a word such as "car", might cause people to unconsciously think of an associative such as "truck". If the word truck is later presented to them, they may state they recognize seeing the item when they had actually generated it themselves. It is believed that the activation from the shown word may also activate the associative word, allowing the information to be easily accessible to the mind. Research has also shown that the more similar the presented and associative words are, or the more similar list items there are, the more likely it is that a false recognition error will be made. Gist-based similarity, the robust encoding of semantic information rather than distinctive encoding, is another cause of false recognition. When studying a list of numerous related words, there is a high level of semantic overlap between memory items. The inability to keep each concepts separate and distinct from one another makes it difficult to recollect specific details, subsequently causing people to make responses based on memory gist's rather than specific details. People may form a well-organized idea of what the semantic gist is, and anything that is semantically similar to that idea may be falsely recognized. Gist-based similarity has also been shown to occur in circumstances in which implicit associative responses are an unlikely source of misattribution. The false recognition error also becomes evident when a time pressure is presented during a recognition decision. Processes that work to discover a source for the basis of recognition take time to execute, as a result of a lack of time, false recognitions errors are made more often. Fuzzy-trace theory, an opposing theory to source monitoring error, stipulates that memories are composed of two components; gist and verbatim traces. Verbatim traces are the surface details of physical stimuli, which encompass the clear visual images and source information of an experience. Though both traces are encoded simultaneously, they are stored in separate regions of the brain, allowing for each trace to posse a distinct lifespan. Verbatim traces, though readily available when a memory is first encoded, deteriorate quickly. Fuzzy-trace theory thus proposes that misattributed memories arise due to the short lifespan of verbatim traces, being that the quality of source information is rapidly declining. The misattribution of memory is therefore more likely to occur as the time between the encoding of an experience and the recall of the subsequent memory increases. It has