Moderator Role of Monitoring in the Inhibitory Control of Adolescents With ADHD

Abstract

Objective: The aim of this research was to analyze the role of monitoring in the causal relationship between inhibitory control and symptoms of combined ADHD. Method: It has been conducted a quantitative investigation of two phases. Results: In the first study, a moderation model was analyzed (N = 144 adolescents with combined ADHD), where monitoring was considered as a moderating variable in the causal relationship between the inhibitory control and the symptomatology of ADHD F(3, 140) = 28.03, p < .001; R² = .37. In the second study, the model through an experimental study was tested (N = 52 adolescents with and without ADHD) where it was found that adolescents with ADHD improve in their inhibitory control when they receive external support to the monitoring F(1, 50) = 21.38, p < .001, η² = .30. Conclusion: Results suggest that monitoring compensates the poor performance of inhibitory control in adolescents with ADHD, which is a contribution to the theoretical construction of ADHD and to the treatments proposed for this condition because it goes beyond the classic conception of a causality chain among the deficit of inhibitory control and ADHD symptomatology to propose a new explanation about this disorder, where neuropsychology intervention of monitoring would diminish ADHD’s symptomatology impact on adolescents.

Keywords

ADHD combined subtype ADHD executive functions inhibitory control monitoring

Introduction

ADHD is a neurodevelopment disorder characterized by presenting attention alterations, high levels of impulsivity, and excessive motor activity (American Psychiatric Association [APA], 2013). Several studies have shown that between 3% and 10% of the population will present this disorder (APA, 2013; Cao et al., 2018; Danielson et al., 2018; De la Barra, Vicente, Saldivia, & Melipillan, 2013; Polanczyk, De-Lima, Horta, Biederman, & Rohde, 2007; Vélez-Van-Meerbeke, Zamora, Guzmán, López, & Talero-Gutierrez, 2013; Wolraich et al., 2014).

With respect to its etiology, currently there is a lack of a theory in psychology which is consistent with the explanation of this disorder and that allows to find a definitive therapeutic solution for children, teenagers, and adults suffering from this disorder (Cardo & Servera, 2008; Nigg, 2012; Ramos & Pérez-Salas, 2015; Servera-Barceló, 2005). Nevertheless, from the cognitive neuropsychology perspective, there have been interesting contributions to explain the causes of this disorder, being Barkley (1997) one of the authors who have contributed the most to enhance the comprehension of the disorder.

According to Barkley’s (1997) theory, ADHD will be the product of inhibitory control impairment, an executive disfunction generating a causality chain for nonverbal memory deficit, self-directed speech, motorization, behavioral reconstitution, and the self-regulation of emotions, motivation, and arousal. As empirical evidence to this theory, different authors (Berthiaume, Lorch, & Milich, 2010; Ramos-Galarza & Pérez-Salas, 2017; Winther, Egeland, Norman, Tore, & Øie, 2014) have reported studies that state that the deficit present in inhibitory control, monitoring and self-directed speech will be the main cognitive alterations present in ADHD.

Even when Barkley’s findings have allowed advancing enormously to understand ADHD, there is still a discussion regarding the approach or projection for intervention based on his theory. In this sense, Servera-Barceló (2005) affirms that the main implication of Barkley’s theory for the understanding of ADHD is the concept of a pharmacologic treatment as the main mean of intervention on inhibitory and self-regulation deficits presents in this disorder.

One of the main critics that this kind of treatment faces lies in the fact that patients who receive psychostimulants show behavioral improvements while they are ingesting the medication and its effect lasts; but in the long run, these improvements will not stay (Catalá-López, Ridao, Sanfélix, & Preiró, 2013; Madaan, Kolli, Bestha, & Shah, 2013). Furthermore, it has been described that even when there is a benefit from the phamacotherapy for ADHD, it has different levels of effectiveness depending the case because there are patients who have presented no desirable side effects which had complicated, even more, this disorder, showing as example, hyporexia, insomnia, headaches, psychotic symptoms and/or other affective disorders, and a lower height or weight growth, with respect to participants who have not received this treatment (Valverde & Inchauspe, 2014).

Despite the fact that the critical movement has manifested its disagreement with the pharmacological treatment for ADHD, it has been reported highly controlled studies which affirm, on one hand, the efficacy of the pharmacological treatment by itself and, on the other hand, the benefit of the interaction among behavioral psychological intervention and pharmacological treatment (Blum, Jaward, Clarke, & Power, 2011; Greenhill, Beyer, & Finkleson, 2002; Horn et al., 1991; Sandoval, Acosta, Crovetto, & León, 2009). Nevertheless, as it was mentioned before, there is the possibility that the treatment based on psychostimulants generates some undesired side effects on patients with ADHD, which nowadays, seems as a controversial treatment (Taylor, 2014). In this sense, the intention of this work is to look deeply for a treatment for ADHD, which would bring a benefit for patient’s symptomatology, trying to reduce to the minimal level the presence of side effects.

Papazian, Alfonso, Luzondo, and Araguez (2009) state that the pharmacologic treatment of ADHD must be used as a last recourse; the training of executive functions should then be the first course of action to follow in these cases. However, until is known, ADHD theoretical description has not yet produced a model based on executive functions, which will permit to test the role of each one of them and their participation in the processes to compensate the functioning of inhibitory control.

Opposite to Barkley’s (1997) proposal, authors such as Anderson and Reidy (2012); Brown (2008), Gioia, Isquith, Retzlaff, and Espy (2002); and Sergeant (2005) have described that inhibitory control has the same hierarchy level as the rest of the executive functions. This allows to conclude that all executive functions support cognitive and behavioral regulation. Being at the same level implies that there is no preponderance between one executive function and another, and that compensation process can take place among the different executive abilities (Lubrini, Periáñez, & Ríos-Lago, 2009).

