Topic 13: Music

Question 1

What is amusia?

Answer 1

the term amusia refers to a deficit in musical perception that cannot be attributed to a more general auditory dysfunction, intellectual disability, or lack of musical exposure

some people are born with amusia (the congenital form) and some people “develop” it later in life (acquired amusia)

Question 2

How does the heterogeneity associated with acquired forms of amusia complicate our understanding of the underlying neural mechanisms?

Answer 2

this can be true for various reasons, including…

differences in the areas/extent of damage

comorbidities with other potentially confounding conditions, deficits, etc.

individual differences related to preferences (did you regularly enjoy listening to music before developing amusia), experience (did you ever undergo musical training?), etc.

Question 3

What is “pitch-based” amusia?

Answer 3

amusia can be evident in difficulty singing in-tune, detecting out-of tune singing, and recognizing melodies in different contexts (e.g. without lyrics)

people with (pitch-based) amusia cannot reliably detect deviations in pitch that are smaller than two semitones (in contrast to matched controls, who can often detect differences that are several magnitudes smaller)

Question 4

What brain locations are implicated in acquired amusia?

Answer 4

acquired amusia typically results from lesions in/around the right superior temporal gyrus ad insula (among other things, this area is important processes involving integrating inputs across modalities, salience detection, self-awareness, etc.)

the fact that such lesions sometimes only affect either pitch perception or perception of temporally-relevant information (rhythm and meter) suggests dissociable neural mechanisms

Question 5

What were the results of the Liegeois-Chauvel et al. (1998) study on pitch perception deficits?

Answer 5

examined patients who had undergone surgery for severe epilepsy and found those with…

…left hemisphere resections had deficits more restricted to perception of pitch interval

…right hemisphere resections had impaired contour and pitch interval perception

Question 6

How do amusia patients demonstrate perception without awareness?

Answer 6

even though amusics can’t detect (consciously notice/report) differences in pitch that are less than two semitones, their brain still responds differently to variations i pitch that are as small as an eighth of a tone

this suggests that early stages of sensory processing are largely intact but something else (maybe later in a hierarchical sequence of processes, i.e. downstream) is causing the deficits observed in this population

Question 7

What is the imaging evidence for amusia?

Answer 7

amusia patients demonstrate several early-stage ERP components that are that are comparable to matched controls (MMN, N100, ERN), yet their P3b and P600 components (which are both tied to the conscious detection of a deviant tone) are different in patients with amusia (as compared to controls)

the P3b component tends to occur for events that are judged to be improbable (i.e. unexpected), such as a third beep in a series that has a slightly different pitch than the first two, while the P600 is often related to linguistic processing

changes in the BOLD signal (as measured using fMRI) are also sensitive to smaller gradations in tone that what ca be consciously reported, once again implicating a neural response that is (at least somewhat) dissociated from conscious processing

Question 8

What are the right frontotemporal abnormalities associated with amusia?

Answer 8

various abnormalities observed in the right frontotemporal network of amusia patients have been observed, including:

right inferior frontal gyrus (contains Broca’s area)
right superior temporal gyrus (auditory association cortex)
right arcuate fasciculus (connects the temporal cortex and parts of parietal with frontal)

these abnormalities include difficulties in white matter, gray matter, and connectivity patterns

Question 9

What is a model to explain the perception without awareness that occurs in amusia?

Answer 9

one model to explain the “perception without awareness” that occurs in amusia hypothesizes that the IFG typically processes (by amplifying and refining) the signals that are sent from the STG to provide top-down mediated contributions to their interpretation

in amusics, this step is thought to break down ad therefore interferes with the processes that would otherwise allow conscious detection of subtle changes in auditory stimuli (e.g. a change in pitch that is less than two semitones)

Question 10

What are the steps in the reentrant model of visual object perception proposed by Mumford (1991)?

Answer 10

1. thalamus acts as the destination for feedback processing and the site of integration of information from multiple higher-level brain regions
2. the initial feedforward sweep of signals progresses through regions important for object recognition (e.g., IT cortex)
3. multiple abstract representations get activated in other parts of cortex (e.g. related to memory) that correspond to plausible perceptual hypotheses (“maybe that is a dog?”
4. feedback is sent to the thalamus, which then compared the abstract representations that get activated to the direct sensory input being received via the retinal image
5. the hypothesis with the closest match for the sensory input “wins” and that leads to conscious awareness of what you think you’re seeing

this model views the thalamus as handling “dynamic” representations, whereas cortical regions handle “static” ones

Question 11

What is developmental dyslexia?

Answer 11

affects the accuracy/fluidity of reading

phonetic representations seem to still be processed in the left STG in a relatively typical way for this population

however, abnormalities in the connectivity between the STG and IFG are thought to prevent conscious access to them

Question 12

What is congenital prosopagnosia?

