Cross-cultural perspectives on pitch memory

We examined effects of age and culture on children's memory for the pitch level of familiar music. Canadian 9- and 10-year-olds distinguished the original pitch level of familiar television theme songs from foils that were pitch-shifted by one semitone, whereas 5- to 8-year-olds failed to do so (Experiment 1). In contrast, Japanese 5- and 6-year-olds distinguished the pitch-shifted foils from the originals, performing significantly better than same-age Canadian children (Experiment 2). Moreover, Japanese 6-year-olds were more accurate than their 5-year-old counterparts. These findings challenge the prevailing view of enhanced pitch memory during early life. We consider factors that may account for Japanese children's superior performance such as their use of a pitch accent language (Japanese) rather than a stress accent language (English) and their experience with musical pitch labels.     

Hold your horses: how exposure to different items influences infant categorization

We investigated how exposure to pairs of different items (as compared with pairs of identical items) influences 10-month-olds' (n=79) categorization of horses versus dogs in an object-examining task. Infants responded to an exclusive category when familiarized with pairs of different items but not when familiarized with pairs of identical items (Experiment 1), even when the frequency of exposure to each item was controlled (Experiment 2). When familiarized with pairs of identical items, infants failed to show evidence of memory for the individual exemplars (Experiment 3). Reducing the retention interval between presentations of different items in the identical pairs condition facilitated infants' recognition of an exclusive categorical distinction (Experiment 4). These results are discussed in terms of how exposure to collections of different items, and how opportunities to compare items, influences infants' categorization.     

Visual experience influences 12-month-old infants' perception of goal-directed actions of others

In the present study, we investigated whether infants' own visual experiences affected their perception of the visual status of others engaging in goal-directed actions. In Experiment 1, infants viewed video clips of successful and failed goal-directed actions performed by a blindfolded adult, with half the infants having previously experienced being blindfolded. The results showed that 12-month-old infants who were previously blindfolded preferred to look longer at the demonstrator's successful actions, whereas no such preference was observed in 8-month-old infants. In Experiment 2, infants watched the same 2 actions when the adult demonstrator was not blindfolded. The responses of 12-month-old infants were the opposite of those observed in Experiment 1: they showed a preference for the failed actions. These findings suggest that previous experience influenced the subsequent perception of others' goal-directed actions in the 12-month-old infants. We favor the interpretation that the preference for the successful actions in the 12-months-old infants provided with blindfolded experience demonstrates the influence of perceptual experience on considering the visual status of others engaging in goal-directed actions.     

Bidirectional priming in infants

In associative priming, the direct activation of one concept indirectly activates others that are associated with it, depending on the directionality of the association. We asked whether associative priming in preverbal infants is bidirectional. Infants associated a puppet imitation task with an operant train task by watching an adult model target actions on the puppet in the incidental context of the train. Later, priming of the forgotten memory of the train task reactivated the infants' memory of the puppet task (Experiment 1), and priming of the infants' forgotten memory of the puppet task reactivated their memory of the train task (Experiment 2). The finding that associative priming was bidirectional offers new insights into the nature of the mnemonic networks formed early in infancy. Additionally, the fact that the present association was formed rapidly and incidentally suggests that a fast mapping, general learning mechanism, like that posited to mediate word-object learning, was responsible for its encoding.     

Rapid acquisition of phonological alternations by infants

We explore whether infants can learn novel phonological alternations on the basis of distributional information. In Experiment 1, two groups of 12-month-old infants were familiarized with artificial languages whose distributional properties exhibited either stop or fricative voicing alternations. At test, infants in the two exposure groups had different preferences for novel sequences involving voiced and voiceless stops and fricatives, suggesting that each group had internalized a different familiarization alternation. In Experiment 2, 8.5-month-olds exhibited the same patterns of preference. In Experiments 3 and 4, we investigated whether infants' preferences were driven solely by preferences for sequences of high transitional probability. Although 8.5-month-olds in Experiment 3 were sensitive to the relative probabilities of sequences in the familiarization stimuli, only 12-month-olds in Experiment 4 showed evidence of having grouped alternating segments into a single functional category. Taken together, these results suggest a developmental trajectory for the acquisition of phonological alternations using distributional cues in the input.     

