Cortical plasticity in an early blind musician: an fMRl study

Abstract

Many studies have examined tactile perception and simple auditory perception in the blind, but none have previously investigated the neural basis of musical ability in this group. This topic is of particular interest because it has been suggested that early blind individuals may possess advanced musical skills (such as absolute pitch). Presumably, these skills could be the result of neural plasticity. It has been hard to empirically assess this claim because of the difficulty in recruiting an adequate number of subjects for use in a conventional paradigm. In the present paper, we report data from a congenitally blind musician, subject ML. Behavioral tests show that she possessed absolute pitch abilities that were similar to those of a reference group of AP musicians with normal vision. To examine the neural basis of her abilities we then tested subject ML and five control subjects using an fMRI paradigm. A regions-of-interest analysis found that similar areas (the right secondary auditory cortex, left IFG, left SMG) were activated in ML and the control subjects, to a similar degree, in response to music processing. However, ML showed additional activations in left parietal association cortices and extrastriate regions of the occipital lobe. Subject ML's data are consistent with a vast body of literature on blindness-induced plasticity. They extend these findings by demonstrating that cortical plasticity may underlie special musical skills as well. These data illustrate the potential value of case studies to investigate particularly rare phenotypes.

Neural correlates of absolute pitch differ between blind and sighted musicians

“…Our study showed an involvement of visual association but not primary visual areas within a blind musician with absolute pitch performing a classical pitch memory task. This strongly supports the study by Ross et al [11], who revealed cross-modal plasticity in visual association and parietal areas in a congenitally blind musician while performing a different music task. These authors interpreted their results with a recruitment of visual areas as accessory musical processing regions in response to sensory deprivation.…”

“…So far only one study assessed possible differences in the functional anatomy of an auditory task in a blind musician with absolute pitch in a region-specific comparison with a group of sighted musicians [11]. Participants in this study performed a 'moveable do' solfeggio task, which is familiar to most musicians and can be performed by musicians with and without absolute pitch.…”

Absolute pitch: perception, coding, and controversies

“…In this sense, tonal processing among all but AP possessors may be analogous to 'gist memory' for speech [43], retaining the meaning without the stimulus details. On the other hand, the long-term memory representation for well-known songs might combine both absolute and relative pitch cues, suggesting a hybrid model and supporting the notion of accurate and stable 'pitch memory' distinct from labelling [59,62].…”

“…Early-blind musicians are far more likely to possess AP than sighted ones, with nearly 60% of one sample reporting AP, compared with less than 20% of sighted musicians [57]. This has been attributed to the recruitment of unused neural resources from the visual cortex [58], although one study found that the same cortical networks were activated in a blind AP possessor as in sighted AP musicians [59].…”

Are Supramodality and Cross-Modal Plasticity the Yin and Yang of Brain Development? From Blindness to Rehabilitation

“…For instance, if volumetric properties of the occipital lobe can predict behavioral accuracies in pitch discrimination (Voss and Zatorre, 2012), or if the recruitment of “visual” cortex during Braille reading is modulated by blindness onset (Burton et al, 2002), correlations between performance and crossmodal recruitment of deafferented cortical areas has also been demonstrated in a variety of other tasks, such as olfactory (Renier et al, 2013), auditory (Ross et al, 2003; Voss et al, 2008; Renier et al, 2010) and tactile (Kupers et al, 2006). …”