SPM 2002 Experimental Design

1. SPM 2002Experimental Design Daniel Glaser Institute of Cognitive Neuroscience, UCL Slides from: Rik Henson, Christian Buchel, Karl Friston, Chris Frith, Cathy Price,Ray Dolan The Wellcome Department of Cognitive Neurology, UCL London UK http//:www.fil.ion.ucl.ac.uk/spm

2. Statistical parametric map (SPM) Data transformations Design matrix Image time-series Kernel Realignment Smoothing General linear model Gaussian field theory Statistical inference Normalisation p <0.05 Template Parameter estimates

3. Stimuli SPM{T} + isoluminant stimuli (even) + V5 isochromatic stimuli (odd) speed

4. A taxonomy of design • Categorical designs • Subtraction - Pure insertion and cognitive subtraction • - Differential event-related fMRI • Conjunction - Testing multiple hypotheses • Parametric designs • Linear - Cognitive components and dimensions • Nonlinear - Polynomial expansions and neurometric functions • - Nonlinear event-related fMRI • Factorial designs • Categorical - Additive factors and pure insertion • - Psychopharmacological designs • - Adaptation, modulation and dual-task inference • Parametric - Linear and nonlinear interactions • - Psychophysiological Interactions

5. A categorical analysis Experimental design Word generation G Word repetition R R G R G R G R G R G R G G - R = Intrinsic word generation

6. BOLD EPI fMRI at 2T, TR 3.2sec. Words presented every 16 secs; (i) studied words or (ii) new words Differential event-related fMRI Parahippocampal responses to words SPM{F} testing for evoked responses studied words SPM{F} testing for differences new words Peri-stimulus time {secs}

7. Cognitive Conjunctions Components Object Recognition R Phonological Retrieval P Visual Processing V Tasks Object naming R,P,V,RxP Colour naming P,V Object viewing R,V Colour viewing V The Conjunction [ R,V - V ] & [ R,V,P, RxP - V,P ] R, RxP & R = R Object recognition responses (R) viewing naming

8. A parametric analysis The [nonlinear] effect of time assessed with the SPM{T}

9. Nonlinear parametric responses: Inverted ‘U’ response to increasing word presentation rate in the DLPFC SPM{F} 42 wpm Regression and design matrix

10. Neurometric functions: Extrastriate responses to stimuli of increasing duration: Stimulus-specific or contextual effects? SPM{F} Adaptation of neuronal responses time{ms} Attentional modulation 0 exposure duration {ms} 800

11. Hemodynamic responses to words in the left peri-auditory region State-related responses Event-related 60 wpm BOLD EPI T2* at 2 Tesla TR = 1.7s 34s epochs of aurally presented words at 0, 10, 15, 30, 60 and 90 words per minute 1200 volume time-series 30 wpm 32 secs Peri-stimulus time SPM{F}

12. Context-sensitive responses time stimulus n-1 stimulus n stimulus n+1 interaction between stimuli response n

13. Volterra series - a general nonlinear input-output model input u(t) response y(t) nonlinear saturation Simulated input kernel estimates

14. Nonlinear hemodynamic responses kernel coefficients - h SPM{F} p < 0.001 SPM{F} testing H0: kernel coefficients = h = 0

15. Nonlinear hemodynamic responses - implications Hemodynamic response interference in terms of the effect of a prior stimulus nonlinear saturation

16. Rate-dependent responses: Processing one stimulus in the context of others ERPs - single words Integrated response 42 wpm 1400ms 42 wpm 600ms 1400ms ? 84 wpm 700ms Rate {wpm} nonlinear interactions

17. Peri-auditory responses in PET and fMRI Linear rCBF responses right rCBF left right Nonlinear BOLD responses BOLD Word presentation rate Word presentation rate

18. A factorial analysis Time x condition interactions (i.e. adaptation) assessed with the SPM{T}

19. Interactions and context-sensitive effects A 2 x 2 layout Context 1 (no naming) 1 2 Context 2 (naming) 3 4 without A & with A (e.g.. recognition) interaction effect (A x Context) A A task 1 2 3 4 Context 1 Context 2

20. Interaction effects in the left inferotemporal region A PET study of object naming Components Visual processing V Object recognition R Phonological retrieval P Interaction RxP Conjunction (name object - shape) & (view object - shape) = (R + RxP) & R = R Interaction (name object - shape) - (view object - shape) = (R + RxP) - R = RxP Object-specific activations adjusted rCBF Context: no naming naming

21. Psychopharmacological studies • PET, 6 subjects, 6 conditions • 3 x 2 factorial design, Buspirone x Memory left parahippocampal responses sub- supra- pre- acute- pre acute post post-

22. Dissociating the direct and modulatory effects of context A direct effect of context = C Context-sensitive effect = S x N response response time time C S response response frequency frequency

23. Responses in the right posterior superior temporal region to increasing rates (15 - 90 wpm) of word production 84 rCBF {ml/dl/min} 77 whilst repeating words and producing new ones

24. Interactions between set and event-related responses: Attentional modulation of V5 responses attention to motion attention to colour

25. Non-linear parametric interactions Increasing word presentation rate in a subject and patient with a CVA SPM{F} Differential responses in the left hippocampus

26. Psychophysiological interactions Context X source target Set stimuli Context-sensitive connectivity Modulation of stimulus-specific responses source source target target

27. Psychophysiological interactions in the right inferotemporal region: Modulation of face-selective responses by PPC SPM{Z} Face stimuli Faces PPC adjusted rCBF IT Objects medial parietal activity

28. Psychophysiological interactions: Attentional modulation of V2 - V5 contribution SPM{T} V5 activity Attention time attention V2 V5 activity V5 no attention V2 activity