Lecture 14- The musical brain

Question 1

What is music?

Answer 1

-not just a collection of sounds -a single melody has multiple dimensions

Question 2

What are the dimensions of a single melody?

Answer 2

-pitch: the individual intervals and overall ups and downs -time: tempo, rhythm, metre -distinctive instrumental or human voice (timbre)

Question 3

Can animals perceive elements of music?

Answer 3

• nature vs nurture
• rhesus monkey show octave generalization
• monkey picks speaker that gives the same sound as test
• subjects were able to pick octave differences but not half octaves
• birds sing, whales sing…
• monkey can hear an octave -how many notes within the octave can a monkey detect (we can detect 8) -monkey can tell some aspects of music but not like us
• so an element of nature but lot of nurture

Question 4

Is music hardwired?

Answer 4

• Perani et al (2010) studied babies who had not been exposed to any music
• compared fMRI of babies (1-3 days old) to classical music and compared to silence and dissonant music -region in the temporal lobe when hearing= auditory cortex
• now compared the dissonant and normal music= there are differences in the parts of the brain that are activated = so hardwired to recognise music

Question 5

What are the neural circuits that underpin music?

Answer 5

• similarities with language processing
• grammar, syntax, motor components…
• left side vs right side -in language= motor parts coded in broca’s area -in left handed people that is in the right area -right side of the language= the up and down of language, the prosody of language, melody (controlled by the right side) -if music is about pitch, timbre maybe the same area as the prosody?

Question 6

What was the proof that music is not language?

Answer 6

-Russian composer Vissarion Shebalin(1902-1963) -Had a stroke in 1953: partial paralysis and reduced sensation of right hand and face. -Continued to write music over the next 6 years. -Second stroke 1959: left him paraylsed on right side of body as well as a profound aphasia. -He couldn’’t understand language, nor speak. -Third stroke: 1963. -Postmortem showed massive damage to temporal and inferior parietal regions of left side of brain. -did this affect his music? no , the stroke in the left hemisphere didn’t affect him -can write music even after the second stroke

Question 7

Is the music on the right side or on the left side?

Answer 7

-Asymmetry: Originally thought that left brain was for language; rright for prosody and music. - But, injury to either side can affect musical ability -left: rhythm -right: pitch and melody

Question 8

What is stage 1 in neural circuits involved in music?

Answer 8

Stage 1: Hearing and encoding sound -Hierachical organization. -Music is first processed in the Ascending auditory pathway from the cochlea to primary auditory cortex.

Question 9

What is stage 2 in neural circuits involved in music?

Answer 9

-the role of cortex

Question 10

What are the auditory-motor interaction?

Answer 10

-Motor control systems -Timing, sequencing, spatial organization of movement -Cerebellum, basal ganglia Supplementary motor area. -Auditory processing - Dorsal: auditory-motor (time dependent) -Hierachical control Dorsal and ventral streams -there must be interaction between the auditory and motor system otherwise you couldn’t play the violin or the piano etc. -must have an exquisite control of the motor system

Question 11

What is the coupling between auditory and motor cortices?

Answer 11

• Same brain regions are activitated when musicians listen vs play a piece of music
• when listen= auditory= active -person who is a pianist and know the music= get activation in the premotor cortex
• when play the piece but cannot hear= get the premotor cortex, you cannot hear anything but auditory cortex still lit up
• for musicians there is a connection between the auditory cortex and motor system

Question 12

What is the connection between music and emotion?

Answer 12

-Intense pleasure is derived from certain stimuli eg food, psychoactive drugs, money -Mediated by dopaminergic activity. -Music can also be a potent pleasurable stimulus. -Salimpoor et al 2011: used ligand-based PET to estimate dopamine release from the striatum in response to pleasurable or neutral music.

Question 13

What is the connection between music and dopamine release?

Answer 13

• you could anticipate what you are going to experience
• you know the bit that you like a lot -amout of dopamine is high when the bit of music that you particualrly good
• different parts activated dependant on what you experience

Question 14

What is the music and plasticity: motor cortex?

Answer 14

Ebert et al (1995) - Six violinists and cellist. - Six controls - Measured representation of motor cortex for left digits and right digits. -Cortex encoding left digits greater in size than controls - Indicates that gray matter increases

Question 15

What is the music and plasticity: auditory cortex?

Answer 15

-Pantev et al (1998) -Compared auditory activity to piano tones and pure tones in musicians and non- musicians. -Enlargement (25%) of auditory activity in musicians to piano tones. -pianists have different auditory cortex, larger than control

Question 16

What was the experiment with motor pathways: white matter tracts?

Answer 16

-Bengtsson et al 2005: -Maturation of central fibre tracts continues until at least 30 years of age. - Maturation of corticospinal tracts mirrors the development of fine finger movements. -Tested 8 male pianists (age: 32yrs), 8 male controls - Examined effect of practice: 3 groups-0-11yrs, 12-16, >17yrs. -there is a difference depending on the age the music playing started in the person

Question 17

What is the evidence for practice makes perfect?

Answer 17

-Bengtsson et al 2005: - N= 8 male pianists (age: 32yrs), 8 male controls - Examined effect of practice: 3 groups-0-11yrs, 12-16, >17yrs. - White matter plasticity occurs if practicing occurs during the developmental period. -music can change your brain!

Question 18

Can music make you smarter?

Answer 18

• in terms of IQ no Can Skill acquisition in one area, translate to another? -E.g., spatial skills, maths, verbal skills, general IQ - N=59 children ~9.96yrs old no music -N=41 10yr olds with 3 years of music. -improvement in motor skills, vocabulary, key math basic concept, operations and applications

Question 19

What is the connection between music and stroke?

Answer 19

• Music listening enhances recovery after MCA stroke. - 60 patients MCA: either music, language, control -2 months of listening to music , audio-books or nothing. -Examined at 3 and 6months -people who had to learn the music= -better attention, verbal memory, and less depression= so helps a lot

Question 20

What is the connection between music and depression?

Answer 20

-music therapy helps with depression music therapy= comb of singing, playing an instrument -N=79 with unipolar depression-individual music therapy plus standard care or standard care alone.

Question 21

What is the connection between music and dementia?

Answer 21

-Music therapy is used to reduce anxiety and stress in patients in aged care. -Music therapy can be receptive (ie listening) or active (playing instruments). -Many studies have looked at: -Behavioural changes (stress, anxiety), wandering, cognitive decline

Question 22

Do musicians have a slower decline in ageing?

Answer 22

-Musicians are less susceptible to age-related degenerations including dementia. -Arcuate fasciculus (auditory-motor pathway)

Question 23

What is the connection of music and cognitive decline?

Answer 23

-Verghese et al (2003): NEJM -469 subjects (older 75) -Examined leisure activities and evaluated development of dementia over 5 year period.

Question 24

Summary?

Answer 24

• Music doesn’’t just enrich our lives. - It stimulates a vast array of neural pathways. - Induces plasticity in motor, auditory areas and white matter tracts. -Plasticity changes can be used as a way of enhancing recovery from stroke, neurodegenerative disease and depression.