How Rhythm affects our Judgments about Pitch

1. How Rhythm affects our Judgments about Pitch Mari Riess Jones Talk presented at Society for Music Perception & Cognition August 2001 1

2. Special Thanks to… Edward Large (modeling) Heather Moynihan Noah MacKenzie Jennifer Puente Nathan Vaughan

3. Outline I. Introduction: Attention and Timing II. Theoretical Background III. Four Experiments on Pitch Judgments IV. Conclusions: Expectancies about pitch have a temporal component. 3

4. The musical beat…. derives from how tones mark time Consider the simplest case: Successive tone onsets mark Inter-Onset-Intervals of time (IOIs) . IOI An IOI is the time interval from one tone onset to the next.

5. Timing and Expectancies • I will claim that in music, • Tone onsets and IOIs, by virtue of inducing an internal beat, are actually pacing one’s attending. The IOIs afford stimulus-based expectancies.

6. The pacing of attending…. high Pitch space expected time low early Time Temporal context is given by tone onsets and IOIs It may pace attending to expected locations in time.

7. Temporal Expectancies Some onsets in a melody can be anticipated in time: Expected Others can be Unexpected : Early or Late

8. Some Theoretical Background How tone onsets might pace attending….. Regular Stimulus Onsets Period Phase Expected points in time Attentional Tracking Attentional pulses Large & Jones, 1999; Barnes & Jones, 2000

9. Theoretical Parameters In other research, we separately manipulated the phase and period parameters: Phase adaptation …. Quick responsive shift to unexpected tone onsets. Period adaptation…..Slow adaptive response to unexpected time intervals.

10. The attentional pulse is a focus in time. Expected time point Three Pulses of Attending Time Attentional focus is pulse width: Narrow or Wide

11. The pacing of attentional focus implies a role for stimulus timing With pacing the temporal location and width of a pulse varies

12. Attention and Timing Originally we developed this model using time judgment tasks. Recently, we have begun to examine dynamic attending to a ‘nontemporal’ property, pitch. Today I discuss pitch judgments. 16

13. Temporal Context and Focus Basically, we address two questions about context and attentional focus. 1. Does context affect “where” in time people focus attending? 2. Does context affect the “width” of an attentional focus? 17

14. Basic Pitch Judgment Task Is a comparison pitch: “same”, “higher” ,”lower” than a standard pitch? Distracting context tones Critical IOI “Ignore these varying pitches!” “higher” same” “lower” Standard pitch Comparison pitch 21

15. Effects of Temporal context On location of attentional focus Experiment 1: Expected/Unexpected Comparisons Experiment 2: Periodic Extrapolations On width of attentional focus Experiment 3: Regular vs Irregular temporal context Experiment 4: Regular Higher Order Rhythm 20

16. Experiment 1: Expected and Unexpected Comparison Timing Is the comparison pitch “same”, “higher” ,”lower” than the standard pitch? Critical IOI “higher” same” “lower” Standard pitch Comparison pitch All inter-onset-intervals (IOIs) are 600 ms except the last one, the critical IOI. This IOI is variable. Standard & Comparisons are 150ms. Context tones, drawn from chromatic scale, are 60 ms in duration.

17. Experiment 1: Are average listeners more accurate when a comparison occurs at the expected time? • Pitch Judgment Task: Compare standard and comparison pitches Report: Same, Higher, Lower • Independent variable: • Critical IOI: Onset time of Comparison Pitch: • Expected, early, late, and very early, very late

18. Experiment 1 Rationale Location of attentional pulse If rhythm of an auditory context paces attending, then… Attentional focus is targeted to the expectedlocation of a comparison. Accuracyof pitch judgments should be: Highest for expected comparison onsets, and Lowest for very unexpected ones. 24

19. One prediction from this framework involves …. a quadraticExpectancy Profile: Attentional Pulse

20. Onset Times of Comparison Pitch Expected Onset Time of Comparison: IOI of 600 ms Unexpected Comparison Onset Times: Early : -21 ms (IOI = 579 ms) Late : + 21 ms (IOI = 621 ms) Very Early : -76 ms (IOI = 524 ms) Very Late: +76 ms (IOI = 676 ms)

21. P<.005

22. Experiment 1 Conclusions Contextual timing of to-be-ignored distractors significantly influenced performance. Listeners are more accurate when a comparison tone occurs at an expected rather than an unexpected temporal locus in time. 27

23. Does an expectancy persist over time as pacing implies? In other words: “Does the beat go on…..?” Experiment 2 considers this question. 28

