Attentional modulation of orthographic neighborhood effects during reading: Evidence from event-related brain potentials in a psychological refractory period paradigm

It is often assumed that word reading proceeds automatically. Here, we tested this assumption by recording event-related potentials during a psychological refractory period (PRP) paradigm, requiring lexical decisions about written words. Specifically, we selected words differing in their orthographic neighborhood size–the number of words that can be obtained from a target by exchanging a single letter–and investigated how influences of this variable depend on the availability of central attention. As expected, when attentional resources for lexical decisions were unconstrained, words with many orthographic neighbors elicited larger N400 amplitudes than those with few neighbors. However, under conditions of high temporal overlap with a high priority primary task, the N400 effect was not statistically different from zero. This finding indicates strong attentional influences on processes sensitive to orthographic neighbors during word reading, providing novel evidence against the full automaticity of processes involved in word reading. Furthermore, in conjunction with the observation of an underadditive interaction between stimulus onset asynchrony (SOA) and orthographic neighborhood size in lexical decision performance, commonly taken to indicate automaticity, our results raise issues concerning the standard logic of cognitive slack in the PRP paradigm

Asset-Preise als geldpolitische Zielgröße: Das Beispiel der USA

Die internationalen Börsen erleben derzeit einen Crash auf Raten. Gleichzeitig ist die amerikanische Federal Reserve Bank bemüht, mit Zinssenkungen dagegenzuhalten. Wie konnte es zu der Kursblase kommen? Hat die Geldpolitik hier versagt? --

Die Finanzmärkte im Spannungsfeld der New Economy

Die Aktienmärkte in Europa und vor allem in den USA melden seit Jahren Rekorde. Skeptiker befürchten jedoch, dass sich diese Hausse als spekulative Blase erweist. Wie ist die derzeitige Entwicklung im historischen Vergleich mit dem Crash von 1929 zu beurteilen? Sind die Kurssteigerungen durch die Entwicklung der Fundamentaldaten gerechtfertigt? Sollten die Notenbanken steuernd eingreifen? --

A Structurally Flat Triangular Form Based on the Extended Chained Form

In this paper, we present a structurally flat triangular form which is based on the extended chained form. We provide a complete geometric characterization of the proposed triangular form in terms of necessary and sufficient conditions for an affine input system with two inputs to be static feedback equivalent to this triangular form. This yields a sufficient condition for an affine input system to be flat.Comment: arXiv admin note: substantial text overlap with arXiv:2002.0120

A Flat System Possessing no (x,u)-Flat Output

In general, flat outputs of a nonlinear system may depend on the system's state and input as well as on an arbitrary number of time derivatives of the latter. If a flat output which also depends on time derivatives of the input is known, one may pose the question whether there also exists a flat output which is independent of these time derivatives, i.e., an (x,u)-flat output. Until now, the question whether every flat system also possesses an (x,u)-flat output has been open. In this contribution, this conjecture is disproved by means of a counterexample. We present a two-input system which is differentially flat with a flat output depending on the state, the input and first-order time derivatives of the input, but which does not possess any (x,u)-flat output. The proof relies on the fact that every (x,u)-flat two-input system can be exactly linearized after an at most dim(x)-fold prolongation of one of its (new) inputs after a suitable input transformation has been applied

