Spatial-musical Association Of Response Codes Research Articles

The spatial representation of loudness in a timbre discrimination task.

When participants decide whether a presented tone is loud or soft they react faster to loud tones with a top-sided response key in comparison to a bottom-sided response key and vice versa for soft tones. This effect is comparable to the well-established horizontal Spatial-Numerical Association of Response Codes (SNARC) effect and is often referred to as Spatial-Musical Association of Response Codes (SMARC) effect for loudness. The SMARC effect for loudness is typically explained by the assumption of a spatial representation or by the polarity correspondence principle. Crucially, both theories differ in the prediction of the SMARC effect when loudness is task-irrelevant. Therefore, we investigated whether the SMARC effect still occurs in a timbre discrimination task: Participants (N = 36) heard a single tone and classified its timbre with vertically arranged response keys. Additionally, the tone's loudness level varied in six levels. In case of a spatial representation, the SMARC effect should still occur while in case of polarity corresponding principle, the effect should be absent. Results showed that the SMARC effect was still present and that the differences between top-sided and bottom-sided responses were a linear function of loudness level indicating a continuous spatial representation of loudness.

The sound-free SMARC effect: The spatial-musical association of response codes using only sound imagery.

This study provides clear evidence that the human cognitive system automatically codes sound pitch spatially. The spatial-musical association of response codes (SMARC) effect, in which a high-pitched (low-pitched) tone facilitates an upper (lower) response, is considered to reflect the spatial coding of sound pitch. However, previous studies have not excluded the directional effects of sound localization. Because a high-pitched (low-pitched) tone is automatically misperceived as originating from a spatially high (low) location, the location of a perceived sound source might artificially elicit the SMARC effect. This study challenged this unresolved issue. Participants were trained to associate visual stimuli (novel contoured shapes) with sound pitches (high-pitched or low-pitched pure tones). After training, participants completed a discrimination task in which the vertically aligned keys were associated with the visual stimuli in the absence of sound. Even without sound, the SMARC effect was observed in response to the trained visual stimuli (Experiment 1). However, this sound-free SMARC effect was eliminated when training was omitted (Experiment 2). Therefore, the SMARC effect was observed based solely on the activation of sound imagery that was spatial.

Instrumental expertise and musical timbre modulate the spatial representation of pitch.

Humans show a tendency to represent pitch in a spatial format. A classical finding supporting this spatial representation is the Spatial-Musical Association of Response Codes (SMARC) effect, reflecting faster responses to low tones when pressing a left/bottom-side key and to high tones when pressing a right/top-side key. Despite available evidence suggesting that the horizontal and vertical SMARC effect may be differently modulated by instrumental expertise and musical timbre, no study has so far directly explored this hypothesis in a unified framework. Here, we investigated this possibility by comparing the performance of professional pianists, professional clarinettists and non-musicians in an implicit timbre judgement task, in both horizontal and vertical response settings. Results showed that instrumental expertise significantly modulates the SMARC effect: whereas in the vertical plane a comparable SMARC effect was observed in all groups, in the horizontal plane the SMARC effect was significantly modulated by the specific instrumental expertise, with pianists showing a stronger pitch-space association compared to clarinettists and non-musicians. Moreover, the influence of pitch along the horizontal dimension was stronger in those pianists who started the instrumental training at a younger age. Results also showed an influence of musical timbre in driving the horizontal, but not the vertical, SMARC effect, with only piano notes inducing a pitch-space association. Taken together, these findings suggest that sensorimotor experience due to instrumental training and musical timbre affect the mental representation of pitch on the horizontal space, whereas the one on the vertical space would be mainly independent from musical practice.

Spatial-musical association of response codes based on the sound imagery

Spatial-musical association of response codes based on the sound imagery

Spatial-musical association of response codes without sound.

Humans tasked with pressing a key on a computer keyboard in response to a pitch can respond more quickly to a high-pitched sound by pressing a key higher on the keyboard and to a low-pitched sound by pressing a lower key, compared with the opposite configuration. This so-called spatial-musical association of response codes (SMARC) has been considered to reflect the spatial coding of sound pitch rather than to be an artefact of the verbal labels denoting spatial positions for localising sounds. In this study, we completely excluded the latter possibility, that is, the directional effects of automatic sound localisation on the SMARC effect. We did this by examining whether the SMARC effect occurs without sound; that is, we investigated whether the effect would be elicited by written pitch names alone. We found that when musically trained participants judged pitch height labelled by visually presented word stimuli, the SMARC effect still occurred. This also happened among musically naïve participants when the height of the pitch was explicitly comparable with that of a referential pitch. We also found that musically trained participants exhibited the SMARC effect in response to pitch names even when the indicated pitch height was irrelevant to the task they were asked to perform. These results suggest that the SMARC effect can occur at the semantic level in the absence of sound, clearly excluding the directional effects of automatic sound localisation.

