1. Music increases frontal EEG coherence during verbal learning David A. Peterson a,b,c, ∗, Michael H. Thaut b,c a Department of Computer Science, Colorado State University b Program in Molecular, Cellular, and Integrative Neuroscience Colorado State University c Center for Biomedical Research in Music, Colorado State University Ranelle Johnson Neuroscience Letters 412 (2007) 217-221

2. Introduction (others said…) Memory may be subserved by oscillations in recurrent networks within and between brain regions (in theory) Increased multi band spectral power in the EEG during encoding is associated with successful subsequent word recall

3. Introduction In an earlier study… – verbal learning is associated with broadband increases in EEG power spectra –Music influences the topographic distribution of the increased spectral power Present study… – examining spatial coherence in EEG measured during learning phase

4. Independent Variable Treatment Groups –Learning to recall in conventional speaking voice –Learning to recall while singing to melody

5. Dependent Variable Theoretical Construct - verbal learning Operational Definition - Transition from not being able to recall to being able to recall a word that is repeatedly presented in the AVLT

6. Dependent Variable Theoretical Construct –Learning related changes in coherence (LRCC) Operational Definition –Percent increase or decrease in coherence comparing “first recalled” words to the same words not recalled during the immediately preceding trial (all pairs of not learned/learned words)

7. Hypothesis Learning that persists over short- and long- delays will be associated with “learning related change in coherence” (LRCC) in frontal EEG

8. Hypothesis The temporally structured learning template provided by music will strengthen LRCC patterns in frontal EEG compared to conventional spoken learning.

9. Subjects 16 healthy right-handed volunteers –Normal hearing –No history- neurological or psychiatric conditions Randomly assigned to one of two experimental conditions in a in between-subjects design Age range –18-26 (mean=19.8, SD=2.8) –18-21 (mean=19.0, SD=1.0) Each group contained 7 females

10. Method Rey’s Auditory Verbal Learning Test (AVLT) –15 semantically unrelated words –Repeated in 5 learning trials –Subjects free recalled as many words as possible after each recall –6 th trial- distracter list, 20 minute visual

11. Method Fig. 1. Rey’s Auditory Verbal Learning Test (AVLT) and the operational definitions of: learning (thickest arrows, during the learning trials—e.g. words 2, 14, 15); short-delay memory (medium thick arrows to M1—e.g. words 2, 15); long-delay memory (thinnest arrows to M2—e.g. word 2).

12. Method Pre-recorded female voice (both conditions) Music condition- sang simple, repetitive and unfamiliar melody Made both groups’ list of words same durations (15sec)

13. Method Electroencephalogram (EEG) –Continuous EEG from continuous 32 scalp electrodes –Neuroscan’s QuickCap using low- and high- frequencies 1 and 100 Hz, 1kHz sampling frequency –Computed interelectrode coherence over 500 ms window 250ms after each word’s onset For electrode pairs in theta, alpha, gamma frequency bands

14. Analysis Computed coherence for –left and right prefrontal areas, within and between LRCC for each group- compared to no change using one-tailed t-test, alpha=.05 LRCC between the two groups- compared using two-tailed t-test, alpha=.05 Bonferroni adjustment by factor of 3 for multiple comparison

15. Results (performance) Both groups recalled about 6 more words on the last learned trial than on the first –mean=11 & 4.9 (spoken) –mean=9.7 & 4.3 (music) Significant improvement in performance –t(16)= 9.6 & 6.3, p<0.0001 Recall was not significantly different between spoken and musical groups on any trial –t(16) 0.1

16. Results (spoken) Involves a mix of (+) & (-) LRCC None of LRCC values differed significantly from zero Except… –Negative right frontal gamma LRCC –t(42)=2.2, p=.03 and t(36)= 2.2, p=.03

17. Results (musical) Involved (+) LRCC within & between the hemispheres Short-delays –Increased frontal coherence significant for left gamma, t(39)=2.6, p=.003 –Interhemispheric theta, t(39)=2.6, p=.01

18. Results (musical) Between Group Comparisons –Higher LRCC for music group in all 3 frequency bands –Music showed greater increase in theta coherence for short- & long- delay learning t(81)=2.1, p=.04 (short- delay) –Music showed increase and spoken a decrease for right alpha coherence (both short- and long- delay) t(66)=2.5, p=.01 (long delay learning) –Music showed greater increase (spoken decrease) in right gamma coherence in b/t groups for long- delay learning t(66)=2.7, p=.009

19. Results In each cell:.Values are mean coherence relative to previous unlearned trial (i.e. 100 is no change in coherence). Bold values indicates p < 0.05 in one-tailed T-test after Bonferroni correction. Highlighted values indicates p < 0.05 in between-group, two-tailed T-test after Bonferroni correction.

20. Results Fig. 2. Learning-related change in coherence (LRCC). Left: LRCC for short-delay recall; right: LRCC for long-delay recall. Scale bar is percent change. Straight line and box overlays indicate absolute changes in LRCC greater than 5%: box for local quadrant LRCC, and line for interquadrant (interhemispheric) LRCC. Thin box (e.g. spoken group’s long-delay right frontal gamma LRCC) indicates a decrease of greater than 5%.

21. Discussion Music condition had increased frontal coherence whereas spoken condition had no significant change Music group had stronger temporal synchronization in frontal areas

22. Discussion Lack of coherence in spoken condition may be due to form of measure Spoken learning involves more focal changes Musical learning shows more topographical broader network synchronization

23. Discussion Performance effect “nullified” Transfer appropriate processing theory –Subjects asked to recall material in different way that it was encoded Physiological results not due to differences in performance Physiological results not due to different sensory processing (music vs. spoken stimuli) –Data for LRCC measured with recalled word compared to the same word not recalled in previous trial

24. Discussion How does music effect synchronization then? –Early attentional mechanism Selective attention associated with greater coherence with multiple spatial skills –Music is known to form expectancy, listeners can predict musical aspects, this could increase coherence –Studies suggest that music related processing involves more widely distributed subcortical and cortical networks

25. What do I think? Uuuuuummmmm??? I don’t know enough about the interpretations of EEG to really be able to criticize a whole lot… But like they said, use more subjects They could try testing performance by having the words sung back and see if it makes a difference on performance I don’t understand how you can measure a not recalled word

26. BUT MOST IMPORTANTLY….

27. –widely distributed z, t, F =