If we agree that these results also can be addressed as a transfer effect, then, it is obvious that a special training effect is likely to be seen as an operant conditioning. The task establishes a synaptic link between synchronically stimulated areas which is efficient even if only one neuronal track is activated. Learning, then, tends to establish those links, or in other words: to develop a dense neuronal network of connections that enables co-representations.   Fig. 1 Co-activation of the primary sensorimotor cortex in the auditory task (left), and of the frontolateral and temporal cortex in the motor task (right). Aus: M.Bangert, D.Parlitz, E.Altenmüller: Neuronal Correlates of the Pianists' Inner Ear. Oslo 1999 (2) In a long-term investigation on young children's music learning (Gruhn 2000) we collected data from 13 children age 1 to 2 (distribution from 8 to 27 months, mean 19 months) over a period of 15 months. 58 criteria were selected for observation relevant to attention, movement, audiation, voice production (imitation, improvisation, creativity), and listening. Each section was analysed separately, individually and as a group means. Then, we correlated the data of each criterion with any other. Significant correlation was found only between accuracy in voice production and the coordination and synchronisation of movement. m voice m rhythm patterns m m m tonal patterns m m songs m m m m m m m m m movement m consist.tempo m accuracy m intonation m pitch rhythm flow m .77* .74* m .86** m .84** .83** m m m m m mv m mm m m m coordination m .80** .74* m .81** m .70** .70** m synchronization m .82** .80** m .91** m .81** .81** m Fig. 2 Signifikant correlations between voice and movement after 6 months (© W.Gruhn 1999) The better the children performed continuous flow and coordinated movements, the more accurately and precisely they imitated tonal and rhythm patterns and songs or chants. For that, what educators and artists like Rudolf von Laban, Emile Jacques-Dalcroze, Heinrich Jacoby or Edwin Gordon have intuitively stated or empirically observed, we now have the data: there must be a neurophysiological link between fine motor control in movement and in muscles engaged in the vocal apparatus. It is not a co-activation like in the auditory and motor task, rather it must be seen as a transfer effect within the neuronal transmission tracks. In view of these results of brain research, the answer to our initially raised question, whether brain research supports the hope for transfer effects, is not easily to be answered. Although some indications occur, 'hard-core data' confirming transfer-effects of musical ablities on other cognitive domains are rare or even missing (Altenmüller et al. 1999). As to now, we must accept that there is little evidence for an inevitable external transfer effect from one intelligence to another; but there is strong evidence for internal correlation between different brain functions and brain activation areas that tempt us to believe in or hope for external transfer effects as well.