Tandra Ghose (Univ. of Kasierslautern, Germany), in collaboration with Frouke Hermens (Univ. of Aberdeen, U.K.) and Johan Wagemans (Univ. of Leuven, Belgium)

Funded by European Union Marie Curie Career Integration Grant

Project No. 293901

Sometimes entities present in the displays changes (modulates) the pattern of EM subconsciously (implicit process). For such processes, can some factors lead to more of the involuntary modulation than others, i.e., are some factors stronger than others for grouping? Can we find a trend in how strength of factors modulates EM? Can the pattern of EM on a scene be used to make inferences about the strength of grouping factors based on results of the previous questions? Is the measure developed as an outcome of iPOEM similar to the measures already out there? If not what is different about iPOEM?

Objective: Quantitative measures of PO from implicit modulation of EM

  • Objective-1: Investigation of ways in which eye movement patterns can be modulated by the presence of holistic emergent properties in a scene.
  • Objective-2: Development of implicit measures of strength of factors that lead to the holistic organization based on specific eye-movement patterns

Objective-1: Investigation of ways in which eye movement patterns can be modulated by the presence of holistic emergent properties in a scene.

Choice of Eye Movement - Saccades

Eye Movement Based Measures

Perceptual Organization (Grouping)

Exploring Saccadic Metrics

Result: Based on three experiments we decided to choose saccadic latency (reaction time to start the saccade after target onset) as the implicit measure.

Objective-2: Evaluating eye movememnt based implicit measure of grouping strength.

Different Grouping Cues used

Manual response is not a good implicit measure of grouping strength

Saccadic latency shows modulation with grouping strength

Results were confirmed by interference in heatmaps

Result: Based on these experiments we conclude saccadic latency can be used as a reliable implicit measure for perceptual grouping, an aspect that cannot be captured by manual response tasks.