Congenital amusia york 2012


Published on

Lecture given in York in February 2012 which features many of the studies from the Music, Mind and Brain group based at Goldsmiths University of London.

Published in: Technology, Health & Medicine
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide
  • Triangles represent individuals with lower (better) perception thresholds compared to production thresholds, while circles represent individuals with lower production thresholds compared to perception thresholds.
  • Reduces the involvement of decision criteria: w hich eliminates the effect of any bias amusic individuals may have toward favoring a more conservative “no change” response.
  • The finding that amusics‟ pitch direction perception thresholds are sensitive to task demands suggests that the extent to which individual amusic participants show relatively preserved perception thresholds depends on the extent to which internal representations of pitch direction are associated with a) conventional labels (“up; down”) and b) the mapping of these representations onto the vocal apparatus; both abilities are likely to vary across amusic individuals.
  • Not all amusics have pitch perception difficulties The stimuli used in the tone span task were 10 triangle-waveform tones, with fundamental frequencies drawn from between 262 and 741 Hz in equally tempered, whole tone steps (from C4 to F#5). Rise and fall times were linear over 20 ms and tone durations were 500 ms. A trial began when the experimenter pressed the spacebar. A 500-ms pause was followed by two successive sequences. There was an inter-stimulus interval of 383 ms and an intersequence interval of 2 s, based on the timings of the original paradigm. The two sequences contained the same number of items, selected from the pool of 10 items by constrained random sampling without replacement. Temporally adjacent digits differed by at least two in absolute value while adjacent tones differed by at least two whole tones. Digit sequence presentation started off at four items while tone sequences began at two items. Tones were selected from the pool of 10 tones ranging from C4 to F#5 in equally tempered,
  • Connects receptive areas of temporal lobe with pre-motor areas in frontal cortex Previously associated with conduction aphasia
  • But structural imaging studies fail to shed any light on the functional aspects of the disorder. ERPs hold special promise is this regard since the high temporal resolution of this approach is highly suited to measuring neural processing of dynamically evolving stimuli such as music.
  • Also a P2 latency effect – task difficulty and speed of processing?
  • Congenital amusia york 2012

    1. 1. The Musical Mind: Insights from Congenital Amusia Dr. Vicky Williamson
    2. 2. Overview <ul><li>What is amusia? How is it diagnosed? </li></ul><ul><li>Behavioural studies – what is difficult? </li></ul><ul><li>How music overlaps with other cognitive processes </li></ul><ul><li>Neurological studies; structural and functional </li></ul><ul><li>How their abilities and brain structure inform about typical music processing </li></ul>
    3. 3. We are born ‘musical’ <ul><li>Preference for consonance at 2 days (Deaf parents: Masataka, 2006). </li></ul><ul><li>Notice changes to contour (ups and downs) but not intervals (Trehub et al,1997) </li></ul><ul><li>Respond to phrase structure in Mozart (Krumhansl & Jusczyk, 1990) </li></ul><ul><li>Can distinguish different rhythm deviations at 2 days (Winkler et al. 2008) </li></ul>
    4. 4. Natural musical development <ul><li>Newborn – perceive and remember pitch sequences, sensitivity to contour, preference for consonance </li></ul><ul><li>4-6yrs – Respond to tonal more than atonal music </li></ul><ul><li>7yrs – Sensitive to the rules of implied harmony </li></ul><ul><li>10yrs – Understand finer aspects of key structure </li></ul><ul><li>12yrs – Begin to develop tastes and recognition of definite styles </li></ul>
    5. 5. What is amusia? <ul><li>People are born with the ability to internalize the music of their own culture (Hannon & Trehub, 2005) </li></ul><ul><li>Amusia: Lifelong difficulties with music perception (production) </li></ul><ul><li>Not acquired </li></ul><ul><li>Estimated ~4% of the population (Kalmus & Fry, 1980) </li></ul><ul><li>No hearing loss, lack of exposure to music, social or cognitive impairments (Peretz et al., 2002; Ayotte et al., 2002) </li></ul>
