These tasks were designed to induce asymmetric between-task competition, with the location task expected to be the stronger task of the pair.
In particular, we aimed at delineating regions that showed significantly stronger task-dependent and task-independent connectivity with the anterior versus posterior cluster and vice versa.
Thus, our findings indicate that preparation for shape repetitions was less cognitively demanding than preparation for task switches or for repetitions of the stronger task.
Significantly stronger task-dependent and task-independent connectivity of the anterior versus the posterior cluster was observed for its left homotope region (MNI-coordinates: −30, 53, 12) and the ACC (MNI-coordinates: 9, 33, 18) (Fig. 3).
Allport and colleagues [ 16] have argued that the extra inhibition of the stronger task set is required to enhance performance with the weaker task set, and therefore, inhibition carries over to the next trial.
Finally, this work shows that nestmate recognition has a stronger task allocation component than previously thought, as colonies can nearly always achieve perfect nestmate recognition if it is cost effective for them to do so at the colony level.
These CNV findings complement and extend existing theoretical accounts of switching asymmetries observed behaviorally, which have typically been taken to show that execution of the weaker task makes the switch toward the stronger task more difficult (Gilbert and Shallice 2002; Yeung and Monsell 2003).
In contrast, the IPS, i.e., the parietal region more closely connected to the ventral seed, featured significantly stronger task-based and task-independent functional connectivity with bilateral ventral extrastriate visual cortex, the anterior insula, (pre-) SMA, and the posterior inferior frontal gyrus.
Conversely, significantly stronger task-dependent and task-independent connectivity of the posterior versus anterior cluster was again found for its left homotope region (MNI-coordinates: −42, 29, 23) as well as for a bilateral region in the IPS (MNI-coordinates: 36, −53, 44/−42, 29, 23; areas hIP1 and hIP3) (Fig. 4).
The conjunction analysis across both approaches, hence demonstrated bilateral significantly stronger task-based and task-independent functional connectivity of the ventral seeds with Broca's region (BA 44, BA 45), anterior insula, caudal part of the LPFC, (pre-) SMA, intraparietal sulcus (hIP1-3), and extrastriate visual cortex as well as the basal ganglia.
