Date of Award


Degree Type


Degree Name

Doctor of Philosophy




Dr. Tutis Vilis

Second Advisor

Dr. Jody Culham


Object recognition requires that an object be segregated from its background by grouping the elements of the object using various distinguishing binding cues. Temporal synchrony is one such cue, in which object elements are presented simultaneously on top of a preexisting background. We showed that upon removal of this binding cue (but not of the object elements themselves), as in other studies using motion and color cues, temporal synchrony was able to elicit “persistence”, a phenomenon in which an object percept lingers before disappearing into the background. In Chapter 2 we showed that temporal stimulus synchrony had a longer persistence duration than that elicited by motion and colour binding cues and that these durations can be correlated with lateral occipital (LO) activity measures using fMRI. In Chapter 3, a series of experiments determined why pre-presenting backgrounds with embedded objects elicited shorter persistence durations than backgrounds without embedded objects. This reduction in persistence duration disappeared when the objects were rotated, presumably because rotating the objects prevented adaptation in early visual areas. In Chapter 4, we examined the distribution of persistence related activity throughout the occipital lobe and found that it gradually increased from early visual area V1 to LO, peaking in V4, whereas activity elicited by iconic memory peaked in LO. Finally, in Chapter 5, we compared the activation related to persistence elicited by temporal stimulus synchrony to persistence activity elicited by colour and motion cues and found that regardless of binding cue, persistence showed a similar pattern of activation across early visual areas, the one exemption being that persistence elicited by colour showed more activation in V4 compared to the other binding cues.



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