The Effect of Sleep Deprivation on Visual Short-Term Memory Capacity and Resolution

Abstract

Visual short-term memory is a field of psychology and neuroscience riddled with opposing viewpoints due to conflicting neural and behavioral data. While most research converges on the existence of a limited storage capacity in visual short-term memory, the data tend to leave us asking what exactly these limitations are. As we understand that these limitations can significantly affect our cognitive abilities, the present study expands on the literature by examining the effect of 22 ± 2 hours of total sleep deprivation on the capacity and resolution components of visual short-term memory compared to a wellrested state. This study called for the use a short-term recall paradigm—in which subjects were asked to use a color wheel to report the color of a probed square from arrays of different set sizes—to measure the parameters that we used to calculate memory capacity and resolution. Our findings confirmed Chee & Chuah’s (2007) results that memory capacity was significantly affected by sleep deprivation. Additionally, this study produced data demonstrating a significant effect of set size on VSTM resolution, which is consistent with what was put forth by Zhang & Luck (2008). Most importantly perhaps, this thesis adds novel information to the field by suggesting weak evidence for an effect of sleep deprivation on VSTM resolution (p = 0.06). With the present data, this thesis is able to resolve the controversy regarding whether or not memory capacity is affected by sleep deprivation, as well as open a discourse regarding the effect of sleep deprivation on memory resolution. Finally, this thesis provides a comprehensive review of the current literature on representation of visual short-term memory in the brain. Keywords: visual short-term memory, sleep deprivation, capacity, resolution