Perception of Mooney faces by young infants: the role of local feature visibility, contrast polarity, and motion

We examined the ability of young infants (3- and 4-month-olds) to detect faces in the two-tone images often referred to as Mooney faces. In Experiment 1, this performance was examined in conditions of high and low visibility of local features and with either the presence or absence of the outer head contour. We found that regardless of the presence of the outer head contour, infants preferred upright over inverted two-tone face images only when local features were highly visible (Experiment 1a). We showed that this upright preference disappeared when the contrast polarity of two-tone images was reversed (Experiment 1b), reflecting operation of face-specific mechanisms. In Experiment 2, we investigated whether motion affects infants' perception of faces in Mooney faces. We found that when the faces appeared to be rigidly moving, infants did show an upright preference in conditions of low visibility of local features (Experiment 2a). Again the preference disappeared when the contrast polarity of the image was reversed (Experiment 2b). Together, these results suggest that young infants have the ability to integrate fragmented image features to perceive faces from two-tone face images, especially if they are moving. This suggests that an interaction between motion and form rather than a purely motion-based process (e.g., structure from motion) facilitates infants' perception of faces in ambiguous two-tone images.     

Developmental changes in infants' processing of happy and angry facial expressions: a neurobehavioral study

Event-related brain potentials were measured in 7- and 12-month-old infants to examine the development of processing happy and angry facial expressions. In 7-month-olds a larger negativity to happy faces was observed at frontal, central, temporal and parietal sites (Experiment 1), whereas 12-month-olds showed a larger negativity to angry faces at occipital sites (Experiment 2). These data suggest that processing of these facial expressions undergoes development between 7 and 12 months: while 7-month-olds exhibit heightened sensitivity to happy faces, 12-month-olds resemble adults in their heightened sensitivity to angry faces. In Experiment 3 infants' visual preference was assessed behaviorally, revealing that the differences in ERPs observed at 7 and 12 months do not simply reflect differences in visual preference.     

Learning about occlusion: initial assumptions and rapid adjustments

We examined 6-month-olds abilities to represent occluded objects, using a corneal-reflection eye-tracking technique. Experiment 1 compared infants' ability to extrapolate the current pre-occlusion trajectory with their ability to base predictions on recent experiences of novel object motions. In the first condition infants performed at asymptote ( approximately 2/3 accurate predictions) from the first occlusion passage. In the second condition all infants initially failed to make accurate prediction. Performance, however, reached asymptote after two occlusion passages. This is the first study that demonstrates such rapid learning effects during an occlusion task. Experiment 2 replicates these effects and demonstrates a robust memory effect extending 24h. In occlusion tasks such long-term memory effects have previously only been observed in 14-month-olds (Moore & Meltzoff, 2004).     

Cross-modal and intra-modal binding between identity and location in spatial working memory: The identity of objects does not help recalling their locations

In this study we tested incidental feature-to-location binding in a spatial task, both in unimodal and cross-modal conditions. In Experiment 1 we administered a computerised version of the Corsi Block-Tapping Task (CBTT) in three different conditions: the first one analogous to the original CBTT test; the second one in which locations were associated with unfamiliar images; the third one in which locations were associated with non-verbal sounds. Results showed no effect on performance by the addition of identity information. In Experiment 2, locations on the screen were associated with pitched sounds in two different conditions: one in which different pitches were randomly associated with locations and the other in which pitches were assigned to match the vertical position of the CBTT squares congruently with their frequencies. In Experiment 2 we found marginal evidence of a pitch facilitation effect in the spatial memory task. We ran a third experiment to test the same conditions of Experiment 2 with a within-subject design. Results of Experiment 3 did not confirm the pitch–location facilitation effect. We concluded that the identity of objects does not affect recalling their locations. We discuss our results within the framework of the debate about the mechanisms of “what” and “where” feature binding in working memory.     

Good pitch memory is widespread

Abstract - Here we show that good pitch memory is widespread among adults with no musical training. We tested unselected college students on their memory for the pitch level of instrumental soundtracks from familiar television programs. Participants heard 5-s excerpts either at the original pitch level or shifted upward or downward by 1 or 2 semitones. They successfully identified the original pitch levels. Other participants who heard comparable excerpts from unfamiliar recordings could not do so. These findings reveal that ordinary listeners retain fine-grained information about pitch level over extended periods. Adults' reportedly poor memory for pitch is likely to be a by-product of their inability to name isolated pitches.     

