Biomedical subjects

Heather M Conklin

Publications and source records attributed to Heather M Conklin.

5 recordsLinked to original sources

PubMed2005

Working memory functioning in schizophrenia patients and their first-degree relatives: cognitive functioning shedding light on etiology.

There is accumulating evidence for involvement of the prefrontal cortex (PFC) in the pathophysiology of schizophrenia. A primary function supported by the PFC is working memory (WM). Findings from WM studies in schizophrenia can provide insight into the nature of clinical symptoms and cognitive deficits associated with this disorder, as well as begin to suggest areas of underlying neuropathology. To date, studies have not adequately investigated different WM domains (e.g., verbal, spatial, or object) or processing requirements (e.g., maintenance, monitoring, or manipulation), shown to be associated with distinct patterns of neural activation, in schizophrenia patients and their well relatives. Accordingly, this study evaluated the performance of schizophrenia patients, their first-degree biological relatives, and nonpsychiatric controls on a comprehensive battery of WM tasks and investigated the association among WM deficits and schizophrenia-spectrum psychopathology. The findings indicate that schizophrenia patients are consistently impaired on WM tasks, irrespective of WM domain or processing requirements. In contrast, their unaffected relatives are only impaired on WM tasks with higher central executive processing requirements. This pattern of WM performance may further implicate DLPFC dysfunction in the liability for schizophrenia and has implications for future cognitive, genetic, and neurodevelopmental research.

Adult↗

PubMed2004

Adolescents' performance on the Iowa Gambling Task: implications for the development of decision making and ventromedial prefrontal cortex.

Healthy adolescents (79 girls, 66 boys), ages 9-17, completed the Iowa Gambling Task (IGT; A. Bechara, A. R. Damasio, H. Damasio, & S. W. Anderson, 1994) as well as working memory (digit span) and behavioral inhibition (go/no-go) tasks. Cross-sectional age-related changes were seen on all 3 tasks. Gender differences were seen in IGT deck preference and attentional variables (i.e., go/no-go hit rate and forward digit span). After age, gender, and general intellectual abilities were controlled for, IGT performance was not predicted by working memory or behavioral inhibition scores. Findings suggest that the ventromedial prefrontal cortex or its connections are functionally maturing during adolescence in a manner that can be distinguished from maturation of other prefrontal regions. Development of these functions may continue into young adulthood.

Adolescent↗

PubMed2003

At issue: assessment of schizophrenia: getting closer to the cause.

Traditionally, the diagnosis of schizophrenia has depended on the presence of specific behavioral phenomena assessed by way of behavioral observation and patient symptomatic report. Even though the introduction of explicit diagnostic criteria and structured interviews has improved the reliability of schizophrenia diagnosis, it is still unclear how best to define schizophrenia in order to further etiologic research. This situation persists despite ample evidence that schizophrenia is a heritable brain disorder and the existence of laboratory measures that tap into this neurobiological genetic diathesis. We contend that such laboratory measures can be used to supplement traditional clinical assessment in order to improve the definition of schizophrenia, thereby enhancing research into schizophrenia's origins. Ultimately, this increased understanding of the disorder's etiology should facilitate the development of targeted therapeutic interventions.

Brain↗

PubMed2002

Recognition memory for faces in schizophrenia patients and their first-degree relatives.

It has consistently been shown that schizophrenia patients are impaired in recognition memory for faces. However, studies have not examined the specificity of this deficit relative to other cognitive functions nor the relationship between this deficit and particular schizophrenia symptoms. In addition, no studies have examined recognition memory for faces in unaffected biological relatives of schizophrenia patients who likely share some of the genetic diathesis for this disorder without presenting the potential confounds of mentally ill study samples. The Faces subtests from the Wechsler Memory Scale-Third Edition were used to evaluate recognition memory for faces in 39 schizophrenia patients, 33 of their first-degree relatives and 56 normal controls. Both schizophrenia patients and their relatives were impaired, relative to control participants, in recognition memory for faces after partialing out group differences in spatial attention or verbal memory. Further, recognition memory for faces was associated with positive symptoms in the schizophrenia group and schizotypal personality traits in the relative group. These findings may have important implications for reducing etiological heterogeneity among schizophrenia populations, identifying disorder susceptibility among their relatives and furthering understanding of disorder etiology.

Adolescent↗

PubMedDate not supplied

The development of nonverbal working memory and executive control processes in adolescents.

The prefrontal cortex modulates executive control processes and structurally matures throughout adolescence. Consistent with these events, prefrontal functions that demand high levels of executive control may mature later than those that require working memory but decreased control. To test this hypothesis, adolescents (9 to 20 years old) completed nonverbal working memory tasks with varying levels of executive demands. Findings suggest that recall-guided action for single units of spatial information develops until 11 to 12 years. The ability to maintain and manipulate multiple spatial units develops until 13 to 15 years. Strategic self-organization develops until ages 16 to 17 years. Recognition memory did not appear to develop over this age range. Implications for prefrontal cortex organization by level of processing are discussed.

Adolescent↗