'Influence of decision amplitude on Garner interference in manual size estimation' (AsPredicted #115554)
Author(s) Kriti Bhatia (University of Tuebingen) - kriti.bhatia@uni-tuebingen.de Angela Osenberg (University of Tuebingen) - angela.osenberg@student.uni-tuebingen.de Markus Janczyk (University of Bremen) - janczyk@uni-bremen.de Volker Franz (University of Tübingen) - volker.franz@uni-tuebingen.de
Pre-registered on 2022/12/06 - 06:46 AM (PT)
1) Have any data been collected for this study already? It's complicated. We have already collected some data but explain in Question 8 why readers may consider this a valid pre-registration nevertheless.
2) What's the main question being asked or hypothesis being tested in this study? We want to extend the results of Hesse & Schenk (2013, Behavioural Brain Research) to a manual size estimation task. According to those results, we hypothesize that the Garner interference effect might be eliminated in a long decision amplitude condition, but be present in a short decision amplitude condition.
Based on the pattern of results of Hesse & Schenk (2013), we ideally expect a Garner interference effect in the reaction time (RT) and total time (TT) but not movement time (MT) in the short condition. We expect no Garner interference effect in RT, MT or TT in the long condition.
However, our task (manual size estimation) is different from the previous study. Therefore, the distance manipulation may be imperfect such that we may not see a strong dissociation. The modulation of the Garner interference effect should be most pronounced in RT. This is so because with a long amplitude, participants might have enough time during the movement to only then specify the exact size of their manual size estimation (such that participants can start the movement before the exact size has been specified and in consequence there is no effect on RT). A smaller or even absent modulation of the Garner interference effect might be found in MT. TT might show a similar modulation as RT, as RT is contained in TT (see point 3 below).
References:
Hesse, C., & Schenk, T. (2013). Findings from the Garner-paradigm do not support the "how" versus "what" distinction in the visual brain. Behavioural Brain Research, 239, 164-171.
3) Describe the key dependent variable(s) specifying how they will be measured. We will measure RT (time to initiate movement), calculated from data obtained with the Optotrak. We will also measure TT (time to complete movement) measured via a button press (participants will perform the manual size estimation with index finger and thumb of their right hand and---as soon as they show the size of the target object--- press a button with the index finger of their left hand). MT will then be calculated as TT-RT. Our main focus is on RT and MT. For comparison to the literature (where sometimes TT was used), we will also use TT.
4) How many and which conditions will participants be assigned to? There will be four conditions in a within-subjects design. The four conditions result from combining two Garner conditions (baseline vs. filtering) and two decision amplitude conditions (long [30 cm] vs. short [7 cm] distance from the start point to the location where the manual size estimate is performed).
5) Specify exactly which analyses you will conduct to examine the main question/hypothesis. We will calculate means and SEM/confidence intervals where appropriate and use those to compare our results to the results from the literature. For statistical testing, we will perform a two-way repeated-measures ANOVA with factors 'Garner condition' (baseline vs. filtering) and 'Decision amplitude' (long vs. short) on the variables RT, MT, and TT. We will further conduct post-hoc paired-samples t-tests. The significance threshold is set to alpha = 0.05.
6) Describe exactly how outliers will be defined and handled, and your precise rule(s) for excluding observations. All participants will be right-handed. Trial exclusions will be based on the criterion used by Hesse & Schenk (2013): Outliers corresponding to RTs of less than 100 ms and of more than 2.5*SD above the mean of the participant (in a certain condition) will be excluded from the analysis. Based on pilot experiments, a further exclusion criterion will be used: outliers corresponding to MT and/or TT beyond the mean ± 2*SD for each participant (in a certain condition) will also be excluded from the analysis. Moreover, trials with missing Optotrak markers (no position information available at certain times) will be excluded. If more than 25% of the trials of a participant are rejected, they will be excluded from our analyses.
7) How many observations will be collected or what will determine sample size? No need to justify decision, but be precise about exactly how the number will be determined. We will collect data from 32 participants (after exclusions). This is based on a power analysis (paired t-test, one-sided) with d = 0.5 (from previous experiments), alpha = 0.05, power > 80%.
8) Anything else you would like to pre-register? (e.g., secondary analyses, variables collected for exploratory purposes, unusual analyses planned?) We have already collected the data from 10 participants. This was necessary to comply with the schedule of a research seminar. Unfortunately, due to time-constraints, we were not able to submit the pre-registration before now. We believe this is not a major problem in this case, as the hypotheses are based on the results of Hesse & Schenk (2013).