Diffusion model drift rates can be influenced by decision processes: an analysis of the strength-based mirror effect

Area of Science:

• Cognitive Psychology
• Memory Research
• Decision Making

Background:

• The strength-based mirror effect (SBME) describes improved memory for studied items and better rejection of similar, unstudied items (lures) with increased study.
• Previous research suggested SBME arises from memory trace differentiation, where stronger memories better distinguish targets from lures.
• An alternative explanation involves changes in decision criteria, independent of memory trace quality.

Purpose of the Study:

• To differentiate between the memory differentiation and decision criterion accounts of the SBME.
• To investigate whether manipulating memory strength at retrieval alone can produce SBME effects.
• To determine the primary mechanism underlying the SBME.

Main Methods:

• Three experiments were conducted manipulating list strength at encoding and/or retrieval.
• Diffusion model drift rates were analyzed to assess memory processes.
• Participants studied word lists with varying repetition (strength) and underwent tests manipulating strength at retrieval.

Main Results:

• The SBME was observed, with lower drift rates for lures on strong tests compared to weak tests.
• This effect persisted even when memory strength was manipulated solely at retrieval.
• Results indicated that decision processes, not memory differentiation, drove the SBME.

Conclusions:

• The findings support the drift criterion account of the SBME.
• Memory strength influences decision-making at retrieval, rather than solely enhancing memory trace distinctiveness.
• The SBME is primarily a phenomenon of response bias influenced by retrieval conditions.