Anneliese Dörr

Efectos del consumo de marihuana en escolares sobre funciones cerebrales demostrados mediante pruebas neuropsicológicas e imágenes de neuro-SPECT

SUMMARY Comparative study based on 565 adolescent school children coming from four schools in the metropolitan area of Santiago, Chile. All were interviewed in order to select a sample that was stratified for sex, class and condition of consumer or non-consumer. The variables of intellectual coefficient and socioeconomical level were maintained constant. With this selection we conformed two groups: 40 consumers exclusively of marihuana and 40 non-consumers. We compared the results obtained in both groups in the neuropsychological tests while the neuroSPECT studies of consumers were compared against a normal database for the same age group. The adolescent consumers of marihuana demonstrate less cognitive capacity related to the process of learning such as attention, concentration, ranking, viso-spatial integration, immediate retention and visual memory. The differences between both groups are statistically significant. The findings of neuroSPECT demonstrate subgenual hypoperfusion bilaterally, more marked on the left side, in area 25 of Brodmann. This area controls mood. There is also frontal bilateral hypoperfusion (area 10 and area 32 of Brodmann). Area 32 is pre-anterior cingulate gyrus. Also hypoperfusion of the anterior cingulate gyrus (area 24 of Brodmann) and hypoperfusion of area 36 of Brodmann that projects over the hippocampus. Students that were consumers exclusively of marihuana demonstrate coincident abnormal findings of neuroimages and neuropsychological tests in areas of the brain related with learning and also significant differences between consumers with non-consumers in the neuropsychological tests.

Género y Autoconcepto: Un Análisis Comparativo de las Diferencias por Sexo en una Muestra de Niños de Educación General Básica (EGB) (1992-2003)

El interes de este estudio es determinar los cambios en el autoconcepto de ninos y ninas producidos en un periodo de 10 anos, en relacion a los roles de genero culturalmente asignados. Para ello se analizan las diferencias en los niveles de autovaloracion de ninos y ninas de 3o, 4o, 5o y 6o ano de EGB, del area Metropolitana de Santiago de Chile, de niveles socioeconomicos alto, medio y bajo, observadas entre los anos 1992 y 2003. En ambas evaluaciones se utiliza la misma prueba de medicion y las mismas variables de estratificacion de la muestra. Los resultados permiten concluir que se produjo una inversion de los resultados obtenidos en 1992, en el sentido de que hoy las ninas superan a los varones en sus niveles generales de autoestima, aventajandolos tambien en varias de las subescalas consideradas por separado. Adicionalmente, se discute la posibilidad de que los cambios socioculturales producidos en el periodo, hayan tenido impacto en la autopercepcion de rol de genero de ninos y ninas.

Marijuana, Experience of Temporality, and School Performance from a Qualitative and Quantitative Approach

The study aims at knowing how low marijuana doses affect cognitive ability in postprimary students. The objective of the quantitative research was to analyze the results of neuropsychological and Neuro-SPECT tests comparing schoolchildren who smoke marijuana with those who do not, with emphasis on the effects on cognitive functions involved in learning. We wanted to assess the effects on the cerebral function of marijuana-only users. It was a comparative study based on the total sample of 565 school adolescents coming from four schools in the metropolitan area of Santiago, Chile. All were interviewed in order to select a sample that was stratified by sex, class and consumption of marijuana. The following two groups were made: 40 marijuana-only users and 40 nonusers. We took as a reference a study performed by the authors in 2007, in which the correlation between the consumption of marijuana and effects on cognitive functions involved in scholastic learning were established. The findings show statistically significant differences in the following areas: subgenual bilateral hypoperfusion, more marked on the left side (Brodmann area 25), frontal bilateral hypoperfusion (Brodmann’s areas 10 and 32), front cingulate gyrushypoperfusion (Brodmann area 24) and hypoperfusion of Brodmann area 36 that projects to the hippocampus. The results are highly matched with the neuropsychological tests given in the sense that, like with the 2007 study, significant differences are found between the two groups as far as the tests measuring cognitive functions are concerned. A qualitative research: we wanted to investigate the experience of time in high school students who regularly smoke marijuana, given that this substance has effects on the prefrontal lobe and on the hippocampus, brain areas related to the ability to plan tasks (executive function) and to memory. Moreover, adolescence is a delicate stage in regard to planning of the future. At the same time, the idea was to understand and make use of the concepts of temporariness and anticipation, which as a general rule will be handled only by