Biomedical subjects

Nicholas Wymbs

Publications and source records attributed to Nicholas Wymbs.

4 recordsLinked to original sources

PubMed2005

Neural correlates of conflict processing.

In this study we examined the neural correlates of conflict processing in the Stroop, counting, and digit-location tasks using event-related brain potentials (ERPs). The behavioral data revealed robust interference in response time and accuracy for all tasks. The interference effect for response time was greater in the Stroop task than the other tasks; in contrast, the interference effect for response accuracy was greater in the counting tasks than the other tasks. The N450 and sustained potential (SP) were elicited in each task. Partial least-squares (PLS) analysis was used to examine the structural relationships between the ERPs, task design, and behavior. TaskPLS analysis revealed that the N450 and SP were associated with a single latent variable leading to the suggestion that a common set of neural generators was recruited during conflict processing across the tasks and that there were differences between ERPs related to early processing across the three tasks. BehavioralPLS analysis revealed that the amplitude of the SP was positively correlated with response time and accuracy, indicating that this modulation of the ERPs may be related to response selection rather than to conflict resolution.

Adolescent↗

PubMed2004

Is detecting prospective cues the same as selecting targets? An ERP study.

Prospective memory represents our ability to realize intentions that must be delayed for some period of time. In this study, we examined modulations of the event-related brain potentials (ERPs) associated with target selection in visual working memory and prospective-cue detection in prospective memory. Targets and prospective cues elicited an N2pc, indicating that a common neural mechanism supports selection in working memory and prospective memory. Partial least squares analysis revealed that the N300 and prospective positivity were associated with a latent variable that contrasted the ERPs elicited by prospective-cue trials with those elicited by target-present and target-absent trials, in agreement with the idea that these modulations of the ERPs are uniquely related to prospective memory.

Adolescent↗

PubMed2003

Effects of intention load and background context on prospective remembering: an event-related brain potential study.

Prospective remembering reflects the ability to realize intentions that must be delayed over some period of time. Recent evidence indicates that distinct modulations of the event-related brain potentials may be associated with the detection of a prospective memory cue (N300) and the recovery of an intention from memory (LPC, slow wave). The present experiments examined the degree to which these modulations were influenced by task manipulations that were expected to differentially influence cue detection and memory-related processes. Varying the number of intentions modulated the amplitude of a slow wave that may reflect memory-related processes. In contrast, varying the distinctiveness of the cues modulated the N300 and the early portion of the LPC indicating that this manipulation primarily influenced detection and categorization processes. These findings indicate that the N300, LPC and slow wave reflect functionally distinct processes associated with prospective memory.

Adolescent↗

PubMed2002

Age-related declines in prospective memory: behavioral and electrophysiological evidence.

Prospective remembering reflects the ability of an individual to form and later realize intentions that must be delayed over minutes, hours, or days. A substantial body of literature, primarily based upon the findings of behavioral studies, indicates that there are robust declines in the efficiency of prospective remembering in later adulthood. However, the cognitive and neural mechanisms mediating age-related deficits in prospective remembering are not well understood. In this review we consider evidence from recent behavioral and electrophysiological studies indicating that decreases in the efficiency of prospective memory in older adults results from age-related differences in those neural mechanisms supporting the encoding of intentions into memory and the detection of prospective memory cues in the environment.

Aging↗