Certain models of spoken-language processing, like those for many other perceptual and cognitive processes, posit continuous uptake of sensory input and dynamic competition between simultaneously active representations. Here, we provide compelling evidence for this continuity assumption by using a continuous response, hand movements, to track the temporal dynamics of lexical activations during real-time spoken-word recognition in a visual context. By recording the streaming x, y coordinates of continuous goal-directed hand movement in a spoken-language task, online accrual of acoustic-phonetic input and competition between partially active lexical representations are revealed in the shape of the movement trajectories. This hand-movement paradigm allows one to project the internal processing of spoken-word recognition onto a two-dimensional layout of continuous motor output, providing a concrete visualization of the attractor dynamics involved in language processing. dynamical systems ͉ psycholinguistics ͉ word recognition

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Two eye-tracking experiments examined spoken language processing in Russian-English bilinguals. The proportion of looks to objects whose names were phonologically similar to the name of a target object in either the same language (within-language competition), the other language (between-language competition), or both languages at the same time (simultaneous competition) was compared to the proportion of looks in a control condition in which no objects overlapped phonologically with the target. Results support previous findings of parallel activation of lexical items within and between languages, but suggest that the magnitude of the between-language competition effect may vary across first and second languages and may be mediated by a number of factors such as stimuli, language background, and language mode.

Bilingualism provides a unique opportunity for exploring hypotheses about how the human brain encodes language. For example, the "input switch" theory states that bilinguals can deactivate one language module while using the other. A new measure of spoken language comprehension, headband-mounted eyetracking, allows a firm test of this theory. When given spoken instructions to pick up an object, in a monolingual session, late bilinguals looked briefly at a distractor object whose name in the irrelevant language was initially phonetically similar to the spoken word more often than they looked at a control distractor object. This result indicates some overlap between the two languages in bilinguals, and provides support for parallel, interactive accounts of spoken word recognition in general.

It is hypothesized that eye movements are used to coordinate elements of a mental model with elements of the visual field. In two experiments, eye movements were recorded while observers imagined or recalled objects that were not present in the visual display. In both cases, observers spontaneously looked at particular blank regions of space in a systematic fashion, to manipulate and organize spatial relationships between mental and/or retinal images. These results contribute to evidence that interpreting a linguistic description of a visual scene requires a spatial (mental model) representation, and they support claims regarding the allocation of position markers in visual space for the manipulation of visual attention. More broadly, our results point to a concrete embodiment of cognition, in that a construction of a mental image is almost "acted out" by the eye movements, and a mental search of internal memory is accompanied by an ocolumotor search of external space.