Bimodal distribution of performance in discriminating major/minor modes

Complex Pitch Perception Deficits in Dyslexia Persist Regardless of Previous Musical Experiences

PURPOSE

Pitch perception is important for speech sound learning, and reading acquisition requires integration of speech sounds and written letters. Many individuals with dyslexia exhibit auditory perception deficits that may therefore contribute to their reading impairment given that complex pitch perception is crucial for categorizing speech sounds. Given rising interest in music training as a reading intervention, understanding associations between prior music experiences and pitch perception is important. This study explored the relationship between pitch perception skills and reading ability in young adults with and without dyslexia with various levels of musical experience.

METHOD

Young adults (18-35 years old) with (N = 43) and without (N = 105) dyslexia completed two pitch perception tasks, reading assessments, and a survey reporting formal music training and childhood home music environment (HME).

RESULTS

Participants with dyslexia performed worse than typically developing peers on both pitch perception tasks. Single-word reading was related to pitch perception in the typically developing group only. Childhood HME positively correlated with mode categorization and simple pitch discrimination in both groups. Formal music training was associated with performance on both pitch perception tasks in the typically developing group, and simple pitch discrimination in the dyslexia group.

CONCLUSIONS

Pitch perception deficits may interfere with complex acoustic categorization and persist in some individuals with dyslexia despite prior music experiences. Future research should investigate the link between pitch perception and phonological awareness in dyslexia and assess whether music interventions targeting these skills improve reading.

The major-minor mode dichotomy in music perception

In Western tonal music, major and minor modes are recognized as the primary musical features in eliciting emotional responses. The underlying correlates of this dichotomy in music perception have been extensively investigated through decades of psychological and neuroscientific research, yielding plentiful yet often discordant results that highlight the complexity and individual differences in how these modes are perceived. This variability suggests that a deeper understanding of major-minor mode perception in music is still needed. We present the first comprehensive systematic review and meta-analysis, providing both qualitative and quantitative syntheses of major-minor mode perception and its behavioural and neural correlates. The qualitative synthesis includes 70 studies, revealing significant diversity in how the major-minor dichotomy has been empirically investigated. Most studies focused on adults, considered participants' expertise, used real-life musical stimuli, conducted behavioural evaluations, and were predominantly performed with Western listeners. Meta-analyses of behavioural, electroencephalography, and neuroimaging data (37 studies) consistently show that major and minor modes elicit distinct neural and emotional responses, though these differences are heavily influenced by subjective perception. Based on our findings, we propose a framework to describe a Major-Minor Mode(l) of music perception and its correlates, incorporating individual factors such as age, expertise, cultural background, and emotional disorders. Moreover, this work explores the cultural and historical implications of the major-minor dichotomy in music, examining its origins, universality, and emotional associations across both Western and non-Western contexts. By considering individual differences and acoustic characteristics, we contribute to a broader understanding of how musical frameworks develop across cultures. Limitations, implications, and suggestions for future research are discussed, including potential clinical applications for mood regulation and emotional disorders, alongside recommendations for experimental paradigms in investigating major-minor modes.

Confirming an antiphasic bicyclic pattern of forward entrainment in signal detection: A reanalysis of Sun et al. (2021)

Forward entrainment refers to that part of the entrainment process that persists after termination of an entraining stimulus. Hickok et al. (2015) reported forward entrainment in signal detection that lasted for two post-stimulus cycles. In a recent paper, Sun et al. (2021) reported new data which suggested an absence of entrainment effects (Eur. J. Neurosci, 1-18, doi.org/10.1111/ejn.15367). Here we show that when Sun et al.'s data are analysed using unbiased detection-theoretic measures, a clear antiphasic bicyclic pattern of entrainment is observed. We further show that the measure of entrainment strength used by Sun et al., the normalized Fourier transform of performance curves, is not only erroneously calculated but is also unreliable in estimating entrainment strength due to signal-processing artifacts.

