Fast mapping

In cognitive psychology, fast mapping is the term used for the hypothesized mental process whereby a new concept is learned (or a new hypothesis formed) based only on minimal exposure to a given unit of information (e.g., one exposure to a word in an informative context where its referent is present). Fast mapping is thought by some researchers to be particularly important during language acquisition in young children, and may serve (at least in part) to explain the prodigious rate at which children gain vocabulary. In order to successfully use the fast mapping process, a child must possess the ability to use 'referent selection' and 'referent retention' of a novel word. There is evidence that this can be done by children as young as two years old, even with the constraints of minimal time and several distractors. Previous research in fast mapping has also shown that children are able to retain a newly learned word for a substantial amount of time after they are subjected to the word for the first time (Carey and Bartlett, 1978). Further research by Markson and Bloom (1997), showed that children can remember a novel word a week after it was presented to them even with only one exposure to the novel word. While children have also displayed the ability to have equal recall for other types of information, such as novel facts, their ability to extend the information seems to be unique to novel words. This suggests that fast mapping is a specified mechanism for word learning. The process was first formally articulated and the term 'fast mapping' coined by Harvard researchers Susan Carey and Elsa Bartlett in 1978. In cognitive psychology, fast mapping is the term used for the hypothesized mental process whereby a new concept is learned (or a new hypothesis formed) based only on minimal exposure to a given unit of information (e.g., one exposure to a word in an informative context where its referent is present). Fast mapping is thought by some researchers to be particularly important during language acquisition in young children, and may serve (at least in part) to explain the prodigious rate at which children gain vocabulary. In order to successfully use the fast mapping process, a child must possess the ability to use 'referent selection' and 'referent retention' of a novel word. There is evidence that this can be done by children as young as two years old, even with the constraints of minimal time and several distractors. Previous research in fast mapping has also shown that children are able to retain a newly learned word for a substantial amount of time after they are subjected to the word for the first time (Carey and Bartlett, 1978). Further research by Markson and Bloom (1997), showed that children can remember a novel word a week after it was presented to them even with only one exposure to the novel word. While children have also displayed the ability to have equal recall for other types of information, such as novel facts, their ability to extend the information seems to be unique to novel words. This suggests that fast mapping is a specified mechanism for word learning. The process was first formally articulated and the term 'fast mapping' coined by Harvard researchers Susan Carey and Elsa Bartlett in 1978. Today, there is evidence to suggest that children do not learn words through 'fast mapping' but rather learn probabilistic, predictive relationships between objects and sounds that develop over time. Evidence for this comes, for example, from children's struggles to understand color words: although infants can distinguish between basic color categories, many sighted children use color words in the same way that blind children do up until the fourth year. Typically, words such as 'blue' and 'yellow' appear in their vocabularies and they produce them in appropriate places in speech, but their application of individual color terms is haphazard and interchangeable. If shown a blue cup and asked its color, typical three-year-olds seem as likely to answer 'red' as 'blue.' These difficulties persist up until around age four, even after hundreds of explicit training trials. The inability for children to understand color stems from the cognitive process of whole object constraint. Whole object constraint is the idea that a child will understand that a novel word represents the entirety of that object. Then, if the child is presented with further novel words, they attach inferred meanings to the object. However, color is the last attribute to be considered because it explains the least about the object itself. Children's behavior clearly indicates that they have knowledge of these words, but this knowledge is far from complete; rather it appears to be predictive, as opposed to all-or-none. An alternate theory of deriving the meaning of newly learned words by young children during language acquisition stems from John Locke's 'associative proposal theory'. Compared to the 'intentional proposal theory', associative proposal theory refers to the deduction of meaning by comparing the novel object to environmental stimuli. A study conducted by Yu & Ballard (2007), introduced cross-situational learning, a method based on Locke's theory. Cross-situtational learning theory is a mechanism in which the child learns meaning of words over multiple exposures in varying contexts in an attempt to eliminate uncertainty of the word's true meaning on an exposure-by-exposure basis. On the other hand, more recent studies suggest that some amount of fast mapping does take place, questioning the validity of previous laboratory studies that aim to show that