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The pilot study demonstrated that the incremental sequence of sample stimuli revealed main effects of the factor Sequence position of HR for match and not for non-match responses, so did the MEG study. The fMRI study additionally showed a main effect of the factor Sequence position of HR for non-match responses. However, the comparison of effect sizes across the studies revealed that there was the same pattern of effect sizes across the response types for every study: First, the effect sizes measured for HR for match responses were always about 0.1 bigger than for non-match responses. Here, for the MEG experiment the weakest effect size for non-match responses altogether were observed (Figure 3-5). Second, the effect sizes measured for RR for match and non-match responses showed for every study that the differences were minor between match and non-match. However, across the studies we measured overall high effect sizes for the pilot study. Prominently for the fMRI study were the high effect sizes for HR for the match responses and discriminability. Whereas for the MEG study high effect sizes for the HR for match responses but also for RR for either match and nonmatch responses was considerable.

The SDT measures discriminability and response bias were only present for the MEG and fMRI studies (Figure 3-5-A). Only for the fMRI study high effect sizes were observed for discriminability, all others were small. However, for the MEG experiment the small effect sizes for response bias refer to a significant effect and the small effect sizes for discriminability to tendency. The comparison of effect sizes regarding the RT across the three studies indicated that the MEG experiment only revealed (very) small effect sizes. These weren’t even visually not detectable in the visualization (Figure 3-5-B). Further,

Figure 3-5: Comparison of the effect size (ES) regarding the main effect for the factor Sequence position across the three studies. A: ES of the different response types. For hit rates of match responses all three studies show a high ES and a significant main effect. This is not the case for hit rates for non-match responses. For match responses, the Pilot study revealed highest ES but regarding this all studies showed a significant main effect. For Discriminability only the fMRI study revealed a high ES and a significant main effect. Here the MEG study revealed a tendency with a small ES only. For response bias the ES are small for both studies but significant for the MEG study. B: ES related to main effects of reaction times were only possible to be comparable between the Pilot and the fMRI studies because the effect sizes regarding the MEG study did not exceed 0.01. For the RT only two main effects were observed in the fMRI study. These were a main effect for RT of match response rate and RT of overall response rate. Both ES refer to high ES. The red dashed line in the background indicates the threshold of an ES called medium (Eta-square 0.06). Asterisks indicate the corresponding main effect to be significant (red asterisks: p<0.001; black asterisks p<0.05). Abbreviations: Hit rates of match (Hit r. M) and non-match (Hit r. N) responses; response rates for match (M. Res.r.) and non-match (M. Res.r.), discriminability (Discrim.) and response bias (R. bias).

we observed two main effects of the factor Sequence position for the RT for the fMRI study. For these two significant main effects, we observed large effect sizes.

The effect sizes with regards to the simple effects are illustrated in Figure 3-6 and picture a remarkably overall result: The first three simple effects revealed in almost all response types the higher effect sizes, and within these the largest was observed in the second or third simple effects. That clarifies that most processes happen in contrast to the first sequential position. This also holds for the discriminability and differs from the response bias. Regarding the response bias, the MEG study revealed a maximum medium effect size only for the third simple effect and all others remained below.

Figure 3-6: Comparison of effect sizes (ES) for the MEG and fMRI study as a function of simple effects for all response types and the signal detection theory measures. Given this overview, the MEG and fMRI studies revealed a similar pattern with minor differences. A: ES for hit rates of match responses: In both experiments, high ES were observed for the first three simple effects. B: ES for hit rates of non-match responses: Only ES below medium were observed. C: ES for match response rates: A medium ES was observed for the third simple effect for both studies only. D: ES for non-match response rates: A medium ES was observed for the third simple effect for both studies only. E: ES for discriminability: The ES regarding the fMRI was always higher and reached high ES for the second simple effect. F: ES for response bias: A medium ES for the third simple effect was observed for the MEG study. The red dashed line in the back ground indicates the threshold of an ES determined medium as proposed by Cohen (1966) (Coh. D < 0.8). Asterisks indicate the corresponding significant simple effect. Red asterisks: p<0.001; black asterisks: p<0.05).