Inadequate pitch-difference sensitivity prevents half of all listeners from discriminating major vs minor tone sequences

Substantial evidence suggests that sensitivity to the difference between the major vs minor musical scales may be bimodally distributed. Much of this evidence comes from experiments using the "3-task." On each trial in the 3-task, the listener hears a rapid, random sequence of tones containing equal numbers of notes of either a G major or G minor triad and strives (with feedback) to judge which type of "tone-scramble" it was. This study asks whether the bimodal distribution in 3-task performance is due to variation (across listeners) in sensitivity to differences in pitch. On each trial in a "pitch-difference task," the listener hears two tones and judges whether the second tone is higher or lower than the first. When the first tone is roved (rather than fixed throughout the task), performance varies dramatically across listeners with median threshold approximately equal to a quarter-tone. Strikingly, nearly all listeners with thresholds higher than a quarter-tone performed near chance in the 3-task. Across listeners with thresholds below a quarter-tone, 3-task performance was uniformly distributed from chance to ceiling; thus, the large, lower mode of the distribution in 3-task performance is produced mainly by listeners with roved pitch-difference thresholds greater than a quarter-tone.

An auditory-visual tradeoff in susceptibility to clutter

Sensory cortical mechanisms combine auditory or visual features into perceived objects. This is difficult in noisy or cluttered environments. Knowing that individuals vary greatly in their susceptibility to clutter, we wondered whether there might be a relation between an individual's auditory and visual susceptibilities to clutter. In auditory masking, background sound makes spoken words unrecognizable. When masking arises due to interference at central auditory processing stages, beyond the cochlea, it is called informational masking. A strikingly similar phenomenon in vision, called visual crowding, occurs when nearby clutter makes a target object unrecognizable, despite being resolved at the retina. We here compare susceptibilities to auditory informational masking and visual crowding in the same participants. Surprisingly, across participants, we find a negative correlation (R = -0.7) between susceptibility to informational masking and crowding: Participants who have low susceptibility to auditory clutter tend to have high susceptibility to visual clutter, and vice versa. This reveals a tradeoff in the brain between auditory and visual processing.

Sensitivity to major versus minor musical modes is bimodally distributed in young infants

The difference between major and minor scales plays a central role in Western music. However, recent research using random tone sequences ("tone-scrambles") has revealed a dramatically bimodal distribution in sensitivity to this difference: 30% of listeners are near perfect in classifying major versus minor tone-scrambles; the other 70% perform near chance. Here, whether or not infants show this same pattern is investigated. The anticipatory eye-movements of thirty 6-month-old infants were monitored during trials in which the infants heard a tone-scramble whose quality (major versus minor) signalled the location (right versus left) where a subsequent visual stimulus (the target) would appear. For 33% of infants, these anticipatory eye-movements predicted target location with near perfect accuracy; for the other 67%, the anticipatory eye-movements were unrelated to the target location. In conclusion, six-month-old infants show the same distribution as adults in sensitivity to the difference between major versus minor tone-scrambles.

How rests and cyclic sequences influence performance in tone-scramble tasks

When classifying major versus minor tone-scrambles (random sequences of pure tones), most listeners (70%) perform at chance while the remaining listeners perform nearly perfectly. The current study investigated whether inserting rests and cyclic sequences into the stimuli could heighten sensitivity in such tasks. In separate blocks, listeners classified tone-scramble variants as major versus minor ("3" task) or fourth versus tritone ("4" task). In three "Fast" variants, tones were played at 65 ms/tone as a continuous, random stream ("FR"), or with a rest after every fourth tone ("FRwR"), or as a repeating sequence of four tones with a rest after every fourth tone ("FCwR"). In the "Slow" variant, tones were played at 325 ms/tone in random order. In both the 3 and 4 tasks, performance was ordered from best to worst as follows: FRwR > FR > FCwR > Slow. Post hoc analysis revealed that performance was suppressed in the Slow and FCwR task-variants due to a powerful bias inclining listeners to respond "major" or "fourth" ("minor" or "tritone") if the 4-note sequence defining the stimulus ended on a high (low) note. Overall, the results indicate that inserting regular rests into random tone sequences heightens sensitivity to musical mode.

