The relation between similarity grouping and perceptual constancy.

In two experiments on whether similarity grouping is based on the retinal or the perceived slopes of lines, observers judged the grouping of diagonal lines when a display of vertical and diagonal lines was presented upright and when it was slanted 75 deg toward the floor. The floorwise slanting of the display improved gouping, as would be expected if the spontaneous organization of a field into groups in strongly influenced by the projection-level representation of stimuli. It is proposed that similarity grouping occurs at the readout stage of stimulus processing and involves segregating a field into groups on the basis of extrafoveal stimulus differences that are responded to in parallel; or if sequentially, very quickly and independently of focal attention.     

Perception of rhythmic grouping: testing the iambic/trochaic law

This study was designed to test the iambic/trochaic law, which claims that elements contrasting in duration naturally form rhythmic groupings with final prominence, whereas elements contrasting in intensity form groupings with initial prominence. It was also designed to evaluate whether the iambic/trochaic law describes general auditory biases, or whether rhythmic grouping is speech or language specific. In two experiments, listeners were presented with sequences of alternating /ga/ syllables or square wave segments that varied in either duration or intensity and were asked to indicate whether they heard a trochaic (i.e., strong-weak) or an iambic (i.e., weak-strong) rhythmic pattern. Experiment 1 provided a validation of the iambic/trochaic law in English-speaking listeners; for both speech and nonspeech stimuli, variations in duration resulted in iambic grouping, whereas variations in intensity resulted in trochaic grouping. In Experiment 2, no significant differences were found between the rhythmic-grouping performances of English- and French-speaking listeners. The speech/ nonspeech and cross-language parallels suggest that the perception of linguistic rhythm relies largely on general auditory mechanisms. The applicability of the iambic/trochaic law to speech segmentation is discussed.     

Categorizing sounds by pitch: effects of stimulus similarity and response repetition

Two experiments were performed to determine whether categorization of the pitch of a probe tone is influenced by the pitch of, and response made to, a preceding prime tone. The prime and the probe could be drawn either from a pool of low-frequency sounds or from a pool of high-frequency sounds. The results of both experiments indicated that the performance obtained was best when the prime and the probe were the same pitch (and therefore required the same response), intermediate when the two sounds differed in pitch and required different responses, and slowest when the prime and the probe differed in pitch but required the same response (i.e., they were drawn from the same frequency pool). The results of Experiment 2 revealed in addition that when a repeated response was required, performance declined as the magnitude of the frequency change increased and that responses were made more quickly and accurately if the direction of the frequency change was away from the alternative category than if it was toward the alternative category. The results demonstrate that categorization of sounds by pitch is accomplished with reference to a previous processing episode.     

Rate and duration memory of naturalistic sounds

Research has shown that the tempi of familiar songs are remarkably well-remembered with a high degree of accuracy. The goal of the present research was to determine whether this ability generalizes to various types of ecological sounds and, if so, how rate information is encoded into the cognitive system. Across three experiments, participants were familiarized with a set of sounds and later asked to remember the rate of each. Experiment 1 revealed that the inherent rate of sounds is incidentally learned such that subsequent recognition is comparable across both prospective and retrospective paradigms. Experiment 2 confirmed these findings through an adjustment task and further demonstrated that memory for event rate remains highly accurate regardless if attending is initially directed toward a sound's rate and/or pitch qualities. Lastly, Experiment 3 assessed the ability to recognize event rate vs. duration when the two dimensions systematically co-vary with one another and revealed that rate variations influence duration recognition but not vice versa. These overall findings are discussed relative to a framework that emphasizes the role of event structure in time judgment behavior.     

Judgments of the duration of visually marked empty time intervals: Linking perceived duration and sensitivity

The capability of subjects to categorize (as short or long) visually marked empty time intervals was investigated in three experiments. Two visual signals, located 18° to the left (L) and to the right (R) of a fixation point in the visual field, established four marking conditions, two unilaterally presented (L-L and R-R) and two bilaterally presented (L-R and R-L). In Experiments 1 and 2, the results show that discrimination is better with unilateral sequences than with bilateral sequences and that the perceived duration is longer with an L-R than with an R-L sequence. In addition, Experiment 2 shows that, in comparison with a condition in which Markers 1 and 2 remain identical for a complete session, varying the markers from trial to trial does not decrease discrimination. Also, Experiment 2 shows that discrimination is better when both visual markers are presented at fovea than it is in the unilateral conditions. Experiment 3 shows that bilateral intervals are perceived as being longer and are better discriminated than are intervals marked by an intermodal sequence (auditory-visual or visual-auditory). The general discussion reports the implications of having different perceived duration and sensitivity levels, in various marker-type conditions, for an internal-clock hypothesis. Some implications of these results for a lateralized-timer hypothesis are also discussed.     