As we can observe, inhibitory control has been conceived as a core factor of the executive function or as a function found at the same level of action as other executive functions (Gioia et al., 2002). Nevertheless, these models are still at a descriptive level, where executive functions are being organized through an exploratory factor analysis methodology (Filippetti & López, 2013) and not as a theory proposal that allows the understanding of the disorder to move forward to an intervention process phase based on the training of ADHD population on executive functions.

On the contrary, diverse studies have reported improvements on symptomatology of inattention, hyperactivity, and impulsivity of population with ADHD to benefit from process of executive functions training such as monitoring, where self-instructions, peer behavioral supervision, modification of irrelevant verbalizations, and other monitoring strategies have shown positive results in favor of neuropsychology treatment methods for this disorder (Corkum, Humphries, Mullane, & Theriault, 2008; Davies & Witte, 2000; Meftagh, Mohammadi, Ghanizadeh, Rahini, & Najimi, 2011; Miranda & Presentación, 2000; Miranda-Casas, Presentación-Herrero, & Soriano-Ferrer, 2002; Ochoa, Panesso, & Valencia, 2006; Ramalho, García-Señorán, & González, 2011).

Even when efficiency of intervening in executive functions as a treatment strategy for ADHD has been described results are yet inconclusive and there is empirical evidence such as the one proposing an opposite perspective, that shows that pharmacological treatment has better results with inhibitory control over the intervention in the monitoring process of the behavior of children with ADHD (Davood et al., 2014).

According to Brown (2008); Corkum et al. (2008); Hughes, Wilson, and Emslie (2013); and Orjales (2007), children and teenagers with ADHD face a significant difficulty in the inhibitory control in addition to their monitoring process, as they have a tendency to externalize thoughts or issue utterances that have no relation to or make any sense with respect to the task they are performing. As consequence, they cannot attain their planned objective nor conceive an action plan, supervise or control an appropriate performance, detect errors, show a capacity to auto-question the actions they are executing, nor verify if they have reached the proposed goal or if they have made the corresponding corrections to succeed in a specific task.

From the described research, two key unresolved issues can be drawn with respect to ADHD. First, the need to develop a model that contributes to the development of the disorder explanation, and second, the contribution to a therapy process that is appropriate for this population. In this sense, the purpose of the current research is to contribute with the theory development and therapy options of ADHD from a cognitive neuropsychological perspective. We plan to analyze a model where the hypothesis is that monitoring acts as a moderator between the relationship of inhibitory control and the symptoms of combined ADHD. Through this supposition, it is considered that monitoring could mitigate the relationship established in prior research between inhibitory control and ADHD symptomatology, so the failures of inhibitory control could be compensated by the moderator role of monitoring.

The methodology used to test empirically the proposed model will take place in two studies. In the first study, the moderator role of monitoring will be analyzed taken inhibitory control as predictor and ADHD combined symptomatology as dependent variable. Then, the model will be applied in a second experimental type study where by manipulating the monitoring process, we will seek to improve the performance of the inhibitory control in adolescents with ADHD.

Method

Study 1

Participants

The sample was conformed by 144 adolescents diagnosed with ADHD subtype combined. This diagnosis was confirmed in three levels; in the first one, by the health and psychology departments from the educative institutions to which participants belonged; second, by the itinerant teams on mental health that assist to the educational system; and in third place, through the analysis of symptomatology described on the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; APA, 2013). Participants’ average age was 16.15 years (SD = 1.23), 62 male participants (43.1%) and 82 female (56.9%). Participants belonged to the educational system of Ecuador to a middle socioeconomic status. According to their educational level, 69 (47.9%) of participants were enrolled in 10th grade, 30 (20.8%) in 11th grade, and 45 (31.3%) in 12th grade of high school.

Measures

The Behavior Rating Inventory of Executive Functions (BRIEF) evaluation questionnaire of executive functions self-report version (Guy, Isquith, & Gioia, 2004) has two indexes: metacognition and behavioral regulation. This is designed with eight subscales: Inhibitory Control, Change, Emotional Control, Monitoring, Work Memory, Planning, Material Organization, and Task Completion. The items of the instrument are scored with three answer options: never (one point), sometimes (two points), and frequently (three points). The current study used the following subscales: (a) Inhibitory Control (13 items) and (b) Monitoring (five items). In previous research, it has been reported an adequate factor adjustment of BRIEF scale, χ² = 52.34, df = 19, p < .01; comparative fit index (CFI) = .086 (90% confidence interval [CI] = [.05, –.11]); standardized root mean square residual (SRMR) = .042, and acceptable internal consistency of applied scales, Inhibitory Control (α = .79) and Monitoring (α = .69; Ramírez, Pérez-Salas, & Ortega, 2017). The current report found for the parameter of internal consistency (calculated using Cronbach’s α) for inhibitory control was α = .77 and for monitoring was α = .60. According to Field (2009) values around α = .70 are necessary to prove the internal consistency of one scale. Notwithstanding, values below this parameter are acceptable as long as the scales have a reduced number of items. This is true in our case for the Monitoring scale.

ADHD Rating Scale IV (DuPaul et al., 1997) is a questionnaire designed with the 18 symptoms of ADHD. The current study was applied using the version validated in Ecuador, following a self-report format, which has reported an adequate factorial adjustment (χ² = 208.50, p < .01, CFI = .87, root mean square error of approximation [RMSEA] = .04, 90% CI = [.03, –.05]) and good internal consistency for the scale (α = .83; Ramos & Pérez-Salas, 2016). Each item was awarded zero points when the behavior had a never frequency, with one when the answer was sometimes, with two when the answer was frequently and with three points when the response was very frequently. The Cronbach’s Alpha of internal consistency of the scale for the present study was α = .71.

Procedure

The research started by requesting authorization for the study to the respective education authorities. Then, it was coordinated with the psychology departments of the different high schools the selection of the participants that met the criteria to be included in the study: (a) combined ADHD diagnosis, (b) lack of another neurodevelopment disorder, (c) intelligence evaluation within standard parameters, and (d) not having an intellectual, motor, or sensory disability of any kind. Once we gathered a group of participants to participate on the study, an informed consent document was prepared and sent to be signed by the students’ representatives. Once it was signed, each participant had to give their informed assent as well by signing a document the day the instruments were applied. Throughout this study, Helsinki’s ethical parameters for human research were respected (Williams, 2008).

