Musical brains: a study of spontaneous and evoked musical sensations without external auditory stimuli.

CONCLUSIONS: Our observations confirm that musical sensations with no external stimuli, either spontaneous or evoked, occur in normal individuals and that a biological substrate can be demonstrated by brain single photon emission computed tomography (SPECT). OBJECTIVES: There are individuals, usually musicians, who are seemingly able to evoke and/or have spontaneous musical sensations without external auditory stimuli. However, to date there is no available evidence to determine if it is feasible to have musical sensations without using external sensory receptors, or if there is a biological substrate for these sensations. SUBJECTS AND METHODS: A group of 100 musicians and another of 150 otolaryngologists were asked if they had spontaneous musical auditory sensations and/or were capable of evoking them. SPECT evaluations with Tc(99m)-HMPAO were conducted in six female musicians while they were evoking these sensations or, in one case, while she was having them spontaneously. In three of them an additional SPECT was conducted in basal conditions (having been asked to avoid evoking music). RESULTS: In all, 97 of 100 musicians had spontaneous musical sensations; all 100 could evoke and modify them. Of the 150 otolaryngologists, 18 (12%) were musicians. Of the 132 nonmusicians, spontaneous musical sensations occurred in 52 (39.4%), 72 (54.5%) could evoke and 23 (17.4%) were able to modify them, 58 (43.9%) did not have spontaneous musical sensations nor could they evoke them. The musical sensations of the 72 otolaryngologists that could evoke were less elaborated than those of musicians. NeuroSPECT during voluntary musical autoevocation demonstrated significant (>2 SD) increased activation of executive frontal cortex in Brodmann areas 9 and 10, secondary visual cortex (area 17), and paracingulate (areas 31 and 32). There was also activation in the para-executive frontal cortex (areas 45 and 46). In the basal ganglia there was activation in thalamus and lentiform nucleus. Deactivation below 2 SD was demonstrated by mean values in the cingulate gyrus, Brodmann areas 23 and 24, and subgenual area 25. Deactivation was also demonstrated when minimal values were analyzed in the same areas plus area 4 and areas 36 and 38, the latter in the pole of the temporal lobes. In three patients comparison of basal state with autoevocation demonstrated activation in executive frontal cortex (areas 8 and 9), para-executive cortex (area 45), primary auditory cortex (area 40), the right thalamus, and lentiform nucleus.

Musical brains: a study of evoked musical sensations without external auditory stimuli: preliminary report of three cases

Existen personas, generalmente músicos, que tienen la capacidad de evocar sensaciones musicales sin un estímulo auditivo externo. Sin embargo, hasta la fecha no hay evidencias que sugieran que sea posible tener estas sensaciones, ni que exista un sustrato biológico para ellas. Diseño del trabajo: Se hicieron dos estudios de neuroSPECT con [99mTc]-HMPAO en cada una de tres mujeres músicos. El primer estudio fue hecho en condiciones basales (sin evocar) y el segundo mientras estaban evocando sensaciones musicales. Resultados: En el estudio de las voluntarias que fueron evaluadas mientras evocaban una composición musical, hubo un aumento significativo de perfusión en los hemisferios derecho e izquierdo en las áreas de Brodmann 9 y 8 (área ejecutiva frontal) y en el área 40 en el lado izquierdo (área auditiva). Sin embargo, en condiciones basales no hubo aumento de perfusión en las áreas 9, 8, 39 y 40. En un caso hubo mayor aumento de perfusión en el área 45 durante la autoevocación respecto a la condición basal. Conclusiones: Estos hallazgos son sugerentes de un sustrato biológico para el proceso de evocar sensaciones musicales.