Psychology of Music Learning

Miksza - Spring ‘09

WEEK TWELVE

Music and Brain Research

…from Hodges (1996)

Hodges (1996)

• Brain, brain stem, spinal cord, peripheral nerves, autonomic nervous system

• Cerebral cortex – most ‘distinctly human’ functions• Occipital lobes – vision• Parietal lobes – sensory processing• Temporal lobes – hearing• Frontal lobes – long-term planning, motor control,

movement control, speech production– Sensory zone – information from the senses– Motor zone – control and coordination of muscle movement– Association zone – cognitive interpretation understanding

Hodges (1996)

• Sensory cortex– A map of the body surface

• Motor cortex– Initializes movement

• Limbic system– Chemical processes and emotions

• Brain stem– Automatic body functions - breathing

• Cerebellum– Muscle coordination, rote movements

Hodges (1996)

• 100 billion neurons– 100 million per cubic inch– Neurons grow in size and connections early in life

– rich sensory environments stimulate the connections – impoverished limits

– Single neuron receives 100,000 to 200,00 signals– Synapses are connecting points– Nerves either fire or they don’t – they don’t range

in intensity, just rate– Synapses are altered by experience

Hodges (1996)

• Cognitive neuroscientists – try to explain behavior based on neurophysiological data

• Competing models of brain function– Triune: reptilian, paleomammalian, neomammalian

• Evolutionary approach

– Split-brain: Hemispheric function• Left: verbal, sequential, logical, analytic• Right: nonverbal, holistic, intuitive, synthesizing

– Varies with handedness

– Neural network: input, middle/hidden, output layers of overlapping processes

• Logarithmic descriptions of brain processes

Hodges (1996)

• See Table 1 for effects of brain damage on musical ability – amusia…

• Although it is often the case, losses of musical ability are not always linked to losses of language abilities

• Some studies suggest that musical abilities may require more widely distributed neural processes than language– Therefore, it is more difficult to draw conclusions about

lateralization and musical abilities

• See page 218 and 219 for methods of testing for various levels/types of amusia

Hodges (1996)

• Dichotic listening tasks and hemisphericity– Two conflicting aural stimuli, one in each ear

(usually with headphones)– Think back to discussion of ipsolateral and

contralateral pathways from the ear…– 70% of nerve fibers go to opposite hemisphere

(contralateral)– Very tentative, general findings – vary greatly with

subtle changes in task and individuals studied• Right hemisphere – sound gestalt• Left hemisphere – sequential, analytic processes• See Table 2 for studies…

Hodges (1996)• Electroencephalogram (EEG)

– Monitoring electrical activity in the brain in terms of frequency (Hz)

– Electrodes near frontal, parietal, occipital and temporal areas

• Delta – deep sleep• Theta – dreaming• Alpha – conscious/relaxed• Beta – full alertness (consider term ‘beta-blocker)

– Interesting results from many studies but significant patterns or generalizations are difficult to find due to methodological differences in stimuli and tasks

Hodges (1996)

• EEG continued…– Alpha production found to decrease with music

listening– Musical expectancy is somewhat detectable in

brain wave activity (other than alpha) – e.g., resolutions

– Musicians show more coherence across hemispheres and adjacent areas (e.g., parietal, occipital)

– Larger planum temporale for musicians who started prior to age 7 or had perfect pitch

– Larger corpus callosum• Raises issue of whether musical training leads to

reorganization of the brain

Hodges (1996)

• Auditory Event-related Potential– Tying stimuli to electrical events in a time-bound

fashion– ERP’s are a result of cognitive processes that are

generated in response or as a result of sensory perception

• N1 – negative wave 100ms after stimulus– Attention

• N4 – negative wave 400ms after stimulus– Violated expectation

• P3 – positive wave 300ms after stimulus– Short-term and long-term memory exchange

» Lack of P3 in subjects with absolute pitch…

Hodges (1996)

• MRI – magnetic resonance imaging– Subject placed inside large magnet– Provides structural, but not functional information

• PET – positron emissions tomography– Radioactive substance in bloodstream– Depicts blood flow in brain– Subtract PET at rest from PET w/musical stimuli to

see activity attributable to musical activity– Can try to pin down localizations for ‘most’ activity,

but many areas of the brain show some activity given musical stimuli

Hodges (1996)• Neuromotor aspects…• Sensory-motor cortex – where body map (i.e., homunculus is

located)– Where conscious decisions to contract muscles are processed– More space is devoted to face and hands– Body map is redrawn with experience

• Basal Ganglia– Sends messages to spinal cord and groups of muscles

• Cerebellum– Maintaining balance, coordinating intricate movements, monitoring

feedback, storing habituated patterns• Motor cortex and cerebellum must work together to carry out

complex tasks…– Cerebellum runs entire sequences of motor activity at once– Important that programming is done correctly early on

• Mental practice– Evidence that mental practice can stimulate the brain in similar ways

to physical practice

Hodges (1996)

• Summary points– All humans are born with a musical brain– Human musical brain is different from animals– Musical brain operates in infancy and perhaps even in fetal

stages– Musical brain is dependent on neural systems has localized

functions, but is widely distributed– Musical brain has cognitive components– Musical brain has affective components– Musical brain has motor components– Degree of lateralization is up for debate– Musical brain is resilient– Early and ongoing training affects the organization of the

musical brain