    6. 6. If you were amusic… <ul><li>You report having the condition for as long as you can remember </li></ul><ul><li>Typically unaware when music, including your own singing, is off-key </li></ul><ul><li>Only ~50% have difficulties with rhythm </li></ul><ul><li>Difficulty discriminating or recognizing melodies without lyrics </li></ul><ul><li>May dislike musical sounds and even avoid public places and situations where music occurs. </li></ul><ul><li>Significantly less likely to “use” music in everyday life or experience reactions such as chills, relaxation or mood enhancement </li></ul><ul><li>( Ayotte et al, 2002; Peretz et al, 2003; McDonald & Stewart, 2008 ) </li></ul>
    7. 7. Psychological Functions McDonald & Stewart, Music Perception (2008)
    8. 8. Some (possible) examples <ul><li>Milton Friedman – Nobel prize winning economist </li></ul><ul><li>President Theodore Roosevelt </li></ul><ul><li>Che Guevara </li></ul><ul><li>Florence Foster Jenkins </li></ul><ul><li>King Alfonso XIII of Spain - (Anthem servant) </li></ul>
    9. 9. Why is amusia interesting? <ul><li>Sheds light on cognitive, neural and potentially genetic basis of normal musical processing </li></ul><ul><li>Can address questions concerning the extent to which musical capacities are associated with other capacities (language, spatial awareness) </li></ul><ul><li>May shed light on possible origins of other developmental (congenital) disorders such as dyslexia, prosopagnosia and dyscalculia </li></ul>
    10. 10. Diagnosis - MBEA The Montreal Battery for the Evaluation of Amusia Hear 2 melodies and say same or different Subtests: Scale, Contour, Interval, Rhythm, Meter (Memory)
    11. 11. 1) Pitch Perception Deficits <ul><li>What is the smallest difference in pitch that can be detected? ( Pitch Change ) </li></ul><ul><li>What is the smallest difference in pitch that can be discriminated? * </li></ul><ul><li>( Pitch Direction ) </li></ul><ul><li>What type of test to use? </li></ul>
    12. 12. Based on Loui et al. (2008) Testing pitch direction 0
    13. 13. Problem: Really excessive thresholds!
    14. 14. An alternative – AXB tasks Pitch Detection Pitch Direction The  advantage  of this task is that it is ''criterion free'' (Macmillan & Creelman, 2005)
    15. 15. AXB thresholds Williamson et al. 2012 Neuropsychologia
    16. 16. Conclusions: Pitch Perception <ul><li>Many amusics can detect pitch changes but have problems discriminating direction </li></ul><ul><li>Right Heschl’s gyrus lesions (Johnsrude et al. 2000), bilateral lesions of AC (Tramo et al. 2002) , and ‘direction poor’ listeners (Mathias, Micheyl & Bailey, 2010) </li></ul><ul><li>Affects the small changes which are often used in ( western ) music (e.g. semitones) </li></ul><ul><li>Amusic thresholds are sensitive to task demands </li></ul>
    17. 17. 2) Pitch memory problems <ul><li>Williamson & Stewart (2010) – Memory </li></ul><ul><li>N = 28 (14 amusics) </li></ul><ul><li>Tone span (how many tones can you remember?) </li></ul><ul><li>Digit span (similar test) </li></ul><ul><li>Both tasks use a list probe recognition paradigm, and a 2up 1down adaptive tracking staircase procedure. </li></ul><ul><li>Working memory span (Operation span – Professor Randall Engle) </li></ul>
    18. 18. Amusic’s tracks Digits Tones Span = Average of last 6 reversals
    19. 19. Findings <ul><li>Amusics have lower spans for tones but not digits </li></ul>
    20. 20. Conclusions: Memory <ul><li>Significantly reduced tone span but comparable digit span </li></ul><ul><li>No general short-term memory problem </li></ul><ul><li>Influence of pitch perception (direction) problems only arguable in two extreme cases. </li></ul><ul><li>Supporting evidence: Inability to maintain pitch sounds in memory (Williamson et al. 2010, Advances in Cognitive Psychology ) </li></ul><ul><li>Around 20% may have reduced working memory = poorer attention? </li></ul>
    21. 21. 3) Speech problems? <ul><li>Pitch is important to audible speech </li></ul><ul><li>Especially if we are apart. </li></ul><ul><li>Tone languages (65%) </li></ul><ul><li>Intonation: Question to statement, convey attitude. </li></ul><ul><li>Speaker Identity </li></ul><ul><li>Do amusics have trouble hearing speech? </li></ul>
    22. 22. Liu et al.(2010) Brain <ul><li>Statement-question discrimination with SUBTLE pitch changes: </li></ul><ul><ul><li>Natural speech </li></ul></ul><ul><ul><li>Gliding tones </li></ul></ul><ul><ul><li>Nonsense speech </li></ul></ul>
    23. 23. Natural speech Gliding tones Nonsense speech * * * amusic control Most amusics have difficulties with all 3 tasks amusic control amusic control
