How does the context in which we see something (for example, a word or an object) influence what we see and how accurately and rapidly we see it? In daily experience and in the experimental laboratory, it is clear that context, such as the sentence surrounding a word or the scene in which an object appears, can help or hurt perception, but just how that happens cannot be understood without addressing some basic questions about visual cognition. Is a written word (for example) first identified solely on the basis of the visual information, with the context having its effects as the word's meaning is integrated with the sentence of which it is a part? Or, does the context play a role in determining how fast the word is seen, or even what word is seen? This research will investigate the interaction of context and stimulus information in seeing and remembering words (and sometimes pictures) at four sequential stages in processing a sentence or list. The four stages or levels will be studied using four techniques, each of which is expected, on theoretical grounds, to tap a different stage. The first studies will make use of a phenomenon called "repetition blindness," in which the second of a pair of identical items on a list tends to "disappear" if it arrives very soon after the first one. This disappearance seems to happen at a very early stage of perception of the second item (perhaps within the first 1/20 of a second); the question is whether surrounding context can affect this early stage. The second set of studies will tap a somewhat later stage (perhaps in the first 1/10 of a second) involving selection of one perceived word from several possible words that the glimpsed word might actually be. A frequent effect that happens at this stage involves mistaking a "nonword" like DACK for a real word such as DECK; the studies will look at the influence of sentence context on that effect. A third stage will be studied by presenting two words simultaneously and briefly, in the middle of a sentence, causing the reader to make an immediate choice of the one that fits the context. A successful choice will indicate that the words must have been processed (perhaps unconsciously). At a fourth stage, after the word itself is recognized, its meaning is "tuned" to fit the sentence as a whole. This stage will be studied by investigating involuntary intrusions of substitute words that may fit better in a given context. The significance of the research lies in its role in helping us understand in detail the process of reading and language comprehension, in order to place the teaching of reading and the use of written communication on a rational scientific foundation.
