Lena Jäger wins best dissertation award for 2015 from the University of Potsdam

Felix Engelmann graduates (PhD) with a summa cum laude

Call for Proposals ESSLLI 2017

Call for Course and Workshop Proposals

29th European Summer School in Logic, Language and Information - ESSLLI 2017
17-28 July, 2017, Toulouse, France
https://www.irit.fr/esslli2017

IMPORTANT DATES

 15 July 2016: Proposal submission deadline
 30 September 2016: Notification

SUBMISSION PORTAL
Please submit your proposals here:

https://easychair.org/conferences/?conf=esslli2017


TOPICS AND FORMAT

Proposals for courses and workshops at ESSLLI 2017 are invited in all areas of Logic, Linguistics and Computing Sciences. Cross-disciplinary and innovative topics are particularly encouraged.

Each course and workshop will consist of five 90 minute sessions, offered daily (Monday-Friday) in a single week. Proposals for two-week courses should be structured and submitted as two independent one-week courses, e.g. as an introductory course followed by an advanced one. In such cases, the ESSLLI programme committee reserves the right to accept just one of the two proposals.

All instructional and organizational work at ESSLLI is performed completely on a voluntary basis, so as to keep participation fees to a minimum. However, organizers and instructors have their registration fees waived, and are reimbursed for travel and accommodation expenses up to a level to be determined and communicated with the proposal notification. ESSLLI can only guarantee reimbursement for at most one course/workshop organizer, and can not guarantee full reimbursement of travel costs for lecturers or organizers from outside of Europe. The ESSLLI organizers would appreciate any help in controlling the School's expenses by seeking complete coverage of travel and accommodation expenses from other sources.

The organizers want to point at the possibility of an EACSL sponsorship, mentioned at the end of this call.

CATEGORIES

Each proposal should fall under one of the following categories.

* FOUNDATIONAL COURSES *
Such courses are designed to present the basics of a research area, to people with no prior knowledge in that area. They should be of elementary level, without prerequisites in the course's topic, though possibly assuming a level of general scientific maturity in the relevant discipline. They should enable researchers from related disciplines to develop a level of comfort with the fundamental concepts and techniques of the course's topic, thereby contributing to the interdisciplinary nature of our research community.

* INTRODUCTORY COURSES *
Introductory courses are central to ESSLLI's mission. They are intended to introduce a research field to students, young researchers, and other non-specialists, and to foster a sound understanding of its basic methods and techniques. Such courses should enable researchers from related disciplines to develop some comfort and competence in the topic considered. Introductory courses in a cross-disciplinary area may presuppose general knowledge of the related disciplines.

* ADVANCED COURSES *
Advanced courses are targeted primarily to graduate students who wish to acquire a level of comfort and understanding in the current research of a field.

* WORKSHOPS *
Workshops focus on specialized topics, usually of current interest. Workshops organizers are responsible for soliciting papers and selecting the workshop programme. They are also responsible for publishing proceedings if they decide to have proceedings.

PROPOSAL GUIDELINES

Course and workshop proposals should follow closely the following guidelines to ensure full consideration.

Each course proposal can be submitted by no more than two instructors, and each workshop by no more than two organizers. All instructors and organizers must possess a PhD or equivalent degree by the submission deadline.

Course proposals should mention explicitly the intended course category. Proposals for introductory courses should indicate the intended level, for example as it relates to standard textbooks and monographs in the area. Proposals for advanced courses should specify the prerequisites in detail.

Proposals must be submitted in PDF format via:

https://easychair.org/conferences/?conf=esslli2017

and include all of the following:

a. Personal information for each proposer: Name, affiliation, contact
   address, email, homepage (optional)

b. General proposal information: Title, category

c. Contents information:
   Abstract of up to 150 words
   Motivation and description (up to two pages)
   Tentative outline
   Expected level and prerequisites
   Appropriate references (e.g. textbooks, monographs, proceedings, surveys)

d. Practical information:
   Relevant preceding meetings and events, if applicable
   Potential external funding for participants

EACSL SPONSORSHIP

The EACSL offers to act as a sponsor for one course or workshop in the areas of Logic and Computation covered by the Computer Science Logic (CSL) conferences. This course or workshop will be designated an EACSL course/workshop. If you wish to be considered for this, please indicate so on your proposal.