Infants' formation and use of categories to segregate objects

Four- and-a-half-month-old infants' (N = 100) category formation and use was studied in a series of five experiments. For each experiment, the test events featured a display composed of a cylinder and a box. Previous research showed that this display is not clearly parsed as a single unit or as two separate units by infants of this age. Immediately prior to testing, infants were shown a set of category exemplars. Knowledge about this category could help infants disambiguate the test display, which contained a novel exemplar of this category. Clear interpretation of the test display as composed of two separate units (as indicated by infants' longer looking at the move-together than at the move-apart test event) was taken as evidence of category formation and use. In Experiments 1 and 5, infants' prior experience with a set of three different boxes that were similar to the test box facilitated their segregation of the test display. Experiment 2 showed that three different exemplars are necessary: prior experience with any two of the three boxes used in Experiment 1 did not facilitate infants' segregation of the test display. Experiment 3 showed that variability in the exemplar set is necessary: prior experience with three identical boxes did not facilitate infants' segregation of the test display. Experiment 4 showed that under these conditions of very brief prior exposure, similarity between the exemplar set and test box is necessary: prior experience with three different boxes that were not very similar to the test box did not facilitate infants' segregation of the test display. Together, these findings suggest that: (a) number of exemplars, variability, and similarity in the exemplar set are important for infants' category formation, and (b) infants use their category knowledge to determine the boundaries of the objects in a display.     

Representational momentum in memory for pitch

When a visual pattern is displayed at successively different orientations such that a rotation or translation is implied, an observer's memory for the final position is displaced forward. This phenomenon of representational momentum shares some similarities with physical momentum. For instance, the amount of memory shift is proportional to the implied velocity of the inducing display; representational momentum is specifically proportional to the final, not the average, velocity; representational momentum follows a continuous stopping function for the first 250 ms or so of the retention interval. In a previous paper (Kelly & Freyd, 1987) we demonstrated a forward memory asymmetry using implied changes in pitch, for subjects without formal musical training. In the current paper we replicate our earlier finding and show that the forward memory asymmetry occurs for subjects with formal musical training as well (Experiment 1). We then show the structural similarity between representational momentum in memory for pitch with previous reports of parametric effects using visual stimuli. We report a velocity effect for auditory momentum (Experiment 2), we demonstrate specifically that the velocity effect depends on the implied acceleration (Experiment 3), and we show that the stopping function for auditory momentum is qualitatively the same as that for visual momentum (Experiment 4). We consider the implications of these results for theories of mental representation.     

Infants prefer higher-pitched singing

Female singers were recorded singing a song in a high and/or a low range. Infants preferred to listen to the higher-pitched versions, suggesting that infants' preference for infant-directed singing and speech is mediated in part by a preference for higher pitch.     

Learning about tools in infancy

These experiments explored the role of prior experience in 12- to 18-month-old infants' tool-directed actions. In Experiment 1, infants' use of a familiar tool (spoon) to accomplish a novel task (turning on lights inside a box) was examined. Infants tended to grasp the spoon by its handle even when doing so made solving the task impossible (the bowl did not fit through the hole in the box, but the handle did) and even though the experimenter demonstrated a bowl-grasp. In contrast, infants used a novel tool flexibly and grasped both sides equally often. In Experiment 2, infants received training using the novel tool for a particular function; 3 groups of infants were trained to use the tool differently. Later, infants' performance was facilitated on tasks that required infants to grasp the part of the tool they were trained to grasp. The results suggest that (a) infants' prior experiences with tools are important to understanding subsequent tool use, and (b) rather than learning about tool function (e.g., hammering), infants learn about which part of the tool is meant to be held, at least early in their exposure to a novel tool.     

Interference in Immediate Spatial Memory: Shifts of Spatial Attention or Central executive Involvement?

Interference in serial spatial memory was investigated in six experiments. Experiment 1 replicated Experiment 2 by Smyth and Scholey (1994) in showing that listening to tones that originated from different directions interfered with spatial memory. Experiment 2 showed, however, that the effect of mere listening was not observed when this was the only interference condition experienced by the subject. In Experiment 3, a binary pitch discrimination task performed on spatially separated tones impaired recall performance to the same extent as did left-right decisions. The same disrupting effect was also observed when the tones were presented from the same direction in the pitch discrimination task (Experiment 4) as well as in a binary loudness discrimination task (Experiment 5). Finally, repeating heard words did not interfere, whereas a pitch discrimination performed on these same words disrupted recall (Experiment 6). It is argued that the disrupting effects reflect not a specifically spatial interference, but a central executive involvement in the rehearsal process in serial spatial memory.     

