About the time-shrinking illusion in the tactile modality

The aim of this study was to examine the occurrence of a so-called time-shrinking illusion in the tactile modality, while it had been tested so far mainly with auditory and visual stimuli. We examined whether the perception of an empty time interval marked by two brief tactile stimuli, S (240 ms), would be influenced by the presence of a preceding time interval, P (160, 240, or 320 ms). Results showed that S was underestimated when P was shorter than S. This underestimation appeared as a kind of perceptual assimilation between P and S, but S was not overestimated when P was longer. The underestimation was rather interpreted as a manifestation of the time-shrinking illusion.Keywords: Perceived duration Empty interval Time shrinking Assimilation Somatosensory modalit

Effects of the temporal structure of sound markers on rhythm perception

第1章 序論 1.1はじめに 1.2本研究の背景 1.2.1時間知覚研究 1.2.3音の時間構造と時間知覚 1.3本研究の目的 1.4本論文の構成 第2章 単独の時間間隔の知覚 2.1はじめに 2.2目的 2.3実験1：持続時間の影響 2.3.1目的 2.3.2実験方法 2.3.3結果と考察 2.4実験2：振幅の影響 2.4.1目的 2.4.2実験方法 2.4.3結果と考察 2.5実験3：音エネルギーの時間分布の影響 2.5.1目的 2.5.2実験方法 2.5.3結果と考察 2.6まとめ 第3章 隣接する時間間隔の知覚 3.1はじめに 3.2目的 3.3実験4：隣り合う時間間隔の長さの比較 3.3.1目的 3.3.2実験方法 3.3.3結果と考察 3.4実験5：隣り合う時間間隔の主観的な長さの測定 3.4.1目的 3.4.2実験方法 3.4.3結果と考察 3.5まとめ 第4章 音の持続時間の知覚 4.1はじめに 4.2目的 4.3実験6：空虚時間と充実時間の主観的な長さの測定１ 4.3.1目的 4.3.2実験方法 4.3.3結果と考察 4.4実験7：空虚時間と充実時間の主観的な長さの測定２ 4.4.1目的 4.4.2実験方法 4.4.3結果と考察 4.5まとめ 第5章 総合考察 5.1はじめに 5.2区切音の持続時間はどのように時間間隔の知覚の仕組みに影響したのか 5.3本研究の結果と従来のリズム知覚研究の結果との関連付け 5.4今後の展望 5.5まとめ 第6章 結論 文献 謝辞Submitted by QIR アルバイト ([email protected]) on 2011-06-29T07:13:20Z No. of bitstreams: 12 01_cover.pdf: 8996 bytes, checksum: 6323c8dff3e0a3cdcf486fd36c07102f (MD5) 02_contents.pdf: 21529 bytes, checksum: 25d2c551730c19c867acb2b5bca0538f (MD5) 03_intoroduction.pdf: 116748 bytes, checksum: c0679fdb8bddf02c9ea97ff177ce7caa (MD5) 04_chapter1(序論).pdf: 81326 bytes, checksum: e26ceafe3ce479322fc036ad9bea4197 (MD5) 05_chapter2.pdf: 217739 bytes, checksum: 1c3761fa83be4e0214e8d1e375913370 (MD5) 06_chapter3.pdf: 274901 bytes, checksum: 310eed0a4938155d3b9a1bd318f43fd5 (MD5) 07_chapter4.pdf: 390250 bytes, checksum: eac9acd28da9762a65bf220a730aa450 (MD5) 08_chapter5.pdf: 77050 bytes, checksum: 5df59098f0f315814a192a971400c712 (MD5) 09_chapter6(結論).pdf: 23551 bytes, checksum: aff2cb6aff5073352d40884c5f6d5556 (MD5) 10_acknowledgement.pdf: 16474 bytes, checksum: cc6275c4aa6c80cf911d3e7ec46049dd (MD5) 11_reference.pdf: 39189 bytes, checksum: 5162155896fa07fd5816c3e4502c97fd (MD5) 12_errata.pdf: 39837 bytes, checksum: 3a5a7b6322b93f9bf1395c4eaa4fba6f (MD5)Made available in DSpace on 2011-06-29T07:13:21Z (GMT). No. of bitstreams: 12 01_cover.pdf: 8996 bytes, checksum: 6323c8dff3e0a3cdcf486fd36c07102f (MD5) 02_contents.pdf: 21529 bytes, checksum: 25d2c551730c19c867acb2b5bca0538f (MD5) 03_intoroduction.pdf: 116748 bytes, checksum: c0679fdb8bddf02c9ea97ff177ce7caa (MD5) 04_chapter1(序論).pdf: 81326 bytes, checksum: e26ceafe3ce479322fc036ad9bea4197 (MD5) 05_chapter2.pdf: 217739 bytes, checksum: 1c3761fa83be4e0214e8d1e375913370 (MD5) 06_chapter3.pdf: 274901 bytes, checksum: 310eed0a4938155d3b9a1bd318f43fd5 (MD5) 07_chapter4.pdf: 390250 bytes, checksum: eac9acd28da9762a65bf220a730aa450 (MD5) 08_chapter5.pdf: 77050 bytes, checksum: 5df59098f0f315814a192a971400c712 (MD5) 09_chapter6(結論).pdf: 23551 bytes, checksum: aff2cb6aff5073352d40884c5f6d5556 (MD5) 10_acknowledgement.pdf: 16474 bytes, checksum: cc6275c4aa6c80cf911d3e7ec46049dd (MD5) 11_reference.pdf: 39189 bytes, checksum: 5162155896fa07fd5816c3e4502c97fd (MD5) 12_errata.pdf: 39837 bytes, checksum: 3a5a7b6322b93f9bf1395c4eaa4fba6f (MD5) Previous issue date: 2011-03-24本研究は，音声や音楽のリズムの基礎となる0.5秒以下の短い時間間隔の知覚に，音の時間構造がどのような影響を与えるかを調べたものである。従来のリズム知覚研究において，知覚されるリズムは，次々に鳴らされる音の始まり（もしくは音の知覚的な始まり）の間の時間間隔の長さによって決まるとされてきた（例えば，Handel, 1993）。一方，リズム知覚と密接に関係する時間知覚研究の分野においては，音の持続時間が知覚される時間間隔の長さに影響することが示されていた（例えば，Woodrow, 1928）。つまり，リズム知覚においても，音の始まりだけでなく，音の持続時間が影響する可能性があった。ただし，従来の時間知覚研究で用いられた刺激パターンや，時間間隔の定義は，リズム知覚研究で対象とされるものと異なっていたため，音の持続時間の影響を直接リズム知覚と結び付けることができなかった。