Development of implicit processing of thematic and functional similarity relations during manipulable artifact object identification: Evidence from eye-tracking in the Visual World Paradigm

• Implicit semantic processing of manipulable artifacts develops over age.
• Thematic and specific function similarity relations are processed from 6.
• Processing of general function similarity relations develops gradually.
• Thematic and functional similarity relations rely on distinct semantic mechanisms.
• Use of complementarity and similarity mechanisms explain developmental differences.

This study assessed the implicit processing development of three types of semantic relations during manipulable artifact identification. Thirteen adults and thirty-nine children (age 6, 8, and 10 years) participated. Fixation temporal dynamics were used to assess competition effects from thematic (e.g., wood), specific function (e.g., axe), and general function (e.g., knife) distractors during target identification (e.g., saw). Competition effects were analyzed depending on distractor type and age group. Developmental results demonstrate emergence of competition effects with general function distractors with age, whereas competition effects with thematic and specific function distractors were stable from 6. Findings highlight fined-grained development of similarity-based semantic mechanism implicit use during object processing from 6 to adulthood. They further suggest that complementarity-based mechanism is efficiently used during object semantic processing starting from 6 and likely involved in processing both thematic and specific function relations.