The following protocol was used for running the SPSS General Linear Mixed Model with Random and Fixed Effects for the publication:Badwal, A., Borgstrom, M., Samlan, R. A., & Miller, J. E. (2020, March 12). Middle Age, a Key Time Point for Changes in Birdsong and Human Voice. Behavioral Neuroscience. Advance online publication. http://dx.doi.org/10.1037/bne0000363

For questions: contact Julie E. Miller, PI: juliemiller@arizona.edu

STEP 1-’Analyze’ ---’Mixed Models’ ---’Linear’ STEP 2

Note that if you want to look at Age in days post hatch then you need to add it in the covariate box.

STEP 3-FIXED TAB STEP 4-RANDOM TAB

STEP 5-ESTIMATION TAB-NO CHANGE STEP 6-STATISTICS TAB STEP 7-EM MEANS TAB

STEP 8- SAVE TAB-SAVING RESIDUALS TO THEN GRAPH TO MAKE SURE THEY FALL IN A NORMAL DISTRIBUTION INDICATINGTHAT YOUR DATA FITS THE MODEL

If you want to look exclusively at one syllable type only-

You can select cases (Data->Select Cases...->"If condition is satisfied"->If...SyllableType="Harmonic"). Make sure "SyllableType" is the right variable and "Harmonic" is spelled indicated.

To take values and log transform them, go to ‘Transform’ and ‘Compute Variable’ …

Go to ‘File’ and ‘New Syntax’ to open the coding window. Syntax Code in SPSS lets you determine if there is a significant interaction with age by syllable type (harmonic, noisy, mixed) with Bird ID as the random intercept and the last line includes the post-hoc comparison.

MIXED CorrIntensity BY SyllType Agecategory/CRITERIA=CIN(95) MXITER(100) MXSTEP(10) SCORING(1) SINGULAR(0.000000000001)HCONVERGE(0,ABSOLUTE) LCONVERGE(0, ABSOLUTE) PCONVERGE(0.000001, ABSOLUTE)/FIXED=SyllType Agecategory SyllType*Agecategory | SSTYPE(3)/METHOD=REML/PRINT=CPS SOLUTION TESTCOV/RANDOM=INTERCEPT | SUBJECT(BirdID) COVTYPE(VC)/SAVE=RESID/EMMEANS=TABLES(OVERALL)/EMMEANS=TABLES(SyllType) COMPARE ADJ(LSD)/EMMEANS=TABLES(Agecategory) COMPARE ADJ(LSD)/EMMEANS=TABLES(SyllType*Agecategory) compare(Agecategory) adj(lsd)

Use your column heads in your SPSS spreadsheet here- ‘Syll Type’ , ‘Agecategory’ : if they are misspelled, programwill not run.

Go to ‘File’ and ‘New Syntax’ to open the coding window. Syntax text that looks at interaction of acoustic feature by age only.

MIXED Intensity BY Agecategory/CRITERIA=CIN(95) MXITER(100) MXSTEP(10) SCORING(1) SINGULAR(0.000000000001)HCONVERGE(0,ABSOLUTE) LCONVERGE(0, ABSOLUTE) PCONVERGE(0.000001, ABSOLUTE)/FIXED=Agecategory | SSTYPE(3)/METHOD=REML/PRINT=CPS SOLUTION TESTCOV/RANDOM=INTERCEPT | SUBJECT(BirdID) COVTYPE(VC) SOLUTION/SAVE=RESID/EMMEANS=TABLES(OVERALL)/EMMEANS=TABLES(Agecategory) COMPARE ADJ(LSD).

Syntax that lets you plot line graphs

GRAPH/LINE(MULTIPLE)=MEAN(CorrIntensity) BY Agecategory BY SyllType/INTERVAL CI(95.0).

Go to ‘File’ and ‘New Syntax’ to open the coding window.

SPSS: SELECT GRAPHS TAB---LEGACY DIALOG---LINESTEP 1-select ‘Multiple’ and ‘Summaries for groups of cases’ STEP 2- Variable is your y-axis- intensity, duration etc

Category Axis is your x-axis

Define Lines by:Syllable Type (Harmonic, Mixed, Noisy)

OPTIONS TAB---

Check-display error bars and determinewhat you want to show

To change the order of the x-axis categories-For example, Young, Middle, Old, go to the ‘Categories’ tab and use the up/downarrows.

To edit the graph, double click on it.