PROGRAMME COMMITTEE

Chair:
        Shravan Vasishth, Universitaet Potsdam
Local co-chair:
        Philippe Balbiani, IRIT, Toulouse
Language and Computation:
        Sebastian Pado, Universitaet Stuttgart
        Mehrnoosh Sadrzadeh, University of London
Language and Logic:
        Denis Bonnay, l’Universite Paris Ouest
        Jessica Rett, UCLA
Logic and Computation:
        Tomer Kotek, Technische Universitaet Wien
        Anna Zamansky, University of Haifa


FURTHER INFORMATION:
Please send any queries you may have to vasishth dot shravan at gmail dot com

Understanding underspecification: A comparison of two computational implementations (Logacev et al) accepted in: Quarterly Journal of Experimental Psychology

Pavel Logačev and Shravan Vasishth. Understanding underspecification: A comparison of two computational implementations. Quarterly Journal of Experimental Psychology, 2015. Accepted. [ pdf ]

Swets et al. (2008) present evidence that the so-called ambiguity advantage (Traxler et al., 1998), which has been explained in terms of the Unrestricted Race Model, can equally well be explained by assuming underspecification in ambiguous conditions driven by task-demands. Specifically, if comprehension questions require that ambiguities be resolved, the parser tends to make an attachment: when questions are about superficial aspects of the target sentence, readers tend to pursue an underspecification strategy. It is reasonable to assume that individual differences in strategy will play a significant role in the application of such strategies, so that studying average behavior may not be informative. In order to study the predictions of the good-enough processing theory, we implemented two versions of underspecification: the partial specification model (PSM), which is an implementation of the Swets et al. proposal, and a more parsimonious version, the non-specification model (NSM). We evaluate the relative fit of these two kinds of underspecification to Swets et al.’s data; as a baseline, we also fit three models that assume no underspecification. We find that a model without unspecification pro- vides a somewhat better fit than both underspecification models, while the NSM model provides a better fit than the PSM. We interpret the results as lack of unambiguous evidence in favor of underspecification; however, given that there is considerable existing evidence for good-enough processing in the literature, it is reasonable to assume that some underspecification might occur. Under this assumption, the results can be interpreted as tentative ev- idence for NSM over PSM. More generally, our work provides a method for choosing between models of real-time processes in sentence comprehension that make qualitative predictions about the relationship between several de- pendent variables. We believe that sentence processing research will greatly benefit from a wider use of such methods.

Congratulations to Lena Jäger for successfully defending her PhD!

Congratulations to Paul Metzner for successfully defending his PhD

Some thoughts after attending a conference in Copenhagen

I just got done with a very nice conference in Copenhagen on grammar vs lexicon.

One thing that struck me afresh about several of the people I spoke to there and the talks I heard there is that scientists feel compelled to hold or stand for a theoretical position. People often design their careers around a position that they hold, and then they proceed to defend it no matter what data comes their way. Doing science is very much like a forecasting problem.  Your job is to come up with a prediction of what will happen if a particular experiment is run.

The way we do science, however, is as follows. We first find out what the experiment showed. Then we make the "prediction" based on our favorite theory.  Researchers routinely use the word prediction even when they already know the outcome of an experiment. If this was a weather forecasting problem, it would be like publishing the probability of rain yesterday. Of course you would get everything right! It is this unfortunate tendency to predict after the fact that people are so confident about their theories and positions. After the fact prediction gives an illusion of being right all the time.

I just read a great review of a book on forecasting by the greatest reviewer I have ever encountered on the web: RK, of RK's musings fame.

He discusses a book, Superforecasters, in which the author lays out the qualities of a good forecaster. I quote from the blog almost verbatim:

• Good back of the envelope calculations
• Starting with outside view that reduces anchoring bias
• Subsequent to outside view, get a grip on the inside view
• Look out for various perspectives about the problem
• Think three/four times, think deeply to root out confirmation bias
• It's not the raw crunching power you have that matters most. It's what you do with it.