UNLV New Horizons Band & Red Rock Saxophone Quartet & UNLV Symphonic Winds

Program listing performers and works performed

Ein sprachvergleichender Ansatz

Table of Contents ______________________________________________________________________ Acknowledgements I Zusammenfassung III Abstract XI General Introduction 1 Sublexical units in visual word recognition 3 The orthographic perspective 4 The morphological perspective 8 The phonological perspective 9 The role of syllabic units 11 The Focus of this investigation 14 Chapter 1 Associated or dissociated effects of syllable-frequency in lexical decision and naming A comparison of Spanish findings with German data 17 Introduction 18 Experiment 1 (Lexical Decision) 23 Method 23 Results and Discussion 25 Experiment 2 (Naming) 27 Method 27 Results and Discussion 27 Reanalysis of Experiments 1 and 2 29 General Discussion 30 Chapter 2 Contrasting effects of token and type syllable frequency in lexical decision Empirical evidence from Spanish and implications for computational modelling 35 Introduction 36 Experiments 1A and B 40 Method 40 Results and Discussion 43 Experiments 2A and B 46 Method 46 Results and Discussion 48 Experiments 3A and B 50 Method 50 Results and Discussion 50 Re-analyses of Experiments 1 and 2 52 General Discussion 56 Chapter 3 Syllables and bigrams: Orthographic redundancy and syllabic units affect visual word recognition at different processing levels. Empirical and simulation data from Spanish 65 Introduction 66 Experiment 1: Syllable frequency and bigram troughs 71 Method 72 Results and Discussion 75 Experiment 2: Manipulation of syllable frequency controlling for bigram frequency 81 Method 81 Results and Discussion 83 Experiment 3: Manipulation of bigram frequency controlling for syllable frequency 84 Method 84 Results and Discussion 85 Simulations with the MROM using the data of Experiments 2 and 3 87 General Discussion 93 Chapter 4 Phonology as the source of syllable frequency effects in visual word recognition: Evidence from French 103 Introduction 104 The Experiment 107 Method 107 Comparison 1: General syllable frequency 109 Results and Discussion 110 Comparison 2: Orthographic vs. phonological syllables 112 Results and Discussion 112 Comparison 3: Number of higher frequency syllabic neighbors 115 Results and Discussion 117 Comparison 4: Effects of phonological syllable frequency with letter cluster frequency controlled for 119 Results and Discussion 121 Comparison 5: Effects of phoneme cluster frequency with syllable frequency held constant 122 Results and Discussion 122 Comparison 6: Effects of phonological syllable frequency as a function of word frequency 124 Results and Discussion 125 General Discussion 127 Outlook 133 References 142 Appendices 157 Stimulus Materials A-II Curriculum Vitae A-XVIII Erklärung A-XIXThis dissertation thesis is about syllable frequency effects in visual word recognition. Before the seminal study of Carreiras, Álvarez and De Vega (1993), only rather sparse empirical evidence for syllabic processing during the process of silent reading had been reported in psycholinguistic research focusing mainly on the English orthography (Lima & Pollatsek, 1983; Millis, 1986; Prinzmetal, Treiman, & Rho, 1986; Spoehr & Smith, 1973; Taft & Forster, 1976; Tousman & Inhoff, 1992). And at least some of these findings have been highly contested: It had been argued that they would possibly occur as a by- product of orthographic processing – given the relation of syllabic structure to orthographic redundancy (see Seidenberg 1987; 1989, see also Schiller 1998; 2000, but see Rapp, 1992). Longstanding evidence for the role of syllabic units had rather been obtained for the domain of speech perception (e.g., Cutler, Mehler, Norris, & Seguí, 1986; Mehler, Dommergues, Frauenfelder, & Seguí, 1981; Morais, Content, Cary, Mehler, & Seguí, 1989). But using the Spanish language, which unlike English is a shallow orthography with a consistent bidirectional spelling to sound relation and transparent syllabic structure, Carreiras et al. (1993, see also Perea & Carreiras, 1998) reported that words comprising high frequency syllables – syllables shared by many other words in identical position – were responded to more slowly in the lexical decision task than words with low frequency syllables. This finding suggested that during visual word recognition, orthographic word forms were automatically segmented into their syllabic constituents. The processing delay for high syllable frequency words was attributed to syllabic neighbours (words sharing a syllable with the target in identical position) interfering with the processing of the target (see the framework of interactive activation models of visual word recognition by McClelland & Rumelhart, 1981). Such syllabic effects present a serious challenge for existing computational models of visual word recognition, because none of these models possesses a layer of syllabic representation units (see e.g., Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001; Grainger & Jacobs, 1996; Jacobs, Graf, & Kinder, 2003; Ziegler, Perry, & Coltheart, 2000; Zorzi, Houghton, Butterworth, 1998; but see Ans, Carbonnel, & Valdois, 1998; for a model of naming polysyllabic words). Most of these models are exclusively implemented for the processing of monosyllabic words. If syllabic effects like the syllable frequency effect on lexical access proved to be reliable and could not be attributed to other than syllabic processing, this would present an important qualitative difference in the processing of polysyllabic words compared to monosyllabic words. In consequence, the scope of these computational models would be severely limited, because most words in most languages are polysyllabic. The inhibitory syllable frequency effect in lexical decision has