Two-alternative forced choice¶
Two-alternative forced choice (2AFC) is a method for measuring the sensitivity of a person or animal to some particular sensory input, stimulus, through that observer's pattern of choices and response times to two versions of the sensory input.
Core Idea¶
Two-alternative forced choice is treated here as the recurring psychophysics identity summarized by this source-grounded definition: Two-alternative forced choice (2AFC) is a method for measuring the sensitivity of a person or animal to some particular sensory input, stimulus, through that observer's pattern of choices and response times to two versions of the sensory input. Two-alternative forced choice (2AFC) is a method for measuring the sensitivity of a person or animal to some particular sensory input, stimulus, through that observer's pattern of choices and response times to two versions of the sensory input.
Scope of Application¶
-
Behavioural experiments. In animals, the 2AFC task has been used to test reinforcement probability learning, for example such as choices in pigeons after reinforcement of trials.
-
Behavioural experiments. In a different application, the 2AFC is designed to test discrimination of motion perception.
-
Biases in decision making. Introducing biases in the 2AFC task is used to modulate decision making and examine the underlying processes.
-
Formal model. The extended DDM allows for selection of A and the starting value of x(0) from separate distributions – this provides a better fit to experimental data for both accuracy and reaction.
-
Race model. The race model is not mathematically reducible to the DDM, and hence cannot be used to implement an optimal decision procedure.
Clarity¶
A clear use of Two-alternative forced choice names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is Two-alternative forced choice (2AFC) is a method for measuring the sensitivity of a person or animal to some particular sensory input, stimulus, through that observer's pattern of choices and response times to two versions of the sensory input.
Manages Complexity¶
Two-alternative forced choice compresses multiple psychophysics details into a stable diagnostic relation. The source shows both the central mechanism—in most experiments, the participant must make a choice response between two directions of motion (e.g. up or down), usually indicated by a motor response such as a saccade or pressing a button.—and the practical consequence—the extended DDM allows for selection of A and the starting value of.
Abstract Reasoning¶
- Type the carrier. Identify the psychophysics entities to which the claim applies.
- State the relation. Use the source-grounded identity: Two-alternative forced choice (2AFC) is a method for measuring the sensitivity of a person or animal to some particular sensory input, stimulus, through that observer's pattern of choices and response times to two versions of the sensory input.
- Check operation and conditions. Introducing biases in the 2AFC task is used to modulate decision making and examine the underlying processes.
- Demand recognition evidence.
Knowledge Transfer¶
Within the home domain. Knowledge about Two-alternative forced choice transfers literally when a new case preserves the same carrier type, relation, and recognition test. In animals, the 2AFC task has been used to test reinforcement probability learning, for example such as choices in pigeons after reinforcement of trials. In a different application, the 2AFC is designed to test discrimination of motion perception. Beyond the home domain. Transfer the broader Evaluation relation when the psychophysics-specific differentia cannot be filled. Retain the name Two-alternative forced choice only when the same carrier, operation.
Relationships to Other Abstractions¶
Current abstraction Two-alternative forced choice Domain-specific
Parents (1) — more general patterns this builds on
-
Two-alternative forced choice is a kind of Evaluation Prime
Two-alternative forced choice is a strict kind of Evaluation: Two-alternative forced choice (2AFC) is a method for measuring the sensitivity of a person or animal to some particular sensory input, stimulus, through that observer's pattern of choices and response times to two versions of the sensory input.
Hierarchy path (1) — routes to 1 parentless root
- Two-alternative forced choice → Evaluation → Comparison → Self Checking
Neighborhood in Abstraction Space¶
Two-alternative forced choice sits in a sparse region of the domain-specific corpus (77th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.
Family — Neural & Cognitive Representation Models (11 abstractions)
Nearest neighbors
- BCM theory — 0.84
- Gain-field encoding — 0.83
- Stimulus–Response Compatibility — 0.83
- Stimulus Control — 0.82
- Hierarchical temporal memory — 0.82
Computed from structural-signature embeddings · 2026-10-08