Psychology

Taylor & Pembrook (1983) proposed several factors to affect short-term memory for melodies. We reassessed their findings using a more controlled stimulus set and a 2-alternative forced choice (Experiment 1) or same/different test (Experiment 2) instead of a dictation or singing-back task. Nonmusicians listened to a total of 158 isochronous 5-tone melodies. Each melody was followed by a same-length retention interval filled with silence, nonsense syllables, a nondiatonic melody, or a diatonic melody, and a subsequent test with same-contour lures. In both experiments and across all conditions listeners showed above-chance short-term recognition performance. We replicated Taylor & Pembrook's recency effect for the 5 th note of the sequences but also found a full J-shaped serial position curve (recency>primacy>center). Secondly, listeners performed better for tone sequences that were either fully ascending or descending than those with melodic direction changes. Thirdly, listeners were better in noticing a changed note that occurred at a point of melodic direction change (e. g., Ù or Ú). In Experiment 1 but not 2, we furthermore found that this " corner note effect " was even more pronounced if that note was preceded by a " skip " (3 or more semitones) instead of a " step " (2 or less semitones) pitch interval. The latter finding was somewhat similar to Taylor and Pembrook's finding that listeners were more accurate in their reproduction of skip as opposed to step intervals when they marked a point of change in melodic direction. Fourthly, type of retention interval had a major effect on participants' performances. When tested with a 2AFC setup, the silence group performed best, when tested with a same/different setup, both the silence and nonsense syllable groups performed best. Results are discussed in reference to related STM studies using short tone sequences and Berz' (1995) working memory model for music.

This chapter focuses on research methodologies used in studying memory for music.  A historical overview traces their development, highlighting both the variety of topics studied and the increasing experimental sophistication that paralleled methodologies used in memory research in general.  A unique challenges section focuses on such factors as the lack of meaning-based representations of musical materials, the variability in musical literacy and training of participants, the limited ways in which memory can be tested, and the largely perceptual nature of music memory.  Discussion of these unique challenges are then interweaved into a review of current behavioral and neuroscientific methodologies within the specific domains of immediate remembering, episodic and semantic memory, implicit memory, metamemory, as well as in studying individual differences.

Previous studies demonstrated mere exposure effects (MEE) with musical tunes (e.g., Peretz et al., 1998; Halpern & Müllensiefen, 2008). Our goal was to investigate the effects of repeated exposures on processing fluency, recognition performance, and liking ratings for unfamiliar tonal and nontonal tunes, with type of tune being manipulated between-participants. Tunes were presented either 1, 3 or 6 times and processed either with a familiarity rating or counting long notes orienting task. We found that participants’ familiarity ratings increased across repeated exposures for both types of tunes.  Likewise, recognition performance for both unfamiliar and nontonal tunes improved with repeated exposures.  The increase in recognition sensitivity for nontonal tunes was steady across six repetitions whereas for unfamiliar tonal tunes the increase decelerated after three repetitions. Liking ratings, too, increased with repeated exposures for both types of tunes and in comparable ways.  Liking ratings were also higher for hits than misses and correlated positively with recognition confidence ratings.  Orienting tasks did not have an effect on liking or recognition. Findings are discussed with reference to the processing fluency account (Reber, Schwarz, & Winkielman, 2004), dual process account (Mandler, 1980) and the fluency misattribution model (Bornstein & D’Agostino, 1992).

Duration distortions have been shown to occur at the time of saccades and following high temporal frequency or contrast adaptation. Under all these conditions, changes in the temporal tuning of M neurons also occur, suggesting that there might be a link between the two phenomena. In order to explore this relationship further, we measured the apparent duration of visual stimuli in the dark, where the temporal impulse response has been reported to lengthen. We first measured a progressive shift and reduction of the occurrence of an apparent motion reversal as we decreased the luminance level, indicating a lengthening of the temporal impulse response. We then measured perceived duration at these luminance levels (0.75, 3, and 50 cd/m2) after matching for apparent contrast and temporal frequency. While perceived temporal frequency did not substantially differ across luminance levels, duration appeared expanded at the lowest luminance level relative to the highest by approximately 60 ms. Thus, we have shown that reduced luminance is associated with both a lengthening of the temporal impulse response and a duration expansion, linking the two and providing further evidence for a relationship between changes in the neuronal tuning in the early stages of the visual system and time perception.