The subjective duration of ramped and damped sounds

Two experiments demonstrate that the perceived durations of sounds as long as 1 sec are influenced by the sounds' amplitude envelopes, extending Schlauch, Ries, and DiGiovanni's (2001) observations on sounds of 200-msec duration. Sounds with a monotonic decay (i.e., damped sounds) are heard as substantially shorter than both steady sounds and those with a monotonic increase of level (i.e., ramped sounds). Neither a reaction time (Experiments 1 and 2) nor a staircase (Experiment 2) procedure supported a sensory explanation for these different subjective durations. The results are compatible with the suggestion of Stecker and Hafter (2000) that listeners exclude part of the tails of damped sounds in the computation of their subjective durations.     

Perceived duration of expected and unexpected stimuli

Three experiments assessed whether perceived stimulus duration depends on whether participants process an expected or an unexpected visual stimulus. Participants compared the duration of a constant standard stimulus with a variable comparison stimulus. Changes in expectancy were induced by presenting one type of comparison more frequently than another type. Experiment 1 used standard durations of 100 and 400 ms, and Experiments 2 and 3 durations of 400 and 800 ms. Stimulus frequency did not affect perceived duration in Experiment 1. In Experiments 2 and 3, however, frequent comparisons were perceived as shorter than infrequent ones, and discrimination performance was better for infrequent comparisons. Overall, this study supports the notion that infrequent stimuli increase the speed of an internal pacemaker.     

The unilateral field advantage in repetition detection: Effects of perceptual grouping and task demands

This study examines interhemispheric interactions in detecting objects that are simultaneously repeated in an array of objects. Previous studies have shown that presenting two identical objects to a single hemifield speeds up repetition detection. This unilateral field advantage (UFA) is often attributed to the relatively low-level processing demands for detecting a perceptual repetition, and more specifically, to more efficient perceptual grouping processes within a hemisphere than between hemispheres. To directly examine the impact of perceptual grouping and task demands on interhemispheric interactions, we asked participants to judge whether four items, one presented in each visual quadrant, were all different, or whether any two were the same, along an instructed dimension. We found that in comparison with the UFA for identical objects, the UFA for repetition detection in accuracy was similar or greater when the matching objects were not perceptually identical and differed in color, size, or viewpoint. Thus, decreasing grouping strength and increasing computational complexity did not reduce the UFA. Results are interpreted in terms of the callosal degradation account of the UFA.     

Memory conjunction errors: The effects of presentation duration and study repetition

The memory-strengthening manipulations of increased presentation duration and increased number of times items were presented were manipulated in the memory conjunction paradigm. Participants viewed parent words once or three times during the study portion of the experiment for 250 ms, 1000 ms, or 3000 ms. After an old/new recognition test participants were asked to give explanations for their answers from the recognition test. The results of true and false recognition as well as recall-to-reject responses (e.g., I know I did not see blackbird since I saw blackmail) indicated that both familiarity and recollection were influenced by the memory-strengthening manipulations. The results provide evidence for dual-process theories of recognition memory and the opposing processes of familiarity and recollection.     

Self-generated sounds of locomotion and ventilation and the evolution of human rhythmic abilities

It has been suggested that the basic building blocks of music mimic sounds of moving humans, and because the brain was primed to exploit such sounds, they eventually became incorporated in human culture. However, that raises further questions. Why do genetically close, culturally well-developed apes lack musical abilities? Did our switch to bipedalism influence the origins of music? Four hypotheses are raised: (1) Human locomotion and ventilation can mask critical sounds in the environment. (2) Synchronization of locomotion reduces that problem. (3) Predictable sounds of locomotion may stimulate the evolution of synchronized behavior. (4) Bipedal gait and the associated sounds of locomotion influenced the evolution of human rhythmic abilities. Theoretical models and research data suggest that noise of locomotion and ventilation may mask critical auditory information. People often synchronize steps subconsciously. Human locomotion is likely to produce more predictable sounds than those of non-human primates. Predictable locomotion sounds may have improved our capacity of entrainment to external rhythms and to feel the beat in music. A sense of rhythm could aid the brain in distinguishing among sounds arising from discrete sources and also help individuals to synchronize their movements with one another. Synchronization of group movement may improve perception by providing periods of relative silence and by facilitating auditory processing. The adaptive value of such skills to early ancestors may have been keener detection of prey or stalkers and enhanced communication. Bipedal walking may have influenced the development of entrainment in humans and thereby the evolution of rhythmic abilities.     

Attending, ignoring, and repetition: on the relation between negative priming and inhibition of return

A series of spatial localization experiments is reported that addresses the relation between negative priming and inhibition of return. The results of Experiment 1 demonstrate that slowed responses to repeated location stimuli can be obscured by repetition priming effects involving stimulus dimensions other than spatial location. The results of Experiments 2, 3A, and 3B demonstrate that these repetition priming effects may occur only when participants are required to respond to the prime display. Together, these results suggest that differences between attended and ignored repetition effects in selective attention studies of spatial localization do not provide a basis for distinguishing between spatial negative priming and inhibition of return.     

