Journal article Open Access
Metzger, Anna; Knut Drewing
In haptic perception information is often sampled serially (e.g. a stimulus is repeatedly indented to estimate its softness), requiring that sensory information is retained and integrated over time. Hence, integration of sequential information is likely affected by memory. Particularly, when two sequentially explored stimuli are compared, integration of information on the second stimulus might be determined by the fading representation of the first stimulus. We investigated how the exploration length of the first stimulus and a temporal delay affect contributions of sequentially gathered estimates of the second stimulus in haptic softness discrimination. Participants subsequently explored two silicon rubber stimuli by indenting the first stimulus 1 or 5 times and the second stimulus always 3 times. In an additional experiment we introduced a 5s delay after the first stimulus was indented 5 times. We show that the longer the first stimulus is explored, the more estimates of the second stimulus’ softness contribute to the discrimination of the two stimuli, independent of the delay. This suggests that the exploration length of the first stimulus influences the strength of its representation, persisting at least for 5s, and determines how much information about the second stimulus is exploited for the comparison.
There are zip files for every experiment (1 & 2), which contain all data relative to the publication. The data of each participant is contained in a separate folder. This folder contains a *.raw file for each session of the experiment and a "data" folder, which contains movement trajectories (*.trj files) and the staircase reversals for each condition (*.pse files) in separate folders for each session.
Variables of Experiment 1 are described in the file VARIABLE_CODES_EXP1.txt and the variables of Experiment 2 are described in the file VARIABLE_CODES_EXP2.txt.