Data analysis

A regression process was conducted to analyze the moderation of the monitoring variable with respect to the causative relationship between inhibitory control and ADHD symptomology of combined ADHD (Figure 1 illustrates the described model). The analysis was conducted using the SPSS software package version 22 (IBM, 2011) through a moderation analysis process proposed by Hayes (2013), which is based in a linear regression and correlation, based in the equation Y = B0 + (B1 × X) + (B2 × X). According to Baron and Kenny (1986) when moderation variable and independent variable are continuous, as in the present analysis, it could be chosen the multiplication of the independent variable times the moderator variable, which must reduce the prediction of X over Y to replace this variable composed by the independent previous variable X × M.

Figure 1.

Graphic representation of the theoretical model of interaction of executive functions with the symptoms of ADHD.

Results

Once the assumptions of normality were set, we proceeded with the analyses. Descriptive data results obtained for the ADHD symptoms variable for the total sample showed a score of M = 18.64 (SD = 5.64); the score for inhibitory control was M = 22.03 (SD = 4.08) and M = 9.69 (SD = 1.86) for monitoring.

During the evaluation of the model through a robust process of maximum probabilities, it was found a statistical significance of F(3,140) = 28.03, p < .001; R² = .37. The significance region Johnson–Neyman technique showed that the moderator variable (monitoring) became statistically significant when it had a value of 6.67 points, which means that the effect is being moderated in 97.22% of the sample’s teenagers with ADHD. This suggests that the greater the monitoring deficit is, the greater is the negative or damaging effect of the inhibitory control deficit over the symptoms of combined ADHD (Figure 2 shows the statistical model).

Figure 2.

Graphic representation of the statistical model with their respective coefficients.

Discussion of Study 1

In this first study, the moderator role of monitoring in the relationship between inhibitory control and symptomatology of combined ADHD was analyzed. Findings suggest that monitoring will modify the negative effect that inhibitory control impairment has on the behavior of a teenager with ADHD. This means that adolescents that have in a better way conserved their monitoring capacity could compensate the effects that inhibitory control deficit have on behavioral regulation. This relates to prior findings from Orjales (2007) and Ramalho et al. (2011).

Furthermore, results contribute to the conception of an explanatory model for ADHD that allows considering neuropsychological type treatments. If is considered that the disorder develops as a consequence of a sole failure of inhibitory control as a causative chain, the main intervention strategy for this scenario will be treatment with medicines. Nevertheless, as stated by Papazian et al. (2009), the first step in ADHD intervention should be the training of executive functions. In this case, it will be more specific to state the need to begin treatment with monitoring training in a process to compensate inhibitory control impairments and from there achieve an improvement of the regulation of general behaviors.

An essential concept that backs up the obtained results is the compensation one. It shows that for cerebral functioning, preserved cognitive functions could assume or support the performance of other cognitive functions that are weakening (Lubrini et al., 2009), as with ADHD where inhibitory control is in detriment (Jiménez-Figueroa et al., 2017) and monitoring, based on regulating behavior and cognition language could compensate its functioning, helping with this the regulation of behavior in adolescents diagnosed with the disorder.

Even when this design has a theoretical reach that contributes along with empirical data to the validation of the proposed hypothesis of moderation, it is not possible to assure the effect of monitoring found due to the correlational characteristics of the study. Based on this, the need to test the model through an experimental study raises. By manipulating monitoring processes intentionally, a change in the performance of the inhibitory control can be triggered. Consequently, next section presents a second study which purpose is to analyze the role of monitoring within an experimental setting and to reach an explanation level for the proposed analyzed theory of the first study.

Study 2

Participants

From the total participants of the first study diagnosed with combined ADHD, 26 students were selected at random to be part of an experimental ADHD group (17 men and nine women, average age was 15.96 years, SD = 1.24). On the contrary, the control group was formed by 26 students (12 men and 14 women) with a normal development and an average age of 15.96 years (SD = 1.31). Using a nonparametric statistical procedure it was found that there are no gender differences, χ²(1, 52) = 1.94, p = .16, and not age differences χ²(4, 52) = 4.66, p = .323, among participants when comparing them according to the experimental and control group. Sociodemographic data are the same as described in the first study. Also, it is important to mention that for both studies no participant received pharmacological treatment.

Experiment

Using the PEBL (Psychology Experiment Building Language) experiment design system (Mueller, 2015; Ramos-Galarza et al., 2017), which is an open code program to design tasks to evaluate neuropsychological functions; two experiments were designed based on the Simon effect (Mueller & Piper, 2014).

According to Kunde and Stocker (2002), Simon effect based experiments are cognitive tasks used to evaluate the inhibitory control of a response. Barkley (2003) states during this task, human beings have an automatic tendency to respond to a hemifield in which the presented stimulus is positioned and when this tendency stops, frontal lobe brain structures are activated allowing the evaluation of the action of inhibitory control.

Based on this statement, two experiments were designed: (a) inhibitory control valuation experiment without external monitoring support and (b) inhibitory control valuation with external monitoring support.

The first version without external monitoring support, consisted in an experiment where a red circle shows up on the screen (needs to be selected with the left hand) or a blue one (needs to be selected with the right hand), one at the time. The participants answered using a button box adjusted for the task. Between the presentation of each circle, a cross showed up (it disappears after 500 ms and then the next stimulus shows up) in the middle of the screen to divide it into a right and left hemifield. Once the blue or red circles appear there is not an automatic timeframe to reply; the circle disappears once the participant submitted his answer.

