The Epilog Chapters. Chapter 36, 37, 38 John JB Allen

Transcription

1 The Epilog Chapters Chapter 36, 37, 38 John JB Allen

2 Recommendations in Reporting Results Chapter 36 The modal viewer: Title Abstract Figures

3 Recommendations in Reporting Results #1: One figure, one idea

4 Cavanagh, Zambrano-Vazquez, Allen 2012

5 Cavanagh, Zambrano-Vazquez, Allen 2012

6 Recommendations in Reporting Results #2: Show Data! Task force (Picton et al., 2000) requires it for ERPs Should be required for Time-Frequency too Can use tfviewerx to decide what is best to show

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8 Recommendations in Reporting Results #2: Show Data! Difference maps or scores may need extra explication

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10 Recommendations in Reporting Results #3: Highlight significance, don t remove nonsignificance John s paraphrase: never look like you re hiding something!

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12 Sanguinettti, Allen, & Peterson, 2014

13 Recommendations in Reporting Results #4: Show Specificity (or Lack Thereof) in Frequency, Time, and Space

14 Allen & Cohen, 2010

15 Recommendations in Reporting Results #5: Use Color! JJBA Corollary: consider color-blind readers

16 Recommendations in Reporting Results #5: Use Color! Keep colors constant across figures Color and grey-scale considerations

17 Hot Hot Desaturated Gray

18 Jet Jet Desaturated Gray

19 Recommendations in Reporting Results #5: Use Color! Keep colors constant across figures Color and grey-scale considerations Use unipolar color scales for depicting metrics that cannot have negative values Hot, Bone, Gray Bipolar scales OK for differences in metrics that cannot have negative values

20 Recommendations in Reporting Results #6: Use Informative Figure Labels and Captions Keep in mind the modal viewer! Can the figure stand alone? First line of figure legend should be a succinct description of the main message of that figure, understandable even to people who have not read the paper. If you use abbreviations in the figures, define them in the legend even if they are also defined in the main text, unless they are commonly used abbreviations such as ms, Hz, cm, or db. Figure 3. Connectivity degree, a measure of large-scale network connectivity, increased over parietal areas after food-deprived subjects were shown pictures of grapefruits.

21 Recommendations in Reporting Results #6: Use Informative Figure Labels and Captions Label the Axes!! Label Color Bars!!

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23 Recommendations in Reporting Results #6: Use Informative Figure Labels and Captions Label the Axes!! Label Color Bars!! Use ridiculously large font, as journals scale figures down to fit the page.

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25 Recommendations in Reporting Results #7: Avoid using representative data OK to show how an analysis works, but. Makes reviewers and readers suspicious How often can we generalize from a single example? Can show single subject data to highlight robustness or variability

26 Recommendations in Reporting Results Mike s figure checklist!

27 Recommendations in Reporting Results Mike and JJBA amalgam Make results easy to read Provide justifications: Introduce the reader to each section, what was done and why Provide interim summary statements: closing sentence to a paragraph or section to summarize Don t separate pieces into Methods and Results Don t provide elaborate interpretations in Results (that s for Discussion) Report p-values consistently (p=.0038 vs p <.05) Keep significant digits constant

28 Recurring Themes (Chapter 37) Theme: Myriad Possible Analyses Follow published papers for a guide Pick tools to match your questions Advice: Avoid the Paralysis of Analysis Instant gratification (like a gambler in Vegas) Focus on the purpose of the study

29 Recurring Themes (Chapter 37) Theme: You Don t Have to Program Your Own Analyses, but You Should Know How Analyses Work Packages and Toolboxes are OK Think: Can I explain this in a talk? Advice: If It Feels Wrong, It Probably Is If it looks too good to be true, naja. Advice: When in Doubt, Plot It Out Matlab friends: plot, hist, imagesc When building scripts, plot at each step

30 Recurring Themes (Chapter 37) Advice: Know These Three Formulas like the Back of Your Hand (they are everywhere!) Sine wave: Aey sine two pie eff tee plus theta Euler s formula: Em ee to the eye kay equals em cosine kay plus eye sine kay Gaussian: ee to the minus tee squared over two ess squared

31 Recurring Themes (Chapter 37) Theme: Connectivity over Trials or over Time Connectivity over time increases sensitivity to simultaneous coupling better for high- frequency connectivity that might not be phase-locked to an experiment event. increased susceptibility to volume conduction relatively poor temporal precision may reflect tonic connectivity in addition to taskrelated connectivity

32 Recurring Themes (Chapter 37) Theme: Connectivity over Trials or over Time Connectivity over trials provides a better link to the timing of task events has higher temporal precision. it can be used only with task data is more affected by having a small number of trials less sensitive to detecting high-frequency connectivity that might not be phase-locked to the time = 0 event Many publications do not specify if connectivity was over time vs trials (tsk tsk)

33 Recurring Themes (Chapter 37) Theme: Most Analysis Parameters Introduce Bias Tradeoffs: Temporal vs Spatial precision Can bias what is seen vs hidden Apply same parameters in all analyses (conditions, groups) Replicate parameters from similar publications

34 Recurring Themes (Chapter 37) Theme: Write a Clear Methods (and Results) Sections so Others Can Replicate Your Analyses Get input from colleagues, others in your lab See SPR Guidelines Papers

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36 Recurring Themes (Chapter 37) Theme: Use Descriptive and Appropriate Analysis Terms Avoid interpretive and ambiguous terms For example spectral perturbation can mean a change in power, phase, connectivity, band-specific graph properties, or other spectral features In my opinion and others may disagree the terms used to describe analyses should refer to the mathematical procedures that underlie those analyses, not to an interpretation of what the results of that analysis might mean in a neurophysiological sense. Interpretations of results are subjective, incite collegial disagreement, change over time as theories develop and new data are acquired, and can be incorrect or misguided.

37 Recurring Themes (Chapter 37) Advice: Interpret Null Results Cautiously Advice: Try Simulations but Also Trust Real Data Advice: Trust Replications Theme: Analyses Are Not Right or Wrong; They Are Appropriate or Inappropriate Be specific and clear about what you did in your results section In the first step of the analysis, we averaged time-frequency power from all conditions and selected a time-frequency window in the gamma band, based on a statistical comparison between time-frequency power over all conditions versus the prestimulus baseline. Note that because this selection procedure was based on the condition average, it is orthogonal to any possible condition differences. In the second step, we extracted power from this time-frequency region separately for each condition and each subject. These values were then entered into a 2 (visibility: low vs. high) 3 (feedback condition: punishment, neutral, reward) ANOVA.

38 Recurring Themes (Chapter 37) Advice: Hypothesis Testing Is Good/Bad, and So Is Data-Driven Exploration Approaches are not mutually exclusive Advice: Find Something That Drives You and Study It For many scientists, science is not just a job, not just something you do during the day to earn money. Instead, it is a career, a passion, and a lifestyle. Whether you love or hate your life as a scientist will affect your happiness and life satisfaction. Pick a research topic that fascinates you and a method that draws you. And keep long-term goals in mind. You won t love every single minute of being a scientist, but very often, the parts you don t like will help get you to the parts you do like. Be sure to have a hobby, both professionally and personally! -- JJBA

39 The Future of Cognitive Electrophysiology (Chapter 38) You will be able to view the results of the analyses remotely, via a 3-D projection system built into your watch. I am not a soothsayer, and I cannot predict the future. (This is evidenced by my failure to pick winning lottery tickets and stocks.) I do not know what cognitive electrophysiology will be like 20 years from now, but I am excited to find out.

40 Function Fun!!!!