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de Lange, F.

Publications and source records attributed to de Lange, F..

2 recordsLinked to original sources

Stimulus predictability does not modulate bottom-up attentional capture

Attention can be involuntarily captured by physically salient stimuli, a phenomenon known as bottom-up attention. Typically, these salient stimuli occur unpredictably in time and space. Therefore, in a series of three behavioral experiments, we investigated the extent to which such bottom-up attentional capture is a function of ones prior expectations. In the context of an exogenous cueing task, we systematically manipulated participants spatial (Experiment 1) or temporal (Experiment 2 and 3) expectations about an uninformative cue, and examined the extent of attentional capture by the cue. We anticipated larger attentional capture for unexpected compared to expected cues. However, while we observed robust attentional capture in all experiments, we did not find any evidence for a modulation of attentional capture by prior expectation. This underscores the automatic and reflexive nature of bottom-up attention.

neuroscience

Differential temporal dynamics during visual imagery and perception

Visual perception and imagery rely on similar representations in the visual cortex. During perception, visual activity is characterized by distinct processing stages, but the temporal dynamics underlying imagery remain unclear. Here, we investigated the dynamics of visual imagery in human participants using magnetoencephalography. We show that, contrary to perception, the onset of imagery is characterized by broad temporal generalization. Furthermore, there is consistent overlap between imagery and perceptual processing around 150 ms and from 300 ms after stimulus onset, presumably reflecting completion of the feedforward sweep and perceptual stabilization respectively. These results indicate that during imagery either the complete representation is activated at once and does not include low-level visual areas, or the order in which visual features are activated is less fixed and more flexible than during perception. These findings have important implications for our understanding of the neural mechanisms of visual imagery.

neuroscience