This thesis presents a series of human psychophysical experiments designed to examine the interaction between the reliability of spatial form information and the neural mechanisms responsible for the processing of sub-second durations. Duration discrimination sensitivity was found to be lower when event durations were defined by stimulus characteristics that caused reductions in spatial form sensitivity. This form-duration sensitivity coupling persisted across stimuli defined both by crossed and uncrossed retinal disparity and within monocularly visible texture-defined stimuli. The interaction was also observed when spatial form was degraded by physical instability within shape borders, and when physically stable borders became perceptually unstable. These effects could not be attributed to artefacts of stimulus visibility, temporal coherence or stimulus size. Adaptation experiments generated aftereffects of perceived duration within stimuli whose durations were defined solely by retinal disparity, providing the first demonstration of duration selectivity within exclusively cortical duration encoding mechanisms. The selectivity of these aftereffects was then investigated using adapting and testing durations defined by matching or opposing retinal disparities. Duration aftereffects were maximal when adapt and test disparities were matched. However, there was partial transfer of duration aftereffects across large changes in retinal disparity, implicating contributions from higher-level extra-striate mechanisms. Collectively, these experiments provide support for duration processing mechanisms that are inextricably linked to the mechanisms underpinning spatial processing across multiple levels of the visuo-spatial hierarchy.

No description available.

No description available.

No description available.

The way in which one perceives a temporal sense of time while listening to or interacting with music is heavily influenced by the way the composer presents their musical or visual materials. This dissertation discusses concepts and technical approaches regarding timelessness in relation to my piece, In einem Augienblick, and the ways in which I explore a displaced approach to interactivity between audio, video, and performance for clarinet and live interactive electronics and video. By referencing the writings of Johnathan Kramer and using models of references from other composers, most notably György Kurtág, this document contemplates and synthesizes a variety of different methodologies and their practical applications to discuss the approach of timelessness, temporal change, and shifts in musical time taken in In einem Augienblick. In my piece, multiple elements of visual and sonic material are utilized in conjunction with each other to create this stagnant but shifting musical world, which will be discussed by presenting examples from the score, video, and electronics to show how each of these elements work together to create moments of timelessness in the piece.

The purpose of the study is to set forth a framework for the research of spatio-environmental factors on the experience of time duration. A literature survey considers the nature of the experience of time as well as the research that has been carried out on different factors in the experience of time duration. The survey also considers different categories of the spatio-environmental realm and how the realm is experienced through the sensory system. Particular attention is directed in the primary hypothesis toward the possible influence of the spatio-environmental factor of complexity, especially visual complexity. Exploratory testing of complexity used 24 college students performing duration estimates with the Production method viewing scale models of different complexity of wall surface and pattern. A secondary aspect of the study is to find support for the possible application of the primary hypothesis to the field of architecture. One undesirable experience of time duration, boredom, is studied in greater detail. Literature support is found for the relationship between boredom and decreased sense input, with decreased perceived visual complexity an example of decreased sense input. The susceptibility of the elderly to decreased sense input is considered, pointing to a possible increased susceptibility of the elderly to certain types of boredom. The scale model testing was modified with a glass screen to simulate decreased visual input, and the relationship between decreased visual input and duration estimation was analyzed for support of the secondary hypothesis. Tests for both hypotheses failed to provide confirmation but offer helpful guidance for future tests. / M. Arch.

