The hazards of time

Top-down control of the phase of alpha-band oscillations as a mechanism for temporal prediction

“…In experiment 1, we established that cues predictive of the moment of target appearance significantly enhanced orientation discrimination and subjective visibility. This step was important because even though much work using temporal cueing paradigms has established that response times improve for targets appearing at predicted moments in time (reviewed in 11,12), it is less clear whether temporal cueing improves perception (13)(14)(15)(16). In a second experiment, we replicated the aforementioned behavioral effect while concurrently recording EEG, and found that temporal predictions led to a bias in the phase of ongoing alpha-band oscillations toward each participant's optimal phase for visual discrimination.…”

“…One intriguing proposal is that cortical oscillations instantiate perceptual predictions by coordinating prestimulus neural activity to process the predicted stimulus optimally (1,2). A candidate neural mechanism for such coordination is low-frequency oscillations in the alpha band (8)(9)(10)(11)(12)(13)(14) Hz) of human electroencephalography (EEG) recordings, which are suggested to route information phasically through task-relevant networks (3,4). As evidence, recent work has demonstrated that the prestimulus alpha-band phase predicts visual detection (5,6), the perception of phosphenes (7), the magnitude of the functional MRI (fMRI) response in visual cortex (8), successful perceptual integration across the visual field and subsequent connectivity between visual and parietal cortex (9), as well as variability in working memory performance (10).…”

“…For example, the phase of ongoing posterior alphaband oscillations (8)(9)(10)(11)(12)(13)(14) immediately before visual stimulation has been shown to predict perceptual outcomes and downstream neural activity. Although this phenomenon suggests that these oscillations may phasically route information through functional networks, many accounts treat these periodic effects as a consequence of ongoing activity that is independent of behavioral strategy.…”

Minding time in an amodal representational space

“…Indeed, learning on a temporal order task does not transfer to a synchrony task (Mossbridge et al 2008). Attention to particular temporal features or changes in temporal expectations (Nobre et al 2007) may affect these thresholds, but it is probably not a coincidence that naturalistic events tolerate large number of delays, i.e. they remain robust despite increase in (temporal) noise.…”

“…Additional key features for this model are the prominent role of thalamocortical networks and re-entrant processes: re-entrant processes enable, for instance, via attentional focus to amplify the incoming signal of interest, thus producing a closed-loop system between bottom-up signal processors and top-down amplification signals. Temporal attention could be one mode by which time becomes the property of interest for the global workspace and research has started to focus on the properties of attentional focus in time (Nobre 2001;Nobre et al 2007), a research topic much less explored than spatial attention. Another implication of the closed-loop system is that this mechanism imposes a temporal resolution or 'granularity' on the stream of consciousness (Dehaene & Naccache 2001b), suggesting that a perceptual moment may have a specific duration.…”