本研究では，従来の時間知覚研究とリズム知覚研究の間を埋めるような刺激パターンを用いた知覚実験によって，リズムに用いられるような時間間隔の知覚においても，音の持続時間の影響がみられることを示した。また，時間間隔を示すひとつひとつの音の時間構造を体系的に操作することによって，どの音の時間構造が時間間隔の知覚にどのように影響するかを明らかにした。第2章では，まずリズムを示すパターンとして最も単純なパターン，すなわち継時的に鳴らされた二つの音の始まりによって示された120-360msの単独の時間間隔を用いて実験を行った。音の始まりの位置は固定したまま，時間間隔を示す二つの音の持続時間をそれぞれ20-100msの範囲で変化させたところ，時間間隔の終わりを示す音の持続時間が長くなるほど時間間隔の主観的な長さが長くなる傾向がみられた。この傾向は，音の振幅が変わっても同様に現れ，また，音の持続時間を固定したまま振幅包絡を変化させることにより音エネルギーの時間分布を変化させただけでは現れなかったことから，音の持続時間自体が変化することが時間間隔の知覚において重要であることが考えられた。続く第3章では，第2 章で発見された，時間間隔の終わりを示す音の持続時間の影響が，時間間隔が隣接するパターンにおいても生ずるかどうかを確かめた。三つの音の始まりによって示された二つの隣接する時間間隔から成るパターンを用いて，二つの時間間隔の主観的な長さを調べる実験を行ったところ，第2章で単独の時間間隔を用いたときと同様に，時間間隔の終わりを示す音の持続時間が長くなると，その時間間隔の主観的な長さが長くなる傾向がみられた。つまり，二つ目の音が長くなると最初の時間間隔の主観的な長さが長くなり，三つ目の音が長くなると後続する時間間隔の主観的な長さが長くなった。一方，条件によっては，単独の時間間隔を用いたときにはみられなかった時間間隔の始まりを示す音の影響もみられ，この効果は，隣接する二つの時間間隔の対比を促進していると考えられた。第4章では，音の持続時間自体の主観的な長さに着目した。過去の研究において，130ms程度よりも短い音の場合，音の持続時間が変わっても音の知覚的な終わりの位置は変化せず，音の主観的な持続時間も変化しないとされたこともあったものの（Efron, 1970），第4章の結果では音の持続時間が20-360msの範囲で長くなるとその主観的な長さも長くなり，第2章および第3章で用いた20-100msという非常に短い音であっても，実験参加者は持続時間の違いを捉えていたことが示唆された。また，音の持続時間の主観的な長さと，第2章と同様に二つの音の始まりによって示された時間間隔の主観的な長さとを比べた結果，200ms以下の時間間隔においては，物理的に同じ長さであっても，実験参加者によって，音の持続時間のほうが二つの音によって示された時間間隔よりも主観的に長くなる場合と，逆に二つの音によって示された時間間隔のほうが音の持続時間よりも主観的に長くなる場合とがあることがわかった。本研究において，音の始まりの位置を固定していても，音の持続時間が変わると時間間隔の主観的な長さが変化したことは，音の物理的な始まりの位置のみによって知覚されるリズムが決まるわけではないことを示している。また，音の持続時間が変化すると音の知覚的な始まりの位置が変化したと考えるだけでは本研究の実験結果を説明することができず，音の持続時間の影響を説明するためには，音の始まりの知覚以外の時間処理への影響についても考える必要があることが示された。本研究は，主に単純な刺激を用いて行われてきた古典的な時間知覚研究と，より複雑で日常的な音を対象として行われてきたリズム知覚研究とを結び付け，知覚されるリズムは音の始まりや音の知覚的な始まりの位置だけでは説明できないことを明らかにした。The present study investigated how the temporal characteristics, particularly durations, of sounds affect the perceived duration of very short inter-onset time intervals (≤ 360ms), which is important for rhythm perception in speech and music. In Experiments 1, 2, and 3, subjective duration of single intervals marked by two sounds was measured utilizing the method of adjustment, while the markers’ durations, amplitude difference (which accompanied the duration change), and sound energy distribution in time were varied. Lengthening the duration of the second marker in the range of 20-100 ms increased the subjective duration of the time interval in a stable manner. Lengthening the first marker tended to increase the subjective duration, but rather unstably. Effects of varying the amplitude difference and the sound energy distribution in time of either marker were very small in the present experimental conditions, thus proving the authenticity of the effects of marker durations as above. In Experiments 4 and 5, the influences of sound durations were examined employing simple rhythm patterns comprised of three successive sounds marking two neighboring time intervals, T1 and T2 in this order. Results showed that lengthening the marker which terminated an interval increased the subjective duration of this interval-lengthening the second marker increased the subjective duration of T1, and lengthening the third marker increased the subjective duration of T2. This was consistent with the findings in Experiments 1-3. Lengthening the first marker increased the subjective duration of T1 when T1 > T2. This effect, which could not be observed with single intervals, seemed to enhance the contrast between T1 and T2. In Experiments 6 and 7, the subjective duration of a sound marker itself (20-360 ms) was measured utilizing the method of adjustment. Although it had been previously assumed that the perceptual duration of all sounds below 130 ms may be equal, results of Experiments 6 and 7 showed that the subjective duration of sounds increased as the physical duration increased, even when the sound duration was varied in the range of 20-100 ms, which suggested that the difference in duration of the markers utilized in Experiments 1-5 should have been noticeable to participants. Possible explanations for these results are discussed as well as their association with rhythm perception studies in which more complex sound patterns were utilized

