directions and navigating. As stated previously this distinction is hard to identify when posed with almost identical definitions, nevertheless there is a distinction. In some uses, mental map refers to a practice done by urban theorists by having city dwellers draw a map, from memory, of their city or the place they live. This allows the theorist to get a sense of which parts of the city or dwelling are more substantial or imaginable. This, in turn, lends itself to a decisive idea of how well urban planning has been conducted. Acquisition of the cognitive maps The cognitive map is generated from a number of sources, both from the visual system and elsewhere. Much of the cognitive map is created through self-generated movement cues. Inputs from senses like vision, proprioception, olfaction, and hearing are all used to deduce a person's location within their environment as they move through it. This allows for path integration, the creation of a vector that represents one's position and direction within one's environment, specifically in comparison to an earlier reference point. This resulting vector can be passed along to the hippocampal place cells where it is interpreted to provide more information about the environment and one's location within the context of the cognitive map. Directional cues and positional landmarks are also used to create the cognitive map. Within directional cues, both explicit cues, like markings on a compass, as well as gradients, like shading or magnetic fields, are used as inputs to create the cognitive map. Directional cues can be used both statically, when a person does not move within his environment while interpreting it, and dynamically, when movement through a gradient is used to provide information about the nature of the surrounding environment. Positional landmarks provide information about the environment by comparing the relative position of specific objects, whereas directional cues give information about the shape of the environment itself. These landmarks are processed by the hippocampus together to provide a graph of the environment through relative locations. Alex Siegel and Sheldon White (1975) proposed a model of acquisition of spatial knowledge based on different levels. The first stage of the process is said to be limited to the landmarks available in a new environment. Then, as a second stage, information about the routes that connect landmarks will be encoded, at the beginning in a non-metric representation form and consequently they will be expanded