probabilistic learning does occur. A critique to the theory of fast mapping is how can children connect the meaning of the novel word with the novel word after just one exposure? For example, when showing a child a blue ball and saying the word 'blue' how does the child know that the word blue explains the color of the ball, not the size, or shape? If children learn words by fast mapping than they must use inductive reasoning to understand the meaning associated with the novel word. A popular theory to explain this inductive reasoning is that children apply word-learning constraints to the situation where a novel word is introduced. There are speculations as to why this is; Markman and Wachtel (1988) conducted a study that helps explain the possible underlying principles of fast mapping. They claim children adhere to the theories of whole-object bias, the assumption that a novel label refers to the entire object rather than its parts, color, substance or other properties, and mutual exclusivity bias, the assumption that only one label applies to each object. In their experiment, children were presented with an object that they either were familiar with or was presented with a whole object term. Markman and Watchel concluded that the mere juxtaposition between familiar and novel terms may assist in part term acquisition. In other words, children will put constraints on themselves and assume the novel term refers to the whole object in view rather than to its parts. There have been six lexical constraints proposed (reference, extendibility, object scope, categorical scope, novel name, conventionality) that guide a child's learning of a novel word. When learning a new word children apply these constraints. However, this purposed method of constraints is not flawless. If children use these constraints there are many words that children will never learn such as actions, attributes, and parts. Studies have found that both toddlers and adults were more likely to categorize an object by its shape than its size or color. The next question in fast mapping theory is how exactly is the meaning of the novel word learned? An experiment performed in October 2012 by the Department of Psychology by University of Pennsylvania, researchers attempted to determine if fast mapping occurs via cross-situational learning or by another method, 'Propose but verify'. In cross-situational learning, listeners hear a novel word and store multiple conjectures of what the word could mean based on its situational context. Then after multiple exposures the listener is able to target the meaning of the word by ruling out conjectures. In propose but verify, the learner makes a single conjecture about the meaning of the word after hearing the word used in context. The learner then carries that conjecture forward to be reevaluated and modified for consistency when the word is used again. The results of the experiment seems to support that propose but verify is the way by which learners fast map new words. There is also controversy over whether words learned by fast mapping are retained or forgotten. Previous research has found that generally, children retain a newly learned word for a period of time after learning. In the aforementioned Carey and Bartlett study (1978), children who were taught the word 'chromium' were found to keep the new lexical entry in working memory for several days, illustrating a process of gradual lexical alignment known as 'extended mapping.' Another study, performed by Markson and Bloom (1997), showed that children remembered words up to 1 month after the study was conducted. However, more recent studies have shown that words learned by fast mapping tend to be forgotten over time. In a study conducted by Vlach and Sandhofer (2012), memory supports, which had been included in previous studies, were removed. This removal appeared to result in a low retention of words over time. This is a possible explanation for why previous studies showed high retention of words learned by fast mapping.:46 Some researchers are concerned that experiments testing for fast mapping are produced in artificial settings. They feel that fast mapping doesn't occur as often in more real life, natural situations. They believe that testing for fast mapping should focus more on the actual understanding of a word instead of just its reproduction. For some, testing to see if the child can use the new word in a different situation constitutes true knowledge of a word, rather than simply identifying the new word. When learning novel words, it is believed that early exposure to multiple linguistic systems facilitates the acquisition of new words later in life. This effect was referred to by Kaushanskaya and Marian (2009) as the bilingual advantage. That being said, a bilingual individual's ability to fast map can vary greatly throughout their life. During the language acquisition process, a child may require a greater amount of time to determine a correct referent than a child who is a monolingual speaker. By the time a bilingual child is of school age, they perform equally on naming tasks when compared to monolingual children. By the age of adulthood, bilingual individuals have acquired word-learning strategies believed to be of assistance on fast mapping tasks. One example is speech practice, a strategy where the participant listens and reproduces the word in order to assist in remembering and decrease the likelihood of forgetting .Bilingualism can increase an individual's cognitive abilities and contribute to their success in fast mapping words, even when they are using a nonnative language.