Event-rate effects in the flanker task: ERPs and task performance in children with and without AD/HD

Abstract

Demanding tasks require a greater amount of effort, in which case individuals are required to alter their energetic-state to a level appropriate to perform the task. According to the Cognitive-Energetic Model (CEM), children with AD/HD are unable to effectively modulate their energetic state, leading to task underperformance. Using an Eriksen flanker task with varying event-rates, the current study compared the ability of typically-developing children and children with AD/HD to modulate their energetic state. In line with the CEM, it was predicted that children with AD/HD would underperform in the fast and slow eventrates. Results indicated that the groups did not differ in commission errors (i.e., incorrect responses). However, children with AD/HD made more omission errors to incongruent stimuli at the fast and slow eventrates, compared to controls. N2 amplitude was significantly larger for the AD/HD than control group in the slow event-rate. It is concluded that the energetic state modulation dysfunction in children with AD/HD results in an inability to attend to the task, as opposed to an inability to perform the task itself. Furthermore, these task performance differences did not manifest in either the N2 or P3 ERP components. Therefore, inattention in children with AD/HD may have its locus in response preparation, as opposed to stimulus processing, but more research is required to validate these conjectures. Abstract: Demanding tasks require a greater amount of effort, in which case individuals are required to alter their energetic-state to a level appropriate to perform the task. According to the CognitiveEnergetic Model (CEM), children with AD/HD are unable to effectively modulate their energetic state, leading to task underperformance. Using an Eriksen flanker task with varying event-rates, the current study compared the ability of typically-developing children and children with AD/HD to modulate their energetic state. In line with the CEM, it was predicted that children with AD/HD would underperform in the fast and slow event-rates. Results indicated that the groups did not differ in commission errors (i.e., incorrect responses). However, children with AD/HD made more omission errors (i.e., impulsively early or non-responses) to incongruent stimuli at the fast and slow event-rates, compared to controls. N2 amplitude was significantly larger for the AD/HD than control group in the slow event-rate. It is concluded that the energetic state modulation dysfunction in children with AD/HD results in an inability to attend to the task, as opposed to an inability to perform the task itself. Furthermore, these task performance differences did not manifest in either the N2 or P3 ERP components. Therefore, inattention in children with AD/HD may have its locus in response preparation, as opposed to stimulus processing, but more research is required to validate these conjectures. Highlights Children with AD/HD unable to effectively modulate energetic state  Event-rate varied during interference control in c...

Generalized lapse of responding in trait impulsivity indicated by ERPs: The role of energetic factors in inhibitory control

“…An enhanced N2c was obtained in the incongruent condition, in line with our assumptions and former findings (Heil et al, 2000;Johnstone and Galletta, 2013;Kopp et al, 1996). Independently, the N2c was also enhanced with the increased difficulty of visual stimulus discrimination.…”

“…Increased RT and errors are usually demonstrated for incongruent compared to neutral flankers (interference effect), while congruent flankers reduce RT and Running head: Energetic factors in impulsivity 4 errors (facilitation effect) (Kopp et al, 1996). This task has been extensively used to examine interference control (e.g., Brydges et al, 2012;Johnstone and Galletta, 2013;Johnstone et al, 2010;Kopp et al, 1996).…”

“…Arousal and activation pools provide energetic supply to the specific computational processing stages. In a task with varying cognitive load, the effort pool could provide a compensatory mechanism to mobilize and regulate the other two energetic resources in order to adjust behavior and to Running head: Energetic factors in impulsivity 5 achieve an optimum level of performance (Johnstone and Galletta, 2013;Sanders, 1983;Sergeant, 2000;Smulders and Meijer, 2008). However, performance improves only at a moderate level of task difficulty.…”

“…A frequent finding of ERP studies using the flanker task is that the N2 can be divided into two distinct subcomponents (Gehring et al, 1992;Kopp et al, 1996) reflecting control-related and mismatch-related functions (Folstein and Van Petten, 2008). However, some previous flanker studies failed to find two N2s (e.g., Johnstone et al, 2009;Johnstone and Galletta, 2013), and the classification scheme of the apparent subcomponents (N2a, N2b, N2c) is not always consequent (Folstein and Van Petten, 2008). The N2b is considered to indicate the attentional detection of deviations from the prevailing visual context (Kopp et al, 1996).…”

“…Furthermore, only a small number of studies has tested directly the ERP correlates of certain aspects of the CEM by using different inhibitory control paradigms (Benikos and Johnstone, 2009;Benikos et al, 2013;Johnstone and Galletta, 2013;Johnstone et al, 2010;van Meel et al, 2007). Findings of these studies unequivocally supported the crucial role of energetic pools in inhibitory performance.…”