Task 2 presents two types of trials: (a) congruent (Go), which consist in trials where the circle shows up in the hemifield corresponding to the right answer; for example, blue circles will show up in the right hemifield and red in the left one; and (b) incongruent (No-Go), which consists on the presentation of circles in the hemifield corresponding to the one where the response needs to be inhibit; this means that blue circles will show up on the left and red on the right and the answer needs to be done with the right arm. Go and No-Go stimuli show up randomly with a 50/50 ratio.

During each evaluation 140 trials are presented randomly. As far as the position where they show up, each circle can appear on the right side in 42% of the cases, 42% on the left side, and 16% in the middle of the screen. It was counted as inhibitory control error the number of times where the participant did not inhibit the tendency to elicit an automated response. For example, when a blue circle shows up in the left hemifield and the participant answered with the left hand instead of the right one.

The experiment version that has external support for monitoring is based on the characteristics described on the prior version, plus the contribution to monitoring that, according to our hypothesis, will generate the compensation of inhibitory control. Each one of them is described as follows:

Feedback after each incorrect response to the No-Go stimuli

This external help is shown in the screen with the image of a doll and tag that reads “What Should I Do?” and it also has an audio played which says, “I made a mistake, what do I need to do in this game, remember, you need to answer with your left hand if you see a red circle and with a right one when you see a blue circle.”

Feedback after correct answers to Go and No-Go stimuli

This consisted in having a doll displayed on the screen with a sign that reads “Good Job!” and an recording that plays “good job, you are doing great, you answered with the right hand for blue circles and with the left hand for red circles.”

External verbalizations to help with the planning of the activity

Showing on the screen a doll with the question “what do I need to do in this activity?” and an audio that plays,

what do I need to do in this activity, I need to pay attention for the blue and red circles that will be shown on the screen, I need to answer with my right hand for the blue circles and with the left for the red ones.

External verbalization to verify the achieved goals

This consisted on the presentation, after 120 trials, of a doll with the tag saying, “Am I reaching the objective?” and a clip playing “am I reaching the objective?, remember to give your best answer when you see the circles, with the left hand for red ones and with the right for blues.”

Questions and audios to improve the supervision of the task execution

This support consisted of showing a doll with a sign that reads “How am I doing?” and an audio that plays “How am I doing? (according to the number of rights and wrongs) you have 10 correct answers and 1 mistake, keep it up, you are doing a great job.” If the participant has more than five mistakes then the recording will say “you need to pay more attention to your answers, you have 6 mistakes.”

The audio content was customized, so it was recorded, edited, and saved as a master version with the support of an audio technician; during all evaluations, these aids were played and presented in the same amount for all participants. Figure 3 shows a print screen of the experiment.

Figure 3.

Sequence example of one of the external monitoring support when there is a failure of the inhibitory control during the execution of the experiment (figure shows a red circle that demands a left hand answer and when it is done with the right hand it triggers an external monitoring assistance).

The experiment was programed so external support to the monitoring process is presented graphically and through audio reproductions. To ensure that participants listen actively during the execution of the task, they wore headphones.

Procedure

Once it was obtained all the authorizations, consent, and agreement signatures, the groups of participants with and without ADHD were established. Then a pilot study of the experiment was conducted, which consisted in (a) the evaluation of four expert professionals with a postgraduate title in neuropsychology and a broad experience in the evaluation of executive functions, who helped with the programing of the external support provided to monitoring, the number of stimuli, audio content, screen color, brightness, and buttons/keys of the equipment used. Once the experiment was ready, it was applied to a group of eight participants (not included in the evaluations of the research), who helped regulate other aspects such as the volume of the audio feedback, image characteristics, and other elements of the environment where the experiment was taking place.

All evaluations were done individually in a room set up for the activity, which counted with a table and a chair, the computer screen, headphones, and the button’s box to enter the answers. All other stimuli that could interfere or serve as a distraction during the development of the task were removed from the room. The evaluations were done in the morning and both, the group of ADHD teenagers and the control one, performed the activity under the same conditions.

A counterbalance technique was used for the order of the presentation of both levels of the experimental moderator variable with external support. The purpose of this was to avoid possible task learning effects drawn from the order of presentation. Both experiments were applied in sequence. For each group, 50% of participants were selected first at random and assigned to respond the task that had external support, whereas the other half responded the task without monitoring external support. During the entire study all ethical parameters related to human research stated in Helsinki were respected (Williams, 2008).

Data analysis

From the application of each experiment, an Excel file was created in which the number of errors of inhibitory control for each participant was recorded. These data were inputted into SPSS version 22 (IBM, 2011) program, where statistical analysis took place. Data analysis was based on a mixed 2 × 2 ANOVA. As an intragroup factor, repeated measurements were considered: (a) external monitoring support and (b) no monitoring support. The different-group factor considered was (a) ADHD group and (b) non-ADHD group.

Results

First, the assumptions to apply the mixed design ANOVA technique were evaluated. For descriptive values, the mean of inhibitory control errors for the group of teens with ADHD when facing the experiment without external monitoring support was 9.69 (SD = 4.47), whereas it decreased to 4.00 (SD = 2.09) when they received external monitoring assistance. For the group of teens without ADHD, the control group, the mean when not exposed to external support was 4.38 (SD = 3.00) and it improved to 3.12 (SD = 1.88) when they received external support. Figure 4 shows graphically the results from both groups under both experimental conditions.

Figure 4.

Graphic representation of the results in terms of errors of inhibitory control for both ADHD and non-ADHD groups, after performing the experiment with and without external monitoring support.

The ANOVA 2 × 2 analysis shows that there is an interaction effect derived from been or not been exposed to external monitoring assistance ADHD/non and the ADHD condition, F(1, 50) = 21.38, p < .001, η² = .30. These results confirm that external monitoring support did not have the same effect in participants with ADHD and the ones without the disorder.