since been replicated in two other languages, French (Mathey & Zagar, 2002) and German (Conrad & Jacobs, 2004). Therefore, an assumed automatic syllabic processing cannot be understood as a phenomenon specific to the Spanish language neither as occurring exclusively in Roman languages (but see Macizo & Van Petten, 2007, for a failure to replicate the effect in English). In contrast to the inhibition caused by syllable frequency in a task requiring lexical access but no overt pronunciation, words starting with high frequency syllables produced shorter naming latencies than words with low initial syllable frequency in naming tasks with visually presented word stimuli in Spanish (Perea & Carreiras, 1998; see also Carreiras and Perea, 2004, as well as Brand, Rey, Peereman, & Spieler, 2002, for similar data obtained in French). This dissociation of syllable frequency effects across different tasks was explained by a shift of the locus of effect to the level of motor output in the naming task (see Levelt & Wheeldon, 1994; Levelt, Roelofs, & Meyer, 1999). The experimental work presented in this thesis tried to further examine the nature of syllabic processing in visual word recognition focusing on different aspects of syllable frequency effects. Results are presented in four chapters using a cross language approach as general guideline of research: The transparency of syllabic structure varies considerably across different languages. This leads to the question of whether visual word recognition in different languages would be characterized by an automatic syllabic processing to the same extent, or whether specific differences regarding syllabic processing could be observed that might be attributed to specific features of syllabic structure in a particular language. Chapter 1 The cross language approach in investigating effects of syllabic processing motivated the investigating of whether the same dissociation of syllable frequency effects across lexical decision and naming as suggested by the literature for the Spanish language would be observable using a manipulation of initial syllable frequency in German words and nonwords. In contrast to the findings of Perea & Carreiras (1998) and Carreiras & Perea (2004a) an inhibitory effect of syllable frequency was obtained in both tasks for German word stimuli. Shorter naming latencies due to initial syllable frequency were restricted to the German nonword stimuli. This pattern of results suggests that processes related to lexical access are more strongly influencing the production of overt pronunciation of polysyllabic word stimuli in German compared to Spanish. This finding might relate to different stress assignment of polysyllabic words’ in the two languages. In contrast to Spanish where stress is syllable timed – with the penultimate syllable receiving stressed -, stress in German bisyllabic words is lexically assigned depending, for instance, on a word’s morphology. Lexical access – being inhibited by initial syllable frequency – is therefore necessary in order to know which of the two syllables within a bisyllabic German word has to be stressed. Stress information, on the other hand, is a necessary prerequisite for correct pronunciation. This might be the reason why syllable frequency seems to influence not only lexical decision but also naming latencies for German words in an inhibitory manner. In contrast, the same involvement of lexical processing seems not necessarily to be given in Spanish, because for all Spanish words with other than penultimate stress, stress assignment can de inferred via prelexical processing using orthographic accents or the identity of the last letter in a word as sufficient stress information. Therefore, overt pronunciation in Spanish could theoretically already be initiated before lexical access has been completed and syllable frequency’s facilitative role for motor output processes is not cancelled out by its potential to inhibit lexical access. Only in the case of German nonwords, where first syllable stress is probably assigned by default, participants naming latencies could be shown to be influenced by the assumed facilitation of motor output processes due to initial syllable frequency. Chapter 2 Previous research documenting inhibitory effects of syllable frequency in lexical decision had uncritically applied different measures of syllable frequency. They had either used the number of syllabic neighbours (a type measure), the cumulated frequency of syllabic neighbours (a token measure) or the number of higher frequency syllabic neighbours (being suggested by Perea & Carreiras, 1998, as probably responsible for the empirical effect) as independent variables. This was clearly weakening comparability between different studies and made a theoretical attribution of the empirical effect in general more difficult - see the differential effects of orthographic neighbourhood density and frequency in visual word recognition (see Andrews, 1997, for a review) - especially because all these different measures of syllable frequency are highly correlated. Furthermore, the question of whether a type or a token based measure of syllable frequency effect is driving the empirical effect has important implications for any future attempt to simulate this effect using computational modelling. The question of potentially differential effects of these different measures of syllable frequency was addressed by several experiments conducted in the Spanish language presented in Chapter 2. In the first of these experiments involving the independent manipulation of type and token syllable frequency, the typical inhibitory effect of syllable frequency on lexical access was obtained only for the token measure of syllable frequency, whereas the type measure produced a tendency of facilitation on