Peter of Abano (c.1250-c.1316) on intersensory coordination in speech
Hearing is obviously the principal sense involved in speech perception. Yet the acoustical signal provides far too much information to be directly useful for speech. To pick the speech signal out of the maze of acoustic information requires the cooperation of the sensory modalities of hearing, sight, and tactile-kinesthesis, along with a rhythmic entrainment of attention not unlike that needed for catching a ball. According to a widely accepted though still controversial point of view, the motor theory of speech perception, an evoked potential or sub-movement of the speech organs is a necessary accompaniment to listening in order for speech perception to occur.
Medieval conceptions of neuropsychology and physiology were based chiefly on the works of Aristotle, Galen, Avicenna and other Arabic/Persian writers. The coordination of speech and hearing came up in discussing why the deaf do not speak, and how young children are able to repeat new words they hear. The functional answer, that the deaf do not speak because they never have heard words, whereas normal children can repeat even difficult words because they do hear them, was widespread, but unsatisfying to physicians, who sought an organic explanation, although Galen confessed that he was unable to find one. But the question raised the issue of the inner coordination of the sense of hearing with the action of speech.
Peter of Abano, a natural philosopher and professor of medicine at Padua who represents the pinnacle of thinking attained in these fields in the late 13th-early 14th centuries, addresses this question and provides a very interesting way of understanding it, with both psychological and neuroanatomical comparisons.
Session III -- Psychiatric and Philosophical Aspects of the Neurosciences
Sixth Annual Meeting of the International Society for the History of the Neurosciences (ISHN) and