The post hoc Bonferroni analysis found that the obtained interaction suggests that external monitoring support mostly benefits participants with ADHD. When comparing the differences between both groups, the number of inhibitory control errors is statistically significant when there is no external support for the monitoring process t(1, 50) = 5.02, p < .001. Nevertheless, this difference is not statistically significant when they are exposed to monitoring external assistance t(1, 50) = 1.60, p = .11. External support improves the results of both groups but the improvement in participants with the disorder is greater than the one for the participants that have a normal development.

Discussion of Study 2

The second study seeks to empirically test the tried model of Study 1. Among the results, it can be concluded that monitoring external support improve the inhibitory control performance of teenagers from the control and experimental group; although, the improvement is significantly higher for the group of participants with ADHD.

Data found in this study are consistent with the revision by Moos and Ringdal (2012), who mentioned that the improvements in metacognitive abilities such as monitoring contribute to a better performance in the execution of tasks. The external support provided to the monitoring process, which was applied in the experiment, will achieve to emulate in some way a self-regulation process, characteristic of a student with a proper behavioral self-regulation, as individuals with such ability tend to use constant self-questioning and self-verbalizations related to the task they are executing at the time or with respect to fulfilling their objectives.

From a neuropsychological perspective, Norman and Shallice (1986) state that when humans activate executive actions such as monitoring functions when performing a task demanding conscious behavior, they use a cognitive mechanism called attention supervising system; and when they act in an automatic way, they do it through a mechanism called conflict settlement. Our results, related to those mentioned by Norman and Shallice, make sense when adolescents with ADHD do not have an external source of monitoring support they will behave under their conflict settlement process, meaning to have an automatic response. On the contrary, when there is an external support for monitoring processes present, it becomes a positive influence so the attention supervising system can guide the participant toward the successful accomplishments of the objectives of the experiment which are to control an automatic response before a No-Go stimulus.

According to Miyake et al. (2000) the improvements in the performance, impulsive control that was found in both groups, especially in ADHD group, would be present because of the execution of a conscious act, it is determined by the capacity of actualization of monitoring, which sends information that renew the content of the working memory, which would explain the improvement in participants diagnosed with ADHD, in whom is present a high deficit on these executive functions.

Furthermore, our results add to the ones found by Ramalho et al. (2011), Ochoa et al. (2006), and Davies and Witte (2000) who had reported studies where is mentioned that intervention in the monitoring process of children with ADHD is efficient to improve the performance of subprocesses of attention, impulsivity, and school performance. With respect to the mentioned results, the current study contributes to the ADHD research line by confirming that external monitoring support influences positively in cognitive processes of high order such as inhibitory control.

The results obtained from the experiment could approach Barkley’s (1990) theory assumption that states that the capability to be aware of the objectives and the consequences of behaviors will depend on the linguistic capacity of human beings. This capacity influences the ability to monitor our own behavior. Furthermore, Corkum et al. (2008) have reported that children with ADHD produce verbalizations that do not contribute to the monitoring process during the execution of an inhibitory control task, opposed to children with a normal development who have linguistic abilities which allow them to have an appropriate control of automatic responses. In this sense, the experiment that had external monitoring support will somehow contribute to the restructuration of this linguistic capability concerned with a weakened monitoring process found in participants with ADHD.

For Martinussen and Major (2011), and Meftagh et al. (2011) the use of external or open verbalizations aid the regulation of behaviors and the performance of cognitive processes such as attention or working memory. The process of language internalization has a great influence over the execution of tasks and the organization of the activity itself. Besides, in this second experiment, through external monitoring support, participants with ADHD will improve their planning, supervision, and verification of their answer when presented with the stimuli of the experiment. This will become empirical evidence useful for the development of strategies based on monitoring training as a mean to compensate the lack of impulse control that affects behavior regulation on participants that suffer from the disorder.

It is important to mention that this external support to monitoring generated in the experiment, acts as a "cognitive prosthesis" in the execution of inhibitory control. Even when this support is external, by becoming a projection of the individual’s cognition, it is as valid in the development of monitoring as all intrinsic resources that humans without any cognitive deficiencies have (Broncano, 2006).

The validity of this “cognitive prosthesis” as a strategy is based on the concept of the interaction of adjustments proposed by Sireci (2008), according to which the customizations made to the experiment should improve significantly the execution of the group that suffers from the disorder (in this case the low inhibitory control found in the ADHD group). Thus, we can affirm that the group with ADHD does not improve in the posttest simply because the second condition is easier than the first one but because a secondary deficiency is being compensated (inhibitory control) through the external support of monitoring processes (which is also deficient).

Finally, the findings in this second study have an important implication in multiple contexts where an adolescent with ADHD performs. For example, in the educational context, these results reveal the need to implement in the future metacognitive monitoring training programs to be applied by teachers at school and as well for parents to apply the training at home. In the clinical context, results invite to develop techniques which imply self-monitoring training in the execution of tasks and behavioral supervision; this would be an essential strategy that must be applied in population with ADHD. In the same manner, in the development of technological devices that could compensate this executive function from external monitoring, for example, developing cellphone applications where adolescents have an external input for the supervision of their behavior and tasks. It is a long journey to follow to build effective therapeutic processes for population diagnosed with ADHD, which do not generate undesired side effects and with permanent results. It is important to mention that these findings contribute with an interesting investigation line of training monitoring processes for ADHD population.

General Discussion

The current investigation analyzes the moderator role that monitoring has in the causal relationship between inhibitory control and the symptomatology of ADHD. To accomplish this, two studies have been performed. First, the analysis of a theory model was conducted and second this model was tested using a experimental design.

The results suggest that monitoring executes a process of inhibitory control compensation from a correlational level, it was found that the role as a moderator is significant and at an experimental level it was found that the interaction between monitoring and the group with ADHD is statistically significant. Findings showed that participants who presented the disorder were the ones that benefit the most from this intervention.

An important aspect of the described results relies in a change of paradigm that invites to develop this article. The usual course of treatment for ADHD patients is with a pharmaceutical one, and the current study describes the process of compensation of brain functions based on the intervention of monitoring processes instead. This can become an efficient treatment strategy for the population with this disorder.

