DOCSLIB.ORG

The Kappa Effect in Pitch/Time Context Dissertation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Kappa Effect in Pitch/Time Context Dissertation THE KAPPA EFFECT IN PITCH/TIME CONTEXT DISSERTATION Presented in Partial Fulfillment of the Requirements for the degree Doctor of Philosophy in the Graduate School of The Ohio State University By Noah MacKenzie, M.A. ***** The Ohio State University 2007 Dissertation Committee: Professor Mari Jones, Adviser Professor Mark Pitt Approved by Professor James Todd Adviser Psychology Graduate Program ABSTRACT The kappa effect, an effect of spatial extent on the perception of time, is, relatively speaking, poorly understood, especially in the auditory domain. Five experiments demonstrate the kappa effect in the auditory domain by instructing listeners to judge the timing of a tone (Tone X) in relation to a tone immediately preceding it (Tone A) and immediately following it (Tone B). These three tones, together, are referred to as a kappa cell. Experiments 3, 4, and 5 illustrate how the serial context of kappa judgments can influence the strength of the effect. Experiment 1 served as a control experiment to demonstrate the effectiveness of the independent variables. Experiment 2 replicated Shigeno (1986), perhaps the clearest presentation to date of the auditory kappa effect, yet used pitch (frequency on a logarithmic scale) rather than frequency (on a linear scale) as an independent variable. Experiment 3 added a three-tone serial context to the kappa cell. Experiment 4 added a serial context to the kappa cell that strongly conflicted with its pitch trajectory. Experiment 5 examined kappa cells with larger pitch motion (or change in pitch per unit time). Results are discussed in terms of auditory motion and the assumption of constant velocity. ii Dedicated to my wife. iii ACKNOWLEDGMENTS I wish to thank my adviser, Mari Riess Jones, for her support and patience during my graduate school career. Thanks to Heather Moynihan Johnston, Ralph Barnes, and Jennifer Puente for unwavering and tenacious belief. Thanks to Doug Reeder; without him there is no data analysis. Thank you to my mother, who instilled in me a love of learning. Finally, thank you to my wife who has been a constant source of love, encouragement, and comfort throughout this experience. iv VITA May 2, 1975 ..................................................Born – Anchorage, AK 1997 ...............................................................B.A. Psychology, Penn State University 2000 ...............................................................M.A. Psychology, The Ohio State University 2001 – 2005 ...................................................Graduate Teaching and Research Associate, The Ohio State University 2005 – Present ...............................................Lecturer, University of Wisconsin PUBLICATIONS 1. Jones, M.R., Moynihan, H., MacKenzie, N., & Puente, J.K. (2002). Stimulus- driven attending in dynamic arrays. Psychological Science, 13(4), 313-319. 2. Jones, M. R., Barnes, R., Brunetti, R., Ellis, R., Johnston, H., Large, E. et al. (2006). News from the roar lab at the Ohio State University. Cognitive Processing, 7(1), 60-64. v FIELDS OF STUDY Major Field: Psychology vi TABLE OF CONTENTS Page Abstract .....................................................................................................................ii Dedication .................................................................................................................iii Acknowledgments .....................................................................................................iv Vita ............................................................................................................................v List of Tables .............................................................................................................viii List of Figures ...........................................................................................................ix Chapters: 1 Time and (pitch) space revisited ...................................................................1 2 Baseline studies..............................................................................................25 3 Replication of kappa studies..........................................................................38 4 Kappa in serial context...................................................................................51 5 Kappa with opposing serial context...............................................................71 6 Kappa cells with greater pitch motion ...........................................................81 7 General discussion .........................................................................................104 List of References ......................................................................................................115 vii LIST OF TABLES Table Page 1 Possible pitch values for Tone X in Experiment 1 by Pitch Direction