Publications

Abstract

Many contemporary texts include shortcuts, such as cu or phones4u. The aim of this study was to investigate how the meanings of shortcuts are retrieved. A primed lexical decision paradigm was used with shortcuts and the corresponding words as primes. The target word was associatively related to the meaning of the whole prime (cu/see you – goodbye), to a component of the prime (cu/see you – look), or unrelated to the prime. In Experiment 1, primes were presented for 57 ms. For both word and shortcut primes, responses were faster to targets preceded by whole-related than by unrelated primes. No priming from component-related primes was found. In Experiment 2, the prime duration was 1000 ms. The priming effect seen in Experiment 1 was replicated. Additionally, there was priming from component-related word primes, but not from component-related shortcut primes. These results indicate that the meanings of shortcuts can be retrieved without translating them first into corresponding words.

Abstract

The human cerebellum plays an important role in language, amongst other cognitive and motor functions [1], but a unifying theoretical framework about cerebellar language function is lacking. In an established model of motor control, the cerebellum is seen as a predictive machine, making short-term estimations about the outcome of motor commands. This allows for flexible control, on-line correction, and coordination of movements [2]. The homogeneous cytoarchitecture of the cerebellar cortex suggests that similar computations occur throughout the structure, operating on different input signals and with different output targets [3]. Several authors have therefore argued that this ‘motor’ model may extend to cerebellar nonmotor functions [3], [4] and [5], and that the cerebellum may support prediction in language processing [6]. However, this hypothesis has never been directly tested. Here, we used the ‘Visual World’ paradigm [7], where on-line processing of spoken sentence content can be assessed by recording the latencies of listeners' eye movements towards objects mentioned. Repetitive transcranial magnetic stimulation (rTMS) was used to disrupt function in the right cerebellum, a region implicated in language [8]. After cerebellar rTMS, listeners showed delayed eye fixations to target objects predicted by sentence content, while there was no effect on eye fixations in sentences without predictable content. The prediction deficit was absent in two control groups. Our findings support the hypothesis that computational operations performed by the cerebellum may support prediction during both motor control and language processing.

Abstract

Earlier studies had shown that speakers naming several objects typically look at each object until they have retrieved the phonological form of its name and therefore look longer at objects with long names than at objects with shorter names. We examined whether this tight eye-to-speech coordination was maintained at different speech rates and after increasing amounts of practice. Participants named the same set of objects with monosyllabic or disyllabic names on up to 20 successive trials. In Experiment 1, they spoke as fast as they could, whereas in Experiment 2 they had to maintain a fixed moderate or faster speech rate. In both experiments, the durations of the gazes to the objects decreased with increasing speech rate, indicating that at higher speech rates, the speakers spent less time planning the object names. The eye-speech lag (the time interval between the shift of gaze away from an object and the onset of its name) was independent of the speech rate but became shorter with increasing practice. Consistent word length effects on the durations of the gazes to the objects and the eye speech lags were only found in Experiment 2. The results indicate that shifts of eye gaze are often linked to the completion of phonological encoding, but that speakers can deviate from this default coordination of eye gaze and speech, for instance when the descriptive task is easy and they aim to speak fast.

Abstract

First paragraph: The topic of the workshop from which this volume comes, “Individual Differences in Second Language Learning,” is timely and important for both practical and theoretical reasons. The practical reasons are obvious: While many people have some knowledge of a second or further language, there is enormous variability in how well they know these languages. Much of this variability is, of course, likely to be due to differences in the time spent studying or being immersed in the language, but even in similar learning environments learners differ greatly in how quickly they pick up a language and in their ultimate level of proficiency.

