Isolating the effects of visual imagery on prospective memory.

Two experiments investigated the role of visual imagery in prospective memory (PM). In experiment 1, 140 participants completed a general knowledge quiz which included a PM task of writing a letter "X" next to any questions that referred to space. Participants either visualised themselves performing this task, verbalised an implementation intention about the task, did both, or did neither. Performance on the PM task was enhanced in both conditions involving visual imagery but not by implementation intentions alone. In experiment 2, 120 participants imagined themselves writing a letter "X" next to questions about space, or in a bizarre imagery condition imagined themselves drawing an alien next to those questions. Relative to the control condition, PM was significantly enhanced when participants imagined writing a letter "X" next to the target questions, but not by the bizarre imagery task. The findings indicate that the robust effects of imagery observed in retrospective memory also extend to PM.

Eyewitness memory: The impact of a negative mood during encoding and/or retrieval upon recall of a non-emotive event.

The police often appeal for eyewitnesses to events that were unlikely to have been emotive when observed. An eyewitness, however, may be in a negative mood whilst encoding or retrieving such events as mood can be influenced by a range of personal, social, and environmental factors. For example, bad weather can induce a negative mood. This experiment compared the impact of negative and neutral moods during encoding and/or retrieval upon eyewitness recall of a non-emotive event. A negative mood during encoding had no impact upon the number of correct details recalled (provided participants were in a neutral mood at retrieval) but a negative mood during retrieval impaired the number of correct details recalled (provided participants were in a neutral mood at encoding). A negative mood at both time points enhanced the number of correct details recalled, demonstrating a mood-dependent memory enhancement. The forensic implications of these findings are discussed.