The Score Magazine April 2020 | Page 44

Tonal regularity in a scale and its relation to temporal processing centers of the brain Key Words : Music and the mind, Music, tonal regularity, subdominant and dominant tones, temporal accuracy, temporal processing, neural synchrony Written by
Prof B.Sai Kiran Kumar Consultant neurofeedback trainer BCIA USA, Sharath Manjunath Psychologist and certified Neurofeedback trainer Presidency college, Bangalore Musical expressions are derived out of combinations that arise from a definitive scale relevant to a respective emotion as a precursor. The root note becomes an identifying factor for the entire expression of the emotion played in a sequence. The temporal lobe in our brain is activated and also adheres to notes that are relevant to the root, sub- dominant and dominant portions of the scale which is the first, fourth and fifth notes. The reason associated with this kind of response is the tonal regularity and resolving nature of the musical expression when these three notes are used in a melody. It also creates a network of memory related neuronal pathways associated with recall value and rhythm. These tones played at regular intervals can activate cognitive responses pertaining to perceptual neural mechanisms. Temporal accuracy is an important factor to understand melodic phrases and also cues associated with rhythm and subsequent intervals associated with the root note. This enables a listener to discriminate between identical and non-identical sequences when a piece of music is played which accounts for sensorimotor synchronization. Any alterations in the regular syncopated sequence can cause variability in the judgment and affinity towards a respective piece of music. This is where the concept of genre selection comes in to place wherein the listener make a cognitive choice based upon the sequence of melody played with the feedback received from his temporal cues of accuracy. Musical frequencies are carried by the auditory nerve to the brain. If the chord is harmonic, or "consonant," the notes are spaced neatly enough so that the individual fibers of the auditory nerve carry specific frequencies to the brain. This principle is what scientists call harmonicity and it is linked to temporal lobe of the brain. In the context of Western Music, it has been noted that that two tones whose frequencies were related by a simple ratio like an octave produce the most pleasing, or consonant, musical intervals. Researchers indicates that sensory neurons react differently to different tones. Each sends an electrical signal to a third neuron, called an interneuron, which sends a final signal to the brain. The model’s interneuron fires when it receives input from the sensory neurons. The signals from the sensory neurons arrive at the same time if the tone is consonant, and so the interneuron still fires just once, then waits until it “recharges” before it fires again. The result is a regular train of pulses that reacts according to the harmony played or heard. Reference: Arnheim R. (1984). Perceptual dynamics in musical expression. Music. Q. 70, 295–309. 10.1093/mq/LXX.3.295 Barker A. (1978). Music and perception: a study in Aristoxenus. J. Hellen. Stud. 98, 9–16. 10.2307/630189 Arnal L. H., Giraud A. L. (2012). Cortical oscillations and sensory predictions. Trends Cogn. Sci. 16 390–398. 10.1016/j.tics.2012.05.003 42 The Score Magazine highonscore.com