And here is another quote from the blog, which itself is a quote from the book:

Unpack the question into components. Distinguish as sharply as you can between the known and unknown and leave no assumptions unscrutinized. Adopt the outside view and put the problem into a comparative perspective that downplays its uniqueness and treats it as a special case of a wider class of phenomena. Then adopt the inside view that plays up the uniqueness of the problem. Also explore the similarities and differences between your views and those of others-and pay special attention to prediction markets and other methods of extracting wisdom from crowds. Synthesize all these different views into a single vision as acute as that of a dragonfly. Finally, express your judgment as precisely as you can, using a finely grained scale of probability.

And finally, RK also excerpts a composite portrait of a good forecaster from the book: 

Scientists in psycholinguistics tend to be the exact opposite of a good forecaster. 

They hunker down and defend to death one position, never never never back down in the face of counterevidence, never entertain multiple alternative theories simultaneously, never express any self-doubt (at least not publicly) that their favorite position might be wrong. Whenever we write papers, we end up converging on what we claim is the most plausible explanation for the result we have found. We never end on an equivocation, because that would mean rejection from the top journal we have submitted our paper to.

If anyone other than me is reading this blog, maybe you should read RK's original review of the book, Superforecasters, and maybe also read the book (I know I will), and then think about what's wrong with the way you are doing science, because it is bass-ackwards. We are terrible forecasters, and there's a damn good reason for it!

ESSLLI 2016 course: Sentence Comprehension as a Cognitive Process: A Computational Approach

Felix Engelmann and I will teach a one-week course at ESSLLI 2016 in Bolzano. I made a preliminary web page for the course, available here.

This is our first step towards writing our book (with the same title as the course), on contract with Cambridge University Press.

New paper (Paape and Vasishth, Lang. and Speech): Local coherence and preemptive digging-in effects in German

Dario Paape's new paper has been accepted for publication by Language and Speech:

Title: Local coherence and preemptive digging-in effects in German
Abstract: SOPARSE (Tabor & Hutchins, 2004) predicts so-called local coherence effects: locally plausible but globally impossible parses of substrings can exert a distracting influence during sentence processing. Additionally, it predicts digging-in effects: the longer the parser stays committed to a particular analysis, the harder it becomes to inhibit that analysis. We investigated the interaction of these two predictions using German sentences. Results from a self-paced reading study show that the processing difficulty caused by a local coherence can be reduced by first allowing the globally correct parse to become entrenched, which supports SOPARSE’s assumptions.
pdf: http://www.ling.uni-potsdam.de/~paape/LCpaper.pdf

New paper: Locality and expectation in separable Persian complex predicates

Here's a new paper by Molood Sadat Safavi, Samar Husain, and Shravan Vasishth, which shows evidence from two self-paced reading studies in Persian against one of the key predictions of the expectation accounts (Hale 2001, Levy 2008).

Title:
Locality and expectation in Persian complex predicates

Abstract:
In sentence comprehension, it is well-known that processing cost increases with dependency distance (Gibson 2000, Lewis and Vasishth 2005); this often referred to as the locality effect. However, the expectation-based account (Hale 2001, Levy 2008) predicts that delaying the appearance of a verb renders it more predictable and therefore easier to process. Following up on previous work (Husain et al 2014), we investigated whether strengthening the expectation can increase facilitation at the verb even further. We operationalize strong expectation as prediction of the lexical entry for the verb; by contrast, weak expectation refers to the prediction of some upcoming verb phrase (these are the cases discussed by Levy 2008). We used Persian for this investigation. This language has a special construction called complex predicates, which are separable Noun-Verb configurations in which the verb (the precise lexical item) is highly predictable given the noun.  In two self-paced reading experiments, we delayed the appearance of the verb by interposing a relative clause (Expt 1, 42 subjects) or a long PP (Expt 2, 40 subjects). As a control, we included a simple predicate (Noun-Verb) configuration; the same distance manipulation was applied here as for complex predicates, but here, the exact lexical entry for the verb is not predicted but rather a verb phrase is predicted. Thus, we had a 2x 2 design, with Expectation Strength (Strong/Weak) and Distance (Short/Long). Based on the Husain et al  study, which had a similar design using Hindi complex predicates, we expected a slowdown in the weak expectation condition (i.e., locality effects), but a facilitation in the strong expectation conditions (i.e., expectation effects). Surprisingly, both experiments showed clear effects of locality in both the strong and weak expectation conditions. We also find evidence that could be consistent with expectation effects: the high-predictable verbs are read faster than the low-predictable verbs. However, this result is difficult to interpret because the verbs used in the strong and weak expectation conditions are different. In sum, these studies show strong and unequivocal evidence in favor of argument-verb dependency distance influencing integration processes at the verb, falsifying a key prediction of the expectation based account of Levy 2008.