The relation between social sharing and the duration of emotional experience

People often socially share their emotions to regulate them. Two-mode theory of social sharing states that cognitive sharing will contribute to emotional recovery, whereas socio-affective sharing will only temporarily alleviate emotional distress. Previous studies supporting this theory, measured emotional recovery in terms of residual emotional intensity. Until now, another important time-dynamic aspect of emotions, emotion duration, has been largely ignored. In two experience sampling studies we addressed this gap. In Study 1, participants reported on the duration of anger, fear, and sadness episodes; additionally time-varying information on the occurrence and mode of sharing was collected. This study revealed that sharing led to a shortening in emotion duration, in particular when it was socio-affective in nature. In Study 2 we investigated whether this result could be interpreted in terms of our measure of duration primarily reflecting emotional relief rather than recovery. In this study, the same method as in Study 1 was used; additionally, residual emotional intensity was measured three days after emotion onset. Study 2 largely replicated the findings from Study 1. Furthermore, duration appeared to be empirically distinct from residual intensity. Finally, no relation between sharing and residual intensity was found, even when considering the sharing mode.     

The relation between event processing and the duration of emotional experience

An emotional experience can last for only a couple of seconds up to several hours or even longer. In the present study, we examine to which extent covert intrapersonal actions (cognitions both related and unrelated to the emotion-eliciting stimulus) as well as overt interpersonal actions (social sharing) account for this variability in emotion duration. Participants were asked to report the duration of their anger, sadness, joy, and gratitude episodes on a daily basis during five days. Furthermore, information was collected with regard to their cognitions during the episodes and their social sharing behavior. Discrete-time survival analyses revealed that for three of the four emotions under study, stimulus-related cognitions with the same valence as the emotion lead to a prolongation of the episode; in contrast, both stimulus-related and stimulus-unrelated cognitions with a valence opposite to the emotion lead to a shortening. Finally, for the four emotions under study, social sharing was associated with a prolongation. The findings are discussed in terms of a possible process basis underlying the time dynamics of negative as well as positive emotions.     

Perceptual grouping between successively presented stimuli and its relation to visual simultaneity and masking

Summary A 4×4 matrix of dots was presented by a tachistoscope. The first and the third columns of the stimulus pattern were presented first for 20 ms and then the second and the fourth columns were presented for 20 ms with SOAs of 0 to 170 ms. Luminous dots on a dark background, black dots on a white background, and black dots and small outline circles on a white background were used in Experiments I, II, and III, respectively. In each experiment, 5 Ss were asked to report whether the stimulus dots were seen as 4 horizontal rows or 4 vertical columns, and whether they were seen simultaneously or successively. The experimental results showed that the time range of successive grouping was nearly the same as that of perceptual simultaneity in Experiments I and II, but was much greater than the latter in Experiment III where the similarity factor favored successive grouping. Successive grouping generally occurred in the same time range with visual masking of dot patterns by random dots, temporal organization of patterns from successive stimulus elements. But the time range was generally wider than those of contrast reduction caused by temporal luminance summation, metacontrast, and apparent movement.A part of this study was conducted during the junior author's stay at Chiba University and presented by him at the 20th International Congress of Psychology at Tokyo, August 13–19, 1972 (Yamada and Oyama, 1972)     

Sex difference in subjective duration of looming and receding sounds

Looming sounds (sounds increasing in intensity over time) are more salient than receding sounds (a looming sound reversed in time). For example, they are estimated as being longer, louder, and more changing in loudness than receding sounds. Some authors interpret the looming salience as evolutionarily adaptive, because it increases the margins of safety of the perceiver in the case of preparatory behaviours (e.g., a motor reaction to an approaching sound source). Recently, Neuhoff et al (2009, Journal of Experimental Psychology: Human Perception and Performance 35 225-234) found that females more than males show overestimation of the spatiotemporal properties of virtually simulated looming sound sources. Here, I investigated whether the sex difference could be observed for the subjective duration of looming and receding sounds, and found that females more than males overestimate the duration of looming sounds in comparison to receding sounds.     

Differences in duration discrimination of filled and empty auditory intervals as a function of base duration

In the present experiments, participants were presented with two time intervals that were marked by auditory signals, and their task was to decide which of the two was longer in duration. In Experiment 1, the base durations were 50 and 1,000msec, whereas in Experiment 2, seven different base durations ranging from 50 to 1,000 msec were employed. It was found that filled intervals (continuous tones) were discriminated more accurately than empty intervals (with onset and offset marked by clicks) at the 50-msec base duration, whereas no performance differences could be shown for longer ones. The findings are consistent with the notion of a unitary timing mechanism that governs the timing of both filled and empty auditory intervals, independent of base durations. A likely conceptual framework that could explain better performance with filled as compared with empty intervals represents an information-processing model of interval timing that evolved from scalar timing theory. According to this account, a performance decrement observed with empty intervals may be due to a misassignment of pulses generated by an internal pacemaker.