Purpose of this experiment is to study infant’s perceptual sensitivity to sound symbolism. The infant sits on the caregiver’s lap facing a facing a computer monitor on which visual stimuli will be presented. Target items are a round-shaped object labeled X and a spiky shaped object labeled Y. The procedure consists of a pretest phase, an habituation phase, and two test phases. The pre-test phase consists of four familiarization trials presenting filler and test items pairs without labels and two referential trials each presenting a single additional object with labels. The habituation phase consists of a series of trials presenting the test items with labels. The trials are repeated until the infant’s attention over a block of trials drops below a preset citerion. The test phase consists of four filler trials and four target trials. For each trial an item pair is presented visually with an auditory cue. For the target trials the auditory cue matches or mismatches the visually presented object.

Looking times are measured using an eye-tracker, where looking means gaze falls inside a circular AOI around a stimulus and gaze outside the AOI (or no gaze detected) means not looking.

This example is a slightly modified version of an experiment template created on behalf of a language acquisition researcher.

  1. Download experiment package: wordobject_demo.zip

  2. Install the experiment package as described in Installing a Zep experiment script

  3. Run the experiment as described in Running a Zep experiment

On successful completion of the experiment session the experiment results database will contain the results for the session as defined by the experiment. The experiment will also have produced one eye-tracking data file for each phase (i.e. pretest, habituation, test and test2) in a subdirectory of the experiment folder.

Screencast of the experiment

This screencast shows running the experiment from ZepMan with a adult participant. For the sake of demonstration the participant’s gaze is shown in the test screen (you would obviously not do this for an actual test). Due to the load caused by the screen capturing software the animations are not as smooth as they normally are. Video not yet narrated.

This experiment produces trial results in the Experiment Results Database. This experiment has four phases and for each phase you will have results. The experiment defines one table for the pretest and test phases and two tables for the habituation phase. We can use ZepMan to extract these results from the database:

wordobject_demo-pretest-1.csv
wordobject_demo-habituation-1.csv
wordobject_demo-habituation-2.csv
wordobject_demo-test-1.csv
wordobject_demo-test2-1.csv

Since we ran just one session the database will only contain data for that single session. Normally you would extract the database contents after having tested all participants taking part in the study.

In addition to the regular trial results four eye-tracking data files are created, one per phase. Since the looking times per object are determined on-the-fly we don’t really need the eye-tracking data files. If however if the regular results suggests there something going on with a particular participant you could have a closer look at the actual eye-tracking data.

References

Imai M., Miyazaki M., Yeung H. H., Hidaka S., Kantartzis K., Okada H., et al. (2015). Sound symbolism facilitates word learning in 14-month-olds. PLoS ONE 10:e0116494. 10.1371/journal.pone.0116494) https://doi.org/10.1371/journal.pone.0116494