Long-term memory for music: infants remember tempo and timbre

We show that infants' long-term memory representations for melodies are not just reduced to the structural features of relative pitches and durations, but contain surface or performance tempo- and timbre-specific information. Using a head turn preference procedure, we found that after a one week exposure to an old English folk song, infants preferred to listen to a novel folk song, indicating that they remembered the familiarized melody. However, if the tempo (25% faster or slower) or instrument timbre (harp vs. piano) of the familiarized melody was changed at test, infants showed no preference, indicating that they remembered the specific tempo and timbre of the melodies. The results are consistent with an exemplar-based model of memory in infancy rather than one in which structural features are extracted and performance features forgotten.     

Memory for surface features of unfamiliar melodies: independent effects of changes in pitch and tempo

A melody’s identity is determined by relations between consecutive tones in terms of pitch and duration, whereas surface features (i.e., pitch level or key, tempo, and timbre) are irrelevant. Although surface features of highly familiar recordings are encoded into memory, little is known about listeners’ mental representations of melodies heard once or twice. It is also unknown whether musical pitch is represented additively or interactively with temporal information. In two experiments, listeners heard unfamiliar melodies twice in an initial exposure phase. In a subsequent test phase, they heard the same (old) melodies interspersed with new melodies. Some of the old melodies were shifted in key, tempo, or key and tempo. Listeners’ task was to rate how well they recognized each melody from the exposure phase while ignoring changes in key and tempo. Recognition ratings were higher for old melodies that stayed the same compared to those that were shifted in key or tempo, and detrimental effects of key and tempo changes were additive in between-subjects (Experiment 1) and within-subjects (Experiment 2) designs. The results confirm that surface features are remembered for melodies heard only twice. They also imply that key and tempo are processed and stored independently.     

Infants' memory processing of a serial list: list length effects

Six-month-olds, trained with a three-mobile serial list, exhibit a primacy effect 24 h later. In three experiments, we demonstrated that increasing list length impairs their memory for serial order. In all experiments, 6-month-olds were trained with a five-mobile list. In Experiment 1, infants failed to exhibit a primacy effect on a 24-h delayed recognition test, recognizing mobiles from all serial positions. In Experiment 2, infants did exhibit a primacy effect on a reactivation (priming) test, suggesting that they may originally have encoded serial-order information. Experiment 3 confirmed that serial-order information was represented in infants' training memory. After the reactivation treatment, infants were precued with one list member and tested for recognition of another. When precues specified valid order information, infants recognized test mobiles from the later serial positions. The memory dissociation for serial order on delayed recognition and reactivation tests adds to the growing evidence that young infants possess two functionally distinct memory systems.     

Infants use meter to categorize rhythms and melodies: implications for musical structure learning

Little is known about whether infants perceive meter, the underlying temporal structure of music. We employed a habituation paradigm to examine whether 7-month-old infants could categorize rhythmic and melodic patterns on the basis of the underlying meter, which was implied from event and accent frequency of occurrence. In Experiment 1, infants discriminated duple and triple classes of rhythm on the basis of implied meter. Experiment 2 replicated this result while controlling for rhythmic grouping structure, confirming that infants perceived metrical structure despite occasional ambiguities and conflicting group structure. In Experiment 3, infants categorized melodies on the basis of contingencies between metrical position and pitch. Infants presented with metrical melodies detected reversals of pitch/meter contingencies, while infants presented with non-metrical melodies showed no preference. Results indicate that infants can infer meter from rhythmic patterns, and that they may use this metrical structure to bootstrap their knowledge acquisition in music learning.     

Magnitude estimation of conceptual data dimensions for use in sonification

Sonifications must match listener expectancies about representing data with sound. Three experiments showed the utility of magnitude estimation for this. In Experiment 1, 67 undergraduates judged the sizes of visual stimuli and the temperature, pressure, velocity, size, or dollars they represented. Similarly, in Experiment 2, 132 listeners judged the pitch or tempo of sounds and the data they represented. In both experiments, polarity and scaling preference depended on the conceptual data dimension. In Experiment 3, 60 listeners matched auditory graphs to data created with the results of Experiment 2, providing initial validation of scaling slopes. Magnitude estimation is proposed as a design tool in the development of data sonifications, with the level of polarity preference agreement predicting mapping effectiveness.