The simultaneity judgment (SJ) and temporal order judgment (TOJ) tasks are the two widely used methods for measuring the window of multisensory integration; however, there are some indications that these two tasks involve different cognitive processes and therefore produce unrelated results. The present study measured observers’ visuotactile window of integration using these two tasks in order to examine whether or not SJs and TOJs produce consistent results for this particular pairing of modalities. Experiment 1 revealed no significant correlations between the SJ and TOJ tasks, indicating that they appear to measure distinct processes in visuotactile integration, and in addition showed that both sensory and decisional factors contribute to this difference. These findings were replicated in Experiment 2, which, along with Experiment 3, also showed that the reliability of the SJ and TOJ tasks may in part be responsible for the lack of agreement between these two tasks. A secondary result concerned the point of subjective simultaneity (PSS), which were tactile-leading across all three experiments. This contradicts some of the previous literature in visuotactile integration. Manipulating the spatial distance between the visual and tactile stimulus (Experiment 2) and the certainty of stimulus location (Experiment 3) did not lead to significant changes of the location of the PSS. / Thesis / Master of Science (MSc) / Perception often involves the use of more than one sensory modality at the same time; for example, touching an object usually produces sensory signals in the visual and tactile modalities. Since the amount of time needed to transmit and process sensory signals is different among the modalities, the brain allows for a certain time difference between signals of various pairs of modalities that it will consider as coming from one event. Two tasks commonly used to measure these allowable time differences are the simultaneity judgment (SJ) and temporal order judgment (TOJ) tasks. Although they are usually used interchangeably, the present data show that the results from these tasks in the visuotactile pairing of modalities are unrelated, and a major contributing reason appears to be that these tasks are not the most reliable.

Previous research shows that integration of the senses is interchangeably dependent by  temporal neural mechanisms. One unsolved problem is how sensory timing differences in the brain is processed. In this systematic review (K = 18), audio-visual behavioral task paradigms are investigated with a focus on temporal binding window estimates. The results showed among other things that temporal integration is an adaptive neural process and that temporal acuity increases with age. Measurements between studies were sometimes incompatible which limited conclusions. Future studies should focus on standardizing operational parameters and compare within and between group designs.

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.