Behavioral and electrophysiological signatures of expectation, interference and discrimination in time perception

Duzcu, Halil
Expectation, interference and temporal discrimination ability are three crucial factors which affect human time perception. In this thesis, expectation is obtained by temporal location manipulation and results indicate that attentional time-sharing between keeping track of time and doing the concurrent task leads to timing disruption which supports the working memory maintenance accounts (Exp-1-2-3). Expectation effect is also studied through electrophysiological markers (Exp-4-5). Results indicate that the change in the CNV (Contingent Negative Variation) course – which is a marker of growing expectation – predicts the subjective timing responses for intervals which are longer than expected. Moreover, the N1 peak shows higher amplitudes when the offset of the interval is not expected in comparison to the threshold. Evidence for interference between timing and a concurrent task is provided by all behavioral experiments. An independent response inhibition effect on timing occurs during the reproduction stage indicating an overlap between the central response requirements of the timing task and the concurrent task (Exp-3). Moreover, the overlap between the tasks at the end of the interval caused a further disruption in timing in the reproduction stage. Difficulty in discrimination occurs in situations in which the expectation of a temporal event does not provide a clue for an apparent response. Findings show that the interval offset P2 peak is sensitive to subjective responses in intervals with no apparent accurate response (Exp-4). A P2 peak modulation in terms of the accuracy in the task performance occurs when there is difficulty in terms of the relevant timing response (Exp-5).  
Citation Formats
H. Duzcu, “Behavioral and electrophysiological signatures of expectation, interference and discrimination in time perception,” Ph.D. - Doctoral Program, Middle East Technical University, 2017.