Answer 12

is a deficit related to facial recognition

the right fusiform face area (FFA) shows relatively normal responses within this population, yet there is a reductio in white matter connecting the FFA to frontal and temporal regions

Question 13

What do Royal, Paquette, and Tranchant (2019) suggest that dyslexia, prosopagnosia, and amusia have in common?

Answer 13

a breakdown in the communication pathways between a core sensory area and a higher-order brain region that are required for the conscious detection of subtle perceptual differences

Question 14

What are some possible treatments for amusia?

Answer 14

as a suggestive (but not directly relevant) reference point, Costanzo et al. (2016) reported the use of tDCS improved reading behavior in a sample with dyslexia

more specifically tied to amusia, Schaal, Pfeifer, Krause, and Pollock (2015) found that transcranial alternating current stimulation (tACS) improved pitch memory in amusics

Question 15

What is musical anhedonia?

Answer 15

perhaps unsurprisingly given the nature of their deficits, amusics tend not to seek out music for recreational purposes

musical anhedonia refers to a lack of pleasure derived from listening to music

Question 16

What is the musical anhedonia case study of IR?

Answer 16

case study IR developed acquired amusia after cerebral aneurysms (in the left/right cerebral arteries)

she lost her ability to perceive slight variations in pitch, yet continued to enjoy listening to music and dancing

indicates an apparent dissociation between pitch perception and the potential for reward related to musical experiences

Question 17

What is the musical anhedonia case study by Hirel et al. (2014)?

Answer 17

the case study developed acquired amusia after a stroke affecting the superior temporal gyrus (STG), primary auditory cortex, as well as parts of the middle temporal gyrus (MTG), amygdala, and insula

he could accurately perceive emotional content in various domains (including music) but was worse than controls at identifying the intensity of emotion within musical pieces

also reported a loss of emotional engagement (and interest) with music

this seem consistent with the hypothesis that musical anhedonia could result from a disconnection between the perception and experience of an emotion

Question 18

What is the relationship between musical anhedonia and activity in the nucleus accumbens?

Answer 18

individuals with musical anhedonia demonstrate reduced levels of activity in the nucleus accumbens while listening to music

importantly, this is despite the fact that (activity in) this region resembles that of controls during a gambling task

this would seem to imply the reward centre is more or less working typically, yet certain kinds of input that would usually produce feelings of reward i the average person do not do so in this population… could this implicate differences in connectivity?

Question 19

What areas have decreased functional connectivity in musical anhedonia?

Answer 19

this population also shows decreased functional connectivity between right auditory cortex and the ventral striatum

this is in contrast to participants with above average responses to music, which show enhanced connectivity between those regions

all taken together, the various work done on musical anhedonia implies a role for connections between auditory areas and subcortical structures associated with reward-network-relevant activity in response to musical stimuli

Question 20

What are binaural beats?

Answer 20

binaural beats are auditory stimuli that present slightly different frequencies to each ear (e.g. 124 Hz to the left ear and 114 Hz to the right ear)

these stimuli can produce an illusion which results in the perception of a tone that is equivalent to the different in frequencies being presented

Question 21

What are the mechanisms of binaural beats?

Answer 21

the mechanisms that lead to the illusion are not well understood but are thought to originate in subcortical structures (reticular activating system and the inferior colliculus) which are presumed to engage in “phase locking” behavior to represent the sound

this phase locking then spreads to the cortex and has the potential to exert various effects there (e.g. on cognition)

Question 22

What is phase locking?

Answer 22

a synchronization between the sound wave and pattern of hair cell firing

Question 23

What are the ways that the effects of binaural beats operate?

Answer 23

more specifically, these stimuli are thought to have the potential to alter neural oscillations (the frequency that neurons are firing at) to match the frequency of the stimuli being represented, i.e. entertainment

e.g. present a 10 Hz (alpha) frequency binaural beat (e.g. 210 in left ear, 200 in right ear, 210 -200 = 10) to increase the umber of neurons “operating” (i.e. firing) at the alpha frequency

Question 24

What are neural oscillations?

Answer 24

have been hypothesized to play a role in various functions/processes

e.g. beta-band activity may play a role in beat/rhythm perception, memory-relevant processes, and/or general arousal

gamma associated with intentional/controlled (top-down mediated) retrieval of memories

alpha associated with lower arousal and divergent thinking

Question 25

How do binaural beats affect neural oscillations?

Answer 25

this effect can be observed using EEG we also know that some studies have reported various cognitive effects that seem to be associated with exposure to binaural beats however, it is not entirely clear how this works, and whether the hypothesized mechanisms (modulating the frequency that neurons are firing at) is actually the most proximal (i.e. direct) cause of any associated effects (i.e. are the changes in oscillations caused by binaural beats responsible for changes in cognition?)