New paper (Engelmann, Jäger, Vasishth)

Here is a new paper by Felix Engelmann and Lena Jäger and myself that people interested in sentence comprehension processes may be interested in.

Title:
The determinants of retrieval interference in dependency resolution: Review and computational modeling

Abstract:
We report a comprehensive literature review of retrieval interference in reflexive-antecedent dependencies, number agreement, and non-agreement subject-verb dependencies, and computationally evaluate the predictions of cue-based retrieval theory with reference to published results. A novel finding from the review and modeling is that, contrary to claims in the literature, results on number agreement are not entirely compatible with cue-based retrieval theory. We also show that the cue-based retrieval account in its current form cannot explain several reported interference effects, such as (i) speed-ups observed in presence of a syntactically unlicensed distractor when the correct dependent is a full match to the retrieval cues and (ii) slow-downs when the correct dependent only partially matches the retrieval cues.  We demonstrate that these effects can be explained by two theoretical and independently motivated constructs: distractor prominence and cue confusion. The cue-based retrieval model is therefore extended to incorporate distractor prominence and cue confusion, and quantitative predictions are derived from this extended model. We show that the extended cue-based retrieval model provides a better explanation of published results than the classical retrieval account.

The pdf is here:

http://www.ling.uni-potsdam.de/~engelmann/publications/EngelmannEtAl_JML_subm_150825.doc.pdf

Two new papers from our lab

We have several new papers that have come out recently, both part of Lena Jaeger's dissertation.

Lena A. Jäger, Felix Engelmann, and Shravan Vasishth. Retrieval interference in reflexive processing: Experimental evidence from Mandarin, and computational modeling. Frontiers in Psychology, 6(617), 2015. [ DOI | pdf ]

We conducted two eye-tracking experiments investigating the processing of the Mandarin reflexive ziji in order to tease apart structurally constrained accounts from standard cue-based accounts of memory retrieval. In both experiments, we tested whether structurally inaccessible distractors that fulfill the animacy requirement of ziji influence processing times at the reflexive. In Experiment 1, we manipulated animacy of the antecedent and a structurally inaccessible distractor intervening between the antecedent and the reflexive. In conditions where the accessible antecedent mismatched the animacy cue, we found inhibitory interference whereas in antecedent-match conditions, no effect of the distractor was observed. In Experiment 2, we tested only antecedent-match configurations and manipulated locality of the reflexive-antecedent binding (Mandarin allows non-local binding). Participants were asked to hold three distractors (animate vs. inanimate nouns) in memory while reading the target sentence. We found slower reading times when animate distractors were held in memory (inhibitory interference). Moreover, we replicated the locality effect reported in previous studies. These results are incompatible with structure-based accounts. However, the cue-based ACT-R model of Lewis and Vasishth (2005) cannot explain the observed pattern either. We therefore extend the original ACT-R model and show how this model not only explains the data presented in this article, but is also able to account for previously unexplained patterns in the literature on reflexive processing.

Lena A. Jäger, Lena Benz, Jens Roeser, Brian W. Dillon, and Shravan Vasishth. Teasing apart retrieval and encoding interference in the processing of anaphors. Frontiers in Psychology, 6(506), 2015. [ DOI | http ]

Two classes of account have been proposed to explain the memory processes subserving the processing of reflexive-antecedent dependencies. Structure-based accounts assume that the retrieval of the antecedent is guided by syntactic tree-configurational information without considering other kinds of information such as gender marking in the case of English reflexives. By contrast, unconstrained cue-based retrieval assumes that all available information is used for retrieving the antecedent. Similarity-based interference effects from structurally illicit distractors which match a non-structural retrieval cue have been interpreted as evidence favoring the unconstrained cue-based retrieval account since cue-based retrieval interference from structurally illicit distractors is incompatible with the structure-based account. However, it has been argued that the observed effects do not necessarily reflect interference occurring at the moment of retrieval but might equally well be accounted for by interference occurring already at the stage of encoding or maintaining the antecedent in memory, in which case they cannot be taken as evidence against the structure-based account. We present three experiments (self-paced reading and eye-tracking) on German reflexives and Swedish reflexive and pronominal possessives in which we pit the predictions of encoding interference and cue-based retrieval interference against each other. We could not find any indication that encoding interference affects the processing ease of the reflexive-antecedent dependency formation. Thus, there is no evidence that encoding interference might be the explanation for the interference effects observed in previous work. We therefore conclude that invoking encoding interference may not be a plausible way to reconcile interference effects with a structure-based account of reflexive processing.

