irrelevant information in interference tasks when compared with normal control children. The present study supports the evidence-based mechanisms of auditory and visual interference control in visuospatial working memory of children with ADHD.

Limitation and future studies

The present study has some limitations that should be addressed by the future research. First, the small sample size was used in the study from limitation in the number of children with ADHD. Therefore, the study did not control the characteristic of subtypes of ADHD because of the number of children with ADHD who could attend in this study and met the criteria. Future studies would be beneficial to determine whether there are distinct in performance of interference control among each subtype of children with ADHD. Moreover, the computerized test is the laboratory testing, and it may not be directly generalized in real-life settings of children with ADHD. Thus, the ecological validity should be considered in the future studies.

Conclusion

The results of this study indicate that auditory and visual interference could affect visuospatial working memory performance in children with ADHD. They performed less interference control on visuospatial working memory tasks with irrelevant information of auditory and visual interference experiment compared with normal control children. These findings indicate that children with ADHD exhibited inefficient control over themselves, especially in the interference condition tasks in which they performed more error responses when interacting in the tasks.

Financial support and sponsorship

The study was supported by the Graduate School and Faculty of Associated Medical Sciences, Chiang Mai University.

Conflicts of interest

There are no conflicts of interest.

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