Eyewitness decisions in simultaneous and sequential lineups: a dual-process signal detection theory analysis

Area of Science:

• Cognitive Psychology
• Forensic Psychology
• Eyewitness Identification Research

Background:

• Sequential lineups are often preferred over simultaneous lineups to reduce false identifications.
• Concerns exist that sequential lineups might alter response criteria without enhancing accuracy.

Purpose of the Study:

• To investigate whether sequential lineups improve eyewitness discrimination accuracy or merely shift response criteria.
• To explore the phenomenological basis of criterion shifts in eyewitness identification.

Main Methods:

• Employed signal detection theory to measure eyewitness performance.
• Conducted four experiments manipulating lineup type (simultaneous vs. sequential) and conditions affecting response criteria.
• Utilized the remember-know-guess procedure to assess subjective experience.

Main Results:

• Results supported signal detection theory predictions, indicating a conservative criterion shift with sequential lineups.
• Sequential lineup presentation was associated with reduced familiarity-based responding.
• Simultaneous presentation may facilitate fluency-based processing due to lineup member similarity.

Conclusions:

• Sequential lineups appear to influence response criteria rather than discrimination accuracy.
• The shift in criteria is linked to decreased reliance on familiarity.
• Lineup presentation format impacts cognitive processing during eyewitness identification.