EEG investigations of duration discrimination: the intermodal effect is induced by an attentional bias.

Previous studies indicated that empty time intervals are better discriminated in the auditory than in the visual modality, and when delimited by signals delivered from the same (intramodal intervals) rather than from different sensory modalities (intermodal intervals). The present electrophysiological study was conducted to determine the mechanisms which modulated the performances in inter- and intramodal conditions. Participants were asked to categorise as short or long empty intervals marked by auditory (A) and/or visual (V) signals (intramodal intervals: AA, VV; intermodal intervals: AV, VA). Behavioural data revealed that the performances were higher for the AA intervals than for the three other intervals and lower for inter- compared to intramodal intervals. Electrophysiological results indicated that the CNV amplitude recorded at fronto-central electrodes increased significantly until the end of the presentation of the long intervals in the AA conditions, while no significant change in the time course of this component was observed for the other three modalities of presentation. They also indicated that the N1 and P2 amplitudes recorded after the presentation of the signals which delimited the beginning of the intervals were higher for the inter- (AV/VA) compared to the intramodal intervals (AA/VV). The time course of the CNV revealed that the high performances observed with AA intervals would be related to the effectiveness of the neural mechanisms underlying the processing of the ongoing interval. The greater amplitude of the N1 and P2 components during the intermodal intervals suggests that the weak performances observed in these conditions would be caused by an attentional bias induced by the cognitive load and the necessity to switch between modalities

