Archives of Medical Research 32 (2001) 214–220 0188-4409/01 $–see front matter. Copyright © 2001 IMSS. Published by Elsevier Science Inc. PII S0188-4409(01)00273-9 ORIGINAL ARTICLE Event-Related Brain Potentials During a Continuous Performance Test (CPT) Task in Normal Children Andrés Antonio González-Garrido,* Fabiola Rebeca Gómez-Velázquez,** Thalia Fernández-Harmony,*** José Luis Oropeza de Alba* and José Luis Ruiz-Sandoval* *Unidad de Neurociencias, Hospital Civil de Guadalajara, Jalisco, Mexico **Laboratorio de Neurofisiología Clínica, Instituto de Neurociencias, Universidad de Guadalajara, Jalisco, Mexico ***Escuela Nacional de Estudios Profesionales (ENEP), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico Received for publication June 7, 2000; accepted February 7, 2001 (00/091). Background. Continuous Performance Test (CPT) is a commonly used paradigm to as- sess attention disorders that could involve working memory processes. Methods. Event-related potentials (ERPs) during a CPT (X-AX) test were obtained in 16 healthy male students, with ages ranging from 9 to 11 years (X = 10.3). In grouped aver- aged ERPs, an endogenous slow positive potential was recorded in the first task (infre- quent letter detection); maximum was at 460 msec with a slight lateralization tendency to- ward left parietal area. In the second task (target detection with an A as warning signal), an early (maximum at 330 msec) and more acute peak was detected without evidence of any lateralization. Results. Reaction times were significantly shorter for the second task. Electrophysiologic differences between both target conditions showed an early, remarkable, and statistically significant component located at the parietal area at 340 msec. Conclusions. These ERPs findings could be interpreted as correlates with working mem- ory processes in children. © 2001 IMSS. Published by Elsevier Science Inc. Key Words: Children, ERPs, CPT, Working memory. Introduction Developmental failure in school is probably the most fre- quent and least understood problem in infancy. Independent of its nature or clinical features, it represents a large pool of disorders that may affect not only the academic activities of the children but also their social lives and the basis for their futures. In this regard, these children are frequently grouped in clinical practice as attention-deficit hyperactivity disorders or learning disabilities, postulating disturbances on such processes such as intention, working memory (WM), and executive function on their physiopathologic basis. Using neuropsychologic methods, some researchers suggest that encoding processes (particularly WM) are critically identi- fied as deficient for children with these conditions (1), but there are no reliable electrophysiologic parameters to evalu- ate these processes, even for normal children, at early stages of development. Continuous Performance Test (CPT) is a go-no go para- digm commonly used to assess vigilance disorders, but it has been stated that this test may better reflect response readiness than actual vigilance (2). Some CPT versions (see Reference 3 for review) seem to clearly involve WM pro- cesses. Due to its high temporal resolution, event-related poten- tials (ERPs) have been used recently to study some attention and memory functional attributes. The family of the P300 endogenous component is one of the most representative electrophysiologic changes associated with these processes. In general, P300 can be easily obtained during the execu- tion of behavioral tasks in which the subject effects a binary Address reprint requests to: Dr. Andrés Antonio González Garrido, Torre de Especialidades, 8° piso, Servicio de Neurología y Neurocirugía, Hospital Civil de Guadalajara, Hospital 270, Col. El Retiro, 44280 Guad- alajara, Jalisco, México. Tels.: (+52) (3) 613-4016, 817-2119; Fax: (+52) (3) 817-2183; E-mail: aagonza@prodigy.net.mx