PhD positions in Northwestern

The Language and Computation Lab in the Department of Linguistics at Northwestern University, directed by Dr. Klinton Bicknell, is currently looking for Ph.D. students to join the lab. Candidates should have a strong academic background, and especially desirable skills include some experience in computer science and/or math. Interested students should apply to the Ph.D. program in the Department of Linguistics, which admits students to the department as a whole rather than to a specific lab and offers all admitted students competitive five-year funding packages not tied to a specific advisor. International applications are welcome. The department's deadline to receive applications for starting in Fall 2015 is November 30, 2014. Research in the Language and Computation Lab investigates how the human brain solves the computational problems of language comprehension, production, and acquisition. We use techniques from machine learning, computational linguistics, and statistics to build computational models of such language behaviors. We test these models by analyzing large behavioral and neuroscientific datasets, and also by gathering new empirical data, especially via eye tracking and crowdsourcing. For more information on current research, see the lab website at http://lcl.northwestern.edu/. The Department of Linguistics at Northwestern has a wealth of excellent language researchers, as does the university more broadly in the Psychology, Communication Sciences & Disorders, and Electrical Engineering & Computer Science departments. Students are highly encouraged to collaborate both within Linguistics and across departments. Students can also take advantage of the university's location in the dynamic Chicago metro area. Feel free to direct any questions to Klinton at kbicknell a_t northwestern.edu.

Two new papers: Lena Jäger et al (JML), and Logačev et al (Cognitive Science)

Two new papers have been accepted for publication by our PhD students Lena Jäger and Pavel Logačev:

Lena Jäger, Zhong Chen, Qiang Li, Chien-Jer Charles Lin, and Shravan Vasishth. The subject-relative advantage in Chinese: Evidence for expectation-based processing. Journal of Memory and Language, in press. [ DOI | .pdf ]

Chinese relative clauses are an important test case for pitting the predictions of expectation-based accounts against those of memory-based theories. The memory-based accounts predict that object relatives should be easier to process than subject relatives because, in object relatives, less linguistic material intervenes between the head noun and the gap (or verb) that it associates with. By contrast, expectation-based accounts such as surprisal predict that the less frequently occurring object relative should be harder to process than the subject relative, because building a rarer structure is computationally more expensive. Previous studies on Chinese relative clauses have the problem that local ambiguities in subject and object relatives could be confounding the comparison. We compared reading difficulty in subject and object relatives (in both subject- and object-modifications) in which the left context leads the reader to predict a relative clause structure as the most likely continuation; we validate this assumption about what is predicted using production data (a sentence completion study and a corpus analysis). Two reading studies (self-paced reading and eye-tracking) show that the Chinese relative clause evidence is consistent with the predictions of expectation-based accounts but not with those of memory-based theories. We present new evidence that the prediction of upcoming structure, generated through the probabilistic syntactic knowledge of the comprehender, is an important determiner of processing cost.

Pavel Logačev and Shravan Vasishth. A Multiple-Channel Model of Task-Dependent Ambiguity Resolution in Sentence Comprehension. Cognitive Science, 2014. Accepted pending minor revision.

Traxler et al. (1998) found that ambiguous sentences are read faster than their unambiguous counterparts. This so-called ambiguity advantage has presented a major challenge to classical theories of human sentence comprehension (parsing) because its most prominent explanation, in the form of the unrestricted race model (URM), assumes that parsing is non-deterministic. Recently, Swets et al. (2008) have challenged the URM. They argue that readers strategically underspecify the representation of ambiguous sentences to save time, unless disambiguation is required by task demands. When disambiguation is required, however, readers assign sentences full structure — and Swets et al. provide experimental evidence to this end. On the basis of their findings they argue against the URM and in favor of a model of task-dependent sentence comprehension. We show through simulations that the Swets et al. data does not constitute evidence for task-dependent parsing because it can be explained by the URM. However, we provide decisive evidence from a German self-paced reading study consistent with Swets et al.’s general claim about task-dependent parsing. Specifically, we show that under certain conditions, ambiguous sentences can be read more slowly than their unambiguous counterparts, suggesting that the parser may create several parses, when required. Finally, we present the first quantitative model of task-driven disambiguation which subsumes the URM, and show that it can explain both Swets et al.’s results and our findings.

