Chapter 26 Exercises: The Neuroscience of Music

Part A: Auditory Anatomy and Pathway

A1. Trace the path of a sound wave from the pinna to the auditory cortex. Name and briefly describe the function of each major anatomical structure along the way (at minimum: pinna, ear canal, tympanic membrane, ossicular chain, cochlea, auditory nerve, cochlear nucleus, superior olivary complex, inferior colliculus, medial geniculate nucleus, primary auditory cortex). For each structure, specify what transformation it performs on the signal.

A2. The ossicular chain performs "impedance matching" between air and the fluid-filled cochlea. (a) Define acoustic impedance in plain language. (b) Without impedance matching, approximately what percentage of sound energy would be reflected? (c) The ossicular chain achieves the match through two mechanical advantages — what are they? (d) What would hearing be like if the ossicular chain were damaged but the cochlea were intact?

A3. The cochlear hair cells come in two types: inner and outer. Compare and contrast these two cell types in terms of: (a) number, (b) arrangement, (c) innervation pattern (how many nerve fibers each connects to), (d) primary function. What happens to hearing when outer hair cells are progressively damaged by noise exposure?

A4. The traveling wave on the basilar membrane performs a physical frequency decomposition. (a) Describe how the mechanical properties of the basilar membrane change from base to apex and why this creates frequency selectivity. (b) A concert A (440 Hz) stimulates the basilar membrane at approximately 24 mm from the base; the highest piano note (4,186 Hz) at approximately 6 mm. Is this relationship linear or logarithmic? What does this tell you about the perceptual scale of pitch? (c) What would happen to sound perception if the basilar membrane were stiffened to be uniform along its entire length?

A5. The acoustic reflex (stapedius reflex) stiffens the ossicular chain in response to loud sounds. (a) What is the protective function of this reflex? (b) The reflex has a delay of approximately 25–150 ms. What does this mean for protection against sudden impulsive sounds (like a gunshot) versus sustained loud sounds (like a concert)? (c) Singers and wind musicians often show reduced acoustic reflex thresholds (the reflex activates at lower sound levels). Propose a functional explanation for this adaptation.

Part B: Neural Processing and Brain Systems

B1. Explain the concept of tonotopic organization. (a) Where does tonotopic organization originate? (b) Through how many anatomical relay stations is it preserved? (c) What is the perceptual consequence of tonotopic organization — that is, what auditory phenomenon does it directly explain? (d) If the tonotopic map in the auditory cortex were disrupted (but the cochlea remained intact), what specific perceptual abilities would be most impaired?

B2. The auditory pathway has both ascending (bottom-up) and descending (top-down) projections. (a) Give two examples of top-down influences on auditory processing described in Chapter 26. (b) What does the existence of top-down projections from cortex to thalamus (and from thalamus to brainstem) imply about the model of the brain as a passive sensory receiver? (c) How might top-down projections explain the "cocktail party effect" — the ability to selectively attend to one voice in a noisy environment?

B3. fMRI (BOLD imaging) is the most widely used neuroimaging tool in music neuroscience. (a) What does BOLD stand for and what physiological variable does it measure? (b) What is the "hemodynamic lag" and why does it create a problem for studying music? (c) Design a simple fMRI experiment to test whether a specific musical feature (e.g., the transition from dissonance to consonance) activates the nucleus accumbens. Be specific about your stimulus design, baseline condition, and how you would interpret activation in that region. (d) Name two specific limitations of your experimental design that would prevent you from concluding definitively that "dissonance-to-consonance resolution activates the reward system."

B4. The musician's brain shows structural differences from non-musicians in several regions. For each of the following: describe the direction of the difference (larger/smaller/more/less) and explain why musical training would produce that specific change. (a) Corpus callosum (anterior portion); (b) Motor cortex representation of the fingers; (c) Primary auditory cortex; (d) Cerebellum; (e) Planum temporale in musicians with absolute pitch.

