Resource limitations in bimanual pointing.

Performing coordinated bimanual movements, that is, movements with two hands simultaneously, is a requirement in many activities. At the same time, these movements are subject to temporal and spatial constraints. Here, we focus on the constraints that become observable when pointing movements of different (asymmetric) rather than same (symmetric) amplitudes have to be executed ("spatial interference effect"). The respective performance costs are larger when the stimuli used to indicate the movement targets are symbolic compared with when the endpoints of the movements are cued directly. Previous studies have thus concluded that the source of spatial interference is both 'cognitive' and 'motoric', or more precisely occurs during response selection as well as motor programming. We here asked whether the contribution from motor programming is motoric in the sense as envisaged in dual-task models, that is, whether it can run in parallel to, and interference-free with, other processing stages. In two PRP experiments, Task 1 was bimanual pointing and Task 2 was auditory pitch-discrimination. Based on the effect propagation-logic, the results suggest that the motor programming contribution to bimanual interference also taps into capacity-limited resources and cannot be construed as running in parallel as assumed for the motor stage in dual-task models.

Presuppositions of determiners are immediately used to disambiguate utterance meaning: A mouse-tracking study on the German language.

The present study investigated how listeners understand and process the definite and the indefinite determiner. While the definite determiner clearly conveys a uniqueness presupposition, the status of the anti-uniqueness inference associated with the indefinite determiner is less clear. In a forced choice production task, we observed that participants make use of the information about number usually associated with the two determiners to convey a message. In a subsequent mouse-tracking task, participants had to select one of two potential referents presented on screen according to an auditorily presented stimulus sentence. The data revealed that participants use the information about uniqueness or anti-uniqueness encoded in determiners to disambiguate sentence meaning as early as possible, but only when they are exclusively faced with felicitous uses of determiners.

Capacity limitations of processing presuppositions triggered by determiners.

Definite determiners trigger existence- and uniqueness-presuppositions, that is, the speaker assumes that it is taken for granted that there exists exactly one of the mentioned object in the relevant discourse. Indefinite determiners are associated with anti-uniqueness, that is, that there are several of the mentioned object. Applying the Maximize Presupposition principle, this additional meaning component arises as an anti-presupposition and involves first considering the definite determiner's uniqueness-presupposition and then its negation. We here investigate processing of the two determiners in more detail and ask whether this processing is automatic or requires limited central capacities. To do so, we employed the Psychological Refractory Period (PRP) approach and the locus of slack-logic. We observed more difficult processing for the indefinite compared to the definite determiner in felicitous sentences, and also in infelicitous compared to felicitous sentences. Further, immediate processing of the indefinite determiner appears capacity-limited. These results support the Maximize Presupposition principle and are an important step forward toward understanding cognitive processing of presuppositions.

Is Immediate Processing of Presupposition Triggers Automatic or Capacity-Limited? A Combination of the PRP Approach with a Self-Paced Reading Task.

Informally speaking, presuppositions are meaning components which are part of the common ground for speakers in a conversation, that is, background information which is taken for granted by interlocutors. The current literature suggests an immediate processing of presuppositions, starting directly on the word triggering the presupposition. In the present paper, we focused on two presupposition triggers in German, the definite determiner the (German der) and the iterative particle again (German wieder). Experiment 1 replicates the immediate effects which were previously observed in a self-paced reading study. Experiment 2 then investigates whether this immediate processing of presuppositions is automatic or capacity-limited by employing the psychological refractory period approach and the locus of slack-logic, which have been successfully employed for this reason in various fields of cognitive psychology. The results argue against automatic processing, but rather suggest that the immediate processing of presuppositions is capacity-limited. This potentially helps specifying the nature of the involved processes; for example, a memory search for a potential referent.

Pragmatic processing: An investigation of the (anti-)presuppositions of determiners using mouse-tracking.

A presupposition is a condition that has to be met in order for a linguistic expression to be appropriate. The definite determiner (as in the banana) triggers the uniqueness-presupposition that there is a uniquely identifiable banana in the relevant discourse context. The indefinite determiner (as in a banana) is similarly associated with anti-uniqueness (that there are several bananas). Application of the Maximize Presupposition principle to the indefinite determiner suggests that this latter effect results indirectly as an anti-presupposition from considering the uniqueness-presupposition of the definite determiner, which is then negated. This results in increased processing difficulty. We utilized mouse-tracking to compare processing of definite and indefinite determiners when used felicitously and infelicitously in a particular context. First, processing of the indefinite determiner was associated with more processing difficulties compared with the definite determiner. Second, we also observed evidence for an initial temporary activation and evaluation of the uniqueness-presupposition, just as derived from anti-presupposition theory and the Maximize Presupposition principle.