Tetsufumi Ito University of Toyama

To understand the SHITSUKAN of sound, value information of the sound, such as comfort or discomfort, is essentially important. The fact that some sounds are innately comfortable, and others are uncomfortable, suggests that sounds are classified in the brain, and values are given to each class of sound. The neuronal circuitry of sound classification is the central auditory pathway from the inferior colliculus in midbrain to auditory cortex, and the classes are represented as sound class maps. On the other hand, bestowal of value on classified sound or the neuronal circuitry which connects between the sound class maps and the circuit of value representation is not well known. The current study is consisted of (1) characterization of innate values of sound classes, (2) visualization of the neuronal circuitry that assigns emotional values on the sound classes, (3) visualization of the neuronal circuitry of sound classification which works particularly for sounds with innate values, and (4) clarification of roles of the neuronal circuitry of sound classification on emotional response by manipulating activity of the elements of the circuitry. From these experiments, we will obtain better understanding of the neuronal circuitry that gives SHITSUKAN on sounds.