For theoretical and practical reasons, most accounts of incrementality focus on encoding of the first increment of a message and sentence – i.e., on the selection of a starting point that initiates the mapping of a preverbal message onto language ( Bock et al., 2003 and Bock et al., 2004). Experimental evidence for these accounts comes largely from eye-tracking studies where speakers are asked to describe pictures on a computer screen: the pattern of speakers’ eye movements directed to different parts of the display reveals what they encode with priority at various points in time when preparing
their utterances, providing insight into the online formulation of preverbal messages and their corresponding linguistic descriptions (e.g., Brown-Schmidt and Tanenhaus, 2006, Griffin, 2004, Griffin and Bock, 2000 and Meyer and Lethaus, 2004). In the case of sentences describing Veliparib cell line coherent pictured events (e.g., a dog chasing a mailman), starting points may be selected on the basis of different types of information. One way of selecting a starting point is to quickly identify a salient character and encode it as the Akt inhibitor first character of the sentence (i.e., the grammatical subject in English). The
strongest support for this proposal comes from studies showing that the perceptual salience of a character is sufficient to anchor this character as a starting point. For example, Gleitman et al. (2007) presented subliminal cues
in the location of a character in an upcoming pictured event and showed increased production of descriptions with the cued character in subject position. Importantly, the cues directed speakers’ gaze to this character within 200 ms of picture onset and speakers continued fixating this character preferentially until speech onset (approximately 2 s later). This pattern of eye movements supports two conclusions: it suggests that the timing of visual uptake of information in a scene can control the order of encoding operations (the character that is fixated first is also encoded first) and that the first-fixated character can be assigned to subject position Galeterone without extensive encoding of the second character. As a result, the first increment of the message and sentence may consist only of information specific to one character (non-relational information) and not of information about its role in the event (relational information). The rest of the message and sentence is then built to accommodate production of the cued character in subject position: speakers shift their attention and gaze to the second character only around speech onset and begin adding it to their message and sentence as the sentence object.