Some combinations of musical notes sound pleasing and are termed "consonant," but others sound unpleasant and are termed "dissonant." The distinction between consonance and dissonance plays a central role in Western music, and its origins have posed one of the oldest and most debated problems in perception. In modern times, dissonance has been widely believed to be the product of "beating": interference between frequency components in the cochlea that has been believed to be more pronounced in dissonant than consonant sounds. However, harmonic frequency relations, a higher-order sound attribute closely related to pitch perception, has also been proposed to account for consonance. To tease apart theories of musical consonance, we tested sound preferences in individuals with congenital amusia, a neurogenetic disorder characterized by abnormal pitch perception. We assessed amusics' preferences for musical chords as well as for the isolated acoustic properties of beating and harmonicity. In contrast to control subjects, amusic listeners showed no preference for consonance, rating the pleasantness of consonant chords no higher than that of dissonant chords. Amusics also failed to exhibit the normally observed preference for harmonic over inharmonic tones, nor could they discriminate such tones from each other. Despite these abnormalities, amusics exhibited normal preferences and discrimination for stimuli with and without beating. This dissociation indicates that, contrary to classic theories, beating is unlikely to underlie consonance. Our results instead suggest the need to integrate harmonicity as a foundation of music preferences, and illustrate how amusia may be used to investigate normal auditory function. music perception | aesthetic preferences | roughness

Objectives: There are presently no data available concerning Internet addiction (IA) problems among adolescents in Canada and the province of Quebec. The goal of this study is thus to document and compare the influence of gender on Internet use and addiction.Method: The study data were collected from a larger research project on gambling among adolescents. Activities conducted online (applications used and time spent) as well as answers to the Internet Addiction Test (IAT) were collected from 3938 adolescents from grades 9 to 11. The two most often employed cut-off points for the IAT in the literature were documented: (40-69 and 70þ) and (50þ).Results: Boys spent significantly more time on the Internet than did girls. A greater proportion of the girls made intense use of social networks, whereas a greater proportion of the boys made intense use of massively multiplayer online role-playing games, online games, and adult sites. The proportion of adolescents with a potential IA problem varied according to the cut-off employed. When the cut-off was set at 70þ, 1.3% of the adolescents were considered to have an IA, while 41.7% were seen to be at risk. At a 50þ cut-off, 18% of the adolescents were considered to have a problem. There was no significant difference between the genders concerning the proportion of adolescents considered to be at risk or presenting IA problems. Finally, analysis of the percentile ranks would seem to show that a cut-off of 50þ better describes the category of young people at risk.

This study investigated the ability of normal-hearing listeners to process random sequences of tones varying in either pitch or loudness. Same/different judgments were collected for pairs of sequences with a variable length (up to eight elements) and built from only two different elements, which were 200-ms harmonic complex tones. The two possible elements of all sequences had a fixed level of discriminability, corresponding to a d(') value of about 2, irrespective of the auditory dimension (pitch or loudness) along which they differed. This made it possible to assess sequence processing per se, independent of the accuracy of sound encoding. Pitch sequences were found to be processed more effectively than loudness sequences. However, that was the case only when the sequence elements included low-rank harmonics, which could be at least partially resolved in the auditory periphery. The effect of roving and transposition was also investigated. These manipulations reduced overall performance, especially transposition, but an advantage for pitch sequences was still observed. These results suggest that automatic frequency-shift detectors, available for pitch sequences but not loudness sequences, participate in the effective encoding of melodies.

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Internet gambling among adolescents is a growing phenomenon that has received little attention to date. This study examines associations between Internet gambling and the severity of gambling, substance use (SU), and delinquent behavior among 1,870 Quebec students aged 14 to 18. The results show a higher proportion of Internet-gambling (IG) students reporting problematic substance use and delinquency, compared with nongamblers (NG) and non-Internet gamblers (NIG). Furthermore, a higher proportion of at-risk and probable pathological gamblers are found among IG compared with NIG. A moderating effect (Baron & Kenny, 1986) of the gambler categories (NIG, IG) was found in the relationship between the associated problems and the severity of gambling. Among IG, the severity of delinquency and of substance use contributes to explaining gambling severity whereas, among NIG, the severity of delinquency is the only factor that significantly contributes to such an explanation. Discussion of the results is based on Jessor, Donovan, and Costa's (1991) general deviance syndrome theory.

Recent theories suggest that the basis of neurodevelopmental auditory disorders such as dyslexia or specific language impairment might be a low-level sensory dysfunction. In the present study we test this hypothesis in congenital amusia, a neurodevelopmental disorder characterized by severe deficits in the processing of pitch-based material. We manipulated the temporal characteristics of auditory stimuli and investigated the influence of the time given to encode pitch information on participants’ performance in discrimination and short-term memory. Our results show that amusics’ performance in such tasks scales with the duration available to encode acoustic information. This suggests that in auditory neuro-developmental disorders, abnormalities in early steps of the auditory processing can underlie the high-level deficits (here musical disabilities). Observing that the slowing down of temporal dynamics improves amusics’ pitch abilities allows considering this approach as a potential tool for remediation in developmental auditory disorders.

Pitch plays a fundamental role in audition, from speech and music perception to auditory scene analysis. Congenital amusia is a neurogenetic disorder that appears to affect primarily pitch and melody perception. Pitch is normally conveyed by the spectro-temporal fine structure of low harmonics, but some pitch information is available in the temporal envelope produced by the interactions of higher harmonics. Using 10 amusic subjects and 10 matched controls, we tested the hypothesis that amusics suffer exclusively from impaired processing of spectro-temporal fine structure. We also tested whether the inability of amusics to process acoustic temporal fine structure extends beyond pitch by measuring sensitivity to interaural time differences, which also rely on temporal fine structure. Further tests were carried out on basic intensity and spectral resolution. As expected, pitch perception based on spectro-temporal fine structure was impaired in amusics; however, no significant deficits were observed in amusics' ability to perceive the pitch conveyed via temporal-envelope cues. Sensitivity to interaural time differences was also not significantly different between the amusic and control groups, ruling out deficits in the peripheral coding of temporal fine structure. Finally, no significant differences in intensity or spectral resolution were found between the amusic and control groups. The results demonstrate a pitch-specific deficit in fine spectro-temporal information processing in amusia that seems unrelated to temporal or spectral coding in the auditory periphery. These results are consistent with the view that there are distinct mechanisms dedicated to processing resolved and unresolved harmonics in the general population, the former being altered in congenital amusia while the latter is spared.