The evolution of masked priming effects using the incremental priming technique

Transcription

1 The evolution of masked priming effects using the incremental priming technique Eva Van den Bussche & Astrid Vermeiren ASSC /11/2012 Herhaling titel van presentatie 1

2 Introduction Masked priming paradigm (Marcel, 1983) 9 17ms ## 33ms 2 480ms ## Smaller than 5 Larger than Pag. 2

3 Introduction Masked priming paradigm (Marcel, 1983) Congruent condition Incongruent condition Prime 6 1 Target 9 9 Difference (RT_I - RT_C) = priming effect Both > 5 One <, one > 5 Faster RTs Slower RTs Pag. 3

4 Introduction Strong and robust masked priming effects across the experimental literature (e.g. Van den Bussche et al., 2009, Psych Bull) Subliminal information can influence our behavior! Pag. 4

5 Introduction What is the time-course of masked priming effects? When do masked priming effects first emerge? Do they reach a ceiling-effect? Are masked priming effects caused by inhibition or facilitation or both? When do people become aware of the masked information? Pag. 5

6 Incremental priming Prime intensity/duration is gradually increased Jacobs, Grainger & Ferrand (1995) Provides additional information on nature (facilitatory VS inhibitory) and time-course of priming effects Letter/word recognition, neighbor priming, translation priming (E.g.,: De Moor et al., 2007; Grainger & Jacobs, 1999; Ziegler et al., 2000) Pag. 6

7 Incremental priming Uses 2 baseline conditions: Across-condition baseline: compare a prime condition with a different condition (e.g., congruent VS incongruent condition) Within-condition baseline: compare a prime condition with its own zero point (i.e., point where prime intensity = minimal, null priming effect) If RT compared to 0 facilitation If RT compared to 0 inhibition Pag. 7

8 Method N=31 Primes: 1-9, Targets: 1,4,6,9 Both novel and old primes Prime duration was gradually increased 480ms 17ms variable ## 9 ## 2 Smaller than 5 Larger than Pag. 8

9 Method Iiyama Vision Master Pro monitor, 200Hz, 800 x 600 pixels Refresh rate = 5ms 2 chains of prime durations (96 trials/block): Chain 1 (N=15): ms 9 blocks Chain 2 (N=16): ms 9 blocks Afterwards: prime visibility assessment Same chain (32 trials/block) Apply same instructions to primes instead of targets Pag. 9

10 Results: across-condition Chains were grouped (i.e. dur1 = 5ms for subjects with chain 1 and 10ms for subjects with chain 2) 1. Across-condition baseline: Repeated measures Within-subject factors: congruency (congruent or incongruent), prime (old or novel) and prime duration (9 levels) Between-subject factor: chain (1 or 2) Pag. 10

11 Results: across-condition RTs: Significant priming effects, but only when prime duration 25ms (F(8,22)=18.47, p<.001) (no 3-way IA) Priming effect (in ms) Prime duration Pag. 11

12 Results: across-condition Error rates: Significant priming effects, when prime duration 15ms (F(8,22)=18.47, p<.001) (no 3-way IA) Priming effect 8,50 6,50 4,50 2,50 0,50-1,50 ** * Prime duration Pag. 12

13 Results: prime visibility 2. Prime visibility % correct prime classifications 50% = chance level Repeated measure with prime (old or novel) and prime duration (9 levels) as within-subject factors and chain (1 or 2) as between-subject factor (Analyses with d instead of %: similar pattern of results) Pag. 13

14 Results: prime visibility Prime visibility increases with prime duration, but this interacts with nature of the prime (F(8,22)=4.36, p=.003) % correct prime classifications 1,00 0,90 0,80 0,70 0,60 0,50 0,40 novel old Prime duration Pag. 14

15 Results: prime visibility Significant CUBIC trend (F(1,29)=82.26, p<.001) % correct prime classifications 1,00 0,90 0,80 0,70 0,60 0,50 0,40 novel old Prime duration Pag. 15

16 Results: prime visibility Do we observe priming for those durations where prime visibility is at chance level? Prime duration Prime visibility RT priming effect Error rate priming effect Novel 5-10ms 48% 2ms 0,3% 15-20ms 49% 1ms 2,4%* 25-30ms 55% 23ms 0,9% 35-40ms 65% 33ms 1,3% Old 5-10ms 48% 8ms -2,4%* 15-20ms 51% 14ms* 1,5% 25-30ms 54% 29ms 2,7%* 35-40ms 62% 31ms 2,7% Pag. 16

17 Results: within-condition 2. Within-condition baseline: Separate repeated measures for each condition (congruent and incongruent) Within-subject factor: prime duration (9 levels) Between-subject factor: chain (1 or 2) Zero point = RTs on duration 1 RTs on all other durations are compared with this zero point Pag. 17

18 Results: within-condition a) RTS: Congruent trials: significant quadratic trend (F(1,29)=7.14, p=.012) ** * RT (in ms) * * * Prime duration Pag. 18

19 Results: within-condition b) RTs: Incongruent trials: significant linear (F(1,29)=92.08, p<.001) and quadratic trend (F(1,29)=10.31, p=.003) RT (in ms) ** Pag. 19 Prime duration

20 Results: within-condition RTs: Congruent and Incongruent trials: RT (in ms) congruent incongruent Prime duration Pag. 20

21 Results: within-condition a) Error rates: Congruent trials: small significant linear trend (F(1,29)=4.50, p=.042) 5 Error rate (in %) 4,5 4 3,5 3 2,5 * * ** * 2 Prime duration Pag. 21

22 Results: within-condition b) Error rates: Incongruent trials: significant linear trend (F(1,29)=42.76, p<.001) ** 8 7 * ** Error rate (in %) Prime duration Pag. 22

23 Results: within-condition Error rates: Congruent and Incongruent trials: 12 Error rate (in %) congruent incongruent 2 Prime duration Pag. 23

24 Conclusions Priming effects and prime visibility increase with prime duration Significant priming when visibility is at chance level Increase in priming effects is linear/quadratic, increase in prime visibility is cubic Incongruent trials produce massive inhibition and congruent primes a small inhibition (RT) or facilitation (Error rates) of RTs masked priming effects are mostly inhibitory in nature when compared to this zero point Pag. 24

25 Contact Eva Van den Bussche Vrije Universiteit Brussel Department of Psychology Pleinlaan Brussels Belgium Eva.Van.den.Bussche@vub.ac.be Pag. 25

26 Results c) Novel trials: significant linear (F(1,29)=54.01, p<.001) and quadratic trend (F(1,29)=6.26, p=.018) RT (in ms) * Prime duration Pag. 26

27 Results d) Repeated trials: significant linear (F(1,29)=17.92, p<.001) and quadratic trend (F(1,29)=10.58, p=.003) RT (in ms) ** ** 420 Prime duration Pag. 27

28 Results Novel and repeated trials: RT (in ms) novel repeated 420 Prime duration Pag. 28