The influence of synchrony/asynchrony effect on eyewitness memory performance

Abstract

Introduction/Objectives: People can be classified according to their chronotype, which is their individual preference to develop certain activities at the time-of-day in which the peak of physical and mental activity is reached. There are three main types of chronotype: morning-, evening- and neither-type. Research so far has suggested that the synchrony between time-of-day and chronotype could potentially result in better performance and productivity. On the other hand, asynchrony with our internal rhythms could cause negative effects, such as decline in cognitive performance.This study aimed to analyse a possible interaction between chronotype (morning type/evening-type) and time-of-day (morning/end of day) and how this interaction could influence the eyewitness’s memory performance. Methods: To this end, 44 participants (24 evening-types and 20 morning-types) performed two memory tasks that took place in two online sessions, at different times of the day: one in the morning (optimal time-of-day for morning-types and non-optimal for evening-types) and another at the end of the day (optimal time-of-day for evening-types and non-optimal for morning-types). In each session (interval between sessions of one week), it was requested to each participant to visualise two videos, one of a crime scene and another of a neutral situation, answer questions related to the videos and complete questionnaires to collect additional variables that influence memory (e.g., stress, depression and anxiety). The order of the sessions (synchrony/asynchrony) and the presentation of the videos were counterbalanced across participants. Results: In general, the results indicated that the participant’s memory performance was better in the synchrony moment when compared to the asynchrony moment. In the crime videos it was found a statistically significant difference between synchrony (M=11.27, DP=3.42) and asynchrony (M=9.52, DP=3.20) moments in the central details correctly recalled (p=.006) and in the neutral videos was shown a statistically significant difference in peripheral details correctly recalled (synchrony: M=8.09, DP=3.75, asynchrony: M=6.16, DP=2.25; p=.003). It was also found that the type of chronotype did not influence the obtained results, which means that what explains the differences is just the fact that the chronotype is in synchrony or asynchrony. Finally, it was also found an influence of stress, anxiety and depression, more pronounced in neutral videos. Conclusions: These results allowed to improve knowledge about the influence that the synchronization between the time of day and the chronobiological rhythm can have on eyewitness memory performance. This study also could have important implications to research and to interrogation practices.