Abstract
Pitch patterns, such as melodies, consist of two levels of structure: a global level, comprising the pattern of ups and downs, or contour; and a local level, comprising the precise intervals that make up this contour. An influential neuropsychological model suggests that these two levels of processing are hierarchically linked, with processing of the global structure occurring within the right hemisphere in advance of local processing within the left. However, the predictions of this model and its anatomical basis have not been tested in neurologically normal individuals. The present study used fMRI and required participants to listen to consecutive pitch sequences while performing a same/different one-back task. Sequences, when different, either preserved (local) or violated (global) the contour of the sequence preceding them. When the activations for the local and global conditions were contrasted directly, additional activation was seen for local processing in right planum temporale and posterior superior temporal sulcus (pSTS). The presence of additional activation for local over global processing supports the hierarchical view that the global structure of a pitch sequence acts as a “framework” on which the local detail is subsequently hung. However, the lateralisation of activation seen in the present study, with global processing occurring in left pSTS and local processing occurring bilaterally, differed from that predicted by the neuroanatomical model. A re-examination of the individual lesion data on which the neuroanatomical model is based revealed that the lesion data equally well support the laterality scheme suggested by our data. While the present study supports the hierarchical view of local and global processing, there is an evident need for further research, both in patients and neurologically normal individuals, before an understanding of the functional lateralisation of local and global processing can be considered established.
Highlights
Cognitive neuropsychological studies have demonstrated that pitch patterns, such as melodies, consist of two structural levels: the contour or pattern of ups and downs–synonymous with the ‘global’ level; and the precise intervals that make up this contour– synonymous with the ‘local’ level
In order to assess separately areas that are involved in the processing of local differences and global differences, we performed the following contrasts Local: ([Local Different (Ldiff)–Same]) and Global: ([Global Different (Gdiff)–Same])
The aim of this study was to test both aspects of the model put forward by Peretz and colleagues [5,6] which holds that the processing of pitch sequences involves a hierarchy and differential hemispheric lateralisation of these stages
Summary
Cognitive neuropsychological studies have demonstrated that pitch patterns, such as melodies, consist of two structural levels: the contour or pattern of ups and downs–synonymous with the ‘global’ level; and the precise intervals that make up this contour– synonymous with the ‘local’ level. Behavioural support for this hierarchical model came from same/different tasks in which pairs of novel pitch sequences could differ at a local level, where contour is preserved, or at a global level, where the overall contour is violated [1]. Selective deficits in discriminating melodies that shared the same contour were seen without accompanying deficits in discriminating melodies that differed in contour. This pattern was associated with damage to different hemispheres: RHD patients were worse than normal control (NC) participants for the detection of both types of differences, while LHD patients performed significantly better for contour-violated than contour-preserved differences
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