24. Experiment 2:Can people periodically extrapolate the expected locus? Experiment 2 uses longer critical IOIs. The expected comparison now appears after a critical IOI of 1,200 instead of 600 ms; an extrapolated temporal locus. 33

25. Experiment 2: Missing Beat Same Task Distracting context tones “Ignore these !” Missing beat: 1,200ms IOI “higher” same” “lower” Standard pitch Comparison pitch The final expected IOI now is twice 600 ms

26. Experiment 2: Rationale If a regular temporal context induces a beat, i.e. paces periodic attending, then the internal periodicity should persist. Attentional focus should be targeted to periodically designated locations over silent intervals. “Does a critical IOI that is double the context IOI sustain the expectancy profile? “ 30

27. Experiment 2: Missing Beat P <..0001

28. Experiment 2 Conclusions • Attentional pace appears to persist through a longer time interval (missing beat). “The beat goes on…..” 2. A strong, reliable, expectancy profile emerges. 35

29. Temporal Context and attentional focus width. If the regular time pattern of distractor onsets efficiently paces attending. Then an irregular time pattern may not do this. In Experiment 3, we ask if an irregular pattern of IOIs changes the Expectancy Profile. 39

30. Experiment 3: Regular versus Irregular Timing We presented a new group of listeners with Irregular timing of distractor tones. In all respects, but context timing, the task was identical to the regularly timed sequences of Experiment 2

31. Experiment 3 Rationale Regular Onsets Attentional focus narrows Irregular Onsets Attentional focus widens Irregular timing widens attentional focus: This produces a flatter expectancy profile Large & Jones, 1999; Barnes & Jones, 2000

32. Context Timing Irregular Onsets: Context IOIs were random. Constraints: 1. First and last context IOI were 600ms; 2. Mean IOI remained 600 ms; 3. Std.Dev. Was 211 ms in ½ sequences and 249 ms in other ½ (counterbalanced). As in Experiment 2, a 1,200 IOI preceded the OnTime comparison.

33. ns P< .0001 Context x TimingP < .00001

34. Experiment 3 conclusions 1. Irregular context timing flattens the Expectancy Profile. 2. No overall difference in accuracy appears as function of Timing: Listeners in irregular condition do relatively well with very unexpected onsets….

35. Attentional Focus: Narrow and Wide Theoretically, irregular context timing should flatten an expectancy profile … Because it widens the attentional pulse. Large & Jones, 1999

36. What About Higher Order Rhythm? This question was raised by an Undergraduate Honors student, Nate Vaughan. Nate had been reading about the rhythm established by the joint occurrence of pitch and time accents.

37. Experiment 4 BACKGROUND To this point, context pitches (of the chromatic set) have been haphazardly ordered in the distractor sequence (with certain constraints). Nate decided to investigate whether a higher-order rhythm, supplied jointly by pitch and time accents , would affect performance.

38. Experiment 4: Higher-Order Rhythm Manipulates accent timing in distractor tones. Timing of accents is either regular or irregular All IOIs are the same: 600 ms

39. Experiment 4: Rationale Regular accent timing in a context melody means that pitch-time accents mark constant Inter-Accent Intervals, termed IAIs. These should produce: A quadratic expectancy profile. Irregular accent timingmeans thatthe IAIs between prominent accents are not constant. This higher order rhythm should a less pronounced expectancy profile.

40. Regular Joint Accent Structure Rhythms IAI IAI

41. Irregular Joint Accent Rhythms S C

42. Predictions

43. Experiment 4: JAS

44. Experiment 4 Conclusions • Prominent accents can outline a compelling higher order time pattern; here accents are jointly defined by lengthened tone durations and pitch peaks. 2. Relative timing of such accents affects pitch judgments about forthcoming accents. 3. In pitch judgment tasks, regular accent timing induces a pronounced expectancy profile whereas irregular accent timing does not.

45. General Conclusions 1. In auditory sequences, successive onsets can pace attending in a subtle, perhaps automatic, fashion. 2. Pacing happens even when listeners are told to ignore distractors; it is tacit. 3. Rhythmic pacing affects judgments about a tone’s pitch yielding a quadratic expectancy profile (PC) when a rhythm (IOIs or IAIs) is regular. 4. Pacing results in flatter expectancy profiles for pitch judgments when either a lower or higher rhythm irregular.

46. Thanks for your attention!!

48. Irregular Higher-Order Rhythm PC

49. Regular Higher Order Rhythm PC