condition………………………………................................................................42 2 Possible pitch values for Tone X in Experiment 5................................................85 viii LIST OF FIGURES Figure Page 1 Schematics of patterns used in Experiment 1a (panel a) and Experiment 1b (panel b) sequences....................................................................................29 2 p(B) as a function of X Time in Experiment 1a..............................................32 3 p(B) scores as a function of the X Time variable in Experiment 1b..............34 4 Mean p(B) scores in Experiment 1, as a function of X Time and Context, Present (Experiment 1b) or Absent (Experiment 1a)......................................36 5 Schematic of an Up sequence in Experiment 2..............................................41 6 p(B) responses as a function of the pitch distance of Tone X from Tone A for Experiment 2.........................................................................................45 7 PC scores as a function of the X Time variable in Experiment 2.................. 46 8 PC as a function of the temporal distance (ms) and pitch distance (ST) of Tone X from Tone A for Experiment 2......................................................... 47 9 PSE scores as a function of X Pitch in Experiment 2.................................... 48 10 Schematic of a sequence with Serial Context = 0 in Experiment 3.............. 53 11 p(B) responses as a function of X Pitch for Experiment 3.............................57 12 A significant interaction of X Pitch and Serial Context on p(B) in Experiment 3.................................................................................................. 58 13 Interaction of X Time and X Pitch in Experiment 3...................................... 60 ix 14 PC scores as a function of the X Time variable in Experiment 3...................61 15 PC as a function of X Pitch in Experiment 3..................................................62 16 PC as a function of the temporal distance (ms) and pitch distance (ST) of Tone X from Tone A for Experiment 3......................................................... 63 17a PC as a function of the temporal distance (ms) and pitch distance (ST) of Tone X from Tone A for Experiment 3 (where SC=0).................................. 64 17b PC as a function of the temporal distance (ms) and pitch distance (ST) of Tone X from Tone A for Experiment 3 (where SC=4).................................. 65 17c PC as a function of the temporal distance (ms) and pitch distance (ST) of Tone X from Tone A for Experiment 3 (where SC=8).................................. 66 18 PSE scores as a function of X Pitch in Experiment 3.................................... 68 19 Schematic of a sequence in Experiment 4..................................................... 72 20 Effect of X Time on p(B) judgments in Experiment 4...................................76 21 Null effect of X Pitch on p(B) judgments in Experiment 4. The SC 4 condition from Experiment 3 is plotted for comparison.................................77 22 p(B) scores as a function of the X Time variable in Experiment 1b.............. 88 23 p(B) responses as a function of X Pitch for Experiment 5.............................89 24 p(B) responses as a function of Serial Context for Experiment 5..................91 25 Interaction of X Time and X Pitch in Experiment 5...................................... 92 26 Effect (ns) of X Pitch and Serial Context on p(B) in Experiment 5...............93 27 p(B) judgments as a function of X Pitch for the combined SC0 conditions of Experiments 3 & 5. Larger values for X Pitch (x-axis) indicate greater distances (in semitones) of Tone X from Tone A.......................................... 96 x 28 p(B) judgments as a function of X Pitch and Kappa Cell conditions for SC0 patterns. No kappa effect is present for the KC4 condition (Experiment 3) while a kappa effect is present in the KC8 condition (Experiment 5)............................................................................................... 97 29 p(B) judgments as a function of X Time and Kappa Cell condition for SC0 patterns....................................................................................................98 30 Significant effect of X Pitch on p(B) scores from the SC0 condition of Experiment 5...................................................................................................100 31 Significant interaction of X Time and X Pitch for the SC0 condition of Experiment 5...................................................................................................101 32 PSE scores as a function
Load more

Recommended publications
  • A Test of an Auditory Motion Hypothesis for Continuous and Discrete Sounds Moving in Pitch Space
