RESUMEN
Attention deficit disorder (ADD) refers to a neurobehavioral condition commonly initiated in childhood. Its clinical diagnosis involves poor attention, distractibility, difficulties to inhibit motor behaviors and cognitive impulsivity. It is suggested that ADD is classified in two general types correlated with different neurocognitive qualities. One is manifested in executive frontal dysfunctions (ADD). In the other type dominates hyperactivity/ impulsivity (ADHD) and it is associated with deficiencies in working memory and alterations in the dorsolateral prefrontal cortex. Results obtained by using electroencephalography, event-related potential paradigms and voxel brain morphometry suggest anomalies in the brain structure and function correlated with ADD, particularly in the frontal, parietal and temporal cortices, in addition to regions involved in the fronto-estriatal connections. On the other hand, functional magnetic resonance imaging (fMRI) constitutes a technique to obtain brain images which can be interpreted as regions and networks of neural activity elicited during the performance of a cognitive process. Based on the information that the ADD patients are susceptible to cognitive interferences, some researches have applied the classical and the counting versions of the Stroop task paradigms in fMRI. In comparison with control subjects, adult patients show alack of neural activation in the anterior cingulated cortex. Nevertheless, results in children are more controversial and attribute neurobiological and social factors in the ADD etiology. The anterior cingulated cortex and prefrontal region of the human brain conform the execution system of attention and their function is essential for emotional processes. The neurocognitive relation between attention and emotion involves the influence of the affective system in the alert and execution systems of attention through reciprocal connections between limbic and frontal regions, which permit a mnemonic and affective valuation of the attended environment. Understanding the relations between attention and emotion is essential in basic and clinical approaches, due to the co-morbidity of ADD with some emotional disorders, such as the oppositional defiant disorder, anxiety and impulsive aggression, the last one elicited by uncontrolled experiences of anger. In this sense, some studies describe that the metabolic brain activity correlated with the experience of anger is manifested in the frontal, anterior cingulated and insular cortices and the temporal pole. Clinical situations require individualized decisions on the immediate and emergent treatment of one case. Furthermore, when the clinical case refers to a behavioral disorder probably related with neurobiological dysfunctions, a comparison of test with control subjects is necessary. In this sense, the present work constitutes an fMRI study designed to evaluate neurological functional alterations in a child patient diagnosed with ADHD, with persistent severe impulsive aggression behaviors that required a swift evaluation to enhance the diagnosis and treatment proposed by other clinical techniques. Besides the patient, three infant participants were evaluated. One of them was diagnosed with ADD but did not manifest aggressive or impulsive behaviors and was not under any pharmacological treatment. The other two healthy children had no neurological and psychiatric disorders history. All the participants presented similar intellectual coefficient and performed the same cognitive and emotional tests. In the case of the patient, test were applied in two conditions: under the proposed pharmacological treatment and without medication. The attention test consisted in a version of the counting Stroop task in Spanish language, presented in a block design through the E-Prime software. Subjects practiced the task in a personal computer before the functional image acquisition and were trained to answer by using a bottom response system that will be used in the scanner. For the emotional-anger paradigm, children were interviewed about scenes and situations of their personal experience which elicited anger and calm. Situations were ordered and planned in a block design to be executed in the magnetic resonance instrument. During the functional images acquisition children listened to the situations conducted by imaginery techniques. Functional images were acquired in a 1.5 T G.E. instrument in the Magnetic Resonance Unit of the Hospital Ángeles Metropolitano in Mexico City. Data were analyzed by using the SPM 5 software applying a contrast using FWE with p < 0.05. Brain coordinates obtained in SPM 5 were converted to the Talairach Deamond system in order to obtain the Brodmann areas related to those coordinates. During the performance of the counting Stroop task, the patient with ADHD under medication manifested activation in frontal areas, but not during the medication suspension trial. Frontal activity identified in this patient in the treatment trial was similar to that identified in the unaggressive ADD patient. In both cases, ADHD without medication and ADD, a lack of activity was identified in the anterior cingulate cortex (ACC). Nevertheless, activation in ACC, in parietal and temporal regions was present in the aggressive patient under treatment but not in the suspension condition. These results may suggest that an inadequate attention process distort the environment