Tonal structures benefit short-term memory for real music: Evidence from non-musicians and individuals with congenital amusia.

Congenital amusia is a neurodevelopmental disorder of music processing, which includes impaired pitch memory, associated to abnormalities in the right fronto-temporal network. Previous research has shown that tonal structures (as defined by the Western musical system) improve short-term memory performance for short tone sequences (in comparison to atonal versions) in non-musician listeners, but the tonal structures only benefited response times in amusic individuals. We here tested the potential benefit of tonal structures for short-term memory with more complex musical material. Congenital amusics and their matched non-musician controls were required to indicate whether two excerpts were the same or different. Results confirmed impaired performance of amusic individuals in this short-term memory task. However, most importantly, both groups of participants showed better memory performance for tonal material than for atonal material. These results revealed that even amusics' impaired short-term memory for pitch shows classical characteristics of short-term memory, that is the mnemonic benefit of structure in the to-be-memorized material. The findings show that amusic individuals have acquired some implicit knowledge of regularities of their culture, allowing for implicit processing of tonal structures, which benefits to memory even for complex material.

Discrimination of tonal and atonal music in congenital amusia: The advantage of implicit tasks.

Congenital amusia is a neurodevelopmental disorder of music perception and production, which has been attributed to a major deficit in pitch processing. While most studies and diagnosis tests have used explicit investigation methods, recent studies using implicit investigation approaches have revealed some unimpaired pitch structure processing in congenital amusia. The present study investigated amusic individuals' processing of tonal structures (e.g., musical structures respecting the Western tonal system) via three different questions. Amusic participants and their matched controls judged tonal versions (original musical excerpts) and atonal versions (with manipulated pitch content to remove tonal structures) of 12 musical pieces. For each piece, participants answered three questions that required judgments from different perspectives: an explicit structural one, a personal, emotional one and a more social one (judging the perception of others). Results revealed that amusic individuals' judgments differed between tonal and atonal versions. However, the question type influenced the extent of the revealed structure processing: while amusic individuals were impaired for the question requiring explicit structural judgments, they performed as well as their matched controls for the two other questions. Together with other recent studies, these findings suggest that congenital amusia might be related to a disorder of the conscious access to music processing rather than music processing per se.

Implicit learning of nonlocal musical rules: a comment on Kuhn and Dienes (2005).

In a recent study, G. Kuhn and Z. Dienes (2005) reported that participants previously exposed to a set of musical tunes generated by a biconditional grammar subsequently preferred new tunes that respected the grammar over new ungrammatical tunes. Because the study and test tunes did not share any chunks of adjacent intervals, this result may be construed as straightforward evidence for the implicit learning of a structure that was only governed by nonlocal dependency rules. It is shown here that the grammar modified the statistical distribution of perceptually salient musical events, such as the probability that tunes covered an entire octave. When the influence of these confounds was removed, the effect of grammaticality disappeared.

The time course of emotional responses to music.

Two empirical studies investigate the time course of emotional responses to music. In the first one, musically trained and untrained listeners were required to listen to 27 musical excerpts and to group those that conveyed a similar emotional meaning. In one condition, the excerpts were 25 seconds long on average. In the other condition, excerpts were as short as 1 second. The groupings were then transformed into a matrix of emotional dissimilarity that was analyzed with multidimensional scaling methods (MDS). We compared the outcome of these analyses for the 25-s and 1-s duration conditions. In the second study, we presented musical excerpts of increasing duration, varying from 250 to 20 seconds. Participants were requested to evaluate on a subjective scale how "moving" each excerpt was. On the basis of the responses given for the longer duration, excerpts were then sorted into two groups: highly moving and weakly (or less) moving. The main purpose of the analysis was to identify the point in time where these two categories of excerpts started to be differentiated by participants. Both studies provide consistent findings that less than 1 s of music is enough to instill elaborated emotional responses in listeners.