The Spatial Musical Association of Response Codes does not depend on a normal visual experience: A study with early blind individuals.

Converging evidence suggests that the perception of auditory pitch exhibits a characteristic spatial organization. This pitch-space association can be demonstrated experimentally by the Spatial Musical Association of Response Codes (SMARC) effect. This is characterized by faster response times when a low-positioned key is pressed in response to a low-pitched tone, and a high-positioned key is pressed in response to a high-pitched tone. To investigate whether the development of this pitch-space association is mediated by normal visual experience, we tested a group of early blind individuals on a task that required them to discriminate the timbre of different instrument sounds with varying pitch. Results revealed a comparable pattern in the SMARC effect in both blind participants and sighted controls, suggesting that the lack of prior visual experience does not prevent the development of an association between pitch height and vertical space.

Linear representation of pitch height in the SMARC effect

The Spatial-Musical Association of Response Codes (SMARC) effect consists in faster and more accurate responses to low (vs. high) pitched tones when they are executed in the bottom/left (vs. top/right) space. This phenomenon has many similarities with the Spatial-Numerical Association of Response Codes (SNARC) effect which, however, has been more extensively investigated and theoretically debated. The first theoretical account of the SNARC effect suggests the existence of a direct mapping between the position of a number on a mental number line and the external space of response execution. Conversely, following accounts claim that numbers are automatically categorized in two opposing categories (e.g., small vs. large) and then associated to response alternatives (left vs. right). A modified task, consisting in unimanual close/far responses relative to a reference key, has been employed to disentangle between the opposite theoretical accounts of the SNARC effect. However, this modified task has never been applied to pitch height and currently there are no specific theoretical accounts for the SMARC effect. The aim of this study is to fill this gap of knowledge. Contrary to what has been found for numbers, our data are more in line with the "direct mapping" account and suggests a linear representation of pitch height. Our data suggest that SNARC and SMARC effects might have different origins and might require different theoretical accounts.

When speech enhances Spatial Musical Association of Response Codes: Joint spatial associations of pitch and timbre in nonmusicians.

Previous studies have shown that the effect of the Spatial Musical Association of Response Codes (SMARC) depends on various features, such as task conditions (whether pitch height is implicit or explicit), response dimension (horizontal vs. vertical), presence or absence of a reference tone, and former musical training of the participants. In the present study, we investigated the effects of pitch range and timbre: in particular, how timbre (piano vs. vocal) contributes to the horizontal and vertical SMARC effect in nonmusicians under varied pitch range conditions. Nonmusicians performed a timbre judgement task in which the pitch range was either small (6 or 8 semitone steps) or large (9 or 12 semitone steps) in a horizontal and a vertical response setting. For piano sounds, SMARC effects were observed in all conditions. For the vocal sounds, in contrast, SMARC effects depended on pitch range. We concluded that the occurrence of the SMARC effect, especially in horizontal response settings, depends on the interaction of the timbre (vocal and piano) and pitch range if vocal and instrumental sounds are combined in one experiment: the human voice enhances the attention, both to the vocal and the instrumental sounds.

Naturally together: pitch-height and brightness as coupled factors for eliciting the SMARC effect in non-musicians.

Pitch-height is often labeled spatially (i.e., low or high) as a function of the fundamental frequency of the tone. This correspondence is highlighted by the so-called Spatial-Musical Association of Response Codes (SMARC) effect. However, the literature suggests that the brightness of the tone's timbre might contribute to this spatial association. We investigated the SMARC effect in a group of non-musicians by disentangling the role of pitch-height and the role of tone-brightness. In three experimental conditions, participants were asked to judge whether the tone they were listening to was (or was not) modulated in amplitude (i.e., vibrato). Participants were required to make their response in both the horizontal and the vertical axes. In a first condition, tones varied coherently in pitch (i.e., manipulation of the tone's F0) and brightness (i.e., manipulation of the tone's spectral centroid); in a second condition, pitch-height varied whereas brightness was fixed; in a third condition, pitch-height was fixed whereas brightness varied. We found the SMARC effect only in the first condition and only in the vertical axis. In contrast, we did not observe the effect in any of the remaining conditions. The present results suggest that, in non-musicians, the SMARC effect is not due to the manipulation of the pitch-height alone, but arises because of a coherent change of pitch-height and brightness; this effect emerges along the vertical axis only.

The effect of musical expertise on the representation of space.