stimuli, which is necessary for the subject's correct affective evaluation of the situation. During the experience of anger, the patient under treatment manifested activity in the parahippocampal region, as well as in the anterior and posterior cingulate cortices. Results discussed in this work agree with those previously reported and offer cues to complement the diagnosis and treatment of ADD/ADHD and their relations with emotional disorders. Particularly, the design used here could be used for the analysis and evaluation of some pharmacological and behavioral treatments clinically applied in ADD. In addition, it helps to understand the participation of multipotential brain regions and neural networks involved in several cognitive processes, such as attention, working memory and emotion. Finally, we proposed some ideas to interpret these results using fMRI and ADD: 1. It is necessary a consensual and standard integration of neuropsychological tests which identify different cognitive qualities of ADD. 2. The selection of children samples to study the neurobiology of ADD must include several variables associated with its etiology, such as parental relations, social and scholar environments. 3. Experimental paradigms could be designed to be performed using different neuroimaging techniques, such as fMRI or event-related potential. Thus, the results of the same test can be used to complement different approaches. 4. Results obtained by fMRI must not be understood in a phrenologycal and deterministic approach, but as brain region activations indicating dynamic neural networks.
El trastorno por déficit de atención (TDA) es un padecimiento neuroconductual iniciado en la infancia, cuyos criterios diagnósticos incluyen dificultades en la inhibición motora e impulsividad conductual. Tomando en cuenta la evidencia de que los pacientes con TDA son susceptibles a la interferencia cognitiva, la técnica de resonancia magnética funcional ha permitido la obtención de imágenes cerebrales que pueden interpretarse como redes de actividad neuronal, las cuales fueron desencadenadas durante la realización de la tarea Stroop o de interferencia. Algunos hallazgos en individuos sanos sugieren actividad predominante en la corteza anterior del cíngulo durante el proceso de atención selectiva requerido en la ejecución de esta tarea, en tanto que pacientes diagnosticados con TDA muestran ausencia de tal actividad. Diversos autores han señalado la relación neurocognitiva entre la atención y la emoción, a partir de la interacción entre estructuras límbicas y regiones frontales del cerebro. En el caso del TDA, esta relación es relevante debido a su comorbilidad con trastornos de tipo emocional, en particular en el caso de la agresión impulsiva. Ésta es desencadenada por estados incontrolables de ira, cuya experiencia inducida se ha correlacionado con la actividad cerebral de la región frontal, del polo temporal, de la corteza anterior del cíngulo y de la ínsula. Ahora bien, en el ámbito clínico es recurrente la necesidad de una evaluación individualizada y la decisión del tratamiento inmediato y urgente de un caso. El presente trabajo muestra un diseño utilizado en la valoración de alteraciones neurológicas funcionales en un paciente infantil diagnosticado con TDA, cuyos repetidos episodios de comportamientos agresivos requerían una evaluación pronta que complementara el diagnóstico y tratamiento provenientes de otras herramientas clínicas. Con un equipo de resonancia magnética de 1.5 T se registró la actividad cerebral del paciente durante la ejecución de una versión en español de la tarea Stroop por conteo y de un paradigma emocional que consistió en la evocación dirigida de escenas que desencadenaran ira en el sujeto. La obtención de imágenes funcionales se real izó tanto bajo el efecto del tratamiento farmacológico que seguía el paciente, como bajo la suspensión del mismo. Después, se comparó la actividad cerebral del paciente con otro caso infantil diagnosticado con TDA, pero sin presencia de comportamientos agresivos. La actividad cerebral de ambos casos de TDA se comparó con la registrada en dos niños con edad y coeficiente intelectual homogéneos, carentes de historial neurológico y psiquiátrico. Ninguno de los participantes manifestó alteraciones estructurales cerebrales. Los resultados funcionales durante la ejecución Stroop identificaron menor actividad en la corteza anterior del cíngulo en los dos casos diagnosticados con TDA. Durante la experiencia del estado de ira y en comparación con los otros participantes, el paciente bajo efecto del tratamiento manifestó actividad en la región parahipocampal, así como en las cortezas anterior y posterior del cíngulo. Los resultados coinciden con hallazgos reportados sobre la neurobiología del TDA y de la experiencia de ira. Además, otorgan herramientas para el diagnóstico y tratamiento de trastornos de la atención y su relación con trastornos emocionales. Este tipo de diseños contribuye al análisis y observación del efecto de algunos tratamientos, tanto farmacológicos como conductuales, aplicados en la clínica del TDA. En este caso, el tratamiento aplicado al paciente parece actuar a nivel del proceso de atención, pero no en el ámbito del control de la ira. También, proporciona pautas para comprender la participación de regiones cerebrales multipotenciales y las redes neuronales que involucran diferentes procesos cognitivos, como la emoción y la atención.
