Real-World Processing of Word-Referent Pairs in Adults

The process of pairing words with their referents in the real world is often ambiguous; the same word may refer to different objects, the same object may be referred to by different words, and there may just be insufficient environmental cues to assist us in the process. Thus, how is it that adults are able to go about this, particularly when the word-referent pairings are not constant? Three different experiments were completed which tested the ability of adults to pair up novel words and shapes after being exposed to a learning phase where the words referred to the correct object either 50% or 75% of the time, in order to simulate the ambiguity of real-world referents and determine to what extent that ambiguity impairs their ability to correctly match them. The results showed that although all adults were able to determine word boundaries within the stream of speech, the difference in ability between the two conditions on pairing the words with their referents was not significantly different. Word-Referent Pairing 3 Real-World processing of Word-Referent Pairs in Adults In our daily lives, we are constantly matching up words with their referents in order to better understand our world. This word-referent pairing, however, is not a simple task; sometimes one word may refer to multiple objects (e.g. “ball” might mean baseball or soccer ball), an object might be able to be defined by multiple words (e.g. the device you use to turn on a television might be called a remote control or a clicker), and sometimes the object in reference is not even present (e.g. it is in the next room). These are just a few of the difficulties that arise in matching up words with objects as we go about our lives. Because the process of word-referent pairing is so difficult and often ambiguous, how is it that we do it so easily on a daily basis without even a second thought? Developmental psychologists have looked into this question with the idea that understanding how the process occurs in infants may give us insight into how we go about matching up words with referents so easily as adults. In the process of language learning in infants, it is first required that words are able to be parsed from a stream of speech. Multiple theories have been thrown around about how this process works, and whether or not the parsing of words from sentences is based on experience. Crain (1991) suggested that language tasks such as determining word boundaries are not experience-driven due to the fact that the language that infants are exposed to is often incomplete, grammatically incorrect, or skewed from what normal speech sounds like due to the infant-directed nature of talking to children. Others, Word-Referent Pairing 4 however, have argued that experience may be more pertinent in language learning than previously assumed. Saffran, Aslin, and Newport (1996) argued for the idea that word boundaries are defined by being repeatedly exposed to speech such that statistical regularities arise. They found that upon giving infants a stream of nonsense speech comprised of novel words, 8-month-olds were able to differentiate between words and part-words during the test trials by utilizing the transitional probabilities that arose during habituation; syllables that comprised a word had a transitional probability of 1.0, whereas the probability between words was 0.33 (Saffran et. al., 1996), which infants were able to pick up on as determined by their looking times. Thus, it can be assumed from this research that infants first learn to parse words in a sentence by utilizing probabilities, which is an experience-driven process. Now that it has been shown that infants are able to determine word boundaries, we can extend this further by asking how infants use these words to refer to an object. One study relating to determining word-object pairs was conducted by Gogate and Bahrick (1998). In this study, 7-month-old infants were presented with objects on the screen, and each object had an arbitrary vowel that was spoken in tandem with it. The conditions were defined by either a moving object or a static object, with the vowels being either synchronous or asynchronous with the object. The results indicated that infants were best able to detect word-object pairings during the moving-synchronous condition, which is the condition that can be defined by the most redundancy. Thus, it can be Word-Referent Pairing 5 implied that intermodal redundancy helps to make word-object relationships more salient and allows infants of this age to be capable of knowing what word (or vowel, in this case) refers to which object. Other studies have had similar findings, stating that presentation of stimuli using an intermodal approach is pertinent (Kuhl and Meltzoff, 1984; Bahrick, 1994; MacKain et. al. 1983) and synchrony between the auditory and visual stimuli enables the pairings to be made (Lyons-Ruth, 1977). The above research has shown that infants are capable of determining word boundaries and finding word-object relations, but how does this apply to adults? Studies have shown that like infants, adults have a better performance rate when bimodal rather than unimodal cues are used and when redundancy is present as well, particularly in word-object relation tasks (Miller, 1982), but applicable to spatial localization tasks also (Neil et. al., 2006). Another, more recent adult study conducted by Yu and Smith (2007) looked at the ability of adults to pair up multiple spoken words with multiple pictures over various trials. Participants were not given specific instructions to learn the word-objects pairs, but rather were just presented with both stimuli simultaneously. Despite this fact, results showed that participants were still able to match up the word-referent pairs accurately. It was also found that participants learned the word-referent pairs better when there are more pairs to be learned, indicating that the size of the data set is more important than the number of repetitions of the wordreferent pairs, which is an important factor to keep in mind. Word-Referent Pairing 6 All of the previously discussed studies have shown that both infants and adults are successful at matching up words with their referents when the two are matched up 100% of the time. However, in the real world, words often do not refer to the same object all the time, which is an important factor to take in consideration when trying to generalize. Thus, the current study asks the question of just how good adults are at matching up words with their referents when they are not paired together 100% of the time. Two different conditions (50% matched and 75% matched) were used to determine if a threshold exists where individuals are no longer able to match the words with their correct referents past a certain point. Since it has already been shown that individuals can match up words and referents when they are paired all the time, it is hypothesized in this study that participants will be significantly more accurate at pairing in the 75% condition compared to the 50% condition, suggesting that the threshold for word-referent pairing exists between the two percentages.