TY - JOUR A1 - Beim Graben, Peter A1 - Frisch, Stefan T1 - Is it positive or negative? On determining ERP components N2 - In most experiments using event-related brain potentials (ERPs), there is a straightforward way to define-on theoretical grounds-which of the conditions tested is the experimental condition and which is the control condition. It, however, theoretical assumptions do not give sufficient and unambiguous information to decide this question, then the interpretation of an ERP effect becomes difficult, especially if one takes into account that certain effects can be both a positivity or a negativity on the basis of the morphology of the pattern as well as with respect to peak latency (regard for example, N400 and P345). Exemplified with an ERP experiment on language processing, we present such a critical case and offer a possible solution on the basis of nonlinear data analysis. We show that a generalized polarity histogram, the word statistics of symbolic dynamics, is in principle able to distinguish negative going ERP components from positive ones when an appropriate encoding strategy, the half wave encoding is employed. We propose statistical criteria which allow to determine ERP components on purely methodological grounds Y1 - 2004 SN - 0018-9294 ER - TY - JOUR A1 - Beim Graben, Peter A1 - Jurish, B. A1 - Saddy, Douglas A1 - Frisch, Stefan T1 - Language processing by dynamical systems N2 - We describe a part of the stimulus sentences of a German language processing ERP experiment using a context- free grammar and represent different processing preferences by its unambiguous partitions. The processing is modeled by deterministic pushdown automata. Using a theorem proven by Moore, we map these automata onto discrete time dynamical systems acting at the unit square, where the processing preferences are represented by a control parameter. The actual states of the automata are rectangles lying in the unit square that can be interpreted as cylinder sets in the context of symbolic dynamics theory. We show that applying a wrong processing preference to a certain input string leads to an unwanted invariant set in the parsers dynamics. Then, syntactic reanalysis and repair can be modeled by a switching of the control parameter - in analogy to phase transitions observed in brain dynamics. We argue that ERP components are indicators of these bifurcations and propose an ERP-like measure of the parsing model Y1 - 2004 SN - 0218-1274 ER - TY - JOUR A1 - Frisch, Stefan A1 - Beim Graben, Peter A1 - Schlesewsky, Matthias T1 - Parallelizing grammatical functions : P600 and P345 reflect different cost of reanalysis N2 - It is well-known from psycholinguistic literature that the human language processing system exhibits preferences when sentence constituents are ambiguous with respect to their grammatical function. Generally, many theories assume that an interpretation towards the subject is preferred in such cases. Later disambiguations which contradict such a preference induce enhanced processing difficulty (i.e. reanalysis) which reflects itself in late positive deflections (P345/P600) in event-related brain potentials (ERPs). In the case of phoric elements such as pronouns, a second strategy is known according to which an ambiguous pronoun preferentially receives the grammatical function that its antecedent has (parallel function strategy). In an ERP study, we show that this strategy can in principle override the general subject preference strategy (known for both pronominal and nonpronominal constituents) and induce an object preference, in case that the pronoun's antecedent is itself an object. Interestingly, the revision of a subject preference leads to a P600 component, whereas the revision of an object preference induces an earlier positivity (P345). In order to show that the latter component is indeed a positivity and not an N400-like negativity in the same time range, we apply an additional analysis based on symbolic dynamics which allows to determine the polarity of an ERP effect on purely methodological grounds. With respect to the two positivities, we argue that the latency differences reflect qualitative differences in the reanalysis processes Y1 - 2004 SN - 0218-1274 ER - TY - JOUR A1 - Saddy, Douglas A1 - Drenhaus, Heiner A1 - Frisch, Stefan T1 - Processing polarity items : Contrastive licensing costs N2 - We describe an experiment that investigated the failure to license polarity items in German using event-related brain potentials (ERPs). The results reveal distinct processing reflexes associated with failure to license positive polarity items in comparison to failure to license negative polarity items. Failure to license both negative and positive polarity items elicited an N400 component reflecting semantic integration cost. Failure to license positive polarity items, however, also elicited a P600 component. The additional P600 in the positive polarity violations may reflect higher processing complexity associated with a negative operator. This difference between the two types of violation suggests that the processing of negative and positive polarity items does not involve identical mechanisms. (C) 2003 Elsevier Inc. All rights reserved Y1 - 2004 SN - 0093-934X ER - TY - JOUR A1 - Frisch, Stefan A1 - Hahne, A. A1 - Friederici, A. D. T1 - Word category and verb-argument structure information in the dynamics of parsing N2 - One of the core issues in psycholinguistic research concerns the relationship between word category information and verb-argument structure (e.g. transitivity) information of verbs in the process of sentence parsing. In two experiments (visual versus auditory presentation) using event-related brain potentials (ERPs), we addressed this question by presenting sentences in which the critical word simultaneously realized both a word category and a transitivity violation. ERPs for sentences with both types of violation clustered with the patterns for sentences with a word category violation only, but were different from the patterns elicited by argument structure violations in isolation, since only the latter elicited an N400 ERP component. The finding that an argument structure violation evoked an N400 only if the phrase structure of the respective sentence was correct suggests that a successful integration of the word category information of a verb functionally precedes the application of its argument structure information. (C) 2003 Elsevier B.V. All rights reserved Y1 - 2004 SN - 0010-0277 ER -