Inferring mental operations from reaction-time data:
How we compare objects

"The study of the time relations of mental phenomena is important from several points of view: it serves as an index of mental complexity, giving the sanction of objective demonstration to the results of subjective observation; it indicates a mode of analysis of the simpler mental acts, as well as the relation of these laboratory products to the processes of daily life; it demonstrates the close inter-relation of psychological with physiological facts, an analysis of the former being indispensable to the right comprehension of the latter; it suggests means of lightening and shortening mental operations, and thus offers a mode of improving educational methods; and it promises in various directions to deepen and widen our knowledge of those processes by the complication and elaboration of which our mental life is so wonderfully built up."

-- Joseph Jastrow (1890), The Time-Relations of Mental Phenomena.

Table of Contents


Introduction
A Three-Attribute Stimulus Set
Major Issues in Comparing Multi-Attribute Objects
- - Holistic Versus Feature Comparison
- - Sequential Versus Parallel Tests
Some Typical Data
- - Data From Geometric Patterns
- - Data From Letter Strings
Plan of the Chapter
Theories, Models, and Data
Reaction Time to Judge "Different"
Sequential Tests: Defining Properties
Sequential Tests: Prediction of the Number of Tests
- - Effect of Number of Mismatching Features on Number of Tests
- - Effect of Number of Relevant Features on Number of Tests
- - A General Statement of the Two Effects on Number of Tests for "Different" Responses
Sequential Tests: Relation Between the Number of Tests and Mean Reaction Time
- - The Contribution of Residual Operations to Reaction Time
- - Implications of Four Constraints on Test Durations
Sequential Tests: Application to Letter-String Data
- - The Fully Constrained Model
- - Relaxing Constraint 1: Allowing Variable Test Durations
- - Relaxing Constraint 2: Allowing Unequal Residual Durations for "Same" and "Different" Responses
- - Relaxing Constraint 3: Allowing Unequal Durations of Matches and Mismatches
- - Relaxing Constraint 4: Allowing Unequal Mean Test Durations for Different Attributes
- - Implications of a Non-Ballistic Response Process
- - Status of the Sequential-Test Model
Parallel Tests: Defining Properties
- - Statistical Facilitation and the Effects of Process Variability
Parallel Tests: Effect of Number of Relevant Features on Mean Reaction Time
Parallel Tests: Effect of Number of Mismatching Features on Mean Reaction Time
- - Parallel Variant 1: Equal Fixed Test Durations
- - Parallel Variant 2: Unequal Mean Test Durations with Limited Variability
- - Parallel Variant 3: Variable Test Durations with Unconstrained Means
- - Parallel Variant 4: Variable Test Durations with Equal Means and Identical Distributions
- - Status of the Parallel-Test Model
Sequential versus Parallel Tests: Inferences Based on Differential Mismatch Durations
Sequential versus Parallel Tests: Conclusions from "Different" Responses
Reaction Time to Judge "Same"
Difficulties for Sequential Tests
Parallel Tests Revisited
- - Parallel Variant 1: Equal Fixed Test Durations
- - Parallel Variant 4: Variable Test Durations with Equal Means and Identical Distributions
- - Parallel Variant 2: Unequal Mean Test Durations with Limited Variability
- - Parallel Variant 3: Variable Test Durations with Unconstrained Means
Two-Process Mechanisms and Holistic Stimulus Comparison
Separate Mechanisms for "Same" and "Different" Responses, and their Temporal Arrangement
The Nature of the Sameness-Detection Process
Concluding Remarks
Appendix 1: Error Rates and the Interpretation of Reaction-Time Data
Appendix 2: Donders' Subtraction Method and Modern Variants
Glossary
Suggestions for Further Reading
Questions for Further Thought
References