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Biomedical subjects

M L Cepeda

Publications and source records attributed to M L Cepeda.

6 recordsLinked to original sources
PubMed2001

Methylphenidate effects on task-switching performance in attention-deficit/hyperactivity disorder.

OBJECTIVE: To examine the specificity of methylphenidate effects on the processes that support the ability to rapidly and accurately coordinate the performance of multiple tasks in children with attention-deficit hyperactivity disorder (ADHD). METHOD: Twenty children with ADHD performed the task-switching paradigm while on and off medication. The paradigm involves switching between two different tasks, discriminating the value of a number presented on a computer screen and deciding how many numbers were present on the screen. The children also performed single-task control conditions. RESULTS: Analyses of variance indicated the medication selectively enhanced the children's ability to rapidly and accurately switch between tasks and to focus attention on the currently relevant response set. CONCLUSIONS: This study helps to elucidate the nature of methylphenidate effects on the cognitive processes which support the ability to coordinate the performance of multiple tasks. Medication appears to selectively enhance inhibitory processes which support task-switching.

Adolescent↗
PubMed2000

Task switching and attention deficit hyperactivity disorder.

The main goal of the present set of studies was to examine the efficiency of executive control processes and, more specifically, the control processes involved in task set inhibition and preparation to perform a new task in attention deficit hyperactivity disorder (ADHD) and non-ADHD children. This was accomplished by having ADHD children, both on and off medication, and non-ADHD children perform the task-switching paradigm, which involves the performance of two simple tasks. In nonswitch trials, an individual task is performed repeatedly for a number of trials. In switch trials, subjects must rapidly and accurately switch from one task to the other, either in a predictable or unpredictable sequence. Switch costs are calculated by subtracting performance on the nonswitch trials from performance on the switch trials. These costs are assumed to reflect the executive control processes required for the coordination of multiple tasks. ADHD children showed substantially larger switch costs than non-ADHD children. However, when on medication, the ADHD children's switch performance was equivalent to control children. In addition, medication was observed to improve the ADHD children's ability to inhibit inappropriate responses. These data are discussed in terms of models of ADHD and cognition.

Attention↗
PubMed2000

Physical growth, sexual maturation, body image and sickle cell disease.

PURPOSE: This study assessed delays in physical growth and sexual maturation, self-esteem and body image in youth with homozygous sickle hemoglobin disease (HgbSS). METHOD: A consecutive sample of 30 subjects age 8 through 19 with homozygous sickle cell disease (hemoglobin SS) and a similar number of control subjects matched for age, race, gender and socioeconomic status and free of chronic illness were examined for height, weight and Tanner staging of sexual development. Subjects also completed the Body Cathexis Scale and Piers-Harris Self-Concept Scale. Assessments were with paired samples t-tests. RESULTS: The subjects with sickle cell disease had significantly lower weights and were shorter than matched control subjects. Sexual development (physical) was also delayed in the sickle cell subjects. The study failed to find significant differences for either body image or self-esteem. CONCLUSIONS: The latency age and adolescent subjects with sickle cell disease had significant delays in physical (height, weight, secondary sexual characteristics) maturation. The study failed to find significant differences in either self-esteem or body image between the two groups. Theoretical constructs from the literature were presented which questioned the belief that these expected delays in physical growth and sexual maturation have an adverse effect upon self-esteem and body image.

Adolescent↗
PubMed1997

Mental disorders in children and adolescents with sickle cell disease.

This study compares the rate of mental disorders in children and adolescents with sickle cell disease with the rate in a corresponding control population. Using the clinical interview, a diagnosis based on DSM-III-R criteria for the presence of 13 mental disorders common to childhood was considered in a sequential sample of 39 subjects with sickle cell disease and a convenience sample of 26 same-race control subjects. Thirty-one percent of the sickle cell group and 42% of the control group screened positive for one or more of the selected mental disorders. The difference was not significant. When subgroups of mental disorders were considered (anxiety disorders, depressive disorders, disruptive behavior disorders, psychotic disorders, and other selected disorders), the differences were still not significant. This study suggests that children and adolescents with sickle cell disease do not have a greater risk for clinically significant mental disorders than same-race outpatient clinic controls. This study supports other reports in the medical literature that suggest that children attending outpatient medical clinics are at a higher risk for mental disorder than is seen in epidemiologic studies of nonmedical populations.

Adolescent↗
PubMed1981

Sudden infant death syndrome: helping bereaved parents talk with children.

Management of sudden infant death syndrome must address the psychologic effect upon all family members. A child's level of cognitive development will determine the way in which the death is understood. There are guidelines for helping parents talk with children about what happened in a way appropriate to their own age.

Adolescent↗