<p dir="ltr">Timing and time perception is essential to humans, whose lives and biology are organized around clocks. From the simple give-and-take of conversation to understanding cause and effect, individuals rely on accurate time perception to successfully complete tasks and organize their lives. However, accurate time perception is vulnerable to all manner of influence, from both internal and external sources, including affect. A robust body of literature suggests that negative affect is positively associated with time dilation, or subjective lengthening of time, whereas positive affect is positively associated with time constriction, or subjective shortening of time. Collectively, these are known as time distortion, which has been preliminarily linked to increased impairment in anxiety, depression, and BPD. However, this literature features two key limitations. First, researchers have mostly examined time perception as an objective measure, through the use of measures such as the temporal bisection tasks, which limits our understanding of the subjective experience of time distortion and how it may contribute to psychopathology. Second, across studies, time perception is most often studied as an outcome, rather than examining the role of time perception in predicting affective change, i.e., contextualizing the role of time distortion in clinically-relevant research questions. The current project aimed to address these gaps in the literature through two studies which examined (1) the roles of brief affect and time perception manipulations on affective change and subjective time perception in an online study (Study 1) and (2) the effect of a longer time perception manipulation on affective change during an in-person experimental protocol (Study 2).</p><p dir="ltr">Across studies, participants included a community-based sample of U.S. adults over age 18 and two separate undergraduate samples recruited from introductory psychology courses at Purdue University. In Study 1, the final sample size exceeded 750 and was comprised of community-based and undergraduate participants. Online participants reported on dispositional levels of clinical measures [e.g., rumination, borderline personality disorder (BPD) features] and then completed an experimental protocol with brief mood and time perception manipulations while repeatedly reporting on their negative affect. Results suggested that the time perception manipulation was not effective, but that across the protocol, negative affect rose and positive affect decreased. Further, participants reported overall that time seemed to be passing by slower than usual during the protocol. These findings informed the design of Study 2, which lengthened the time perception manipulation and eliminated the mood induction component in order to address the more basic question of whether time perception manipulation influences mood, particularly during neutral cognitive tasks.</p><p dir="ltr">One hundred and twenty-seven undergraduate participants completed Study 2. As in Study 1, participants filled out self-report surveys about dispositional symptoms of psychopathology (e.g., rumination, emotion dysregulation, and symptoms associated with BPD, depression, and anxiety) before completing an experimental protocol which included a manipulated clock (accelerated or control clock), three runs of a modified Erkisen flanker task, and repeated measures of negative and positive affect. Primary results suggested that the time perception manipulation was successful but that the influence of time distortion was more nuanced than hypothesized. Specifically, individuals with elevated clinical symptoms exhibited lower rating of negative and positive affect levels in the accelerated clock condition, compared to individuals endorsing low symptoms, who reported higher positive affect and higher negative affect in the accelerated clock condition.</p><p dir="ltr">Altogether, the results across studies highlight the complexity of time perception in influencing affect and help provide foundational information regarding the empirical convergence between cognitive and clinical phenomena.</p>

No / When formulating an estimate of event time, the human sensory system has been shown to possess a degree of perceptual flexibility. Specifically, the perceived relative timing of auditory and visual stimuli is, to some extent, a product of recent experience. It has been suggested that this form of sensory recalibration may be peculiar to the audiovisual domain. Here we investigate how adaptation to sensory asynchrony influences the perceived temporal order of audiovisual, audiotactile and visuotactile stimulus pairs. Our data show that a brief period of repeated exposure to asynchrony in any of these sensory pairings results in marked changes in subsequent temporal order judgments: the point of perceived simultaneity shifts toward the level of adaptation asynchrony. We find that the size and nature of this shift is very similar in all three pairings and that sensitivity to asynchrony is unaffected by the adaptation process. In light of these findings we suggest that a single supramodal mechanism may be responsible for the observed recalibration of multisensory perceived time.

No / Our sensory systems face a daily barrage of auditory and visual signals whose arrival times form a wide range of audiovisual asynchronies. These temporal relationships constitute an important metric for the nervous system when surmising which signals originate from common external events. Internal consistency is known to be aided by sensory adaptation: repeated exposure to consistent asynchrony brings perceived arrival times closer to simultaneity. However, given the diverse nature of our audiovisual environment, functionally useful adaptation would need to be constrained to signals that were generated together. In the current study, we investigate the role of two potential constraining factors: spatial and contextual correspondence. By employing an experimental design that allows independent control of both factors, we show that observers are able to simultaneously adapt to two opposing temporal relationships, provided they are segregated in space. No such recalibration was observed when spatial segregation was replaced by contextual stimulus features (in this case, pitch and spatial frequency). These effects provide support for dedicated asynchrony mechanisms that interact with spatially selective mechanisms early in visual and auditory sensory pathways.

No / The task of deciding how long sensory events seem to last is one that the human nervous system appears to perform rapidly and, for sub-second intervals, seemingly without conscious effort. That these estimates can be performed within and between multiple sensory and motor domains suggest time perception forms one of the core, fundamental processes of our perception of the world around us. Given this significance, the current paucity in our understanding of how this process operates is surprising. One candidate mechanism for duration perception posits that duration may be mediated via a system of duration-selective 'channels', which are differentially activated depending on the match between afferent duration information and the channels' 'preferred' duration. However, this model awaits experimental validation. In the current study, we use the technique of sensory adaptation, and we present data that are well described by banks of duration channels that are limited in their bandwidth, sensory-specific, and appear to operate at a relatively early stage of visual and auditory sensory processing. Our results suggest that many of the computational principles the nervous system applies to coding visual spatial and auditory spectral information are common to its processing of temporal extent.