Music:Music and the brain
From Arcthon
Source: http://en.wikipedia.org/wiki/Music_and_the_brain
Contents |
Pitch
When we hear a certain **pitch**, a corresponding part of the tonotopically organized basilar membrane in the inner ear responds, and sends the signal to the auditory cortex. Studies suggest that once the signal arrives, there are specific regions for each band of pitch such that the area is organized into sections of cells that are responsive to certain frequencies which range from very low to very high in pitches [1]. This organization may not be stable and the specific cells that are responsive to different pitches may change over days or months [2].
Rhythm
The belt and parabelt areas of the right hemisphere are involved in processing rhythm. When individuals are preparing to tap out a rhythm of regular intervals (1:2 or 1:3) the left frontal cortex, left parietal cortex, and right cerebellum are all activated. With more difficult rhythms such as a 1:2.5, more areas in the cerebral cortex and cerebellum are involved.[3]EEG recordings have also shown a relationship between brain electrical activity and rhythm perception. Snyder and Large (2005) performed a study examining rhythm perception in human subjects, finding that activity in the gamma band (20 – 60 Hz) corresponds to the 'beats' in a simple rhythm. Two types of gamma activity were found by Snyder et al: (2005); induced gamma activity, and evoked gamma activity. Evoked gamma activity was found after the onset of each tone in the rhythm; this activity was found to be phase-locked (peaks and troughs were directly related to the exact onset of the tone) and did not appear when a gap (missed beat) was present in the rhythm. Induced gamma activity, which was not found to be phase-locked, was also found to correspond with each beat. However, induced gamma activity did not subside when a gap was present in the rhythm, indicating that induced gamma activity may possibly serve as a sort of internal metronome independent of auditory input.
Tonality
Emotion
When unpleasant melodies are played, the posterior cingulate cortex activates, which indicates a sense of conflict or emotional pain.[3] The right hemisphere has also been found to be correlated with emotion, which can also activate areas in the cingluate in times of emotional pain, specifically social rejection (Eisenberger). This evidence, along with observations, has led many musical theorists, philosophers and neuroscientists to link emotion with tonality. This seems almost obvious because the tones in music seem like a characterization of the tones in human speech, which indicate emotional content. The vowels in the phonemes of a song are elongated for a dramatic effect, and it seems as though musical tones are simply exaggerations of the normal verbal tonality.
