After seeing the same images almost every day, such as the letters of the alphabet, the brain will automatically recognize these objects over and over again, and process and understand these images. can be almost instantaneous. However, if the orientation of these images is changed, the brain must undergo additional processing in order to differentiate that it is in fact the same object, but the time required to understand this is much more than an instant. The idea of ​​mental rotation refers to the brain's ability to imagine in one's mind a particular object, oriented in an unusual or uncommon way. The brain can move (or imagine moving) objects in space to assume their correct orientation. A stimulus can be any image present in the environment that is modified in some way; a mental rotation then occurs in order to understand what the modified object is. The first test of these correlations was carried out in 1971 by Shepard and Metzler and has since inspired numerous studies related to this phenomenon. Studies using blind or blindfolded subjects have tested and proven the theory of mental rotation (Carpenter & Eisenberg, 1978). . Carpenter and Eisenberg's study, as well as many other studies that have investigated mental rotation with various variables (such as gender, dominant hand, and intelligence), all essentially measure the effect of mental rotation through the time required for an individual to correctly identify whether or not an object is different, or whether it is simply the orientation that has changed (Silvia et. al., 2013). The way this is typically tested is by asking a subject to compare two objects (which can be 3-dimensional objects, 2-dimensional objects, or just letters from the...... middle of paper.... .corrected with the individual subject's sex or dominant cerebral hemisphere, but it measures the effect of both angle and object type. There will likely be effects of both angle and. of object type on reaction time, due not only to a dissimilarity between the objects and what subjects are accustomed to seeing, but also due to the unfamiliar nature of 2-dimensional random figures. We hypothesized that the more an image is rotated, the longer the reaction time will be due to the additional mental processes that must take place in order to correctly complete object recognition. that angle would overall have a greater impact on two-dimensional images than letters. will overall affect reaction time more significantly.