Comorbidity of dyslexia in the diagnosis of ADHD PDF

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Comorbidity of dyslexia in the diagnosis of ADHD...

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Comorbidity of dyslexia in the diagnosis of ADHD INTRODUCTION Attention deficit disorder with / without hyperactivity and learning disorder in reading hinder the overall development of children and adolescents. The percentage of children diagnosed with dyslexia is between 8 and 10 percent, this is independent of geographical area and ethnic characteristics. Dyslexic children experience reading and writing difficulties; difficulties that are not attributable neither to mental retardation, nor to psychiatric or neurological disorders, nor even to a significant psychoeducational deficiency (Puente, 2011). Dyslexia is associated with difficulties with learning to read in which confusion occurs between some letters. The reality of this neurodevelopmental disorder is that it involves some difficulties beyond those of reading. It is a disorder that shows a deficit in working memory, specifically with audio-linguistic processes, laterality, visual-motor difficulties, problems in sequencing and directionality and a scarce or poor development of language in general (Abdo, Murphy, & Schochat, 2010). Attention Deficit Hyperactivity Disorder (ADHD) is a disorder that involves both genetic and environmental factors. ADHD is a conduct disorder that appears in childhood, and that usually begins to be diagnosed around the age of 7, although in some cases this diagnosis can be made earlier. It manifests as an increase in physical activity, impulsivity, and difficulty maintaining attention in an activity for a continuous period of time, and is one of the most controversial and widely debated issues in the area of special education. The child exhibits developmentally inappropriate signs of excessive activity, inattention, and impulsivity. This disorder manifests itself in three clinical forms. The most frequent subtype is the combined one, followed by predominantly hyperactive-impulsive and lastly predominantly inattentive (less frequent of all). The latter is manifested more in girls than in boys, the opposite occurs in the previous two (APA, 2013). When we talk about attention, we add that they are divided into three types, sustained, selective and divided attention. The experimental psychologist Donald Broadbent explains with his model, using the "filter metaphor", selective attention (concentration on an activity excluding distractors), divided attention 1

(simultaneity with various demands of the environment) and sustained, selective and divided attention. The experimental psychologist Donald Broadbent explains with his model, using the "filter metaphor", selective attention (concentration on an activity excluding distractors), divided attention (simultaneity with various demands of the environment) and sustained, selective and divided attention. The experimental psychologist Donald Broadbent explains with his model, using the "filter metaphor", selective attention (concentration on an activity excluding distractors), divided attention (simultaneity with various demands of the environment) and

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sustained attention (permanence in the activity without making mistakes) closely related to the level of activation (arousal) involved in the reading processes (Puente, 2011). According to current models of attentional theories, there are several aspects related to eye movement and attention (involvement in reading). Richard Posner, in his attentional theory (Posner & Petersen, 1990), states that these two aspects are carried out by the same brain structure (posterior attentional network). Stelmach, Campsall and Herdman (1997) found that the amplitude of eye movements during reading is adjusted to adapt to the structure of the new information, which seems to indicate that attention is moving forward to prepare for this movement (Castillo, 2006). To this must be added the presence of certain predispositions that hinder reading learning, such as the search for immediate gratification, the scarcity or absence of self-control, According to Artigas, García and Rigau (2009), a large part of children with ADHD show as their first symptom phonological difficulties, language delay or both problems. These children are at high risk of having difficulties in learning to read and write. On the other hand, results of several investigations indicate that relationships between ADHD and dyslexia have been found from a cognitive and neuroanatomical point of view. The common nexus of this relationship stems from the connection of both with working memory. The phonological affectation is attributed to the repercussion on said memory and consequently it would make the appearance of symptoms typical of ADHD more likely. In other words, the impairment in working memory translates into alterations in the attentional processes necessary for reading. (Artigas, 2009). In another study carried out by Shaywitz et al (2009), they state, in reference to the effect of methylphenidate on dyslexia, which is used in ADHD treatments, that it seems to be a promising strategy that deserves in-depth investigation, given the difficulties in intervene in the processes of reading fluency. The results obtained corroborate that in children with ADHD and associated dyslexia, the start of treatment with stimulants could be considered opportune for the improvement to be noticeable.

