Page 78 - It' about time: Studying the Encoding of Duration
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                                The duration after-effect does not reflect adaptation to perceived duration  matched stimuli but did differ from the DAE for the perceptually matched stimuli. In other words, participants adapted to the onset-offset duration, and not to a duration corresponding to the perceived duration of the illusion- inducing stimulus. This result supports the proposal that duration channels are sensitive to the temporal distance between the onset and offset responses that result from a sensory event; possibly via neurons that show onset-dependent offset responses (Heron et al., 2012). We conclude that channel-based duration encoding is based on the temporal distance between the onset and offset of an event and does not necessarily corresponds to the perceived duration of that same event. Our results demonstrate that duration-tuned mechanisms are sensitive to the temporal distance between the onset and offset responses that result from the sensory event that is being encoded. As a result, the duration encoded by these mechanisms does not necessarily correspond to the duration eventually perceived by the observer. This suggest that channel- based encoding reflects an initial processing step, the output of which is then further transformed during subsequent processing. This idea is consistent with 4 a more hierarchical view of duration encoding in which duration information is accumulated from multiple sources across multiple stages of processing (van Wassenhove, 2009). In line with this idea, Heron and colleagues (2013) demonstrated that the channel-based encoding of duration occurs before the integration of duration information from the different senses. In addition, several studies have demonstrated that duration perception depends on a wide range of factors that reflect different stages of cognitive processing. For example, studies on memory and memory mixing have demonstrated that memory about other magnitudes can influence estimations of duration (Cai & Wang, 2014; Rammsayer & Verner, 2015). Furthermore, studies focusing on the role of contextual experience have demonstrated that duration estimates can be influenced by both the sensory and response history of previous duration estimates (Jazayeri & Shadlen, 2010; Roach, McGraw, Whitaker, & Heron, 2017). In addition to these behavioral findings, a large number of cortical and subcortical areas have been implicated in the processing of duration information (see for example: Hayashi et al., 2015; Jantzen, Steinberg, & Kelso, 2005; Meck et al., 2008; Mello et al., 2015; Merchant, PĂ©rez, et al., 2013; Spencer & Ivry, 2013). Together, these studies support the notion that duration processing occurs in multiple stages throughout the brain in a distributed and possibly task-specific manner.  77 


































































































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