Loci of contextual effects in judgment

Area of Science:

• Psychology
• Cognitive Science
• Psychophysics

Background:

• Contextual effects significantly influence human judgment and perception.
• Understanding the locus of these effects is crucial for developing accurate judgment theories.

Purpose of the Study:

• To investigate whether contextual effects, specifically stimulus spacing, impact scale values or judgment functions.
• To differentiate the locus of contextual effects in within-modality versus cross-modality judgments.

Main Methods:

• Three experiments were conducted using dot patterns to assess judgments of darkness.
• Experiment 1: Category ratings and magnitude estimations with varied stimulus spacing.
• Experiments 2 & 3: Judgments of differences and ratios, manipulating stimulus spacing and range for within- and cross-modality tasks.

Main Results:

• Stimulus spacing similarly affected category ratings and magnitude estimations in Experiment 1.
• Scale values remained independent of spacing in within-modality judgments (Experiment 2).
• Stimulus range and spacing influenced scale values in cross-modality judgments (Experiment 3).

Conclusions:

• Contextual effects of stimulus spacing operate within the judgment function for within-modality judgments.
• Contextual effects influence scale values in cross-modality judgments.
• A unified contextual theory for both within- and cross-modality judgment is proposed.