ABSTRACT
Communicating with one's environment requires efficient neural interaction between action and perception. Neural substrates of sound perception and production are connected by the arcuate fasciculus (AF). Although AF is known to be involved in language, its roles in non-linguistic functions are unexplored. Here, we show that tone-deaf people, with impaired sound perception and production, have reduced AF connectivity. Diffusion tensor tractography and psychophysics were assessed in tone-deaf individuals and matched controls. Abnormally reduced AF connectivity was observed in the tone deaf. Furthermore, we observed relationships between AF and auditory-motor behavior: superior and inferior AF branches predict psychophysically assessed pitch discrimination and sound production perception abilities, respectively. This neural abnormality suggests that tone deafness leads to a reduction in connectivity resulting in pitch-related impairments. Results support a dual-stream anatomy of sound production and perception implicated in vocal communications. By identifying white matter differences and their psychophysical correlates, results contribute to our understanding of how neural connectivity subserves behavior.
Subject(s)
Deafness/classification , Deafness/physiopathology , Pitch Discrimination/physiology , Psychophysics/methods , Acoustic Stimulation/methods , Adult , Auditory Perception/physiology , Deafness/diagnosis , Female , Humans , Male , Middle Aged , Pitch Perception/physiology , Psychophysics/trends , SyndromeSubject(s)
Ear Diseases/history , Medicine, Chinese Traditional/history , Otolaryngology/history , Acupuncture Therapy/history , China , Deafness/classification , Deafness/history , Ear Diseases/therapy , History, 16th Century , History, 17th Century , History, 20th Century , History, 21st Century , History, Ancient , Humans , Moxibustion/historyABSTRACT
A new approach to the design of time windows is presented for detection of transient-evoked otoacoustic emissions (TEOAE). The windows are designed with reference to a minimum mean square error criterion involving the correlation properties of the ensemble of responses. Latency information is introduced in the detection process by windowing at different scales that result from wavelet decomposition. The significance of both subject- and population-specific time windows is investigated. The detection performance is evaluated on a health screen database consisting of 4989 records. The results show that the present approach to windowing yields a significantly better performance in separating normal-hearing subjects from hearing-impaired subjects when compared to detection based on unwindowed signals. With time windowing, the specificity increased with almost 15% at a fixed sensitivity of 90%.