Question 26

What are the various lines of evidence that form the hypothesis that dopamine promotes creative thinking?

Answer 26

a positive mood can enhance creativity people with schizophrenia (which may involve atypically high levels of dopamine in certain parts of the brain) often demonstrate higher than average levels of creativity, as compared to the general population people sometimes (at least subjectively) feel more creative under the influence of various substances that alter dopamine function

Question 27

What is convergent thinking?

Answer 27

involves looking for a singular solution to what could be considered a relatively well-defined problem

Question 28

What is divergent thinking?

Answer 28

represents a style of thinking that allows idea generation, in a context where the selection criteria are relatively vague and more than one solution is correct

Question 29

What is the frontal dopaminergic pathway?

Answer 29

is thought to support focused attention on a specific target this may be particularly important for convergent thinking (which the remote associates test is thought to measure)

Question 30

What is the striatal dopaminergic pathway?

Answer 30

is thought to support mental flexibility, including the ability to switch between different kinds of mental representations this may be particularly important for divergent thinking (which the unusual uses task is thought to measure)

Question 31

What is spontaneous eye blink rate (EBR)?

Answer 31

spontaneous eye blink rate (EBR) is related to striatal dopaminergic activity, so measuring this may provide an estimate of the relative level of dopaminergic activity in that pathway at a given point in time previous work has found that EBR is correlated with performance on divergent thinking tasks

Question 32

What was the hypothesis of the Reedijk, Bolders, and Hommel (2013) study?

Answer 32

tested the hypothesis that creative thinking can be enhanced by presenting binaural beats

Question 33

What stimuli were manipulated in the Reedijk, Bolders, and Hommel (2013) study?

Answer 33

they manipulated what stimuli participants were exposed to prior to completing a series of experimental tasks binaural beats representing the alpha frequency (10 Hz) binaural beats representing the gamma frequency (40 Hz) a control condition consisting of a constant 340 Hz tone

Question 34

What was measured in the Reedijk, Bolders, and Hommel (2013) study?

Answer 34

performance in two creativity tasks: alternative uses test (thought to primarily measure divergent thinking) remote associates test (thought to primarily measure convergent thinking) self-reported mood (using both the positive/negative affect scale and an affect grid) spontaneous eye-blink rate (to estimate dopaminergic levels in the striatal pathway) they also controlled for time of testing

Question 35

What is an example of the alternative uses test?

Answer 35

how many unusual/alternate uses can you think of for a coffee mug

Question 36

What is an example of the remote associate test?

Answer 36

e.g. pine, crab, sauce solution = apple pineapple, crab apple, apple sauce

Question 37

What were the results of the Reedijk, Bolders, and Hommel (2013) study?

Answer 37

they found that presenting either type of binaural beat tested (alpha and gamma) enhanced performance on divergent thinking (as assessed with the alternate uses test) no apparent effect on convergent thinking (as assessed with the remote associates test), nor any moderating effect of mood (i.e. changes in self reported mood did not predict changes in performance) participants with low EBRs (which suggests they have relatively low dopaminergic activity in that pathway) experienced larger benefits for the alpha binaural beats participants with high EBRs tended to respond differently, either not showing these benefits or, in some cases, actually performing worse

Question 38

What was the interpretation of the results of the Reedijk, Bolders, and Hommel (2013) study?

Answer 38

the fact that the manipulations affected divergent but not convergent creative thinking speaks to these two aspects of creativity being dissociable (e.g. different underlying processes/mechanisms, etc., like STM and LTM) the benefits observed suggest binaural beats ca affect cognitive processes, like creativity, and can enhance those processes under certain circumstances the moderating affect of baseline dopamine levels (i.e. people with low EBRs benefited in ways those those with high EBRs did not) suggest binaural beats are not necessarily a widely generalizable cognitive aid (speaking to the importance of considering individual differences) all taken together, the method allowed for measurement of not only effects on behavior but also the mechanisms which are potentially supporting these effects

Question 39

What is the correlational evidence for the effects of musical training?

Answer 39

musical training can enhance auditory-motor network variation in brain structure associated with this network are sometimes related to performance

Question 40

What kinds of variables do researchers typically measure to investigate effects of musical training?

Answer 40

differences in grey matter (e.g. neuronal bodies) differences in white matter (e.g. axons) differences in connectivity patterns (e.g., resting state, functional, etc.)

Question 41

What is Heschl's gyrus?

Answer 41

also known as the transverse temporal gyri refer to various gyri in/around primary auditory cortex

Question 42

What is a gyrus?

Answer 42

a ridge or fold between two clefts on the cerebral surface of the brain

Question 43

What are the structural differences in the auditory region found in musicians compared to non-musicians?

Answer 43

enhancements in various auditory regions are most commonly reported difference in the brains of musicians (as compared to non-musicians), especially Heschl's gyrus larger cortical thickness and/or grey matter volume

Question 44

What variations are changes in Heschl's gyrus related to?

