The Impact of the fMRI Environment on Cognitive Function: A Visual Working Memory Study
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The environment within an fMRI scanner can be intimidating, featuring characteristics such as extreme noise levels, postural constraints, and claustrophobic conditions. It is likely that these external pressures can have a detrimental affect of cognition. We used a change detection task to investigate the impact that these stressors may have on Visual Working Memory (VWM) performance. 24 Participants completed the change detection task, once in a normal laboratory setting, and once in an fMRI simulator, which emulated an actual fMRI scanner in all dimensions, and played a recording of the Echo-Planar Imaging (EPI) gradient at 80db. Analysis of correct responses comparing both environments was approaching significance, and trends in the data suggest that the fMRI environment does have an impact on performance. Improvements to the fMRI process are discussed. In addition, the change detection task was designed to offer an insight into the workings of VWM, with the aim of determining whether complex objects are stored as separate features held together in working memory, or if they are stored as one bound representation. We found a significant effect of condition, indicating that complex objects are held as one bound representation in memory. Our results support the Object Unit Hypothesis (Luck and Vogel, 1997), and also suggest that high levels of attention are not necessary to hold features together in VWM, as the stressors of the fMRI environment are assumed to act as an intense external distracter.