    A TEST OF AN AUDITORY MOTION HYPOTHESIS FOR CONTINUOUS AND DISCRETE SOUNDS MOVING IN PITCH SPACE Molly J. Henry A Dissertation Submitted to the Graduate College of Bowling Green State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2011 Committee: J. Devin McAuley, Advisor Rodney M. Gabel Graduate Faculty Representative Jennifer Z. Gillespie Dale S. Klopfer ii ABSTRACT J. Devin McAuley, Advisor Ten experiments tested an auditory motion hypothesis, which proposes that regular pitch- time trajectories facilitate perception of and attention to auditory stimuli; on this view, listeners are assumed to use velocity information (pitch change per unit time) to generate expectations about the future time course of continuous and discrete sounds moving in pitch space. Toward this end, two sets of experiments were conducted. In six experiments reported in Part I of this dissertation, listeners judged the duration or pitch change of a continuous or discrete comparison stimulus relative to a standard, where the comparison’s velocity varied on each trial relative to the fixed standard velocity. Results indicate that expectations generated based on velocity information led to distortions in perceived duration and pitch change of continuous stimuli that were consistent with the auditory motion hypothesis; specifically, when comparison velocity was relatively fast, duration was overestimated and pitch change was underestimated. Moreover, when comparison velocity was relatively slow, duration was underestimated and pitch change was overestimated. On the other hand, no perceptual distortions were observed for discrete stimuli, consistent with the idea that velocity information is less clearly conveyed, or easier to ignore, for discrete auditory stimuli.
    [Show full text]
  • An Investigation of Tactile Localization and Skin-Based Maps
    Where was I touched? – An investigation of tactile localization and skin-based maps Jack Brooks Doctor of Philosophy Neuroscience Research Australia School of Medical Sciences, Faculty of Medicine University of New South Wales November 2017 ii Preface The coding of the position of touch on the skin and of the size and shape of the body are both fundamental for interacting with our surrounds. The aim of this thesis was to learn more about the mechanisms of tactile localization and to characterize the principles by which skin-based representations of the body update. It is commonly accepted that skin-based representations of the body are generated from the statistics of touch and other inputs. My studies required skin stimulation customised to account for inter-individual differences in touch sensitivity and forearm shape. Within the constraints of these methodological challenges, the central questions of this thesis were addressed by performing multiple behavioural experiments. In my first study, I tested how touch intensity and history influence touch localization. The study showed that reducing touch intensity increases the variability of pointing responses to touch and results in spatial biases to the middle of the recent history of touch. Thus, I showed that when uncertain about perceived touch location, a strategy is used that minimises localization errors over time. This error minimisation mechanism stabilises our perception of events on the skin and their sensory features. Next, I investigated uncertainty in a motion stimulus by fragmenting it. Studies in vision suggest that missing sensory inputs are filled-in from the surrounds, while previous tactile studies suggest fragmented motion could influence skin-based representations.
    [Show full text]
  • Space and Time in Perception and Action Edited by Romi Nijhawan and Beena Khurana Index More Information
    Cambridge University Press 978-0-521-86318-6 - Space and Time in Perception and Action Edited by Romi Nijhawan and Beena Khurana Index More information Index absolute time, 1, 232 effect on perceived speed, 233 acceleration, 99, 118, 124, 133, 177, 287, 342, 366, 449, effect on time perception, 269, 272 545 endogenous, 269–271, 532, 543 acuity, visual, 102, 105, 449 exogenous, 269–271 adaptation, 43, 44, 48, 63, 64, 68, 78, 97, 124, 128, 202, 209, in flash-lag effect, 396–403, 414, 423, 479, 487, 493–495 212, 236, 243, 245, 248, 284, 288, 295, 345, 351, 352, in Frohlich¨ effect, 321, 328–331, 334 359, 489, 531, 532 and motion information, 521, 524–526, 528–532 Adelson, E. H., 126, 137, 281, 392, 418, 525, 530 and perceptual asynchrony, 269–271, 516, 517 afference, 13, 57, 95, 97, 211, 423–428, 431, 435, 436, 438, in representational momentum, 343, 348, 358, 367 543–545, 548, 551 and salience, 284, 294 after-image, 13, 33, 95–97, 100 shifts in, 203, 243, 256 aim, target, 109, 110, 113, 118 in temporal order, 170, 174, 272, 286 Alais, D., 233, 240, 272, 273, 402, 479, 481, 482, 493, 546 audiovisual interaction, 236, 243, 245, 247, 278, 279, 284, algorithm, 278, 282, 284, 295, 350, 357, 358 286, 293–295, 303, 546 aliasing. See temporal aliasing audition, 3, 73, 74, 80, 152, 159, 160, 166, 169, 182, 217, 228, allocentric location. See also exocentric location 247, 254, 271, 278, 283, 288, 290, 303, 342, 397, 479, amodal 481, 550 representation, 284 and simultaneity, 232–235, 238, 240, 241, 243, 245, 279, tokens, 278, 279 284, 286, 293–295 Andersen, R.