Two new papers: Hanne et al, and Sorensen and Vasishth

We just submitted two new papers:

1. A tutorial on fitting Bayesian linear mixed models using Stan:
   pdf: http://www.ling.uni-potsdam.de/~vasishth/pdfs/SorensenVasishthJMP.pdf
   abstract: With the arrival of the R packages nlme and lme4, linear mixed models (LMMs) have come to be widely used in psychology, cognitive science, and related areas. In this tutorial, we provide a practical introduction to fitting LMMs in a Bayesian framework using the probabilistic programming language Stan. Although the Bayesian framework has several important advantages, specifying a Bayesian model requires quite a lot of background knowledge compared to frequentist tools like lme4. This tutorial provides the necessary background through two detailed examples of self-paced reading studies with repeated measures. One is a two-condition design, and the other a 2×2 factorial design. These two examples can easily be extended to more complex factorial designs. The data and code associated with this tutorial are available as a supplement.
2. Sentence comprehension in aphasia: Eye-tracking reveals delayed morphological cue integration and late parsing commitments
   http://www.ling.uni-potsdam.de/~vasishth/pdfs/Hanne-Burchert-DeBleser-Vasishth-JNL-submitted.pdf
   abstract: Comprehension of non-canonical sentences can be difficult for individuals with aphasia (IWA). It is still unclear to which extent morphological cues like case-marking or verb inflection may influence IWA’s performance or even help to override deficits in sentence comprehension. Until now, studies have mainly used offline methods to draw inferences about syntactic deficits and, so far, only a few studies have looked at online syntactic processing in aphasia. We investigated sentence processing in German IWA by combining an offline (sentence-picture matching) and online (eye-tracking in the visual-world paradigm) method. Our goal was to determine whether IWA are capable of using inflectional morphology (number-agreement markers on verbs and case markers in noun phrases) as a cue to sentence interpretation. We report results of two visual-world experiments using German reversible SVO and OVS sentences. In each study, there were eight IWA and 20 age-matched controls. Experiment 1 targeted the role of case-morphology, while Experiment 2 looked at processing of number-agreement cues at the verb in case-ambiguous sentences. IWA showed deficits in using both types of morphological markers as a cue to non-canonical sentence interpretation and the results indicate that in aphasia, processing of case-marking cues is more vulnerable as compared to verb-agreement morphology. However, the online data revealed that IWA are in principle capable of successfully computing morphological cues, but the integration of morphological information is delayed as compared to age-matched controls. Furthermore, we found striking differences between controls and IWA regarding subject-before-object parsing predictions. While in case-unambiguous sentences IWA showed evidence for early subject-before-object parsing commitments, they exhibited no straightforward subject-first bias in case-ambiguous sentences, although controls did so for ambiguous structures. IWA delayed their parsing decisions in case-ambiguous sentences until unambiguous morphological information, such as a subject-verb-number-agreement cue, was available. We attribute the differential results for processing of case and agreement markers to differences in the degree of reliability of both morphological cues. We ascribe our findings for erroneous processing of case-unambiguous sentences in aphasia to late parsing commitments and failures in integrating case cues on time. For processing of case-ambiguous sentences in aphasia, we suggest that IWA adopt a wait-and-see strategy and make parsing commitments only when the agreement cue at the verb prompts a particular sentence structure. Our results for IWA further point to deficits in predictive processes during sentence comprehension.

