Neural correlates of proactive cognitive control in preschool and middle childhood

• Author / Creator

  Elke, Sarah E

• The engagement of cognitive control has been described as occurring in two forms: reactive control, where cognitive control is engaged only as needed, and proactive control, where cognitive control is engaged in anticipation of future control demands (Braver, Gray, & Burgess, 2007; Braver, 2012). This study used event-related potentials (ERPs) to investigate the neural correlates of proactive and reactive cognitive control strategies in children. The sample included groups of younger children (n = 18, 4 years, 6 months to 5 years, 11 months) and older children (n = 21, 7 years to 8 years, 6 months). Children completed a cued task-switching paradigm while their EEG was recorded. On each trial, children were presented with a cue indicating whether to sort by colour or shape followed by an image to be sorted by the cued dimension, which children indicated on a touch-screen. Upon cue presentation, the task allowed children to prepare for the upcoming trial (i.e., a proactive strategy), activating the cued task set and selecting their response hand, or wait until stimulus presentation to do so (i.e., a reactive strategy). The paradigm was designed such that children made colour responses with one hand and shape with the other, so that lateralized ERP responses could be analyzed in the cue-stimulus interval to determine whether children were preparing their responses in anticipation of the up-coming stimulus; rule-hand assignment was counterbalanced between participants. Based on previous research, I predicted that younger children would favour a reactive control strategy, whereas older children would favour a proactive strategy. To determine which form of control children were using, I examined the P3 and lateralized readiness potential (LRP), ERP indexes of working memory load and response preparation, respectively. The P3 was analyzed after both the cue and the stimulus, and the LRP was analyzed following the cue. Older children responded more quickly and accurately than younger children and their stimulus-evoked P3s had faster latencies than those of younger children. However, ERP findings suggested that these performance differences were not due to a shift in strategy, as both age groups showed patterns consistent with a reactive strategy. It was found that children had larger cue-P3s in switch trials, when they performed different tasks on consecutive trials, than in stay trials, when they performed the same task on consecutive trials. This effect, however, was found only in younger children following the colourful colour-task cue, suggesting that children were engaging with the visual saliency of the novel cue rather than engaging their cognitive control in a proactive fashion. Children in both age groups had larger stimulus-P3 amplitudes in switch trials than in stay trials. This difference may reflect increased working memory load on switch trials that might have been avoided had children used a proactive strategy. Additionally, LRP onset was widely variable both age groups, without any systematic relation to task and trial demands or participant characteristics, but indicating that children were likely not selecting a response hand consistently following cue presentation, as would have been predicted under proactive control. Together, these results suggest that when presented with a complex task involving maintenance of multiple rule hierarchies, older children may use a reactive strategy, contrary to previous findings in a similar age group but with a more simple task (Chatham, Frank, & Munakata, 2009). Due to differing findings depending on task complexity, future research should examine the interplay between working memory demand and proactive cognitive control in a developmental context.

• Subjects / Keywords

  • Cognitive development
  • Executive function
  • Electroencephalography

• Graduation date

  Fall 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R34Q7QZ3P

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.