Effects of caffeine on anticipatory control processes: Evidence from a cued task‐switch paradigm

Abstract

Effects of caffeine on task switching were studied using ERPs in a cued task-switch paradigm. The need for advance preparation was manipulated by varying the number of task-set aspects that required switching. In a double-blind, within-subjects experiment, caffeine reduced shift costs compared to placebo. ERPs revealed a negative deflection developing within the preparatory interval, which was larger for shift than for repeat trials. Caffeine increased this shift-induced difference. Furthermore, shift costs increased as a function of the number of task-set features to be switched, but this pattern was not modulated by caffeine. The results suggest that caffeine improves task-switching performance by increasing general effects on task switching, related to task-nonspecific (rather than task-specific) anticipatory processes. Caffeine's actions may be mediated by dopaminergic changes in the striatum or anterior cingulate cortex.

An investigation of the neural correlates of attention and effector switching using ERPs

“…In the RT data, the magnitude of the switch costs tended to increase from attention switching to effector switching to attention effector switching. The difference between attention switching and effector switching represents the opposite of what has been observed in some previous research, where switch costs were greater for attention than for effector switching (Kleinsorge & Heuer, 1999;Tieges et al, 2007). It is not clear why our pattern of switch costs differs from that observed in previous studies.…”

“…Over the parietal region of the scalp, the P3b is greater in amplitude for trials in mixed blocks than for trials in pure blocks (Kieffaber & Hetrick, 2005;Kray, Eppinger, & Mecklinger, 2005;West, 2004). The P3b may (Jost, Mayr, & Rösler, 2008;Kieffaber & Hetrick, 2005;Tieges et al, 2007) or may not (Eppinger, Kray, Mecklinger, & John, 2007;West & Moore, 2005) vary in amplitude for different types of trials within mixed blocks. Together these findings indicate that the P3b may reflect processes associated with both cue encoding and task switching (Jost et al, 2008).…”

“…The neural correlates of attention, effector, and attention effector switching were compared in one recent study (Tieges et al, 2007). In this experiment, participants were asked to report whether a stimulus was red or blue, or whether it was a consonant or a vowel, by pressing a set of keys with the index and middle fingers of the right and left hands.…”

“…The present study was designed to examine three questions motivated by the work of Tieges et al (2007). First, we sought to determine whether there might be differential effects of attention and effector switching on the P3b and parietal slow wave.…”

“Smart inhibition”: electrophysiological evidence for the suppression of conflict-generating task rules during task switching

“…Many of these studies have reported that in comparison with task repeat trials, there was a switch-related central-posterior positivity occurring about 400 ms after the cue (Hsieh, 2002;Karayanidis, Coltheart, Michie, & Murphy, 2003;Miniussi, Marzi, & Nobre, 2005;Moulden et al, 1998;Rushworth, (Slagter, Kok, Mol, Talsma, & Kenemans, 2005). This positivity was interpreted by some authors as P3b modulation (Barceló, Periáñez, & Knight, 2002;Kieffaber & Hetrick, 2005;Nicholson, Karayanidis, Poboka, Heathcote, & Michie, 2005;Tieges, Snel, Kok, Plat, & Ridderinkhof, 2007) and by others as a reduction in CNV (Hsieh & Chen, 2006;Lorist et al, 2000). The posterior positivity is sometimes preceded by an early (100 to 300-ms) or moderately early (300 to 500-ms) anterior positivity (Astle, Jackson, & Swainson, 2008;Rushworth et al, 2002) or followed by a late (500 to 1,000-ms) anterior negativity (Astle et al, 2008;Lavric, Mizon, & Monsell, 2008;Moulden et al, 1998).…”