    [Show full text]
  • TRF1: It Was the Best of Time(S)…
    Timing & Time Perception 6 (2018) 231–414 brill.com/time TRF1: It Was the Best of Time(s)… Anne Giersch1 and Jennifer T. Coull2 1INSERM, France 2Laboratoire des Neurosciences Cognitives (UMR 7291), Aix-Marseille University & CNRS, Marseille, France The Timing Research Forum (TRF; http://timingforum.org/) is an interna- tional (Fig. 1), gender-inclusive, and open academic society for timing re- search, founded in 2016 by Argiro Vatakis and Sundeep Teki (Teki, 2016). Following a call to its Committee members in May 2016, we agreed to host the 1st Conference of the Timing Research Forum in Strasbourg, France (TRF1; http://trf-strasbourg.sciencesconf.org). First on the agenda was to decide on eminent keynote speakers to lend credibility to this very first TRF conference. We wanted one talk from the field of psychology and the other from the neurosciences, and so were delighted that both Lera Boro- ditsky and Warren Meck accepted our invitations immediately. Lera kicked off the conference for us, with an extremely entertaining talk about the spatial representation of time in different societies and cultures and how the linguistic metaphors we use to describe time influence our conception of time. Warren highlighted the key role of the striatal dopaminergic sys- tem for timing, illustrating his talk with data from an impressive variety of methodological techniques from the clinical level (performance in patients with Parkinson’s Disease) right down to the cellular (optogenetic studies in mice). Coincidentally, the role of dopamine in timing was also the subject of our third keynote talk. One of the mission statements of TRF is to pro- mote the work of young researchers, and Argiro and Sundeep had the great idea to invite an early-career researcher to give a keynote talk.
    [Show full text]
  • UC Merced Proceedings of the Annual Meeting of the Cognitive Science Society
    UC Merced Proceedings of the Annual Meeting of the Cognitive Science Society Title Does spatiotemporal integration occur with single empty time intervals instead of two neighboring intervals in the visual modality? Permalink https://escholarship.org/uc/item/3705r7j0 Journal Proceedings of the Annual Meeting of the Cognitive Science Society, 36(36) ISSN 1069-7977 Authors Kuroda, Tsuyoshi Grondin, Simon Tobimatsu, Shozo Publication Date 2014 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Does spatiotemporal integration occur with single empty time intervals instead of two neighboring intervals in the visual modality? Tsuyoshi Kuroda ([email protected]) Department of Clinical Neurophysiology, Neurological Institute, Graduate School of Medical Sciences Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan Simon Grondin ([email protected]) École de psychologie, Université Laval, 2325 rue des Bibliothèques Québec, G1V 0A6 Canada Shozo Tobimatsu ([email protected]) Department of Clinical Neurophysiology, Neurological Institute, Graduate School of Medical Sciences Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan Abstract interpreted as indicating a perceptual tendency to overestimate duration when spatial distance is increased. The kappa effect is an illusion involving spatiotemporal integration in the cognitive process and is demonstrated with The kappa effect is explained by the imputed-velocity three successive signals delimiting two neighboring empty model, positing the constancy of motional speed or velocity time intervals. The present experiment was conducted with (Alards-Tomalin, Leboe-McGowan, & Mondor, 2013; single time intervals delimited by two signals, instead of three, Henry & McAuley, 2009; Jones, & Huang, 1982; ten to examine whether perceived duration would be modulated Hoopen, Miyauchi, & Nakajima, 2008).
