Mental imagery and cognitive maps are both very important cognitive process that are used by almost every human on a daily basis. As top-down processes, they both do not require sensory perception; however, they both activate the parts of the human brain that are also used during bottom-down processing. Both processes are currently under research, as scientists have not yet developed a clear picture about the processes involved in storing and alteration of mental images, as well as formation and perception of cognitive maps.
Mental imagery is “the mental representation of stimuli when those stimuli are not physically present” (Matlin 203). In other words, mental images represent what a human brain perceives the stimuli to be like, when such stimuli are absent. Humans use them every day, when remembering the faces of people, the sounds and smells that are not present. The most common and, thus, the most studied images are visual, while images deriving from stimulation of other senses are less common (Matlin 203). Currently, the biggest controversy in the study of mental images is whether they are stored in an analog code or in a propositional code, with the first one being a process of storing perceived images and the second one being a description of an image in a language form, while the language being different from any other known languages (Matlin 205). However, the analysis of researches and experiments shows that both codes are used in storing and processing of different types of images. Thus, researches on rotation of mental images have shown that the time of rotation depended on the complexity and angle of rotation, and such correlation is similar with rotation of an actual physical object (Matlin 207). Moreover, the parts of brain activated during the process of rotation of a mental image correspond with the ones that are active during rotation of the actual object (Matlin 222). The same results were derived from the research of the correlation between the distance between the objects in the mental image and the time it took the participants of the research to scan them, thus, proving that the analog code is also used during such mental image processing (Matlin 209). However, when studying the relation between mental imagery and the shape of an image, the researchers concluded that images with simple shapes used the analog code, while images with ambiguous shapes, their processing and alteration required the more complex propositional code (Matlin 215). Mental imagery and physical stimulus can interfere in the processing of each other by the brain if they use the same brain parts; for example, if a person creates a mental image of a visual stimulus and is presented with a different physical stimulus at the same time, such person will experience problem in detecting a physical stimulus because of the impossibility of simultaneous use of the same brain part for the processing of an image and a stimulus (Matlin 211). The same problem occurs with auditory and motor imagery. In general, the researchers conclude that mental imagery resembles visual perception and does not differ depending on gender, except for mental rotation, where men have shown lesser response time than women (Matlin 219).
Cognitive maps represent the surrounding environment and help a person in everyday life to receive, follow and give directions. Just like mental imagery, cognitive maps are considered to use both analog and propositional codes, as people usually not only evoke images of places, but also have a language-like description of them, their location and surroundings (Matlin 225). Moreover, people also use knowledge received from studying maps and other materials to create an image of a place and its location. Researches have shown that people tend to simplify and systemize their cognitive maps, but these processes have their drawbacks, mainly affecting the accuracy of the maps. The distortions caused by the aforesaid processes affect the perception of distance, shape and relative position of objects (Matlin 226). According to the studies, the distance between two objects usually seems longer if there are many other objects between them, as well as if the road between them is curvy (Matlin 226). Estimation of distance between two objects is also affected by semantic clusters the two objects belong to. If they are in the same semantic cluster, they are usually perceived to be closer to each other, than if they are in different clusters; for example, governmental buildings are more likely to be thought to lie closer to each other than one of them being closer to a shop or a bar (Matlin 227). Finally, the distance to an important location seems smaller than to a less important one, an effect also known as the landmark effect (Matlin 227). A number of heuristics are usually used by a person when interpreting angles, curves and relative positions of objects on cognitive maps. Thus, the 90-degree-angle heuristic is applied even to angles that are a lot less than 90 degree; the symmetry heuristic creates a bias about the curves on a map making them more symmetrical and regular; the rotation heuristic makes tilted lines, including borders, look more vertical or horizontal on the cognitive map; the alignment heuristic makes objects seem situated on one line, when they, in fact, are not aligned (Matlin 228; 229; 230). According to the research by Franklin and Tversky, when analyzing the cognitive map constructed through verbal description, the above-below dimension is the most important for people, the front-back is a less important more, and the right-left is the least important one (Matlin 233).
Both phenomena are equally important in the daily life of a human, as they are exploited during very simple tasks, such as trying to remember the image of a place or a person and to find a way to a place of destination. Both phenomena employ top-down processes and use analog and propositional codes. Understanding cognitive maps, in particular, is very important in many disciplines, including geography and topography, as specialists in these spheres need to understand the peculiarities of human cognition to develop maps and directions.
Matlin, Margaret W. Cognition. 7th ed. Hoboken, NJ: Wiley, 2009. Print.