Answer 44

number of hours spent practicing EEG and MEG responses to auditory stimuli performance in various musical tasks (e.g. melody discrimination, rhythm reproduction)

Question 45

What are the auditory differences in the auditory region found in musicians compared to non-musicians?

Answer 45

although not quite as common as changes to Heschl's gyrus, various enhancements in motor regions are also frequently reported (e.g. cerebellum, basal ganglia) the motor cortex is larger in trained musicians this difference in more pronounced in those who began training at a younger age

Question 46

Why are differences in the corpus callosum of musicians frequently reported?

Answer 46

could relate to the fact that music draws on various processes that can sometimes be lateralized in either hemisphere the earlier training starts, the more apparent these differences are variation in the corpus callosum is also related to hour spent practicing

Question 47

What are the structural differences in white matter found in musicians compared to non-musicians?

Answer 47

musicians also have greater white-matter integrity (measured using DTI) in the arcuate fasciculus, a pathway connecting frontal, parietal, and auditory-relevant regions among other things, the AF connects Broca and Wernicke's areas, which may help explain it's importance for producing/understanding language

Question 48

What are the structural differences in grey matter and cortical thickness found in musicians compared to non-musicians?

Answer 48

larger grey matter volume in various parietal regions involved in sensorimotor transformations/planning relevant for playing instruments both grey matter volume and cortical thickness (in various parts of the brain) have been found to be predictive of performance in a melody discrimination test

Question 49

What were the methods of the Hyde et al. (2009) study on developmental impacts of music?

Answer 49

longitudinal studies can allow the investigation of causal relationships randomly assigned two groups of 5 to 8 year olds to either a piano lesson condition or a control condition and collected various kinds of data over a 15 month period

Question 50

What were the results of the Hyde et al. (2009) study on developmental impacts of music?

Answer 50

no differences at baseline those in piano lessons showed grey matter enhancements in auditory and motor cortex and enlargement of the corpus callosum volume of auditory cortex --> predicted melody/rhythm test performance volume of motor cortex --> predicted performance in a test of fine-motor skills

Question 51

What were the methods of the Habibi et al. (2017) study on developmental impacts of music?

Answer 51

randomly assigned participants ranging from 6 to 8 ears to a musical training program

Question 52

What were the results of the Habibi et al. (2017) study on developmental impacts of music?

Answer 52

greater white-matter integrity in the corpus callosum after two years reduced cortical thinning in right (compared to left) posterior auditory cortex changes occurred in similar regions of auditory-motor network that have been found to differ in correlational studies with adults that have undergone musical training

Question 53

Why are the interactions between development and training a methodological/interpretative challenge?

Answer 53

we have lots of evidence for experience-dependent plasticity in various domains we also know that children who begin musical training at a younger age show more pronounced effects, such as larger increases in the volume of motor cortex and the surface area of the corpus callosum but age of onset of training is typically confounded with years of practice (i.e. the earlier you start, the more practice you tend to have had)

Question 54

How did the Steele et al. (2013) study match several potentially confounding variables?

Answer 54

years of musical experience years of formal training hours of current practice various cognitive measures (auditory working memory, non-verbal IQ) measured performance on musical skills (rhythm reproduction, melody discrimination)

Question 55

What were the results of the Steele et al. (2013) study on the interactions between development and musical training?

Answer 55

larger increases in the volume of the premotor cortex (which is related to performance in a rhythm reproduction task) enhanced white-mater integrity in the corpus callosum better performance in a rhythm reproduction task

Question 56

What is the explanation for the contradiction in cerebellum changes in the brains of musicians?

Answer 56

the contradiction in the direction of change in the cerebellum found for early trained musicians may relate to how the organization of the cerebellum develops peak growth in the cerebellum occurs much later in most parts of the cortex this suggests effects of training on the cerebellum may be rather different than the same on the cortex

Question 57

What is the evidence for near-transfer effects in musical training?

Answer 57

better pitch perception/production correlated with better performance on phonemic awareness tests this relationship held even after controlling for various potentially mediating factors (e.g. intelligence)

Question 58

What were the methods of the Habibi (2016) study on transfer effects?

Answer 58

randomly assigned children to one of three groups: a musical training condition a sports training condition a passive control condition

Question 59

What were the results of the Habibi (2016) study on transfer effects?

Answer 59

the children in the musical training group showed enhanced abilities to detect subtle auditory changes (behaviorally) this was also reflected in changes to their ERPs (reduced P1 amplitude and latency while passively listening to piano tones) note that is isn't necessarily clear whether this change is related simply to enhanced auditory processing, attentional control, both, something else, etc. (which could have implications for whether you consider this to be near transfer, far transfer, etc.)