Music and the Brain, Lecture 5 Flashcards
The Neuroanatomy of Music
The auditory system is responsible for processing and interpreting sound, including music.
The outer ear (pinnae and ear canal) amplifies certain frequencies and is important for locating sounds.
The middle ear (includes malleus, incus, stapes) converts airborne vibrations to liquid-borne vibrations.
The inner ear (includes cochlea) converts liquid-borne vibrations to neural impulses.
There are 4-5 synapses from the ear to cortex, with the medial geniculate nucleus projecting to the primary auditory cortex, also known as the “core”.
The core area is surrounded by secondary auditory cortex, including belt and parabelt regions.
The auditory nerve and auditory cortex have a tonotopic organization.
Music and the Brain:
Music engages many brain functions, including emotion, memory, learning & plasticity, attention, motor control, pattern perception, and imagery.
Perception and Musical Structure:
Music is characterised by perceptual attributes, including pitch, rhythm, timbre, tempo, contour, loudness and spatial location. The brain organises these elements into higher-level concepts such as meter, harmony, and melody. Musical and linguistic grammar allows for the generation of an infinite number of songs or sentences through combinations and rearrangements of these elements.
Pitch:
Pitch refers to the perception of sound frequency and is organised in every culture. Pitch organisation into musical scales divides each octave (double-ing of pitch between C&C) into 12 distinct notes (7 white piano keys).
Modular Model of Music Perception
The Modular Model of Music Perception, proposed by Peretz and Coltheart in 2003, suggests that we are born with a natural capacity for music. This theory is supported by evidence such as:
Hearing working at 4-6 months
Infants having a natural preference for consonance (McDermott & Hauser, 2004)
Easily noticing changes to contour (ups and downs) (Trehub et al., 1997)
Understanding phrase structure in Mozart (Krumhansl & Jusczyk, 1990)
Distinguishing different rhythms at 3 days old (Winkler et al., 2009)
Developmental Evidence
FMRI used to measure brain activity in 1-3-day-old newborns while listening to Western tonal music and altered versions of the same excerpts.
Western music: right-hemispheric activations in primary and higher order auditory cortex. Atonal music: activations emerged in the left inferior frontal cortex and limbic structures.
Infant brain shows a hemispheric specialization in processing music as early as the first postnatal hours.
Neural architecture underlying music processing in newborns is sensitive to changes in tonal key.
Musical development: newborn - perceive and remember pitch sequences, perceive a beat, sensitivity to contour, preference for consonance; 4-6 years - respond to tonal more than atonal music; 7 years - sensitive to the rules of harmony; 10 years - understand finer aspects of key structure; 12 years - develop tastes and recognition of styles.
The Mozart Effect
The Mozart effect refers to claims that people perform better on tests of spatial abilities after listening to music composed by Mozart.
Findings provide evidence that the Mozart effect is an artifact of arousal and mood.
Congenital Amusia
Congenital Amusia is a lifelong disorder characterized by difficulty in perceiving or making sense of music.
Amusics often require a greater change in pitch perception (difference between tones), for example, close to the distance between the first two notes of “Somewhere over the Rainbow.”
Only 4% of the population is affected by “tone-deafness.”
People with amusia often score in the normal range for rhythm perception, although this aspect of the disorder seems variable.
Amusia
Amusics have difficulty perceiving or making sense of music
They often report having the condition since childhood
They are unaware when music, including their own singing, is off-key
They have difficulty discriminating or recognising melodies without lyrics
They may dislike musical sounds and avoid public places or situations where music occurs
They are unlikely to use music in everyday life or experience reactions such as chills, relaxation, or mood enhancement
Why is Amusia interesting?
It sheds light on the cognitive, neural, and possibly genetic basis of normal music processing
It may reveal the association between musical capabilities and other skills such as language and spatial awareness
It may provide insights into the origins of other developmental disorders such as dyslexia, prosopagnosia, and dyscalculia
It can help to clarify what amusics can and cannot do
Pitch Perception Problems:
Many amusics have difficulty telling whether a melody goes up or down, particularly in small changes such as semitones
This can impact real-world music listening
Case Study – Monica:
The first documented case of congenital amusia
Refers to a musical disability that cannot be explained by prior brain lesion, hearing loss, cognitive deficits, socio-affective disturbance, or lack of environmental stimulation. Monica can detect a pitch change of 11 semitones if and only if the pitch change is rising, not when it is falling (red lines) - not a working memory problem.
Anatomical measures supporting functional measures
Measured ERPs in amusic participants while they monitored sequences for the presence of pitch change
Amusics lack responsiveness to semitone changes that violate musical keys
Amusics can track quarter-tone pitch differences but are unaware of them
Emotional Prosody and Protolanguage Hypothesis:
Music and language have a common origin – overlapping functions and shared circuitry
Sensitivity to emotion in speech prosody derives from our capacity to process music
Common evolutionary link between language and music
12 amusics made judgements about emotional expressions of spoken phrases
Music and language share mechanisms that trigger emotional responses
Music and Emotion:
Music can elicit both psychological and physiological changes
Music-induced emotion has been shown to recruit reward-motivational circuitry
Chills effect involves deep and ancient areas such as the Nucleus Accumbens and the Orbitofrontal cortex
Beat has an important link to movement in every culture and is a uniquely human behavior
Music is anticipatory, flexible, robust, cross-modal, and auditory.
