After exposure to a short, constant delay between voluntary movement and sensory stimuli, temporal recalibration (TR) arises to realign asynchronous stimuli. The objective of this study was to determine if awareness of the temporal lag between a motor response (i.e., a keypress) and a sensory event (i.e., a visual flash) is necessary for TR to occur. We further investigated whether manipulating the motor and judgment tasks required modifies the influence of awareness on TR due to the cognitive processes engaged. Participants (n = 22) were randomly divided between two groups (Group 1: Aware and Group 2: Unaware). The Aware group was told of the temporal lag between their keypress and visual flash at the beginning of the experiment, whereas the Unaware group was not. All participants completed 8 blocks of trials, in which the motor tasks (e.g., a single or repetitive tap), judgment tasks (e.g., judging the order of the keypress in relation to the visual flash or judging whether the two stimuli were simultaneous or not), and temporal lag between keypress and visual flash (e.g., a 0 ms or 100 ms lag) varied. TR was determined by comparing judgments between corresponding blocks of trials in which the temporal lag was 0 ms to 100 ms. Results revealed that both the Aware and Unaware groups of participants demonstrated TR across both motor and judgment tasks, and that the magnitude of TR did not vary across Aware and Unaware participants or tasks. Thus, results of the present study revealed that awareness of a temporal lag does not influence the magnitude of motor-sensory TR achieved.

Voluntary actions affect subsequent perception. For example, an action that precedes an auditory stimulus is perceived to have occurred later in time than is actually the case, while the auditory stimulus is perceived earlier in time. This effect is known as intentional binding. Current literature regarding action effects focuses on perception of a single sensory modality while the effects on perception of multiple modalities remain largely unknown. The present thesis explored how actions influenced the timing of perceived multisensory events. Additionally, this thesis investigated differences in voluntary compared to involuntary actions on subsequent perception. In Chapter 2, action effects on perceived onsets of visual and tactile stimuli were explored. This question was extended to other bimodal pairs, including audiovisual and audiotactile, in Chapter 3. Lastly, in Chapter 4, action effects on temporal resolution were investigated. In all the experiments, participants performed a chosen or a fixed button press that followed a bimodal temporal order judgment (TOJ) task. To investigate the influence of spatial proximity between actions and stimuli on binding, in Chapters 2 and 3, each stimulus modality appeared on different sides. In Chapter 4, the critical stimuli appeared at the same location, either close to or far from the preceding action, to explore the effect of action on temporal resolution. The present data provide evidence that actions affect the perceived onsets of multisensory events in an idiosyncratic manner, depending on the subsequent stimuli. Actions appear to preferentially bind to vision, then touch, and lastly, audition, but actions do not always bind to subsequent stimuli. Furthermore, actions degrade temporal resolution of bimodal stimuli. Lastly, the type of action, whether chosen or fixed, did not impact the degree of binding. Together, these data contribute to the action-perception literature, illustrating that our behaviours dynamically affect how we perceive the world. / Dissertation / Doctor of Philosophy (PhD)