    [Show full text]
  • Processing Time Between Visual Events
    Processing time between visual events Processamento temporal entre eventos visuais Simon Grondin ABSTRACT Visual perception is closely related to and associated with the processing of space. Nevertheless, all events occur at some moment in time, and time needs to be processed in the visual mode. After briefly reviewing the many research avenues in which time and vision are linked, this article focuses on the discrimination of visually marked time intervals, emphasizing work from my own laboratory. It presents a theoretical position, that of a single- clock hypothesis, as well as issues and data that show how visual temporal processing can be approached. These issues are partly related to the fact that time is marked by signals from a single source or by signals provided by distanced sources. In the latter case, different questions arise depending on the signals’ exact location. It is known that more distance between flashes can result in longer perceived duration (kappa effect). However, the data reported here, involving signals placed on the same vertical plane, show the opposite effect: briefer perceived duration with more distance between flashes. When flashes are located on the same horizontal plane in different hemi-fields, there is also a lateral effect that may influence time judgments. Keywords: Time perception; Perceived duration; Time markers; Kappa effect From the electrophysiology of retinal or cortical cells to the Gestalt law of organization of visual stimuli, there are a variety of levels for understanding vision and visual perception. In many cases, the visual phenomena to be understood consist of color, form, depth or movement. As can readily be grasped when considering depth or movement, space is often crucial information for the visual system.
    [Show full text]
  • What Drives the Kappa Effect
    RESEARCH ARTICLE Speed Constancy or Only Slowness: What Drives the Kappa Effect Youguo Chen1*, Bangwu Zhang1, Konrad Paul Kording2 1 Key Laboratory of Cognition and Personality (Ministry of Education), Center of Studies for Psychology and Social Development, Faculty of psychology, Southwest University, Chongqing, China, 2 Department of Physical Medicine and Rehabilitation, Rehabilitation Institute of Chicago, Northwestern University, Chicago, Illinois, United States of America * [email protected] a11111 Abstract In the Kappa effect, two visual stimuli are given, and their spatial distance affects their per- ceived temporal interval. The classical model assumes constant speed while a competing Bayesian model assumes a slow speed prior. The two models are based on different OPEN ACCESS assumptions about the statistical structure of the environment. Here we introduce a new Citation: Chen Y, Zhang B, Kording KP (2016) visual experiment to distinguish between these models. When fit to the data, both the two Speed Constancy or Only Slowness: What Drives the models replicated human response, but the slowness model makes better behavioral pre- Kappa Effect. PLoS ONE 11(4): e0154013. dictions than the speed constancy model, and the estimated constant speed is close to the doi:10.1371/journal.pone.0154013 absolute threshold of speed. Our findings suggest that the Kappa effect appears to be due Editor: Wenbo Luo, Liaoning Normal University, to slow speeds, and also modulated by spatial variance. CHINA Received: July 18, 2015 Accepted: April 7, 2016 Published: April 21, 2016 Introduction Copyright: © 2016 Chen et al. This is an open access article distributed under the terms of the The Kappa effect is a spatiotemporal illusion where the perception of elapsed time between the Creative Commons Attribution License, which permits sensory stimuli is systematically distorted by the irrelevant distance between the stimuli [1, 2].
