ADHD (Attention Deficit Hyperactivity Disorder) is one of the most prevalent (most common) psychological disorders in children and adolescents. It is a disorder that has several groups of symptoms and presentation can vary even among children. Without proper treatment, it can lead to problems in the family, at school, and in relationships with peers, and therefore it is of psychological disorders of childhood onset that receives more attention from psychiatrists and child psychologists, as well as research groups worldwide.
Therefore, here is a compendium of articles that will expand on, with the aim of raising awareness of this disorder.
- ADHD and DSM-V diagnostic criteria
- ADHD and emotional memory
- Cerebral cortex development in ADHD
- Restless Leg Syndrome and ADHD
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Title: The Neuroscience of Freedom and Creativity: Our predictive brain.
Author: Joaquín M. Fuster
Publisher: Cambridge University Press, 2013
Joaquin M. Fuster (born in Barcelona in 1930), is one of the most important neuroscientist. His research has focused in the the understanding of the neural structures underlying cognition and behavior, and is the author of several books and hundreds of papers.
Decide is a brain ability to choose between alternatives. For Fuster the hability to take decisions rely on the integrity of the cerebral cortex and the interaction with the environment. One of the main questions is how the brain produces the new from the old. How we can explain creativity. Is clear that the difference between humans and animals is on the prefrontal regions. Prefrontal regions are more than a single director of the orchestra: they play a central role in goal-directed actions and inhibitory control.
Another actor on this play is language and memory. Fuster was the first describing “memory cells” in the primate brain. Our capacity to predict the future rely on our capacity to put ideas on the correct order to create a logical history.
We think that this is a fascinating book you should read!!
“Professor Fuster’s insights regarding brain function are always priceless. Now, based on his unprecedent word on understanding the most complex portion of the brain -the frontal lobes-he has put forth a cogent view of the biological basis underlying the notion of “free will”. Like his other books, this one is a pleasure to read and will be throroughly enjoyed by anyone interested in the relationship between the brain and behavior”
Mark D’Eposito, MD, Professor of Neuroscience and Psychology, and Director of the Henry H. Wheeler, Jr. Brain Imaging Center. University of California, Berkeley.
If you want to contact a psychologist or receive more information, please fill out the contact form.
Tests of verbal ability have been used by many years (Thurstone, 1938; Jones-Gotman & Milner, 1977). On this test, subject is presented with a category (e.g.words beginning with ‘M’, or names of animals) and is asked to produce as many examples of these as possible within a given time of period.
Verbal fluency has demonstrated to be impaired in dysphasic patients, but also in patients with lesions on the left (Benton, 1968) and right frontal lobe (Pendleton et al., 1982).
Naming performance has been used to test disabilities in the population. Longitudinal studies show that naming performance changes across the life span, declining specially in oldest subjects (Au et al., 1995), which reflects a breakdown in perceptual and semantic processes.
One of the most usual tests for examining this ability is the Boston Naming Test (BNT) and the Parietal Lobe Battery. The BNT enjoys and reach database in different countries and different pathologies, as well as normative data across age range.
One important point in fluency tasks is the category of the word. When we test people with mild dementia they perform better naming animals than naming words with specified letter on the beginning, which means that category structure influences retrieval processes (Rosen, 1980).
To test naming fluency is important to control the age of the participants. An effect of aging is observed specially after forty years age and a decline of the verbal ability after the sixties (Rodriguez-Aranda & Martinussen, 2006).
Naming ability is mediated by different strategies. When we compare two measures of verbal fluency, initial letter versus excluded letter (words produced not containing a designated letter), we found that both fluency tasks rely on verbal ability and articulation speed. Excluded letter fluency performance rely more on speak and executive function (Hughes & Bryan, 2002).
Verbal fluency is also a measure of verbal intelligence. In the study of Miller (Miller, 1984), they compared verbal fluency in two groups of patients, one with focal lesions and another with dementia. They use regression to predict fluency from an index of verbal intelligence. When verbal intelligence was taking into account using regression equation, they found that impaired fluency is a specific phenomenon following frontal lesions and not a consequence of intellectual deterioration in dementia.
