Biomedical subjects

Michael Posner

Publications and source records attributed to Michael Posner.

4 recordsLinked to original sources

PubMed2005

Defining the mechanisms of borderline personality disorder.

Understanding the biological connections to mental processes was one of the original goals of psychoanalysis, and the development of cognitive and affective neuroscience and its methods might contribute to actualizing this goal. Personality disorders provide an opportunity to examine the complex mental structures of individuals experiencing extreme difficulties in interacting with their social environment. We provide initial information on a collaboration exploring an approach to one of the most serious personality disorders, borderline personality disorder, based upon the study of normal attention, individual differences in temperament, self definition and attachment organization, with the potential to illuminate the psychology and psychobiology of the disorder and to contribute to psychotherapeutic intervention. This developing model of borderline personality disorder can relate the symptoms to more enduring temperamental aspects of the patients. The goal is to understand the development of neural networks that underlie the abnormalities of adults, and eventually work out the interaction between temperament, genes, and experience that produce the disorder, and potentially inform intervention.

Borderline Personality Disorder↗

PubMed2004

Human attentional networks.

In recent years it has been possible to treat attention as an organ system with its own anatomy, circuitry and set of functions. We view attention in terms of three interrelated neural networks in the human brain. These networks carry out the specific functions of developing and maintaining the alert state, orienting to sensory input, and executive control. Damage to these networks or their chemical neuromodulators can produce specific neurological and psychiatric deficits. We have conducted behavioral, developmental, and patient studies using functional magnetic resonance imaging (fMRI), event related potentials (ERP), genetics, and computational modeling to investigate the anatomy, circuitry, pathology, and development of attentional networks. The Attentional Network Test (ANT) is developed to measure the efficiency of each of the attention networks. The ANT can also serve as an endophenotype for genetic studies on attentional networks. This paper reviews our work with the ANT in studies of normal performance and various forms of psychopathology.

Arousal↗

PubMed2002

Children who witness violence, and parent report of children's behavior.

OBJECTIVES: To examine how much distress children report in response to violence that they have witnessed and how this is associated with parental reports of children's behavior. METHODS: As part of a study of in utero exposure to cocaine, children completed the Levonn interview for assessing children's symptoms of distress in response to witnessing violence. The children's caregivers completed the Exposure to Violence Interview (EVI), a caretaker-report measure of the child's exposure to violent events during the last 12 months. The EVI was analyzed as a 3-level variable: no exposure, low exposure, and high exposure. The caregivers also completed the Children's Behavior Checklist (CBCL). RESULTS: Of 94 six-year-old children, 58% had no exposure to violence, 36% had low exposure to violence, and 6% had high exposure to violence, according to caretaker reports. The children's median+/-SD Levonn score was 64 (SD +/- 19.3). The mean SD +/- CBCL total T-score was 53 (SD +/- 10.2). In multiple regression analyses with gender, low and high exposure on EVI, Levonn, and prenatal cocaine exposure status as predictors, the Levonn score explained 4.8% of total variance in children's CBCL internalizing scores, 9.1% of the total variance in CBCL externalizing score, and 12.2% of the total variance in CBCL total score (P =.04, P =.004, and P<.001, respectively). CONCLUSIONS: After accounting for the caretaker's report of the level of the child's exposure to violence, the child's own report significantly increased the amount of variance in predicting child behavior problems with the CBCL. These findings indicate that clinicians and researchers should elicit children's own accounts of exposure to violence in addition to the caretakers' when attempting to understand children's behavior.

Child↗

PubMed2002

Quantifying practice effects in longitudinal research with the WISC-R and WAIS-R: a study of children and adolescents with hemophilia and male siblings without hemophilia.

OBJECTIVE: To quantify practice effects associated with annual administrations of WISC-R and WAIS-R in children and adolescents with and without hemophilia. METHODS: Participants were young men (age: 7-19; 80 with hemophilia, 30 siblings) enrolled in the Hemophilia Growth and Development Study. Participants with hemophilia completed age-appropriate Wechsler scales at baseline and at four annual follow-ups; the siblings, at baseline and one 2-year follow-up. Regression analyses were used to quantify average changes in scores, adjusting for variables related to test performance. RESULTS: Consecutive annual evaluations were free of significant practice effects for 4 years with the Verbal Scale and for 2 years with the Performance Scale. VIQ decreased, and PIQ increased over time. Baseline VIQ was related to changes in VIQ; baseline PIQ and number of test-specific retests were related to changes in PIQ. CONCLUSIONS: The findings support use of Wechsler scales for annual evaluations to monitor cognitive development in children and adolescents.

Adolescent↗