Consistent evidence suggests that pitch height may be represented in a spatial format, having both a vertical and a horizontal representation. The spatial representation of pitch height results into response compatibility effects for which high pitch tones are preferentially associated to up-right responses, and low pitch tones are preferentially associated to down-left responses (i.e., the Spatial-Musical Association of Response Codes (SMARC) effect), with the strength of these associations depending on individuals’ musical skills. In this study we investigated whether listening to tones of different pitch affects the representation of external space, as assessed in a visual and haptic line bisection paradigm, in musicians and non musicians. Low and high pitch tones affected the bisection performance in musicians differently, both when pitch was relevant and irrelevant for the task, and in both the visual and the haptic modality. No effect of pitch height was observed on the bisection performance of non musicians. Moreover, our data also show that musicians present a (supramodal) rightward bisection bias in both the visual and the haptic modality, extending previous findings limited to the visual modality, and consistent with the idea that intense practice with musical notation and bimanual instrument training affects hemispheric lateralization.

Influence of auditory and audiovisual stimuli on the right–left prevalence effect

When auditory stimuli are used in two-dimensional spatial compatibility tasks, where the stimulus and response configurations vary along the horizontal and vertical dimensions simultaneously, a right-left prevalence effect occurs in which horizontal compatibility dominates over vertical compatibility. The right-left prevalence effects obtained with auditory stimuli are typically larger than that obtained with visual stimuli even though less attention should be demanded from the horizontal dimension in auditory processing. In the present study, we examined whether auditory or visual dominance occurs when the two-dimensional stimuli are audiovisual, as well as whether there will be cross-modal facilitation of response selection for the horizontal and vertical dimensions. We also examined whether there is an additional benefit of adding a pitch dimension to the auditory stimulus to facilitate vertical coding through use of the spatial-musical association of response codes (SMARC) effect, where pitch is coded in terms of height in space. In Experiment 1, we found a larger right-left prevalence effect for unimodal auditory than visual stimuli. Neutral, non-pitch coded, audiovisual stimuli did not result in cross-modal facilitation, but did show evidence of visual dominance. The right-left prevalence effect was eliminated in the presence of SMARC audiovisual stimuli, but the effect influenced horizontal rather than vertical coding. Experiment 2 showed that the influence of the pitch dimension was not in terms of influencing response selection on a trial-to-trial basis, but in terms of altering the salience of the task environment. Taken together, these findings indicate that in the absence of salient vertical cues, auditory and audiovisual stimuli tend to be coded along the horizontal dimension and vision tends to dominate audition in this two-dimensional spatial stimulus-response task.

Action–perception coupling in pianists: Learned mappings or spatial musical association of response codes (SMARC) effect?

The principle of common coding suggests that a joint representation is formed when actions are repeatedly paired with a specific perceptual event. Musicians are occupationally specialized with regard to the coupling between actions and their auditory effects. In the present study, we employed a novel paradigm to demonstrate automatic action-effect associations in pianists. Pianists and nonmusicians pressed keys according to aurally presented number sequences. Numbers were presented at pitches that were neutral, congruent, or incongruent with respect to pitches that would normally be produced by such actions. Response time differences were seen between congruent and incongruent sequences in pianists alone. A second experiment was conducted to determine whether these effects could be attributed to the existence of previously documented spatial/pitch compatibility effects. In a "stretched" version of the task, the pitch distance over which the numbers were presented was enlarged to a range that could not be produced by the hand span used in Experiment 1. The finding of a larger response time difference between congruent and incongruent trials in the original, standard, version compared with the stretched version, in pianists, but not in nonmusicians, indicates that the effects obtained are, at least partially, attributable to learned action effects.

Effects of laterality and pitch height of an auditory accessory stimulus on horizontal response selection: The Simon effect and the SMARC effect

In the present article, we investigated the effects of pitch height and the presented ear (laterality) of an auditory stimulus, irrelevant to the ongoing visual task, on horizontal response selection. Performance was better when the response and the stimulated ear spatially corresponded (Simon effect), and when the spatial-musical association of response codes (SMARC) correspondence was maintained-that is, right (left) response with a high-pitched (low-pitched) tone. These findings reveal an automatic activation of spatially and musically associated responses by task-irrelevant auditory accessory stimuli. Pitch height is strong enough to influence the horizontal responses despite modality differences with task target.

The Mental Space of Pitch Heighta

Through stimulus-response compatibility we tested whether sound frequency (pitch height) elicits a mental spatial representation. Musically untrained and, mostly, trained participants were shown a stimulus-response compatibility effect (Spatial-Musical Association of Response Codes or SMARC effect). When response alternatives were either vertically or horizontally aligned, performance was better when the lower (or leftward) button had to be pressed in response to a low sound and the upper (or rightward) button had to be pressed in response to a high sound, even when pitch height was irrelevant to the task.