B5. Neural oscillations entrain to musical rhythm. (a) What frequency band of neural oscillation corresponds to a beat frequency of 120 BPM? (b) What frequency band corresponds to the level of the bar in a piece played at 120 BPM with 4 beats per bar? (c) Describe what happens to these oscillations when the music stops mid-phrase. (d) Parkinson's disease damages the basal ganglia. Predict the effect on: (i) rhythmic perception, (ii) the ability to walk to music, (iii) rhythmic music-making. How do these predictions align with clinical observations?

Part C: Music and Emotion/Memory/Reward

C1. The nucleus accumbens and caudate nucleus are core components of the brain's reward circuitry. Describe the Salimpoor et al. (2011) study that demonstrated dopamine release during music listening. (a) What was the specific design of the study (what imaging methods, what stimuli, what behavioral measure)? (b) What was the key finding regarding the timing of dopamine release relative to the emotional peak? (c) Why is this finding significant — what does it imply about the relationship between music and the reward system? (d) What alternative explanations should a critical reader consider?

C2. Music-evoked autobiographical memories (MEAMs) are unusually vivid, emotional, and self-referential. (a) Name and explain three separate mechanisms that contribute to the enhanced memorability of music-associated episodic memories. (b) The "reminiscence bump" describes the concentration of vivid autobiographical memories in the 10–25 age range. Why might music listened to during this developmental period be particularly likely to trigger vivid autobiographical memories later in life? (c) What do MEAMs reveal about the relationship between auditory cortex, hippocampus, amygdala, and medial prefrontal cortex?

C3. Blocking opioid receptors with naltrexone reduces the emotional power of music. (a) What does this finding imply about the neurotransmitter system primarily mediating musical pleasure? (b) How does this evidence relate to (but differ from) the dopamine evidence from frisson research? (c) If a patient taking naltrexone for addiction treatment reported that music had lost its emotional power, would you consider this a side effect to be concerned about or a neutral pharmacological observation? Justify your answer with reference to the literature.

C4. The Default Mode Network (DMN) is typically suppressed during active sensory tasks but activated during music that is personally moving. (a) What brain regions comprise the DMN? (b) Why might its activation during aesthetic musical experience reflect something meaningful about the nature of that experience? (c) Compare the neural state of someone deeply engaged with a favorite piece of music (DMN activated) with the state during a difficult mental arithmetic problem (DMN suppressed). What does this comparison suggest about the cognitive relationship between musical engagement and internally-oriented cognition?

C5. Congenital amusia is present in approximately 4% of the population. (a) What are the key features of the condition — which specific perceptual abilities are impaired and which are preserved? (b) Some individuals with amusia show normal skin conductance responses to out-of-tune notes even when they cannot explicitly detect that the note is wrong. Explain what this dissociation reveals about the architecture of music processing. (c) Propose a study that would test whether congenital amusia impairs music-evoked autobiographical memories, and predict what you would expect to find based on the evidence in this chapter.

Part D: Language, Mirror Neurons, and Embodied Music

D1. The ERAN (Early Right Anterior Negativity) and ELAN (Early Left Anterior Negativity) are ERP components evoked by music-syntactic and language-syntactic violations respectively. (a) What is an ERP and how is it measured? (b) Compare the ERAN and ELAN in terms of: latency, hemispheric lateralization, what type of violation triggers them, and what they are thought to index. (c) The fact that both ERAN and ELAN exist as early, automatic responses suggests that music and language share some processing architecture. What specific component of processing might they share? (d) What evidence would you need to see to conclude that music and language use identical (rather than merely overlapping) processing systems?

D2. The OPERA hypothesis proposes that musical training improves language processing through shared neural resources. (a) State the five conditions of the OPERA hypothesis. (b) Describe a specific prediction that the OPERA hypothesis makes about the effect of musical training on children's reading ability. (c) What would be the ideal experimental design to test this prediction? Why is correlational evidence between musical training and reading ability insufficient? (d) What alternative explanation for any correlation between musicianship and reading ability would need to be ruled out?

D3. The embodied simulation hypothesis proposes that musical emotion is partly mediated by motor simulation of the performer's expressive gestures. (a) Describe two pieces of evidence that support this hypothesis. (b) Describe two pieces of evidence or theoretical arguments that complicate or challenge it. (c) Design an experiment that could distinguish between two specific predictions of the embodied simulation hypothesis. (d) How would you explain the emotional response to electronic music (where there is no human performer to simulate) within this theoretical framework?

