Music and the Brain

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Music and the Brain
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What is Music and what is it made of?

• Organized sound

• Some fundamental building blocks of music
• Loudness (energy)
• Pitch (frequency)
• Rhythm (durations of series of pitches)
• Tempo (overall speed)
• Timbre(overall quality)

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This Presentation

• Overview of music and the perceptual processing
  of some of its basic components
• Clinical Applications/Music Therapy

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How does your brain process music?

• Different for different components of music
• Consists of overlapping neuronal networks
  
• left temporal lobe processing of rhythmical,
  temporal and sequential components
• right temporal lobe melodic and timbre
  perception

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Pitch Perception
-In music pitch is used to construct -melodies
patterns of pitch over time -chords the
simultaneous presentation of more than one
pitch -harmonies simultaneous presentation of
more than one melody
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Pitch Perception

• distances of major and minor keys can be
  represented as a tonality surface in prefrontal
  cortex (Janata et al)
• main goal identify cortical areas that exhibit
  tonality tracking

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• The most extensive consistent activation was
  along the superior temporal gyrus (STG) of both
  hemispheres-greater in the right

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Tempo, rhythm, and meter

• Tempo a series of time intervals marked off by
  the onsets of sensory or motor events
• Information derived from brain damaged patients
• rhythm processing can be selectively impaired
  without any deficit in melody processing
• fMRI studies demonstrate activity in the lateral
  cerebellum and basal ganglia during the
  reproduction of rhythm. (Sakai et al)
• distinct representations for sequences with time
  intervals in
• integer ratios (metrical)
• non integer ratios (nonmetrical)

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Rhythm Perception

• Sakai et al used rhythms with their time
  intervals formed with 124, 123, and 12.53.5
  ratio
• The reproduction of 124 and 123 rhythms was
  precise, whereas that of 12.53.5 rhythm was
  inaccurate
• results suggest that a rhythm is represented, by
  default, in a metrical form rather than a
  nonmetrical form.

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Rhythm Perception

• fMRI to detect regions being activated during
  different intervals
• for 123 and 124 rhythms almost the same set
  of brain regions were active 12.53.5 was
  different
• Right cerebellar anterior lobe active in 124,
  123 ratio
• Bilateral cerebellar posterior lobes active for
  12.5 3.5
• results suggest the presence of two distinctive
  neural representations of rhythm

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Timbre Perception

• Amusias often characterized by alternation in
  perceived quality of music
• flat or mechanical
• inability to recognize musical instruments
• timbral deficits usually are associated with
  pitch perception deficits
• dystimbria may arise in association with lesions
  involving the right Superior Temporal Gyrus

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Timbre Perception

• WDK, 65 year old man, experienced selective loss
  of timbre perception for keyboard and percussion
  instruments following a right temporal stroke
  (Kohlmetz et al)
• no de?cits in primary auditory function,
• selective impairment in the perception of timbre
• Similar symptoms of patients who underwent
  temporal lobectomy (epilepsy surgery)

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Emotion

• pleasant music frontal lobes
• Unpleasant music temporal lobes
• dopamine release in ventral striatum and
  tegmental areas during pleasant music
• musical stimuli promote the release of endorphins
  and endocannabanoids into bloodstream
• naloxone (opiod antagonist) decrease pleasant
  sensations evoked by listening to music

• altered emotional response to music despite
  normal perceptual analysis can occur
• lesions involving the right posterior temporal
  lobe and insula

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Music Therapy in Parkinsons Patients

• effective on improving motor, behavioral, and
  emotional dysfunctions of Parkinsons patients
• strong evidence that rhythmical auditory cueing
  enhances walking speed in patients with
  Parkinsons disease (Lim et al)
• In the same study, visual cues (floor markers,
  laser beams) and tactile cuing (shoulder tapping)
  did not elicit significant gait improvement

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Music Therapy in Parkinsons Patients

• Pacchetti et al- Comparison of Music therapy to
  physical therapy in their effect on physical and
  emotional functions
• improvements in motor abilities and emotional
  status related to active MT
• PT improved rigidity but did not induce any major
  changes in other variables
• affective arousal effect of music
• act on motivational and emotional processing.
• improvement in bradykinesia
• activation of the emotional neural-based network
  that involves the dopaminergic mesolimbic
  projections to the ventral striatum
• this circuit is assumed to regulate
  motivational-incentive reinforcements

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Other hopes for music therapy

• Alzheimers
• epilepsy
• depression

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Acknowledgements

• Janata P, Birk JL, Van Horn JD et al The Cortical
  topography of tonal structures underlying Western
  Music. Science 20022982167-70.
• Sakai K, Hikosaka O, Miyauchi S et al. Neural
  Representation of a rhythm depends on its
  interval ratio. J Neurosci 19991910074-81.

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