Given the diversity of results found in the analyzed bibliography, aimed at verifying that participants with ADHD and dyslexics have similar impulsivity problems that hinder the process of learning to read. The objective of the present study is to verify that both groups have similar impulsivity and attention difficulties, which in turn leads to difficulties in the learning process in reading. METHOD Participants In this experiment 12 children of both sexes between 8 and 12 years old participated. The mean age is 10.83 and the standard deviation is 0.83. The participants have been grouped according to diagnosis: -

4 children with dyslexia.

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4 children with ADHD.

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4 children with typical development.

Stratified random sampling. They have been selected taking into account their availability and accessibility, checking that they had the general characteristics of the study population. The sample of children with Dyslexia and ADHD has been drawn from the InPaula Infant Neurorehabilitation Institute of Almería. The control group comes from CEIP Las Marinas located in Roquetas de Mar. Before conducting the study, information about the objectives and procedure of the study was provided to the families, who had to authorize the subjects to participate. In any case, and even with the authorization of the tutors, the children could abandon the tasks at the moment they saw fit.

Instruments To carry out this study, two neurobehavioral tasks designed at the University of Almería have been used to measure motor impulsivity and cognitive impulsivity in children: GO-NO / GO (inhibition of response / sustained attention 500-1000ms) and TWO CHOICE (impulsivity cognitive). In addition to this, the two experimental groups (ADHD and dyslexia) have performed a standardized test to assess reading ability, PROLEC (see ANNEX IV). The tests that have been used to diagnose the participants have been: -

Dyslexia: PROLEC (Battery for the Evaluation of Reading Processes).

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ADHD: WISC IV, ENFEN (Neuropsychological Evaluation of Executive Functions in Children) and Face Test (Difference perception test). In addition to several questionnaires for parents such as the ADHD Questionnaire, and the Abilities and Difficulties Questionnaire (SDQ-Cas).

Process The neurobehavioral tasks have been administered by electronic support, and the rest on paper. The instructions have been read aloud, and the level of understanding has been evidenced. Some have had difficulty understanding the TWO CHOICE double choice task. The presentation of the tasks has been performed by counterbalancing, that is, alternating the order of appearance of the GO-NO / GO task, depending on its duration (500-1000ms). On the other hand, the double choice (TWO CHOICE) has been presented in all cases, between the two response inhibition tasks. (see ANNEX I) The GO-NO / GO test is used to measure the ability of participants to maintain (sustained) attention and control of the response. The participant must issue a response (by pressing the space bar) to one stimulus, while before another they will have to inhibit said response (NOT by pressing the space bar). Stimuli are represented by ghosts of two different colors, green and blue. Specifically

there is a green ghost and three blue ones, arranged at the four corners of the screen. The blue ones will appear at the top (right and left) and at the bottom right (you must respond by pressing the space bar), whereas the green ghost will appear at the bottom left corner (you must not respond). There is a 75% chance for the blue ghost to appear and a 25% chance for the green one to appear. With this task we will be able to evaluate sustained attention, when participants press late on the blue ghost, such as motor impulsivity when they press on the appearance of the green ghost The Two-Choice Task is used to measure the tendency of participants to choose a small immediate reinforcement versus a large and delayed reinforcement. The small and immediate reinforcement (the child must wait 4 seconds to get the reinforcement) will give him 10 points and the large and delayed reinforcement (the child must wait 12 seconds to get the reinforcement) will give him 30. In this way the resistance to delay in reinforcement of participants. The last test carried out is the PROLEC, a standardized test that assesses the reading ability of the participants. This test consists of three parts, in which various abilities that make up the learning of reading are measured. Among them are the knowledge of the name of the letters, the differentiation of words from each other, the reading of them, comprehension of texts of different levels… .etc. Two complementary indices are obtained from these items that will measure reading precision and speed. Prolec was administered to all subjects in the ADHD group and results were collected from subjects who had previously been diagnosed with dyslexia. The performance of these tests was divided into two sessions, depending on the number of tests to be performed. In the case of the control subjects, only one session was needed to carry out the impulsivity and attention tests (Two Choice and Go / NoGo). On the other hand, in the ADHD and dyslexia group it was decided to divide into two different sessions, spaced less than a week apart, always depending on the availability of the subjects. With this we wanted to avoid the possibility that attention was diminishing as the task progressed and that signs of fatigue appeared.