The main limitation of these findings is the small sample. Unfortunately, accessing to a larger and significant sample with participants selected nationwide and who comply with the requirements of inclusion described above is of great complexity. Another important aspect is the location of the participants which is a single city of a South American country. This implies that data permit to understand a reality within the context in which the sample was taken from. However, this setting invites us to perform future research where could be possible to design studies at a nationwide level.

Another limitation worth mentioning is the subjective character implied in the evaluation through a self-report. Even when every participant from the first study had a confirmed ADHD diagnosis, the instruments applied reflect their own perception of their own cognitive and behavioral functioning which could be biased to their personal concept of behavior standards. For the second study, even when almost every variable that could influence the results were controlled, a limitation arises as it was not implemented a double-blind evaluation. Throughout the entire time of the experiment, it was known to which group each participant belonged to; this could have caused a bias or a blind spot.

As a future research line, we seek to replicate the current study with an additional variable at a neuroanatomic level. With this variable, brain patterns that are executed during the monitoring process can be related in participants with and without ADHD. Another interesting topic as future research is to train the monitoring process and to perform a longitudinal follow-up of the performance of inhibitory control when there is no intervention. Finally, further research will seek to compare inhibitory control performance of teenagers with ADHD when they receive external monitoring support as opposed to psychopharmacological compounds.

Footnotes

Ethical Approval

This research was approved by the ethics committee of the Psychology Department at University of Concepcion, Chile. All procedures performed were in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written informed consents were obtained from parents and assent from students prior to the questionnaire administration and the experiment, after explaining the aims and objectives of the study.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was funded by the SENESCYT (Ecuadorian Secretary of Superior Education, Science, Technology and Innovation).

ORCID iD

Carlos Ramos-Galarza

Author Biographies

Carlos Ramos-Galarza is professor at the Faculty of Psychology of the Pontificia Universidad Católica del Ecuador. He obtained his PhD at Universidad de Concepción, Chile. His line of research focuses on attention deficit hyperactivity disorder and executive functions.

Claudia Pérez-Salas is assistant professor at the Psychology Department of Universidad de Concepción, Chile. She obtained her PhD at Pontificia Universidad Católica de Chile. Her current research focuses in developmental disabilities and neurospychological assessment.

References

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.

Anderson

Reidy

(2012). Assessing executive function in preschoolers. Neuropsychology Review, 22, 345-360. doi:10.1007/s11065-012-9220-3

Barkley

(1990). Attention deficit hyperactivity disorders: A handbook for diagnosis and treatment. New York, NY: Guilford Press.

Barkley

(1997). Behavioral inhibition, sustained attention, and executive functions: Constructing a unifying theory of ADHD. Psychological Bulletin, 12, 65-94. doi:10.1037/0033-2909.121.1.65

Barkley

(2003). Issues in the diagnosis of attention-deficit/hyperactivity disorder in children. Brain & Development, 25, 77-83. doi:10.1016/S0387-7604(02)00152-3

Baron

Kenny

(1986). The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Journal of Personality and Social Psychology, 51, 1173-1182.

Berthiaume

Lorch

Milich

(2010). Getting clued in: Inferential proccessing any comprehension monitoring in boys with ADHD. Journal of Attention Disorders, 14, 31-42. doi:10.1177/1087054709347197

Blum

Jaward

Clarke

Power

(2011). Effect of osmotic-release oral system methylphenidate on different domains of attention and executive functioning in children with attention-deficit-hyperactivity disorder. Developmental Medicine & Child Neurology, 53, 843-849. doi:10.1111/j.1469-8749.2011.03944.x

Broncano

(2006). Sujeto y subjetividad en la mente extensa [Subject and subjectivity in the extended mind]. Revista de Filosofía, 31(2), 109-133.

10.

Brown

(2008). ADD/ADHD and impaired executive function in clinical practice. Current Psychiatry Reports, 10, 407-411. doi:10.1007/s12618-009-0006-3

11.

Cao

Yan

Wang

Tao

. . . Tao

(2018). Prevalence of attention-deficit/hyperactivity disorder symptoms and their assocations with sleep schedules and sleep-related problems among preschoolers in mainland China. BMC Pediatrics, 18, Article 70. doi:10.1186/s12887-018-1022-1

12.

Cardo

Servera

(2008). Trastorno por déficit de atención/hiperactividad: estado de la cuestión y futuras líneas de investigación [Attention Deficit Hyperactivity Disorder: The State of the Matter and Further Research Approaches]. Revista de Neurología, 46, 365-372.

13.

Catalá-López

Ridao

Sanfélix

Preiró

(2013). Cost-effectiveness of pharmacological treatment of attention deficit hyperactivity disorder in children and adolescentes: Qualitative synthesis of scientific evidence. Revista de Psiquiatría y Salud Mental, 6, 168-177. doi:10.1016/j.rpsm.2012.12.002

14.

Corkum

Humphries

Mullane

Theriault

(2008). Private speech in children with ADHD and their typically developing peers during problem-solving and inhibition tasks. Contemporary Educational Psychology, 33, 97-115. doi:10.1016/j.cedpsych.2006.12.003

15.

Danielson

Bitsko

Ghandour

Holbrook

Kogan

Blumberg

(2018). Prevalence of parent-reported ADHD diagnosis and associated treatment among U.S. children and adolescents, 2016. Journal of Clinical Child & Adolescent Psychology, 47, 199-212. doi:10.1080/15374416.2017.1417860

16.

Davies

Witte

(2000). Self-management and peer-monitoring within a group contingency to decrease uncontrolled verbalizations of children with attention-deficit/hyperactivity disorder. Psychology in the Schools, 37, 135-147. doi:10.1002/(SICI)1520-6807

17.

Davood

Najimi

Norallah

Ahmad

Rahimi

Amini

(2014). The most effective intervention for attention deficit-hyperactivity disorder: Using continuous performance test. Psychiatria Danubina, 26, 165-171.

