Illusory continuity without sufficient sound energy to fill a temporal gap: Examples of crossing glide tones

The gap transfer illusion is an auditory illusion where a temporal gap inserted in a longer glide tone is perceived as if it were in a crossing shorter glide tone. Psychophysical and phenomenological experiments were conducted to examine the effects of sound-pressure-level (SPL) differences between crossing glides on the occurrence of the gap transfer illusion. We found that the subjective continuity-discontinuity of the crossing glides changed as a function of the relative level of the shorter glide to the level of the longer glide. When the relative level was approximately between -9 and +2 dB, listeners perceived the longer glide as continuous and the shorter glide as discontinuous, that is, the gap transfer illusion took place. The glides were perceived veridically below this range, that is, gap transfer did not take place, whereas above this range the longer glide and the shorter glide were both perceived as continuous. The fact that the longer glide could be perceived as continuous even when the crossing shorter glide was 9 dB weaker indicates that the longer glide's subjective continuity cannot be explained within the conventional framework of auditory organization, which assumes reallocation of sound energy from the shorter to the longer glide. The implicated mechanisms are discussed in terms of the temporal configuration of onsets and terminations and the time-frequency distribution of sound energy. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Effect of cooling rate on size-dependent atomic ordering of CoPt nanoparticles

We report on the effect of cooling rate on the size-dependent atomic ordering of CoPt nanoparticles using aberration corrected high-resolution transmission electron microscopy. It was found that cooling rate plays a crucial role in promoting atomic ordering during the cooling process after annealing. Nanoparticles of ≈3?nm in diameter show the A1-disordered phase after annealing at 873?K for 1?h followed by rapid cooling (110?K/min), while the L1₀-ordered phase is obtained when the cooling rate is slow (1.5?K/min). The disordered phase is also obtained by rapid cooling after annealing at 973?K for 1?h. These results unambiguously indicate that the order–disorder transformation temperature is reduced to a temperature at least lower than 873?K for CoPt nanoparticles smaller than 3?nm in diameter. The slow cooling process promotes the atomic ordering, which resulted in an enhancement of magnetic coercivity as high as 2200?Oe. This study demonstrates that hard magnetic properties of the CoPt nanoparticles can be improved by controlling the cooling rate after heat treatments.     

Subjectively divided tone components in the gap transfer illusion

When a long glide with a short temporal gap in its middle crosses with a continuous short glide at the temporal midpoint of both glides, the gap is perceived in the short glide instead of in the long glide. In the present article, we tested possible explanations for this "gap transfer illusion" by obtaining points of subjective equality of the pitches and durations of the two short tones that are subjectively divided by the gap. The results of two experiments showed that neither an explanation in terms ofenvelope patterns nor explanations in terms of combinationtones or acoustic beats could account for the perception of the short tones in the gap transfer illusion. Rather, the results were compatible with the idea that the illusory tones were formed by the perceptual integration of onsets and offsets of acoustically different sounds. Implications for the perceptual construction of auditory events are discussed.     

Effects of partial avoidance and punishment contingencies on shuttlebox-avoidance learning in Fischer 344 rats

An unsignaled, escapable shock was presented contingent on an avoidance response. Fischer 344 rats responded less to the warning signal in proportion to its temporal distance from the avoidance response. Partial contingency effects were further obtained by variation in the instrumental conditioning space for an aversive stimulus. However, the arbitrary omission of an imminent shock on half the trial in which the rats failed to avoid a shock, led to little avoidance acquisition, and shock-frequency reduction was thus not sufficient to produce the acquisition of the avoidance response. Because early avoidance responses were initiated by escape from shock, a stimulus contingency may be essential for response initiation, and an explicit response contingency is important in maintaining successful avoidance responses.     

The perceptual integration of auditory stimulus edges: an illusory short tone in stimulus patterns consisting of two partly overlapping glides

Two partly overlapping frequency glides can be perceived as consisting of a long pitch trajectory accompanied by a short tone in the temporal middle. It was found that the appearance of this middle tone could not be related to peripheral processes concerned with spectral splatter or combination tones that could have emerged during the overlap of the glides. Furthermore, it was found that the middle tone was perceived even when components of the 2 glides were separated by more than an equivalent rectangular bandwidth at any time during the overlap. The appearance of the middle tone indicates that auditory events can result from the perceptual integration of component parts-that is, stimulus edges-of acoustically different sounds.     

The lateral effects of Dohsa-method relaxation on visual and auditory responses

The effects of relaxation training, using the Dohsa method, on visual and auditory responses were examined. Twelve college students underwent relaxation training either to the left shoulder, left side of the waist, and the left foot, or to the right side. The measures used in this study were weight-bearing, body perception and external perception, visual field, and visual and hearing acuity. Weight-bearing significantly increased for the foot undergoing relaxation training, compared with the untreated foot, indicating that the subjects stood more firmly on the ground on the relaxed foot. Subjects could also perceive positive changes in their "sense of standing firmly on the ground,""sense of activity in the body,""sense of muscular relaxation," and "sense of fullness in the abdomen" on the side of the body receiving relaxation training. There were positive changes in external perception such as "vividness of the external world,""breadth of the visual field," and "active impression of the external world" for subjects' vision on the side receiving relaxation training. Furthermore, visual and hearing acuity on the side on which relaxation training was administered improved significantly.     

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 method.     

Time-shrinking: A discontinuity in the perception of auditory temporal patterns

Recent research at our laboratories in the field of human auditory time perception revealed that the duration of short empty time intervals (<～200 msec) is considerably underestimated if they are immediately preceded by shorter time intervals. Within a certain range, the amount of subjective time shrinking is a monotonous function of the preceding time interval: the shorter it is, the more it shrinks its successor. In the present study, the preceding interval was kept constant at 50 msec, and the following interval for which the duration had to be judged, varied from 40 to 280 msec. The results showed that at up to 100 msec, the perceived duration increased to a much lesser extent than did the objective duration. Beyond 120 msec, the perceived duration quickly increased and reached a veridical value at 160 msec. Such a sudden change of perceived duration in a temporal pattern in which the objective duration varies gradually indicates a typical example of categorical perception. We suggest that such a categorization of the time dimension might be a clue for processes of speech and music perception.