Measuring task structure with transitional response times: Task representations are more than task sets.

Area of Science:

• Cognitive psychology
• Human-computer interaction
• Neuroscience

Background:

• Task representations are typically studied using task-switching procedures.
• These methods rely on experimental assumptions about stimulus-response mappings.
• A novel method is needed to evaluate task structure without these assumptions.

Purpose of the Study:

• To develop and validate a novel method for evaluating task representation structure.
• To compare the efficacy of transitional response times (RTs) analysis with conventional switch cost measures.
• To investigate how stimulus category affects response sequencing and task representation.

Main Methods:

• Participants responded to centrally presented stimuli.
• Transitional response times (RTs) were computed for each response sequence.
• Conventional task-switch analyses were performed for comparison.

Main Results:

• Conventional switch costs did not differ based on stimulus category.
• Transitional RT analysis revealed fine-grained relationships between responses.
• Single stimulus categories showed lower transitional RTs for neighboring responses, forming response chains, which were disrupted with dual categories.

Conclusions:

• Transitional RT analysis provides a more detailed picture of task representation than traditional switch costs.
• This novel approach uncovers structure not detectable by conventional measures.
• The method does not require a priori assumptions about task organization, offering greater flexibility.