    [Show full text]
  • A Bayesian Perceptual Model Replicates the Cutaneous Rabbit and Other Tactile Spatiotemporal Illusions Daniel Goldreich*
    A Bayesian Perceptual Model Replicates the Cutaneous Rabbit and Other Tactile Spatiotemporal Illusions Daniel Goldreich* Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Ontario, Canada Background. When brief stimuli contact the skin in rapid succession at two or more locations, perception strikingly shrinks the intervening distance, and expands the elapsed time, between consecutive events. The origins of these perceptual space-time distortions are unknown. Methodology/Principal Findings. Here I show that these illusory effects, which I term perceptual length contraction and time dilation, are emergent properties of a Bayesian observer model that incorporates prior expectation for speed. Rapidly moving stimuli violate expectation, provoking perceptual length contraction and time dilation. The Bayesian observer replicates the cutaneous rabbit illusion, the tau effect, the kappa effect, and other spatiotemporal illusions. Additionally, it shows realistic tactile temporal order judgment and spatial attention effects. Conclusions/ Significance. The remarkable explanatory power of this simple model supports the hypothesis, first proposed by Helmholtz, that the brain biases perception in favor of expectation. Specifically, the results suggest that the brain automatically incorporates prior expectation for speed in order to overcome spatial and temporal imprecision inherent in the sensorineural signal. Citation: Goldreich D (2007) A Bayesian Perceptual Model Replicates the Cutaneous Rabbit and Other Tactile Spatiotemporal Illusions. PLoS ONE 2(3): e333. doi:10.1371/journal.pone.0000333 INTRODUCTION mechanics. Apparently related to the rabbit is the classic tau effect, How does the brain interpret information from the senses? This in which the more rapidly traversed of two equal distances (defined unresolved question carries fundamental importance for neurosci- by three stimuli) is perceived as shorter [15,16] (Fig.
    [Show full text]
  • Evaluation of an Imputed Pitch Velocity Model of the Auditory Tau Effect
    Attention, Perception, & Psychophysics 2009, 71 (6), 1399-1413 doi:10.3758/APP.71.6.1399 Evaluation of an imputed pitch velocity model of the auditory tau effect MOLLY J. HENRY Bowling Green State University, Bowling Green, Ohio J. DEVIN MCAULEY Michigan State University, East Lansing, Michigan A N D MA RT A ZA LE ha Bowling Green State University, Bowling Green, Ohio This article extends an imputed pitch velocity model of the auditory kappa effect proposed by Henry and McAuley (2009a) to the auditory tau effect. Two experiments were conducted using an AXB design in which listeners judged the relative pitch of a middle target tone (X) in ascending and descending three-tone sequences. In Experiment 1, sequences were isochronous, establishing constant fast, medium, and slow velocity conditions. No systematic distortions in perceived target pitch were observed, and thresholds were similar across velocity conditions. Experiment 2 introduced to-be-ignored variations in target timing. Variations in target timing that deviated from constant velocity conditions introduced systematic distortions in perceived target pitch, indicative of a robust auditory tau effect. Consistent with an auditory motion hypothesis, the magnitude of the tau effect was larger at faster velocities. In addition, the tau effect was generally stronger for descending sequences than for ascending sequences. Combined with previous work on the auditory kappa effect, the imputed velocity model and associated auditory motion hypothesis provide a unified quantitative account of both auditory tau and kappa effects. In broader terms, these findings add support to the view that pitch and time relations in auditory patterns are fundamentally interdependent.