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Summary: Psychometric tests are effective to measure psychological characteristics, including personality, motivation, intellectual abilities and psychopathological traits. The Psychopathological diagnostic could be supported on some of these psychometric tests, which ideally should be of simple and fast application. Two of the most common tests are the Symptom Check List 90 (SCL 90) and the Temperament and Character Inventory (TCI). SCL 90, developed by Derogatis, Lipman and Covi in 1973, is a 90-item self-report inventory that assesses the level of distress experienced by the subject. Items are comprised in nine dimensions: somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation and psychoticism. The SCL 90 has been translated into several languages and has been successfully applied in Argentina and Spain. In Mexico, Cruz-Fuentes et al. and Lara et al. considered that this test can be well used as a psychometric instrument in clinical research. Due to its efficiency and brief time to response (12-15 min.), the SCL 90 has been administered to support psicopathological diagnostics and to complement the research of epilepsy, social-behavior disorders, physical disorders, pharmacological treatment and for the comparison of psychological features in crosscultural studies. The TCI is a self-applied test that describes personality according to Clonninger's psychobiological model. In this model temperament is described as highly heritable and stable during lifetime, and it is divided in four dimensions: novelty seeking, harm avoidance, reward dependence, and persistence. Character is described as being determined by the individual's experience and is modifiable during life-time. It is divided in to three dimensions self-directedness, cooperativeness and self-transcendence. The TCI has been used to correlate personality features to genetics variability and to complement clinical studies that involves psychiatric disorder, such as, obsessive-compulsive disorder, anxiety and depression. This test has been translated and administered in American, French, German, Korean and Spanish populations. In Mexico, Sánchez-Carmona, Páez, López and Nicolini considered that the TCI constitute a psychometric test that can be used to develop the clinical research in Mexican populations. In recent years, research and clinical evaluation in several countries, such as United States and France, have successfully designed and applied computerized versions of the SCL 90 and TCI. These versions provide a quicker rate of testing and a permanent storage of data. In this work, we analyze the validity of viability to apply a computerized version of the SCL 90 and the TCI in Spanish. This computerized version was previously developed at the Instituto de Neurobiología de la Universidad Nacional Autónoma de México. This version involves a computer program in Java language, which give an easy access to the users and is compatible with any computational environment. The sequence to answer the computerized version involves five steps: a) accessing the main control program, b) writing the user's identification data, c) answering SCL 90 test, d) answering TCI test, e) forming the database. The formats employed in these computerized versions are similar to those in paper-and-pencil original versions. Its rate sequences were formed according to the SCL 90 and the TCI's application manuals. The information stored in the computerized program of SCL 90 and TCI, can be imported to the Excel program. By this way, it is possible to import the results to any database in any statistical analysis program. Method. Computerized versions of the SCL 90 and the TCI were administered in different sessions for two 30 participants sample (15 men, 15 women, mean= 30, S.D. 8 years old). Paper-and-pencil versions of both tests were administered, in two different sessions, to a sample within the same sex and age range. Samples were formed by students of the Universidad Nacional Autónoma de México and the Universidad Autónoma de Querétaro. Statistical analysis involved a Student's t test to identify differences between data obtained in computerized and paper-and-pencil versions. Graphic comparisons were made to show the similarity of the results obtained in computerized versions and those of reference samples published in Mexico by Cruz-Fuentes et al. (2005), Lara et al. (2005) and Sánchez de Carmona et al. (1996). Results. The average time invested in both computerized and paper-pencil version for SCL 90 was 15 min. and 25 min. for TCI. No significant differences were founded in the items at any dimensions of the SCL 90 and TCI between the computerized and the paper-and-pencil versions. Graphic