Discovering mental processing stages:
The method of additive factors

"No aphorism is more frequently repeated . . . than that we must ask Nature . . . ideally, one question at a time. The writer is convinced that this view is wholly mistaken. Nature, he suggests, will best respond to a logical and carefully thought out questionnaire; indeed, if we ask her a single question, she will often refuse to answer until some other topic has been discussed."

-- R. A. Fisher (1926), in the paper that reported his invention of the factorial experiment.

Table of Contents:

The Search for Modules
Stages, Selective Modifiability, and Invariant Factor Effects
Plan of the Chapter
Additive and Interacting Factors
Examples from Naming a Numeral
Examples from Searching Memory
Effects of Factors on a Shopping Trip: A Process With Observable Stages
Jim and Alice's Story
The Stages of Jim's Trip and the Factors that Influence them
Details of the Effects of Factors on Stages of the Trip
Trip Duration Data: Additive Factors
Trip Duration Data: Interacting Factors
Conclusions From Jim and Alice's Story
Stage Models and the Effects of Factors on Mental Operations
Stages: the Modules of a Sequential Process
The Subtraction Method of Frans Cornelis Donders (1818-1889)
How Plausible is it for Mental Processes to be Sequential?
An Example: Stages in a Choice Reaction
- - Separate Stages for Stimulus Identification and Response Selection
- - Why are Choices Slowed by Signal Uncertainty?
The Method of Additive Factors
Some Applications of the Additive-Factor Method
What Else Do We Lose When We Lose Sleep?
How We Prepare to Choose
Retrieving Item Versus Context Information From Memory
When We Improve With Practice, What Improves?
Transfer of Information Between the Cerebral Hemispheres
Task Switching and the Frontal Lobes: Inference About Stages from Localized Brain Damage
Stages in Speech Production: Real-Time Evidence of a Stage-Specific Effect
Rotation and Magnification of Mental Images
- - Combining Two Image Transformations
- - Mental Rotation in Detail: Application of the Subtraction Method
Doing Two Things At Once: Why Are We Slower?
- - The Overlapping-Tasks Paradigm
- - The Bottleneck/Deferred-Processing Model
- - Some Implications of the Model
- - Tests of Three Implications of the Model
How Do Repetition and Familiarity Speed Word Recognition?
Do Readers Recognize One Word at a Time?
- - Equivalent Substages
Are Characters Encoded in Parallel, Sequentially, or Both?
What Do We Search For When We Search Memory?
How Do We Benefit from Seeing Ahead When We Search a Display?
The Additive-Factor Method: Concluding Remarks
Processing Stages and Brain Structures
Perspectives from Other Module-Finding Methods
- - Separate Measures
- - Composite Measures
What is "Additive-Factors Logic"?
Extending the Method Beyond the Mean
Non-Stage Architectures That Produce Additive Effects
- - Alternate Pathways
- - Overlapping Processes
Some Strengths and Limitations of the Method
Design Matters
- - Multiple Factors
- - Multiple Levels
Statistical Issues
The Importance of Ronald. A. Fisher (1890-1962)
Suggestions for Further Reading