Advance preparation in task-switching: converging evidence from behavioral, brain activation, and model-based approaches

Abstract

Recent research has taken advantage of the temporal and spatial resolution of event-related brain potentials (ERPs) and functional magnetic resonance imaging (fMRI) to identify the time course and neural circuitry of preparatory processes required to switch between different tasks. Here we overview some key findings contributing to understanding strategic processes in advance preparation. Findings from these methodologies are compatible with advance preparation conceptualized as a set of processes activated for both switch and repeat trials, but with substantial variability as a function of individual differences and task requirements. We then highlight new approaches that attempt to capitalize on this variability to link behavior and brain activation patterns. One approach examines correlations among behavioral, ERP and fMRI measures. A second “model-based” approach accounts for differences in preparatory processes by estimating quantitative model parameters that reflect latent psychological processes. We argue that integration of behavioral and neuroscientific methodologies is key to understanding the complex nature of advance preparation in task-switching.

Task preparation and task inhibition: a comment on Koch, Gade, Schuch, & Philipp (2010)

“…For example, their paradigm has considerable inter-trial conflict centred on response processes, raising the possibility that n-2 repetition costs in such paradigms are-despite the arguments presented in this commentary-impervious to cuebased preparation effects (but see Karayanidis, Jamadar, Ruge, Phillips, Heathcote, & Forstmann, 2010). This possibility predicts that CDFs of the data from Koch's laboratory may also show no effect of preparation, as intertrial conflict in their studies is consistently centred on response processes.…”

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

“…This approach still runs the risk of alpha inflation due to the large number of electrodes being examined. To show that the effects were genuine, we capitalized on the fact that for yet unknown reasons, greater difficulty (e.g., switch vs. repeat) generates positivity during the cue epoch and negativity during the target epoch and response epoch (see Karayanidis et al, 2010, for a review). If the significant results were caused by alpha inflation alone, half of the significant deflections should electrodes attached to the outer canthus of each eye.…”

“…The cognitive and neuronal mechanisms that enable such contextual flexibility have been a target of intense research efforts over the last 15 years or so. Perhaps the most popular paradigm in this research is the taskswitching paradigm (see Karayanidis et al, 2010;Kiesel et al, 2010;Meiran, 2010;Monsell, 2003;Vandierendonck, Liefooghe, & Verbruggen, 2010, for a review; see Koch, Gade, Schuch, & Philipp, 2010, for a review on inhibition in task switching), in which the task context frequently changes.…”

“…A number of studies have focused on cue processing (see Karayanidis et al, 2010, for a review). 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).…”

“…Jamadar et al, 2010. In addition, Karayanidis et al (2010) pointed out another switchspecific preparatory component-that is, the late, slow frontal negativity (fronto-central pretarget negativity)-that is thought to be particularly associated with response set preparation processes (Astle et al, 2008;Jamadar et al, 2010;Mueller, Swainson, & Jackson, 2007). West et al (2010;see also Travers & West, 2008) made a further distinction between four ERP components-namely, frontal P2 (180-200 ms), frontal positivity (375-425 ms), P3 (300-350 ms), and parietal slow wave (400-1,000 ms)-related to task switching.…”