18.

De la Barra

Vicente

Saldivia

Melipillan

(2013). Epidemiology of ADHD in Chilean children and adolescents. ADHD Attention Deficit and Hyperactivity Disorders, 5, 1-8. doi:10.1007/s12402-012-0090-6

19.

DuPaul

Power

Anastopoulus

Reid

Kara

Ikeda

(1997). Teacher ratings of attention deficit hyperactivity disorder symptoms: Factor structure and normative data. Psychological Assessment, 9, 436-444. doi:10.1037/pas0000166

20.

Field

(2009). Discovering statistics using SPSS (3rd ed.). Los Angeles, CA: SAGE.

21.

Filippetti

López

(2013). Las funciones ejecutivas en la clínica neuropsicológica infantil [Executive functions in clinical child neuropsychology]. Psicología desde el caribe, 30, 380-415.

22.

Gioia

Isquith

Retzlaff

Espy

(2002). Confirmatory factor analysis of the Behavior Rating Inventory of Executive Function (BRIEF) in a clinical sample. Child Neuropsychology, 8, 249-257. doi:10.1076/chin.8.4.249.13513

23.

Greenhill

Beyer

Finkleson

(2002). Guidelines and algorithms for the use of methylphenidate in children with attention-deficit/hyperactivity disorder. Journal of Attention Disorders, 6, 89-100. doi:10.1177/070674370200601S11

24.

Guy

Isquith

Gioia

(2004). BRIEF-SR: Behavior rating. Lutz, FL: Psychological Assessment Resources.

25.

Hayes

(2013). Introduction to mediation, moderation, and conditional process analysis. New York, NY: Guilford Press.

26.

Horn

Ialongo

Pascoe

Greenberg

Packard

López

. . . León

(1991). Additive effects of psychostimulants, parent training, and self-control therapy with ADHD children. Journal of the American Academy of Child & Adolescent Psychiatry, 30, 233-240. doi:10.1097/00004583-199103000-00011

27.

Hughes

Wilson

F. T.

Emslie

(2013). Detecting executive deficits in children with ADHD or acquired brain injury using the Behavioural Assessment of Dysexecutive Sndrome (BADS). The Irish Journal of Psychology, 34, 13-23. doi:10.1080/03033910.2012.754323

28.

IBM SPSS Statistic. (2011). IBM SPSS statistic Program, version 22 statistical software packages. New York, NY: IBM Corpotation.

29.

Jiménez-Figueroa

Ardila-Duarte

Pineda

Acosta-López

Cervantes-Henríquez

Pineda-Alhucema

. . . Puentes-Rozo

(2017). Prepotent response inhibition and reaction times in children with attention deficit/hyperactivity disorder from a Caribbean community. ADHD Attention Deficit and Hyperactivity Disorders, 9, 199-211. doi:10.1007/s12402-017-0223-z

30.

Kunde

Stocker

(2002). A Simon effect for stimulus-response duration. Quartely Journal of Experimental Psychology, 55, 581-592. doi:10.1080/02724980143000433

31.

Lubrini

Periáñez

Ríos-Lago

(2009). Estimulación cognitiva y rehabilitación neuropsicológica [Cognitive stimulation and neuropsychological rehabilitation]. In Muñoz

(Ed.), Estimulación cognitiva-Módulo DIdáctico 1 (pp. 1-37) [Cognitive stimulation-Didactic Module 1]. Barcelona, España: Eureca Media S.L.

32.

Madaan

Kolli

Bestha

Shah

(2013). Update on optimal use of lisdexamfetamine in the treatment of ADHD. Neuropsychiatric Disease and Treatment, 9, 977-993. doi:10.2147/NDT.S34092

33.

Martinussen

Major

(2011). Working memory weaknesses in students with ADHD: Implications for instruction. Theory Into Practice, 50, 68-75. doi:10.1080/00405841.2011.534943

34.

Meftagh

Mohammadi

Ghanizadeh

Rahini

Najimi

(2011). Comparison of the effectiveness of different treatment methods in children’s attention deficit-hyperactivity disorders. Journal of Isfahan Medical School, 29, 965-976.

35.

Miranda

Presentación

(2000). Efficacy of cognitive-behavioral therapy in the treatment of children with ADHD, with and without aggressiveness. Psychology in the Schools, 37, 169-182. doi:10.1002/(SICI)1520-6807(200003)

36.

Miranda-Casas

Presentación-Herrero

Soriano-Ferrer

(2002). Effectiveness of a school-based multicomponent program for the treatment of children with ADHD. Journal of Learning Disabilities, 35, 345-362. doi:10.1177/00222194020350060601

37.

Miyake

Friedman

Emerson

Witzki

Howerter

Wager

(2000). The unity and diversity of executive functions and their contributions to complex “Frontal Lobe’ tasks: a latent variable analysis. Cognitive Psychology, 41, 49-100. doi:10.1006/cogp.1999.0734

38.

Moos

Ringdal

(2012). Self-regulated learning in the classroom: A literature review on the teacher’s role. Education Research International, 2012, Article 423284. doi:10.1155/2012/423284

39.

Mueller

(2015). The Psychology Experiment Building Language (Version 0.14) [Software]. Disponible en http://pebl.sourceforge.net

40.

Mueller

Piper

(2014). The Psychology Experiment Building Language (PEBL) and PEBL test battery. Journal of Neuroscience Methods, 222, 250-259. doi:10.1016/j.jneumeth.2013.10.024

41.

Nigg

(2012). Future directions in ADHD etiology research. Journal of Clinical Child & Adolescent Psychology, 41, 524-533. doi:10.1080/15374416.2012.686870

42.

Norman

Shallice

(1986). Attention to action: Willed and automatic control of behavior. In Davidson

Schwartz

Shapiro

(Eds.), Consciousness and self-regulation (pp. 1-18). New York, NY: Plenum Press.

43.