The apparent duration of a visual stimulus has been shown to be influenced by its speed. For low speeds, apparent duration increases linearly with stimulus speed. This effect has been ascribed to the number of changes that occur within a visual interval. Accordingly, a higher number of changes should produce an increase in apparent duration. In order to test this prediction, we asked subjects to compare the relative duration of a 10-Hz drifting com- parison stimulus with a standard stimulus that contained a different number of changes in different conditions. The standard could be static, drifting at 10 Hz, or mixed (a combi- nation of variable duration static and drifting intervals). In this last condition the number of changes was intermediate between the static and the continuously drifting stimulus. For all standard durations, the mixed stimulus looked significantly compressed (∼20% reduction) relative to the drifting stimulus. However, no difference emerged between the static (that contained no changes) and the mixed stimuli (which contained an intermediate number of changes). We also observed that when the standard was displayed first, it appeared compressed relative to when it was displayed second with a magnitude that depended on standard duration. These results are at odds with a model of time perception that simply reflects the number of temporal features within an interval in determining the perceived passing of time.

We investigated the limits of the number of events observers can simultaneously time. For single targets occurring in one of eight positions sensitivity to duration was improved for spatially pre-cued items as compared to post-cued items indicating that exogenous driven attention can improve duration discrimination. Sensitivity to duration for pre-cued items was also marginally better for single items as compared to eight items indicating that even after the allocation of focal attention, distractor items can interfere with the encoding of duration. For an eight item array discrimination was worse for post-cued locations as compared to pre-cued locations indicating both that attention can improve duration dis- crimination performance and that it was not possible to access a perfect memory trace of the duration of eight elements. The interference from the distractors in the pre-cued eight item array may reflect some mandatory averaging of target and distractor events. To fur- ther explore duration averaging we asked subjects to explicitly compare average durations of multiple item arrays against a single item standard duration. Duration discrimination thresholds were significantly lower for single elements as compared to multiple elements, showing that averaging, either automatically or intentionally, impairs duration discrimina- tion. There was no set size effect. Performance was the same for averages of two and eight items, but performance with even an average of two items was worse than for one item. This was also true for sequential presentation indicating poor performance was not due to limits on the division of attention across items. Rather performance appears to be limited by an inability to remember or aggregate duration information from two or more items. Although it is possible to manipulate perceived duration locally, there appears to be no perceptual mechanisms for aggregating local durations across space.

It is well established that the apparent duration of moving visual objects is greater at higher as compared to slower speeds. Here we report the effects of acceleration and deceleration on the perceived duration of a drifting grating with average speed kept constant (108/s). For acceleration, increasing the speed range progressively reduced perceived duration. The magnitude of apparent duration compression was determined by speed rather than temporal frequency and was proportional to speed range (independent of standard duration) rather than acceleration. The perceived duration reduction was also proportional to the standard length. The effects of increases and decreases in speed were highly asymmetric. Reducing speed through the interval induced a moderate increase in perceived duration. These results could not be explained by changes in apparent onset or offset or differences in perceived average speed between intervals containing increasing speed and intervals containing decreasing speed. Paradoxically, for intervals combining increasing speed and decreasing speed, compression only occurred when increasing speed occurred in the second half of the interval. We show that this pattern of results in the duration domain was concomitant with changes in the reported direction of apparent motion of Gaussian blobs, embedded in intervals of increasing or decreasing speed, that could be predicted from adaptive changes in the temporal impulse response function. We detected similar changes after flicker adaptation, suggesting that the two effects might be linked through changes in the temporal tuning of visual filters.

Local adaptation to 20 Hz oscillatory motion or flicker reduces the apparent duration of a 10 Hz dynamic test stimulus, while 5 Hz adaptation has very little influence on apparent duration (Johnston, Arnold & Nishida, 2006, Current Biology, 16(5):472–9). Recently it has been ...