Flipping the stimulus: Effects on scanpath coherence?

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human-Computer Interaction

Background:

• Examining eye movement scan patterns is crucial for understanding dynamic tasks.
• Repetitive trials can lead to long experiments due to the need for filler trials.
• Geometric transformations of stimuli offer a potential method to reduce perceived trial repetition.

Purpose of the Study:

• To investigate if flipping stimulus object trajectories affects scan patterns in multiple object tracking.
• To develop and test novel statistical strategies for comparing scan pattern similarity.
• To assess the feasibility of using geometric transformations in experimental design.

Main Methods:

• Stimuli were geometrically transformed by flipping around the x- and y-axes.
• Two new statistical methods were developed to compare scan pattern similarity.
• These methods were validated using artificial data and applied to multiple object tracking data.

Main Results:

• Flipped trials showed statistically significant differences in scan patterns compared to original trials.
• The observed differences in scan patterns were minimal, with a small increase in overall distance (approx. 13%).
• The developed statistical strategies proved effective for comparing scan pattern groups.

Conclusions:

• Geometric transformations, like flipping, can be used to modify stimuli without drastically altering scan patterns.
• This technique allows for more complex hypothesis testing regarding scan pattern coherence.
• Researchers can potentially shorten experiments by using such transformations, maintaining data integrity.