Abstract

We examined the contribution of executive control to individual differences in response time (RT) for naming objects and actions. Following Miyake, Friedman, Emerson, Witzki, Howerter, and Wager (2000), executive control was assumed to include updating, shifting, and inhibiting abilities, which were assessed using operation-span, task switching, and stop-signal tasks, respectively. Study 1 showed that updating ability was significantly correlated with the mean RT of action naming, but not of object naming. This finding was replicated in Study 2 using a larger stimulus set. Inhibiting ability was significantly correlated with the mean RT of both action and object naming, whereas shifting ability was not correlated with the mean naming RTs. Ex-Gaussian analyses of the RT distributions revealed that updating ability was correlated with the distribution tail of both action and object naming, whereas inhibiting ability was correlated with the leading edge of the distribution for action naming and the tail for object naming. Shifting ability provided no independent contribution. These results indicate that the executive control abilities of updating and inhibiting contribute to the speed of naming objects and actions, although there are differences in the way and extent these abilities are involved.

Abstract

We investigated the time course of conjunctive ''same''-''different'' judgements for visually presented object pairs by means of combined reaction time and on-line eye movement measurements. The analyses of viewing patterns, viewing times, and reaction times showed that participants engaged in a parallel self-terminating search for differences. In addition, the results obtained for objects differing in only one dimension suggest that processing times may depend on the relative codability of the stimulus dimensions. The results are reviewed in a broader framework in view of higher-order processes. We propose that overspecifications of colour, often found in object descriptions, may have an ''early'' visual rather than a ''late'' linguistic origin. In a parallel assessment of the detection materials, participants overspecified the objects' colour substantially more often than their size. We argue that referential overspecifications of colour are largely attributable to mechanisms of visual discrimination.

Abstract

The study investigated the neuronal basis of the retrieval of words from the mental lexicon. The semantic category interference effect was used to locate lexical retrieval processes in time and space. This effect reflects the finding that, for overt naming, volunteers are slower when naming pictures out of a sequence of items from the same semantic category than from different categories. Participants named pictures blockwise either in the context of same- or mixedcategory items while the brain response was registered using magnetoencephalography (MEG). Fifteen out of 20 participants showed longer response latencies in the same-category compared to the mixed-category condition. Event-related MEG signals for the participants demonstrating the interference effect were submitted to a current source density (CSD) analysis. As a new approach, a principal component analysis was applied to decompose the grand average CSD distribution into spatial subcomponents (factors). The spatial factor indicating left temporal activity revealed significantly different activation for the same-category compared to the mixedcategory condition in the time window between 150 and 225 msec post picture onset. These findings indicate a major involvement of the left temporal cortex in the semantic interference effect. As this effect has been shown to take place at the level of lexical selection, the data suggest that the left temporal cortex supports processes of lexical retrieval during production.

Abstract

A series of experiments was carried out investigating the time course of phonological encoding in language production, i.e., the question of whether all parts of the phonological form of a word are created in parallel, or whether they are created in a specific order. a speech production task was used in which the subjects in each test trial had to say one out of three or five response words as quickly as possible. In one condition, information was provided about part of the forms of the words to be uttered, in another condition this was not the case. The production of disyllabic words was speeded by information about their first syllable, but not by information about their second syllable. Experiments using trisyllabic words showed that a facilitatory effect could be obtained from information about the second syllable of the words, provided that the first syllable was also known. These findings suggest that the syllables of a word must be encoded strictly sequentially, according to their order in the word.

Abstract

According to certain theories of language production, lexical access to a content word consists of two independent and serially ordered stages. In the first, semantically driven stage, so-called lemmas are retrieved, i.e., lexical items that are specified with respect to syntactic and semantic properties, but not with respect to phonological characteristics. In the second stage, the corresponding wordforms, the so-called lexemes, are retrieved. This implies that the access to a content word involves an early stage of exclusively semantic activation and a later stage of exclusively phonological activation. This seriality assumption was tested experimentally, using a picture-word interference paradigm in which the interfering words were presented auditorily. The results show an interference effect of semantically related words on picture naming latencies at an early SOA (− 150 ms), and a facilitatory effect of phonologically related words at later SOAs (0 ms, + 150 ms). On the basis of these results it can be concluded that there is indeed a stage of lexical access to a content word where only its meaning is activated, followed by a stage where only its form is activated. These findings can be seen as empirical support for a two-stage model of lexical access, or, alternatively, as putting constraints on the parameters in a network model of lexical access, such as the model proposed by Dell and Reich.