Temporal attention tasks, instead, have been more often shown to lead to activation in the middle temporal gyrus, the superior occipital gyrus and the cerebellum (Coull & Nobre,

1998; Davranche et al., 2011; Li et al., 2012). The neuroimaging findings discussed above, obtained with various methods, indicate similarities but also profound differences in the neural mechanisms underlying temporal and spatial attention. This must in part be due to the dramatic differences between encoding the dimensions of space and time. Temporal attention usually involves processing of time-shifted events, while spatial attention involves competition between (possible) events occurring at about the same time. In other words, during spatial attention a person usually has to focus attention on one out of several isochronous potential events, which are all competing for processing resources at the same time (Desimone & Duncan, 1995). In contrast, GSI-IX while focusing attention in time, potentially relevant events are anisochronous. Depending on the temporal difference between two events, temporal attention can allocate resources flexibly and dynamically to adapt efficiently towards task demands. In the light of this framework, it seems only logical

that temporal and spatial attention may share some similarities Transmembrane Transproters modulator but also display very different outcomes at the behavioural level. While in spatial attention the isochrony of possible events tends to create cross-modal linkage to optimize resources, in temporal attention

events can be cross-modally decoupled as they are anisochronous and resources can be allocated dynamically. Within the present study, we manipulated the participants’ attention through different target probabilities, in terms of its onset times and modality. For example, a more likely modality is also more relevant for participants and therefore it will necessarily drive their endogenous attention. On the other hand, different target probabilities lead also to different target predictabilities and therefore modulate the participants’ expectations (Lange, 2013). Thus, as in most other temporal attention studies, we are well aware that for the RANTES moment these findings must be attributed to a combination of attention and expectation effects. Although attention and expectation can be functionally distinguishable and lead to different effects (Summerfield & Egner, 2009), it is not the goal of this study to measure their different contributions. This study addressed whether orienting attention in time leads to synergistic behavioural cross-modal effects, as shown previously for spatial attention (i.e., Spence & Driver, 1996) and more recently suggested for temporal attention (Lange & Röder, 2006). We found that processing of a likely (primary) modality is enhanced at its expected (most likely overall) time point. This is an expected result.