Two new papers

We have two new papers:

1. Jaeger et al 2014 (under review): The subject-relative advantage in Chinese relatives: Evidence for expectation-based processing, pdf
   abstract: Chinese relative clauses are an important test case for pitting the predictions of expectation-based accounts against those of memory-based theories. The memory-based accounts predict that object relatives should be easier to process than subject relatives because, in object relatives, less linguistic material intervenes between the head noun and the gap (or verb) that it associates with. By contrast, expectation-based accounts such as surprisal predict that the less frequently occurring object relative should be harder to process than the subject relative, because building a rarer structure is computationally more expensive. Previous studies on Chinese relative clauses have the problem that local ambiguities in subject and object relatives could be confounding the comparison. We compared reading difficulty in subject and object relatives (in both subject- and object-modifications) in which the left context leads the reader to predict a relative clause structure as the most likely continuation; we validate this assumption about what is predicted using production data (a sentence completion study and a corpus analysis). Two reading studies (self-paced reading and eye-tracking) show that the Chinese relative clause evidence is consistent with the predictions of expectation-based accounts but not with those of memory-based theories. We present new evidence that the prediction of upcoming structure, generated through the probabilistic syntactic knowledge of the comprehender, is an important determiner of processing cost.
2. Hofmeister and Vasishth 2014: Distinctiveness and encoding effects in online sentence comprehension, pdf
   abstract: In explicit memory recall and recognition tasks, elaboration and contextual isolation both facilitate memory performance. Here, we investigate these effects in the context of sentence processing: targets for retrieval during online sentence processing of English object relative clause constructions differ in the amount of elaboration associated with the target noun phrase, or the homogeneity of superficial features (text color). Experiment 1 shows that greater elaboration for targets during the encoding phase reduces reading times at retrieval sites, but elaboration of non-targets has considerably weaker effects. Experiment 2 illustrates that processing isolated superficial features of target noun phrases — here, a green word in a sentence with words colored white — does not lead to enhanced memory performance, despite triggering longer encoding times. These results are interpreted in the light of the memory models of Nairne 1990, 2001, 2006, which state that encoding remnants contribute to the set of retrieval cues that provide the basis for similarity-based interference effects.

Teaching a course in Paris

I'm teaching a course in Paris starting next week: http://www.labex-efl.org/?q=fr/node/269

Paper submitted: The importance of reading naturally

Here is a new paper from our lab: http://www.ling.uni-potsdam.de/~vasishth/pdfs/MetznerEtAl2014P600.pdf Abstract: Traditionally, a lot of ERP research on language processing uses auto-paced, word-by-word presentation. What is the difference in ERP effects between word-by-word presentation and natural reading? We investigated this question by conducting two experiments; event-related brain potentials were recorded while participants read either word-by-word or naturally. In the natural reading experiment, eye movements were recorded concurrently with the brain potentials. Comprehension difficulty was induced by syntactic (gender mismatch) or semantic violations (implausible association of adjective and noun) that occurred either sentence-medially or sentence-finally. This design allowed us to investigate whether recovery from unexpected input differs in the two modalities. Both the word-by-word and natural reading experiments showed the classical N400 and P600 effects seen in syntactic and semantic violations, replicating published results. However, compared to word-by-word presentation, natural reading led to higher accuracy in judging well-formedness of sentences; and in natural reading, trials with regressive eye movements led to higher accuracy than trials without regressive eye movements. Interestingly, in the sentence-medial violations, a P600 effect was observed when regressions occurred, suggesting that a regressive eye movement event is associated with a recovery process. By contrast, when no regression occurred, no effect was seen in the brain potentials sentence-medially, implying that no recovery process was triggered. In sentence-final position, both violations led to N400 and P600 effects in regression trials, and a sustained negativity in no-regression trials, the latter suggesting that the reader may have detected the violation but was willing to tolerate it. In sum, we show that natural reading leads to higher comprehension accuracy than word-by-word presentation. Additionally, the separation of regression and no-regression trials revealed the strategic choices made by the comprehension system. Thus, although the relative simplicity of the word-by-word presentation paradigm offers clear advantages, important aspects of language comprehension can perhaps be better studied using natural reading.

Vasishth Lab at Ohio State, 2014

We had a very successful trip to the CUNY sentence processing conference at Ohio State; two talks (Paul Metzner and Titus von der Malsburg; and Pavel Logacev), and six posters.

New course on bayesian data analysis for psycholinguistics

I decided to make a fool of myself and teach a course on bayesian methods:

http://www.ling.uni-potsdam.de/~vasishth/advanceddataanalysis.html