distribution of data in SCL 90 and central tendencies measures in the TCI, were similar in both computerized and pa-per-and-pencils reference samples versions. Discussion. The average of time invested to response the computerized versions of both test was similar to that reported in paper-and-pencil versions: 15 min. for SCL 90 and 35 min. for TCI. So, then the time required to administer computerized versions is not higher than required in paper-and pencil versions. The results sustain that the computerized administration of the SCL 90 and TCI in Spanish do not differs from the original paper-and-pencils Spanish versions in any of the test's dimensions. Besides, there are equivalent results in computerized versions and results showed in the reference samples. This allows us to consider that computerized versions of SCL 90 and TCI evaluate the features what were designed for. Even the complete evaluation through SCL 90 and TCI requires a final individualized interpretation, the automatically rating trough computerized version, could decrease human mistakes during the account of answers and items. It allows the elaboration of permanent and extensive database that can be easily used to compare epidemiological and longitudinal behavioral research. Furthermore it could complement neurobiological studies, for example, to evaluate population in neuroimaging studies such functional magnetic resonance studies. We conclude that computerized versions of the Symptom Check List 90 and Temperament and Character Inventory show a good validity to be useful as a psychometric tool.
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Summary This work presents a critical review of the historical, theoretical, and neurobiological bases of the theory of moral emotions. Neuroimaging methods and protocols used to study the neural correlates of moral emotions and the analysis of the brain functions involved in their processing, permit the formulation of hypotheses that attempt to understand some emotional and cognitive processes related to moral emotions. One such hypothesis refers to a neuro-matrix involving sensory systems, brainstemmediated physiological reactions and frontal brain regions processing the interaction between moral and emotional stimuli. Cross-cultural research on human facial expression has identified universal patterns to express basic emotions such as fear, anger, or happiness. Nevertheless, the experience of some emotions and their facial expressions are regulated by social and cultural mechanisms. This type of regulation is observed in moral emotions since they are linked to the interests or welfare either of society as a whole, or of persons other than the judge or agent. Two typical features that identify moral emotions are their typical elicitors and tendencies towards specific actions. The release of a moral emotion is the perception of implicit and explicit violations of social norms and stereotypes included in personal codes, attitudes, and beliefs. In turn, the actions ensuing from moral emotions are communal or prosocial, because they promote a benefit in others and/or in the social order. Although there is not a definitive taxonomy of moral emotions, four families of prosocial feelings are suggested: a) other-condemning emotions (contempt, anger, disgust); b) self-conscious emotions (shame, embarrassment, guilt); c) other-suffering emotions (compassion); d) other-praising emotions (gratitude, awe, elevation). Such emotions are relevant to the concept of morality because this is a complex representation that includes models of prohibited actions, notions of good and bad, concepts of fairness, ideals of justice, or justifications of punitive actions. Moreover, the cognitive processes and behaviors involved in moral emotions are related to the theory of mind that refers the ability to represent the mental and emotional states of others, such as their thoughts, desires, beliefs, intentions, and knowledge. The neurobiological substrate of this capacity involves cerebral regions related to the experience of basic emotions, such as the amygdala and the cingulated cortex, and regions related to complex cognition and emotional-social contexts, such as the prefrontal cortex and the superior temporal sulcus. Neurobiological approaches to moral emotions have become relevant to study psychopathologies linked to antisocial behaviors, particularly the psychopathic or Antisocial Personality Disorder. Psychopaths show decreased emotional and physiological reactions to emotional stimuli and deficiencies to identify emotional expressions. However, they do not fail to represent or to infer others mental states or theory of mind. Therefore, the psychopathic disorder is not only linked to distortions