    [Show full text]
  • The Perception of Timescales in Electroacoustic Music
    Pasoulas, Aki (2011). The perception of timescales in electroacoustic music. (Unpublished Doctoral thesis, City University London) City Research Online Original citation: Pasoulas, Aki (2011). The perception of timescales in electroacoustic music. (Unpublished Doctoral thesis, City University London) Permanent City Research Online URL: http://openaccess.city.ac.uk/1155/ Copyright & reuse City University London has developed City Research Online so that its users may access the research outputs of City University London's staff. Copyright © and Moral Rights for this paper are retained by the individual author(s) and/ or other copyright holders. Users may download and/ or print one copy of any article(s) in City Research Online to facilitate their private study or for non- commercial research. Users may not engage in further distribution of the material or use it for any profit-making activities or any commercial gain. All material in City Research Online is checked for eligibility for copyright before being made available in the live archive. URLs from City Research Online may be freely distributed and linked to from other web pages. Versions of research The version in City Research Online may differ from the final published version. Users are advised to check the Permanent City Research Online URL above for the status of the paper. Enquiries If you have any enquiries about any aspect of City Research Online, or if you wish to make contact with the author(s) of this paper, please email the team at [email protected]. THE PERCEPTION
    [Show full text]
  • University of Bradford Ethesis
    University of Bradford eThesis This thesis is hosted in Bradford Scholars – The University of Bradford Open Access repository. Visit the repository for full metadata or to contact the repository team © University of Bradford. This work is licenced for reuse under a Creative Commons Licence. The role of sensory history and stimulus context in human time perception Adaptive and integrative distortions of perceived duration Corinne FULCHER Submitted for the Degree of Doctor of Philosophy Faculty of Life Sciences University of Bradford 2017 Abstract Corinne Fulcher The Role of Sensory History and Stimulus Context in Human Time Perception Adaptive and Integrative Distortions of Perceived Duration Keywords: Time perception, Duration, Human, Adaptation, Integration, Subsecond, Vision, Audition, Psychophysics, Modelling This thesis documents a series of experiments designed to investigate the mechanisms subserving sub-second duration processing in humans. Firstly, duration aftereffects were generated by adapting to consistent duration information. If duration aftereffects represent encoding by neurons selective for both stimulus duration and non-temporal stimulus features, adapt-test changes in these features should prevent duration aftereffect generation. Stimulus characteristics were chosen which selectively target differing stages of the visual processing hierarchy. The duration aftereffect showed robust interocular transfer and could be generated using a stimulus whose duration was defined by stimuli invisible to monocular mechanisms, ruling out a pre- cortical locus. The aftereffects transferred across luminance-defined visual orientation and facial identity. Conversely, the duration encoding mechanism was selective for changes in the contrast-defined envelope size of a Gabor and showed broad spatial selectivity which scaled proportionally with adapting stimulus size. These findings are consistent with a second stage visual spatial mechanism that pools input across proportionally smaller, i spatially abutting filters.
    [Show full text]
  • Introducing a New Haptic Illusion to Increase the Perceived Resolution of Tactile Displays
    Introducing a New Haptic Illusion to Increase the Perceived Resolution of Tactile Displays Rebekka Hoffmann1,2, Manje A. B. Brinkhuis1, Árni Kristjánsson1 and Runar Unnthorsson2 1Faculty of Psychology, University of Iceland, Sæmundargata 2, Reykjavik, Iceland 2Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, University of Iceland, Sæmundargata 2, Reykjavik, Iceland Keywords: Haptic Illusion, Error of Localization, Tactile Spatial Acuity, Vibrotactile Resolution, Tactile Displays. Abstract: Tactile high-resolution displays gained importance during the last decade due to their wide range of application areas. To maximize the throughput of information developers can be tempted to mount as many tactile actuators (tactors) as possible on a haptic device, thereby risking to overexert the user’s sense of touch, and to critically decrease its usability. Studies therefore explore ways of increasing the perceived resolution of tactile displays by exploiting haptic illusions. We demonstrate a new spatiotemporal haptic illusion that has not been described in literature yet. We conducted an experiment, in which we manipulated the vibration intensity of two successive tactor activations, the direction of consecutive tactor activations (up, down) and inter-tactor distance (40, 20, or zero mm). Fourteen naive participants judged whether the second tactor activation was above or below the first activation. Our results suggest that varying the sequence of activations with different intensities leads to an error of localization. High intensity activations followed by low intensity activations resulted in an illusory downward movement, and vice versa. The haptic intensity-movement illusion provides a promising possibility to enhance the information conveyed in tactile displays, without increasing the tactor density at the cost of the product’s usability, comfort and ergonomy.
    [Show full text]