    24. 24. Conclusions: Speech <ul><li>Difficulty with subtle speech prosody </li></ul><ul><li>No difficulty with ‘natural’ sentence stimuli (Patel et al. 2008) </li></ul><ul><li>Not a huge problem in real life: </li></ul><ul><li>Large pitch leaps (5-12 semitones) </li></ul><ul><li>Semantic and sentence context </li></ul><ul><li>But important processing overlap </li></ul>
    25. 25. 4) A spatial problem? <ul><li>Pitch has a spatial association </li></ul><ul><li>“ Lower” or “Higher” </li></ul><ul><li>The musical stave </li></ul><ul><li>SMARC effect (Rusconi et al., 2006) </li></ul><ul><li>Musicians better on spatial tasks (Brochard et al., 2004) </li></ul><ul><li>Amusia as a failure to implement a spatial representation of pitch? </li></ul>
    26. 26. Supportive evidence NB. No overall difference in reaction times
    27. 27. Visuo-spatial tasks Williamson, Cocchini & Stewart (2011) – Brain and Cognition <ul><li>MBEA </li></ul><ul><li>Pitch detection and direction discrimination thresholds </li></ul><ul><li>Mental Rotation </li></ul><ul><li>– Shepard & Metzler figures </li></ul><ul><li>Visual Patterns Test (VPT) </li></ul><ul><li>– visual memory </li></ul><ul><li>Corsi Blocks </li></ul><ul><li>– spatial sequence memory </li></ul>
    28. 28. Results
    29. 29. Conclusions: Wider cognition <ul><li>Amusia is associated with wider pattern of difficulties than just pitch perception...but... </li></ul><ul><li>All difficulties have a pitch basis </li></ul><ul><li>Spatial difficulties in amusia have not been replicated in two published studies </li></ul><ul><li>Unique view of processes that underlie music cognition </li></ul>
    30. 30. Neurological underpinnings <ul><li>No difference in structure of PAC </li></ul><ul><li>Hyde et al. (2006) measured white matter density between the right frontal and temporal lobes. </li></ul><ul><li>Amusics white matter was thinner, suggests a weaker connection. </li></ul><ul><li>Severity of Amusia = Thinner white matter. </li></ul>
    31. 31. Diffusion tensor tractography studies <ul><li>Loui et al. (2009) – A rcuate fasciculus (AF). </li></ul><ul><li>“ Disconnection” in the temporal-frontal pathway </li></ul><ul><li>Abnormal migration of proteins along tract </li></ul><ul><li>Underdev of higher order musical processing </li></ul>
    32. 32. In 9/10 Amusics the right superior AF (red) was unidentifiable
    33. 33. EEG study of melodic expectancy (Omigie, Pearce, Williamson & Stewart, in revision) <ul><li>Task: Detection of expected or unexpected notes in a melody (Pearce and Wiggins, 2006; Pearce et al. 2010) using an implicit (timbre) and explicit task </li></ul><ul><li>Previous finding: Amusics were comparable in the implicit task but significantly worse at explicit recognition of unexpected notes </li></ul><ul><li>Present study: EEG while listening to real melodies . ERPs associated with the recognition of an unexpected musical event (ERAN/N1; 150ms) </li></ul><ul><li>Hypothesis: Amusics will show attenuated responses </li></ul><ul><li>N = 30 (15 amusics): 58 hymns in electronic piano (32 or 64 notes long), all but first 2-4 notes divided into 3 ‘bins’ of low, medium and high expectancy </li></ul><ul><li>Listen to the melodies and detect any deviation in timbre </li></ul>
    34. 34. Results <ul><li>Less expected notes = ERAN/N1 in controls that was diminished in amusics </li></ul><ul><li>Amusics have internalised the regularities of music but have less robust representation </li></ul><ul><li>Supported by studies of musicians (Koelsch et al. 1999; 2007) </li></ul><ul><li>Early pre-attentive mechanisms increase probability that change will be consciously perceived (Teemu Rinne et al. 2006) </li></ul>Scalp maps showing voltage and illustrating the negativity in the N1 time window for low, medium and high expected notes, and the difference in voltage between the low and high IC conditions. Amusics Controls
    35. 35. Conclusions <ul><li>Congenital Amusia is a neurodevelopment disorder that impacts on music listening (and production) </li></ul><ul><li>Pitch perception problems; discriminating pitch direction </li></ul><ul><li>Pitch memory weaknesses </li></ul><ul><li>Carry over into subtle speech difficulties </li></ul><ul><li>But no spatial difficulties </li></ul><ul><li>Most likely brain origin is a breakdown in pathways that carry pitch-based information to higher centres (role in other ND disorders) </li></ul><ul><li>Diminished explicit awareness of change alongside intact implicit knowledge – links back to task sensitivity issues in pitch perception </li></ul><ul><li>Insight into the organisation of musical mind . </li></ul>
    36. 36. Thanks for listening