Discrimination of two neighboring intra- and intermodal empty time intervals marked by three successive stimuli

We investigated the discrimination of two neighboring intra- or inter-modal empty time intervals marked by three successive stimuli. Each of the three markers was a flash (visual—V) or a sound (auditory—A). The first and last markers were of the same modality, while the second one was either A or V, resulting in four conditions: VVV, VAV, AVA and AAA. Participants judged whether the second interval, whose duration was systematically varied, was shorter or longer than the 500-ms first interval. Compared with VVV and AAA, discrimination was impaired with VAV, but not so much with AVA (in Experiment 1). Whereas VAV and AVA consisted of the same set of single intermodal intervals (VA and AV), discrimination was impaired in the VAV compared to the AVA condition. This difference between VAV and AVA could not be attributed to the participants' strategy to perform the discrimination task, e.g., ignoring the standard interval or replacing the visual stimuli with sounds in their mind (in Experiment 2). These results are discussed in terms of sequential grouping according to sensory similarity.Keywords: Modality-specific timer Multisensory integration Inter-stimulus interval Discrimination Flash Soun

The occurrence of the filled duration illusion: A comparison of the method of adjustment with the method of magnitude estimation

A time interval between the onset and the offset of a continuous sound (filled interval) is often perceived to be longer than a time interval between two successive brief sounds (empty interval) of the same physical duration. The present study examined whether and how this phenomenon, sometimes called the filled duration illusion (FDI), occurs for short time intervals (40–520 ms). The investigation was conducted with the method of adjustment (Experiment 1) and the method of magnitude estimation (Experiment 2). When the method of adjustment was used, the FDI did not appear for the majority of the participants, but it appeared clearly for some participants. In the latter case, the amount of the FDI increased as the interval duration lengthened. The FDI was more likely to occur with magnitude estimation than with the method of adjustment. The participants who showed clear FDI with one method did not necessarily show such clear FDI with the other methodKeywords: Filled interval Empty interval Method of adjustment Magnitude estimation Cluster analysi

Consistency between Modalities Enhances Visually Induced Self-Motion (Vection)

Visually induced illusory self-motion (vection) is generally facilitated by consistent information of self-motion from other modalities. We provide three examples that consistent information between vision and other proprioception enhances vection, ie, locomotion, air flow, and sounds. We used an optic flow of expansion or contraction created by positioning 16,000 dots at random inside a simulated cube (length 20 m), and moving the observer's viewpoint to simulate forward or backward self-motion of 16 m/s. First, We measured the strength of forward or backward vection with or without forward locomotion on a treadmill (2 km/h). The results revealed that forward vection was facilitated by the consistent locomotion whereas vections in the other directions were inhibited by the inconsistent locomotion. Second, we found that forward vection intensity increased when the air flow to subjects' faces produced by an electric fan (the wind speed was 6.37 m/s) was provided. On the contrary, the air flow did not enhance backward vection. Finally, we demonstrated that sounds which increased in loudness facilitated forward vection and the sounds which ascended (descended) in pitch facilitated upward (downward) vection

Mean CNV amplitude.

<p>Mean amplitude recorded during AA, AV, VA and AA intervals at fronto-central (F3, F4, Fz, FCz, C3, C4, Cz) (A) and parietal (P3, P4, Pz) (B) sites. Bars are standard errors.</p

Schematic representation of the experimental paradigm.

<p>The task was to discriminate empty intervals delimited by auditory (A) and/or visual (V) signals. In two sessions, the intervals were defined by two signals of the same modality (intramodal intervals: AA or VV) while in the other two, the signals were delivered from different modalities (intermodal intervals: AV or VA). Each trial began with a fixation point (FP), followed by the presentation of an empty interval (ISI= 450 or 550 ms) bounded by auditory and/or visual stimuli (33 ms each) (S1 and S2 = Stimuli 1 and 2). Then, after the presentation of a fixation point (FP), a visual instruction asked the participants to indicate whether the empty interval corresponded to the short or long interval by pressing respectively “1” or “2” on a Serial Response Box.</p