response latencies and a significant facilitative effect on error rates. In a subsequent experiment using the same independent variables as in the previous manipulation but providing additional control for the number of higher frequency syllabic neighbours, the facilitative effect of type syllable frequency turned out to be significant in both response latencies and error rates, whereas the inhibitory effect of token syllable frequency remained unaffected. This pattern of results provides empirical evidence for what had been formulated in previous theoretical accounts of the syllable frequency effect in lexical decision: The locus of the effect has to be seen at a lexical level of competition between candidate words sharing the initial syllable with the target and competing for identification. The amount of interference caused by these candidates (the syllabic neighbours) does not depend on their mere number, but on their frequency. A similar argument had been used by Perea & Carreiras (1998), who proposed the number of higher frequency syllabic neighbours as being responsible for the inhibitory effect of syllable frequency in the lexical decision task, but the present results could show that also token syllable frequency alone can hold responsible for this effect. Token syllable frequency was accordingly applied for all manipulations of syllable frequency in all other experiments presented in this dissertation. The observed dissociation for the type and the token syllable frequency measures suggests that a syllable’s frequency can influence the reading process in different ways at different processing levels: The high typicality (possibly best reflected by the type measure of syllable frequency) of a syllable seems to facilitate the processing of sublexical units at a prelexical processing stage, whereas the inhibitory potential of syllabic neighbours (reflected in the token measure of syllable frequency) makes lexical access to high syllable frequency words more difficult. Furthermore, the dissociation of these two effects that were obtained in one and the same task environment has important implications for computational modelling, questioning, e.g., the account of the dissociated effects of orthographic neighbourhood density and frequency given by the MROM (Grainger & Jacobs, 1996), which modulated the involvement of different read-out procedures as an adaptation to different task environments in order to successfully simulate the two effects. Chapter 3 All previous studies reporting syllable frequency effects in lexical decision interpreted this empirical effect as evidence for an automatic syllabic segmentation of orthographic word forms during the reading process. It was outlined above why this would present a serious challenge for computational models of visual word recognition. But looking closely at the relation between syllable frequency and orthographic redundancy, the question arises of whether this attribution of the empirical effect has not been premature. Syllable frequency is generally confounded with orthographic redundancy in two ways: First, the bigram straddling the syllabic boundary is typically less frequent than intrasyllabic bigrams. This phenomenon had inspired the bigram trough hypothesis (Seidenberg, 1987; 1989), which argued that the orthographic salience of a relatively low frequent bigram at the syllable boundary might be the only reason for any apparent syllabic segmentation. This would mean that alleged “syllabic” effects might arise as a mere by-product of orthographic processing questioning whether phonologically or orthographically defined syllabic units would possess themselves the status of functional units during visual word recognition. Some empirical studies reporting syllable frequency effects had tried to dismiss this critic by using only words not showing the bigram trough pattern at the syllable boundary (e.g., Carreiras et al., 1993; Perea & Carreiras, 1998). However, the question of whether the kind of orthographic segmentation device proposed by Seidenberg (1987; 1989) had any influence on syllabic processing or not, had never been directly examined. The first experiment presented in Chapter 3 was designed to fill this gap addressing the theoretically interesting question regarding a possible role of orthographic redundancy for syllabic segmentation with bigram troughs facilitating the syllabic parsing process. A manipulation of initial syllable frequency was realized in bisyllabic Spanish words that either showed the bigram trough pattern at the syllable boundary or not. Besides an inhibitory main effect of syllable frequency and a weak facilitation of response latencies in the absence (relative to the presence) of a bigram trough at the syllable boundary that – according to multiple regression analyses - seemed to be attributable rather to global patterns of orthographic redundancy than to the relative position of a bigram with respect to the syllable boundary, no interaction between the two effects was observed. This pattern of results suggesting that syllabic processing in Spanish is completely independent from orthographic redundancy - at least as reflected by the concept of bigram troughs – is partially incompatible with recent results obtained for the French language (Doignon & Zagar, 2005; Mathey, Zagar, Doignon, & Seigneuric, 2006). This discrepancy might present an interesting case of language dependent features of syllabic processing with orthographic redundancy becoming more important for syllabic segmentation in languages where transparency of syllabic structure is attenuated by the inconsistent mapping between phonological syllables and their orthographic representations. But there is a second natural confound between the frequency of syllabic units and orthographic redundancy, which is