Ochoa

Panesso

Valencia

(2006). Las situaciones de resolución de problemas como estrategia de trabajo con niños diagnosticados con TDAH [Problem solving situations as a work strategy with children diagnosed with ADHD]. Pensamiento Psicológico, 2(7), 73-88.

44.

Orjales

(2007). El tratamiento cognitivo en niños con trastorno por déficit de atención con hiperactividad (TDAH) revisión y nuevas aportaciones [Cognitive treatment in children with attention deficit hyperactivity disorder (ADHD) review and new contributions]. Annuary of Clinical and Health Psychology, 3, 19-30.

45.

Papazian

Alfonso

Luzondo

Araguez

(2009). Entrenamiento de la función ejecutiva en preescolares con trastorno por déficit de atención/hiperactividad combinado: estudio prospectivo, controlado y aleatorizado [Training of Executive Function in Preschool Children with Combined Attention Deficit Hyperactivity Disorder: a Prospective, Controlled and Randomized Trial]. Revista de Neurología, 48, S119-S122.

46.

Polanczyk

De-Lima

Horta

Biederman

Rohde

(2007). The worldwide prevalence of ADHD: A systematic review and metaregression analysis. American Journal of Psychiatry, 164, 942-948. doi:10.1176/ajp.2007.164.6.942

47.

Ramalho

García-Señorán

González

(2011). Auto-instruções: estratégia de regulação atencional da TDAH [Self-instruction: Attention-seeking strategy of ADHD]. Psicologia: Reflexão e Crítica, 24, 180-185. doi:10.1590/S0102-79722011000100021

48.

Ramírez

Pérez-Salas

Ortega

(2017). Análisis de la Estructura Jerárquica del Inventario de Conductas de la Función Ejecutiva en una Muestra de Estudiantes Universitarios [Hierarchical Structure Analysis of Behavior Rating Inventory of Executive Functions Self-Report in a Sample of University Student’s]. Revista Iberoamericana de Diagnóstico y Evaluación e Avaliação Psicológica, 45(3), 175-188. doi:10.21865/RIDEP45.3.14

49.

Ramos

Pérez-Salas

(2015). Relación entre el modelo híbrido de las funciones ejecutivas y el trastorno por déficit de atención con hiperactividad [Relationship between the hybrid model of executive functions and attention deficit hyperactivity disorder]. Psicología desde el Caribe, 32, 286-301.

50.

Ramos

Pérez-Salas

(2016). Propiedades psicométricas: ADHD Rating Scale IV en formato auto-reporte [Psychometric properties: ADHD Rating Scale IV self-report]. Revista Chilena de Neuro-Psiquiatría, 24(1), 9-18. doi:10.4067/S0717-92272016000100002

51.

Ramos-Galarza

Jadán-Guerrero

Ramos

Bolaños

Ramos

Fiallo-Karolys

(2017). Neuropsychological evaluation of inhibitory control and interference control: Validation of experimental tasks in the ecuadorian context. Revista Ecuatoriana de Neurología, 26(1), 27-34.

52.

Ramos-Galarza

Pérez-Salas

(2017). Control inhibitorio y monitorización en población infantil con TDAH [Inhibitory Control and Monitoring in Child Population with ADHD]. Avances en Psicología Latinoamericana, 35, 117-130. doi:10.12804/revistas.urosario

53.

Sandoval

Acosta

Crovetto

León

(2009). Enfrentamiento terapéutico del trastorno por déficit atencional en una población infantil escolar perteneciente a la Región Metropolitana de Chile. Revista Chilena de Neuro-Psiquiatría, 47(1), 34-42. doi:10.4067/S0717-92272009000100005

54.

Sergeant

(2005). Modeling attention-deficit/hyperactivity disorder: A critical appraisal of the cognitive-energetic model. Biological Psychiatry, 57, 1248-1255. doi:10.1016/j.biopsych.2004.09.010

55.

Servera-Barceló

(2005). Modelo de autorregulación de Barkley aplicado al Trastorno por Déficit de Atención con Hiperactividad: una revisión [Barkley’s Model of Self-Regulation Applied to Attention Deficit Hyperactivity Disorder: A Review]. Revista de Neurología, 40, 358-368.

56.

Sireci

(2008). Validity issues in acommodating reading tests. Journal Pendidik dan Pendidikan, 23, 81-110.

57.

Taylor

(2014). Uses and misuses of treatments for ADHD. The second Birgit Olsson lecture. Nordic Journal of Psychiatry, 68, 236-242. doi:10.3109/08039488.2013.804118

58.

Valverde

Inchauspe

(2014). Alcance y limitaciones del tratamiento farmacológico del Trastorno pr Déficit de Atención e Hiperactividad en niños y adolescentes y Guías de Práctica Clínica. Una revisión bibliográfica. Revista de la Asociación Española de Neuropsiquiatría, 34, 37-34. doi:10.4321/S0211-57352014000100004

59.

Vélez-Van-Meerbeke

Zamora

Guzmán

López

Talero-Gutierrez

(2013). Evaluación de la función ejecutiva en una población escolar con síntomas de déficit de atención e hiperactividad [Evaluating Executive Function in Schoolchildren with Symptoms of Attention Deficit Hyperactivity Disorder]. Neurología, 28, 348-355. doi:10.1016/j.nrl.2012.06.011

60.

Williams

(2008). Revising the declaration oh Helsinki. World Medical Journal, 54, 120-122.

61.

Winther

Egeland

Norman

Tore

Øie

(2014). Few differences in hot and cold executive functions in children and adolescents with combined and inattentive subtypes of ADHD. Child Neuropsychology, 20, 162-181. doi:10.1080/09297049.2012.753998

62.

Wolraich

Mckeown

Visser

Bard

Cuffe

Neas

. . . Danielson

(2014). The prevalence of ADHD: Its diagnosis and treatment in four schools districts across two states. Journal of Attention Disorders, 18, 563-575. doi:10.1177/1087054712453169