Analysis Due to the characteristics present in this study, a data analysis was carried out with the SPSS statistical program. A non-parametric test has been used, specifically KruskalWallis since it is the most suitable method to compare small populations whose distributions are not normal and which also have different standard deviations between the groups that form it. It is understood that if the significance is less than 0.05 the null hypothesis would be rejected.

RESULTS The results obtained can be seen in the following tables and graphs.

Table 1 Go / NoGo and Two Choice test results

Go / NoGo 500ms hits

X2 = 3.84

Gl = 2

Sig. =

0.46 Commission 500ms

X2 = 2.01

Gl = 2

Sig. =

0.366 Hits 1000ms

X2 = 0.742

Gl = 2

Sig =

0.690 Commission 1000ms X2 = 1,852

Gl = 2

Sig =

Gl = 2

Sig = 0.205

0.396

Two Choice Impulsive

X2 = 3.16

Finally, in the results obtained in the reading assessment test, it is observed that there are no differences between the groups. This graph only shows the data obtained from the experimental groups (ADHD and dyslexia), not being necessary those of the control participants, since the results are compared with the test scales themselves, which are obtained from large and standardized samples. In items 16 and 18, greater difficulties appear in participants with dyslexia than in those with ADHD, these items correspond to the evaluation of the speed of reading pseudowords and the identification of equality or difference between isolated words. On the other hand, the scores decrease in the middle part of the graph, taking into account the difficulties of speed and reading precision in both groups. DISCUSSION The initial hypothesis is that participants diagnosed with ADHD have difficulties with reading, in turn, children with dyslexia would present impulsivity difficulties, but these problems have not been found in these groups. The results found can be explained considering the limited sample evaluated, therefore, it is not representative of the entire population. In addition to this, it is worth noting the possible existence of polluting variables that have not been controlled during the investigation. Among them, the effectiveness of the treatment could be found since all the participating children have been or are currently receiving neuropsychological and speech therapy treatment for said diagnoses, hence some results of the experimental subjects are more positive than in the case of the controls. For future research it would be convenient to modify some aspects of the tests. In the first place, for the Two choice task it would be necessary to offer greater variability of reinforcers, adapting them to the age and preferences of the subjects. In some cases, especially in the older ones, there were no signs of satisfaction when offering them these reinforcers, making the motivation and therefore the execution of the task deficient. It would also be interesting to have a larger sample in such a way that subgroups could be made by age, comparison between sexes, participants with and without medication, subdivide the ADHD group according to the different types in which it can manifest ... etc. .

On the other hand, the spatial, visual and complexity facilitation of the stimulus in the go / nogo task should be adapted to the age of the subject, since in older adults it is easier to identify the stimulus on the screen at a spatial and visual level. . The fact that ghosts of a certain color appear in a certain area of the screen makes it possible for the subject to visualize it more quickly and, therefore, the response has a lower attention load and errors of commission are not easily detected. In the case of the 1000 ms go / nogo task. it is too simple for these groups, so it would be convenient to stay with the 500 ms task and in turn increase the number of trials to better detect attention problems and inhibitory control. Finally, in the double-choice task, the times where the subject has to wait for reinforcements are very short, 4 and 12 seconds are bearable durations for all subjects, enhancing the probability of the appearance of less impulsive behaviors and therefore, decreasing the attentional level....