even more important for a reliable attribution of syllable frequency effects: A high frequency syllable can generally also be described as a high frequency letter cluster the definition of which does not necessarily relate to syllabic structure. None of the experiments reported in the previous literature had controlled for the frequency of the letter cluster formed by the initial syllable when applying a manipulation of initial syllable frequency. Therefore, all empirical effects of syllable frequency might have been triggered by the frequency of a purely orthographically defined letter cluster – regardless of syllabic structure. Such effects of letter cluster frequency might well be accounted for by computational models comprising letter representation units and they would not necessarily present evidence for syllabic processing in visual word recognition (see Schiller, 1998; 2000). Disentangling the empirical confound of syllable frequency and letter cluster frequency, two experiments were conducted using bisyllabic Spanish words starting always with a two letter CV-syllable. These experiments involved a) the manipulation of initial syllable frequency controlling for the frequency of the initial bigram, and b) the manipulation of initial bigram frequency controlling for the frequency of the initial syllable. A perfect contrast for the effects of the frequency of the first two letters within a Spanish word was observed, depending on how this frequency was defined: Syllable frequency had an inhibitory effect on response latencies and error rates, whereas response latencies and error rates decreased with initial bigram frequency. Therefore, it is shown for the first time that syllable frequency effects in the lexical decision task cannot be understood without assuming the involvement of syllabic processing. In contrast to syllabic units, which seem to have an important role for the activation of whole word candidates competing with the target for identification, the frequency of bigrams rather seems to facilitate prelexical orthographic processing (see also Hauk et al., 2006). Simulation data using an extended version of the MROM (Grainger & Jacobs, 1996) is provided showing that a model without syllabic representations is not capable of reproducing the syllable frequency effect when letter cluster frequency is controlled for. On the other hand, global lexical activation in the model (which is responsible for fast-guess responses of the model) was shown to be sensitive to bigram frequency, even though this effect did not reach statistical significance. Future research has to determine whether the facilitative effect of bigram frequency that was obtained for words where the relevant bigram always coincided with the initial syllable has a specific relation to syllabic processing with bigram frequency possibly facilitating the processing of syllabic units. Chapter 4 Even when it was shown in the experiments presented in Chapter 3 that syllabic processing appears to be indeed an automatic feature of polysyllabic visual word recognition, there is one remaining question regarding the nature of this effect. The concept of the syllable is derived from a phonological perspective – a syllable is defined as the largest combination of sounds that can be produced in an uninterrupted stream. This might lead to a bias to implicitly attribute syllabic effects to phonological processing without that the phonological nature – involving the processing of phonological vs. orthographic syllables - of this effect had ever been sufficiently examined. There is evidence for the processing of phonological syllables in visual word recognition from a priming study in Spanish showing comparable priming effects for bisyllabic words preceded by nonwords matching either the target’s initial orthographic and phonological syllable or the target’s phonological syllable alone (Álvarez, Carreiras, & Perea, 2004). But generally, for manipulations of syllable frequency in Spanish and German it is hardly possible to distinguish between effects of orthographic and phonological syllable frequency because of the too consistent spelling to sound relation in these two languages. The French language instead, with its high degree of inconsistency regarding the orthographic representation of phonemes (see Ziegler, Jacobs, & Stone, 1996) offers the possibility to experimentally disentangle the frequencies o

"Leaving them behind" - global trends in forced migration

Regions with civil wars will continue to be characterised by endemic violent conflicts and forced displacement in the coming decade. Accordingly, the number of displaced people from war-like contexts will increase. Due to the absence of durable solutions the number of forcibly displaced people who informally remain in a receiving country without a chance of ever obtaining citizenship of that country will grow. Countries of the Global South are likely to follow the practices of the Global North and refuse reception of refugees or even enforce collective deportation. This makes it all the more difficult to implement international agreements to manage forced displacement. Forced migrants are increasingly seeking protection in urban agglomerations. This increases the risk that social services in the cities will collapse and societal tensions will mount. Against the backdrop of the increasing duration and cyclical recurrence of violent conflict, the operational separation between refugees and IDPs can hardly be maintained. In addition, the boundaries between humanitarian aid and development cooperation will blur ever more. Aid organisations will be caught in a situation in which their engagement in support of displaced people might at the same time contribute to accommodating donors' interests of channelling and impeding refugee movements