Pitch discrimination with mixtures of three concurrent harmonic complexes

In natural listening contexts, especially in music, it is common to hear three or more simultaneous pitches, but few empirical or theoretical studies have addressed how this is achieved. Place and pattern-recognition theories of pitch require at least some harmonics to be spectrally resolved for pitch to be extracted, but it is unclear how often such conditions exist when multiple complex tones are presented together. In three behavioral experiments, mixtures of three concurrent complexes were filtered into a single bandpass spectral region, and the relationship between the fundamental frequencies and spectral region was varied in order to manipulate the extent to which harmonics were resolved either before or after mixing. In experiment 1, listeners discriminated major from minor triads (a difference of 1 semitone in one note of the triad). In experiments 2 and 3, listeners compared the pitch of a probe tone with that of a subsequent target, embedded within two other tones. All three experiments demonstrated above-chance performance, even in conditions where the combinations of harmonic components were unlikely to be resolved after mixing, suggesting that fully resolved harmonics may not be necessary to extract the pitch from multiple simultaneous complexes.

Many listeners cannot discriminate major vs minor tone-scrambles regardless of presentation rate

A tone-scramble is a random sequence of pure tones. Previous studies have found that most listeners (≈ 70%) perform near chance in classifying rapid tone-scrambles composed of multiple copies of notes in G-major vs G-minor triads; the remaining listeners perform nearly perfectly [Chubb, Dickson, Dean, Fagan, Mann, Wright, Guan, Silva, Gregersen, and Kowalski (2013). J. Acoust. Soc. Am. 134(4), 3067-3078; Dean and Chubb (2017). J. Acoust. Soc. Am. 142(3), 1432-1440]. This study tested whether low-performing listeners might improve with slower stimuli. In separate tasks, stimuli were tone-scrambles presented at 115, 231, 462, and 923 notes per min. In each task, the listener classified (with feedback) stimuli as major vs minor. Listeners who performed poorly in any of these tasks performed poorly in all of them. Strikingly, performance was worst in the task with the slowest stimuli. In all tasks, most listeners were biased to respond "major" ("minor") if the stimulus ended on a note high (low) in pitch. Dean and Chubb introduced the name "scale-sensitivity" for the cognitive resource that separates high- from low-performing listeners in tone-scramble classification tasks, suggesting that this resource confers sensitivity to the full gamut of qualities that music can attain by being in a scale. In ruling out the possibility that performance in these tasks depends on speed of presentation, the current results bolster this interpretation.

Scale-sensitivity: A cognitive resource basic to music perception

A tone-scramble is a rapid, randomly ordered sequence of pure tones. Chubb, Dickson, Dean, Fagan, Mann, Wright, Guan, Silva, Gregersen, and Kowalski [(2013). J. Acoust. Soc. Am. 134(4), 3067-3078] showed that a task requiring listeners to classify major vs minor tone-scrambles yielded a strikingly bimodal distribution. The current study sought to clarify the nature of the skill required in this task. In each of the "semitone" tasks, all tone-scrambles contained eight each of the notes G₅, D₆, and G₆ (to establish G as the tonic) and eight copies of a target note. The target note was either A♭ or A in the "2" task, B♭ or B in the "3" task, C or D♭ in the "4" task, E♭ or E in the "6" task, and F or G♭ in the "7" task. On each trial, the listener strove to classify each stimulus according to its target note. Performance was best (and nearly equal) in the 2, 3, and 6 tasks, intermediate in the 4 task and worst in the 7 task. The results were well-described by a model in which a single cognitive resource controls performance in all five semitone tasks. This resource is called "scale sensitivity" here because it seems to confer general sensitivity to variations in scale in the presence of a fixed tonic.