The most used test of verbal fluency is the FAS. It consists on a task in which the participant has one minute to generate words beginning with each letter ‘F’, ‘A’, ‘S’ (phonemic fluency) and animal names (semantic fluency). The FAS has been shown to be more sensitive to the effects of education than age: the number of words increases as the level of education increase, while remains constant until age 60 (Tombaugh, Kozak, & Rees, 1999). Other studies have shown that level of education but not age or gender significantly influence verbal fluency (Mathuranath et al., 2003).
Neural correlates of fluency task
Letter and category fluency tasks are associated with frontal and temporal lobe. Letter fluency presents greater activation in left pre-central and inferior frontal gyrus, while category fluency presents greater activation in left middle frontal gyrus and left fusiform gyrus.
Location and cortical activity can be modulated by varying verbal fluency task demands. Right hemisphere activation is greater during automatic speech in response to over-learned category while left hemisphere activation is greater in letter fluency tasks when demands are on executive function (Birn et al., 2010). Furthermore, the uncinate fasciculus shows positive correlation with Boston Naming Test (Catani et al., 2013).
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Au, R., Joung, P., Nicholas, M., Obler, L. K., Kass, R., & Albert, M. L. (1995). Naming ability across the adult life span. Aging, Neuropsychology, and Cognition, 2(4), 300-311. doi:10.1080/13825589508256605
Benton, A. L. (1968). Differential behavioral effects in frontal lobe disease. Neuropsychologia, 6, 5360.
Birn, R. M., Kenworthy, L., Case, L., Caravella, R., Jones, T. B., Bandettini, P. A., & Martin, A. (2010). Neural systems supporting lexical search guided by letter and semantic category cues: A self-paced overt response fMRI study of verbal fluency. NeuroImage, 49(1), 1099-1107. doi:10.1016/j.neuroimage.2009.07.036
Catani, M., Mesulam, M. M., Jakobsen, E., Malik, F., Martersteck, A., Wieneke, C.,… Rogalski, E. (2013). A novel frontal pathway underlies verbal fluency in primary progressive aphasia. Brain, 136(8), 2619-2628. doi:10.1093/brain/awt163
Hughes, D. L., & Bryan, J. (2002). Adult Age Differences in Strategy Use During Verbal Fluency Performance. Journal of Clinical and Experimental Neuropsychology, 24(5), 642-654. doi:10.1076/jcen.24.5.642.1002
Jones-Gotman, M. & Milner, B. (1977). Design fluency: The invention of nonsense drawings after focal cortical lesions. Neuropsychologia, 15, 653-674.
Mathuranath, P. S., George, A., Cherian, P. J., Alexander, A., Sarma, S. G., & Sarma, P. S. (2003). Effects of Age, Education and Gender on Verbal Fluency. Journal of Clinical and Experimental Neuropsychology, 25(8), 1057-1064. doi:10.1076/jcen.25.8.1057.16736
Miller, E. (1984). Verbal fluency as a function of a measure of verbal intelligence and in relation to different types of cerebral pathology. British Journal of Clinical Psychology, 23(1), 53–57. doi:10.1111/j.2044-8260.1984.tb00626.x
Pendleton, M. G., Heaton. R. K.. Lehman, R. A. W. & Hulihan, D. (1982). Diagnostic utility of the Thurstone word fluency test in neuropsychological evaluation. Journal of Clinical Neuropsychology, 4, 307-3 17.
Rodriguez-Aranda, C., & Martinussen, M. (2006). Age-Related Differences in Performance of Phonemic Verbal Fluency Measured by Controlled Oral Word Association Task (COWAT): A Meta-Analytic Study. Developmental Neuropsychology, 30(2), 697-717. doi:10.1207/s15326942dn3002_3
Rosen, W. G. (1980). Verbal fluency in aging and dementia. Journal of Clinical Neuropsychology, 2(2), 135-146. doi:10.1080/01688638008403788
Thurstone. L. L. (1938). Primary Mental Abilities. Chicago: Chicago University Press
Tombaugh, T. N., Kozak, J., & Rees, L. (1999). Normative Data Stratified by Age and Education for Two Measures of Verbal Fluency: FAS and Animal Naming. Archives of Clinical Neuropsychology, 14(2), 167-177. doi:10.1016/S0887-6177(97)00095-4