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Daniela Roesch-Ely

Publications and source records attributed to Daniela Roesch-Ely.

5 recordsLinked to original sources
PubMed2006

Dopaminergic modulation of semantic priming in healthy volunteers.

BACKGROUND: Semantic priming is a function related to prefrontal cortical (PFC) networks and is lateralized. There is evidence that semantic priming underlies dopaminergic modulation. It is known that the D1-receptor is more abundant in prefrontal networks; however, until now there have been no studies investigating the selective modulation of semantic priming with dopamine agonists. Furthermore, D1 receptor dysfunction has been described in schizophrenia, and patients with formal thought disorder seem to have disturbed focusing of associations and increased indirect priming. METHODS: With a subtraction design, we compared the influence of pergolide (D1/D2 agonist) with bromocriptine (D2 agonist) and placebo, in a randomized, double-blind, crossover design in 40 healthy male volunteers. Subjects performed a lateralized lexical decision task including direct and indirect related prime-target pairs (stimulus onset asynchrony = 750 msec). RESULTS: Only on pergolide a decrease of the indirect priming in the left hemisphere presentations was found. CONCLUSIONS: These findings point to a potential selective modulation of agonists with a D1 component on the focusing of semantic associations. The clinical relevance of this study is that it might help the development of therapeutic strategies for treating cognitive deficits in schizophrenia and Parkinson's disease, which are highly relevant to the functional outcome.

Adult↗
PubMed2004

Differential dopaminergic modulation of executive control in healthy subjects.

RATIONALE: Executive control (EC) has different subcomponents, e.g., response inhibition (measured, for example, by the Stroop task) and working memory (WM-measured, for example, by delayed response tasks, DRT). EC has been associated with networks involving the prefrontal cortex (PFC). Moreover, there is evidence that dopamine agonists, especially those with a D1 profile, may modulate EC, since in the PFC D1 subtype receptors are more abundant. OBJECTIVE: This study aimed to selectively distinguish whether D1 versus D2 dopamine agonism differentially influences EC related to the inhibition of irrelevant information and WM. Because of its D1 component, we predicted that the administration of pergolide (mixed D1/D2 agonist), in comparison with bromocriptine (D2 selective agonist) and placebo, would enhance performance in both EC tasks. Using a lateralized Stroop task, we predicted a decrease in the interference effect, as well as error rates, while no increase in facilitation effects. For the DRT task, we predicted fewer error scores in the delay condition. METHODS: Forty male healthy subjects participated in this randomized, double-blind, placebo-controlled, crossover study. RESULTS: For the Stroop task no superiority of pergolide was found; however, with bromocriptine, decreased interference was found. No modulation of lateralization effects was shown in interference measures. Moreover, subjects on pergolide showed an absence of facilitation effects. No effects of either agonist were found for the DRT. CONCLUSION: Our findings suggest that dopamine agonists modulate two EC tasks differently. Furthermore, there seems to be a selective modulation of different aspects of the Stroop task.

Adaptation, Psychological↗
PubMed2002

Automatic vs. controlled processes in semantic priming--differentiation by event-related potentials.

Semantic network models propose that automatic (e.g. spreading activation) and controlled processes are involved in semantic priming. Behavioural studies propose that the influence of each of these processes depends on the stimulus onset asynchrony (SOA). To investigate this hypothesis with a more sensitive method, we applied high-resolution event-related potential (ERP) measures to a word-pseudoword lexical decision task that contained direct, indirect, and non-related prime-target pairs. SOAs consisted of 150 or 700 ms. The results showed that independently of SOA, increasing semantic distance prolonged reaction times and enlarged N400 amplitudes. Furthermore, the word-pseudoword decision evoked a parieto-central late positive complex (LPC respectively delayed P300), which was sensitive for semantic relatedness in the short SOA only. In addition, we found two early frontal components: a P250 in the short SOA only and a N310 sensitive to semantic relatedness more prominent in the short SOA. We conclude that ERP-differences between both SOAs indicate two separate processes: (1) an access to semantic memory, which is facilitated by spreading activation in the short SOA only; and (2) an SOA-independent, controlled process, which integrates prime and target words into a semantic context.

Adult↗
PubMedDate not supplied

Cognitive inhibition and thought disorder in schizophrenia.

In schizophrenia, inhibitory control is reported to be disturbed and has been associated with formal thought disorder (TD). The negative priming task (NP) is used as a measure for inhibition; however, controversial results are found in the literature. The aim of this study was to evaluate cognitive inhibition in schizophrenia and TD. Additionally, the influence of the course of disease and of medication were evaluated. The NP was used to compare TD patients (n = 17) with non-TD (n = 19) and healthy controls (n = 21). Results showed similar performance among TD and non-TD patients, and controls. No influence of the course of disease or medication was found. Our results are in line with recent studies, where patients, irrespective of TD, show normal performance in the NP.

Adult↗