Institute of Art Design + Technology
Dún Laoghaire

Clíona Gaffrey Moran 

BSc [Hons] Applied Psychology

I have just completed the BSc [Hons] Applied Psychology at IADT in the practice route of the programme. I am particularly interested in pursuing a career in forensic psychology. I aim to complete postgraduate studies in forensic psychology and to gain experience working and researching in the field of forensic mental health, with the goal of becoming a forensic psychologist in the future. My main areas of interest are trauma, psychopathologies, substance use disorders, offender rehabilitation and issues related to family, children, and the law.

Project Overview

My final year project was based on eyewitness memory. Many factors are researched for their potential impact on eyewitness memory and its reliability. Substances that may affect an individual’s memory are included in research on eyewitness memory. Despite regular consumption of caffeine for its simulant effects, current knowledge on caffeine and memory is limited, particularly on eyewitness memory. My study aimed to investigate caffeine’s effects on quality and accuracy of eyewitness memory recall. An experiment was conducted where participants consumed different caffeinated drinks. They viewed a mock crime video of a staged theft and answered questions about the video and to identify the culprit in the video. This data was then analysed to test for caffeine’s effects on eyewitness memory.

Project Description

My project was titled ‘Experimental Investigation of the Effects of Caffeine Consumption on Eyewitness Memory’. The main objective of this study was to address the gaps in the literature on substance effects on eyewitness memory, particularly stimulants such as caffeine. This study aimed to conduct an experiment based on previous studies on substance effects on eyewitness memory to answer the following research question: Does caffeine affect eyewitness memory recall and if so, will it increase the accuracy and quality of eyewitness memory? This study hypothesised that caffeine consumption would affect eyewitness memory quality and line-up identification accuracy. An experimental design with conveniently sampled participants was utilised. Participants consumed beverages with three caffeine levels (none, 32mg or 150mg). One hour after consuming their drink, participants viewed the mock crime video of the staged theft in a bar. Thirty minutes after viewing the video they answered questions about the video and were asked to identify the culprit in the video in a line-up document. The questionnaires and measures were constructed based on previous eyewitness memory experimental research to measure participants’ eyewitness memory recall accuracy, quality of memory and line-up identification accuracy. A caffeine consumption questionnaire was also given to participants to measure their regular caffeine consumption. Data of 95 participants were statistically analysed to investigate the accuracy and quality of eyewitness memory recall based on caffeine consumption, while accounting for regular caffeine consumption.

Project Findings

Overall, results indicated caffeine consumption did not significantly affect eyewitness memory quality or accuracy. There were no differences based on drink consumed and accuracy or quality of memory. Overall, the quality of participants’ eyewitness memory was poor. These findings contradicted findings of previous research and caffeine’s expected stimulant and cognitive enhancing effects. Unexpectedly, a confidence-accuracy effect did occur with the line-up identification. Participants who rated themselves more confidently in identifying the right culprit were more accurate in their identification. This research expanded on previous experimental research on substances and eyewitness memory, particularly addressing a gap on caffeine’s effects, which was not previously experimented. A strength of this study was the experimental control and measures adapted from previous experiments. Overall, this study indicated caffeine consumption does not affect eyewitness memory accuracy, quality, or reliability. Practical implications indicated consuming caffeine consumption does not affect eyewitness accuracy, its reliability or increase the likelihood of remembering an event. However, a limitation of this study was dosage of caffeine administered to participants, suggesting need for future experimental research using higher caffeine dosages. This study can be applied to future experimental research on caffeine, particularly on its cognitive effects and memory applications. These findings can be applied to eyewitness memory recall settings where its accuracy and reliability is questioned based on stimulant consumption. This study contributes to gaps in psychopharmacological research on forensic proceedings.