dualencoding

Dualencoding refers to the cognitive process by which information is encoded using two different representations, typically a verbal-linguistic code and a nonverbal-imagery code. In psychology, this idea is central to dual coding theory, proposed by Allan Paivio in the 1970s, which posits that memory and thought are supported by two interacting subsystems: a verbal system for language and a nonverbal system for mental imagery. Information can be encoded in one or both channels, and when content is represented in both codes, it is more likely to be retained and later retrieved, producing a dual-coding advantage.

The theory accounts for how people process and remember concrete information, such as a scene described in text accompanied by an illustration, better than abstract information presented in only one form. The proposed mechanism is that separate memory traces in the verbal and imagery systems provide complementary retrieval cues. Evidence comes from experiments showing improved recall for material presented with both words and pictures, as well as stronger associations when cross-referencing verbal labels with imagery.

Applications appear in education and instructional design, where textbooks, presentations, and multimedia materials pair captions or narration with relevant illustrations. Principles emphasize aligning visuals with accompanying text, avoiding extraneous content, and managing cognitive load so that the dual codes support rather than compete for attention.

Critiques note that the advantage is not universal and depends on material, prior knowledge, and implementation. Some researchers view dual coding as part of a broader multimedia learning framework, rather than a strictly separate cognitive system, highlighting the role of integration and learner differences.