in interpreting socially-learned moral values, but also to alterations of cognitive processes required to link the affective system to moral values. This assumption is supported by brain-imaging studies demonstrating the involvement of areas associated to the processing of complex social stimulus and language, such as prefrontal cortex, orbitofrontal cortex, polar frontal cortex, and anterior temporal lobe in psychopathic patients. The affected areas also include regions such as the amygdala, ventromedial hypothalamus, thalamus, and caudate nucleus involved in the experience or expression of emotions. Scientific publications directly referring to the neurobiological research of moral emotions and the evaluation of moral judgments occupy a period between 2001 and 2005. The neurobiology of moral emotions has evolved rapidly by the use neuro-imaging techniques such as Functional Magnetic Resonance Imaging (fMRI) and Positron Emission Tomography (PET). Brain images related to moral emotions are obtained by the use of moral stimuli in three types of situations: (a) while subjects resolve cognitive tasks, for example, reading moral emotional statements, (b) during passive or instructed viewing of affective pictures, or (c) during the resolution of moral dilemmas. The brain areas that become significantly active during these tasks provide a neurobiological interpretation of the mental operations involved in moral emotions. Thus, the medial frontal gyrus is activated during the elaborate personal and impersonal moral judgments produced by viewing moral pictures, attributing intentionality of movement, processing of facial expressions, and during the attribution of mental states (theory of mind). The posterior cingulated, restrosplenial, and precuneus cortex are associated with the elaboration of moral judgments elicited by viewing moral pictures and theory of mind. The superior temporal sulcus and the parietal lobe are related with moral judgments while viewing moral and emotional pictures and films, and attributing intentional movements. The superior temporal sulcus is also associated with the processing of social contexts. Orbitofronal and ventromedial frontal cortex is associated with the processing of simple moral judgments while viewing moral pictures, the evaluation of emotionally-charged social events, during empathy and attribution. The temporal pole is also associated with theory of mind, the elaboration of simple moral judgments and with the recalling of emotional situations. The amygdala is activated during the processing of moral pictures and social events based on facial expressions. Other empirical investigations involving a moral interpretation of data such as studies of general emotions, empathy, theory of mind, neurological disorders, and antisocial behavior, are also relevant to understand the brain activation patterns associated to cognitive and emotional social functions. Working models of psychopathologies that manifest antisocial behaviors are also required to interpret neuroimaging data. Meta-analyses of human behavior and proto-moral behavior in non-human species related to the elaboration of moral judgments and emotions are also relevant for the same purpose. Finally, moral emotion research requires the elaboration of accurate protocols based on psychological approaches directed to elicit particular moral emotions which enable the definition and neural substrates of its specific qualities.
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El odontólogo forense juega un papel fundamental como testigo experto antes los juzgados civiles cuando se considera la evidencia dental. Se reporta un caso donde el cadáver de una mujer de 28 años fue sepultado en mayo de 1990, víctima aparente de un arrollamiento por vehículo automotor. La necropsia reveló fracturas complejas con deformidad de los huesos de cráneo y cara, producidas por objeto contundente. Posteriormente, la madre de la occisa consignó ante las autoridades una pieza dental y un fragmento de esmalte dentario, que habían sido encontrados en un sitio diferente al descrito como lugar del accidente. Este hallazgo, aunado a otras experticias policiales, planteó la posibilidad de que se estuviera en presencia de un homicidio, siendo el esposo de la víctima el principal sospechoso. Iniciadas las investigaciones, se ordenó la exhumación. Durante la autopsia bucal, pudo comprobarse que la evidencia dental aportada correspondía a la dentadura de la occisa, complementando así la investigación policial que condujo al esclerecimiento de un crimen, a la identificación del autor material y al dictado de una sentencia firme. Constituyéndose de esta manera, la experticia odontológica en un factor determinante en el proceso penal