Different measurements of pupil size as response to auditory affective stimuli and their application in a visual perception task

Transcription

1 Different measurements of pupil size as response to auditory affective stimuli and their application in a visual perception task 27 August 2015 ECVP Liverpool Sarah Lukas Gabriel Yuras Anke Huckauf PH Weingarten, Referent: Prof. Dr. Mustermann Folie 1

2 Overview Pupil dilation Pupil dilation measurement Pupil dialation as reaction to auditory affective stimuli Visual perception task 532wGt1s8m6sko1_500.gif [retrieved ] Folie 2

3 Introduction to pupil dilation Pupil dilation is a quite easy to use, un-invasive measure for Cognitive load Emotional load There is a huge number of publications using pupillometry to investigate cognitive or emotional load 5360 entries in google scholar 2680 entries since 2010 However no clear guidelines which measurements one should use best Which latencies, maxima, critical points of time are to be expected? Furthermore, in the research of emotions, pupil dilation is assumed to reflect rather arousal than valence Is it as simple as that? Folie 3

4 Auditory affective stimuli Method 30 Stimuli (10 per emotional valence) of the IADS (international affective digitized sounds) Valence: Positive (7.4), Neutral (5.1) and Negative (2.6) on a ninepoint rating scale Arousal: same for positive and negative (6.6 vs. 6.8), less for neutral (4.2) on a nine-point rating scale Partala & Surakka, 2003, International Journal of Human-Computer Studies Folie 5

5 Pupillary response to auditory affective stimuli Partala & Surakka, 2003 Folie 7

6 Questions Can the results of Partala & Surakka be replicated? Which measurements are best to calculate pupillary reactions to affective auditory stimuli? Is there any interaction of valence and arousal? Can auditory files be used to induce affect and to investigate interactions of affect and other cognitive processes (e. g. perception)? Folie 8

7 Experiment 1 Only 1. trial Data recording: 6 s before stimulus onset; during 6 s duration of the stimulus presentation; 6 s after offset of stimulus presentation 10 sec 6 sec 6 sec You can move your eyes Subsequently rating part: each sound was played again and the subject rated it for valence and arousal (without being played again) Randomly 1-4 s without recording; record starts 6 s before sound 6 sec Valence Arousal Folie 9

8 Pupil size change according to Valence Difference between valences only after 2.5 sec until 5.5 sec at time point 6, no significant differences any more only during stimulus presentation, not after difference to Partala & Surakka, 2003 Folie 10

9 Pupil size change according to Arousal Difference between arousal levels only after 3.5 sec until 5 sec at time point 5.5, no significant differences any more longer latency and shorter duration compared to valence After stimulus offset: differences at 9.5 and 10 sec (3.5 sec after stimulus offset) Folie 11

10 Interaction of Valence and Arousal,180,160,140 Pupil change in mm,120,100,080,060,040 low medium high,020,000 negative neutral positive Valence Pupil size only analyzable when aggregated together (and time not as an extra factor) No main effect of valence or arousal Significant interaction of valence and arousal: negatively rated sounds reflect the expected linear pupil size change; exactly the contrast pattern for neutrally rated sounds and no differences in arousal for positive trials but only 7 subjects included in this analysis Folie 13

11 Latency of Maxima 5,0 4,5 4,0 3,5 Number of Maxima 3,0 2,5 2,0 1,5 Negative Neutral Positive 1,0 0,5 0,0-0,5 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 6 6,5 Point of time For neutral sounds, most maxima were reached at 2 sec after tone onset, for the emotional sounds (positive and negative), most maxima were reached at 2.5 sec after tone onset Folie 14

12 Implications Valence can be analysed at different time points than arousal differences in early point of times rather valence; later rather arousal; also after stimulus offset And: arousal and valence seem to have different effects in pupil size, instead of only arousal vs. only valence Interaction of valence and arousal: does pupil size react on arousal depending on the valence of the auditory stimulus? Further research is needed Folie 15

13 Experiment 2: Perception task 72 sounds Landoltrings (up/ down) in two eccentricities (3 and 9 ) Baseline: recognition of Landoltrings without sound Folie 16

14 Pupil size change according to Valence,200,150,100 Pupil size change in mm,050,000 -, Positive Negative Neutral -,100 -,150 -,200 Time in ms Folie 17

15 Perception during exposure of affective auditory sounds Percent correct ms 5000 ms 8000 ms Ring No sound Negative Neutral Positive Folie 19

16 Conclusion Pupillometry can be easy when correctly implemented A careful and responsible treatment with the experimental set up is inevitable Pupillary changes according to auditory affective stimuli have a characteristic pattern, but the critical points of time might vary Analysis of maxima show a similar patttern of results than analysis of critical points of time There might be an interaction of valence and arousal, but this has to be further investigated Auditory affective sound can be used to study influences of affect to perception Folie 20

17 Thank you for your attention. PH Weingarten, Referent: Prof. Dr. Mustermann Folie 21