D4. The predictive coding framework proposes that the brain generates predictions and processes prediction errors. (a) In the context of music, what would "prediction" mean at the level of: (i) a single note within a scale, (ii) the next chord in a harmonic progression, (iii) the entry of a new theme in a sonata? (b) How does the predictive coding framework explain the emotional response to a deceptive cadence (V→vi instead of V→I)? (c) How does the framework explain why very repetitive music (like a simple drum loop) might feel emotionally flat? (d) The ERAN is described as a prediction error signal. Is this description consistent with the latency of the ERAN (~150–200 ms)? Why or why not?

D5. Musical training changes the auditory brainstem response (ABR) — a signal originating far below the cortex. (a) What does it mean for musical training to affect processing at the brainstem level rather than only cortical level? (b) Propose a mechanistic account (however speculative) for how years of practice playing an instrument could change subcortical responses to sound. (c) Musicians show enhanced ABR responses to speech sounds as well as musical sounds. What does this cross-domain transfer tell us about the neural systems underlying musical and linguistic processing? (d) What practical educational implication follows from this finding, if the causal direction (training → brainstem changes, rather than brainstem differences → musical success) is confirmed?

Part E: Synthesis, Critical Analysis, and Application

E1. The chapter presents two major theoretical frameworks for music neuroscience: the predictive coding framework and the BRECVEMA model (introduced briefly at the end). Compare them along the following dimensions: (a) what level of description they operate at (mechanistic, computational, phenomenological); (b) what predictions they make that the other does not; (c) whether they are competing or complementary frameworks; (d) which framework you find more productive for understanding music's emotional power and why.

E2. The "reductionism vs. emergence" theme asks whether neuroscience reduces music to brain states. Write a 400–500 word response to the following prompt: "A complete neural account of why Gorecki's Symphony No. 3 moves people to tears would fully explain the phenomenon." Present the strongest version of both the argument for and the argument against this claim, and then state your own position with justification.

E3. A music therapy program claims that playing familiar music to Alzheimer's patients preserves quality of life and slows cognitive decline. You have been asked to evaluate the scientific basis of this claim. Using only the neuroscientific concepts in this chapter: (a) explain why familiar music might be preserved in Alzheimer's despite other memory losses (you may extend beyond this chapter based on what you know about different memory systems); (b) identify what specific neural mechanisms might underlie any therapeutic effect; (c) describe what type of study (design, control conditions, outcome measures) would be needed to evaluate the "slows cognitive decline" claim; (d) what ethical considerations should govern the use of music as a therapy for non-consenting (cognitively impaired) patients?

E4. Cross-reference question: The chapter describes neural synchronization in a choir audience (Section 26.11) and the Choir & Particle Accelerator running example. (a) What specific neural phenomenon underlies audience neural synchrony — and what measurement technique is required to observe it? (b) Draw out the analogy between neural entrainment in listeners and resonant coupling in physics. At what points does the analogy break down? (c) The chapter suggests that inter-subject neural synchrony is strongest in auditory and frontal cortex. Propose a hypothesis about what role frontal cortex synchrony plays in the shared experience of music listening. (d) Design an experiment to test whether neural synchrony in a live-concert audience is greater than in an equivalent group of people listening to the same music simultaneously through headphones.

E5. Integrative design problem: You are designing a neuroscience-based music recommendation system that claims to suggest music based on the user's current emotional state (measured via a wearable EEG device). (a) Based on the evidence in this chapter, which specific EEG features (frequency bands, electrode locations, response patterns) might provide valid indicators of the user's emotional state? (b) Which aspects of music neuroscience would support the claim that certain musical features will reliably produce specific emotional responses in a given user? (c) What individual-difference factors (discussed in this chapter) would make a one-size-fits-all recommendation system unreliable? (d) What ethical issues arise from a system that monitors brain activity to target emotional states with music, and how might these issues be addressed in system design?