Publications

Abstract

It has been fifty years since Levelt’s monograph On Binocular Rivalry (1965) was published, but its four propositions that describe the relation between stimulus strength and the phenomenology of binocular rivalry remain a benchmark for theorists and experimentalists even today. In this review, we will revisit the original conception of the four propositions and the scientific landscape in which this happened. We will also provide a brief update concerning distributions of dominance durations, another aspect of Levelt’s monograph that has maintained a prominent presence in the field. In a critical evaluation of Levelt’s propositions against current knowledge of binocular rivalry we will then demonstrate that the original propositions are not completely compatible with what is known today, but that they can, in a straightforward way, be modified to encapsulate the progress that has been made over the past fifty years. The resulting modified, propositions are shown to apply to a broad range of bistable perceptual phenomena, not just binocular rivalry, and they allow important inferences about the underlying neural systems. We argue that these inferences reflect canonical neural properties that play a role in visual perception in general, and we discuss ways in which future research can build on the work reviewed here to attain a better understanding of these properties

Abstract

In two experiments, we studied the role of frequency information in the production of deverbal adjectives and inflected verbs in Dutch. Naming latencies were triggered in a position-response association task and analysed using stepwise mixed-effects modelling, with subject and word as crossed random effects. The production latency of deverbal adjectives was affected by the cumulative frequencies of their verbal stems, arguing for decomposition and against full listing. However, for the inflected verbs, there was an inhibitory effect of Inflectional Entropy, and a nonlinear effect of Lemma Frequency. Additional effects of Position-specific Neighbourhood Density and Cohort Entropy in both types of words underline the importance of paradigmatic relations in the mental lexicon. Taken together, the data suggest that the word-form level does neither contain full forms nor strictly separated morphemes, but rather morphemes with links to phonologically andin case of inflected verbsmorphologically related word forms.

Abstract

We investigated the role of syllables during speech planning in English by measuring syllable-frequency effects. So far, syllable-frequency effects in English have not been reported. English has poorly defined syllable boundaries, and thus the syllable might not function as a prominent unit in English speech production. Speakers produced either monosyllabic (Experiment 1) or disyllabic (Experiment 2–4) pseudowords as quickly as possible in response to symbolic cues. Monosyllabic targets consisted of either high- or low-frequency syllables, whereas disyllabic items contained either a 1st or 2nd syllable that was frequency-manipulated. Significant syllable-frequency effects were found in all experiments. Whereas previous findings for disyllables in Dutch and Spanish—languages with relatively clear syllable boundaries—showed effects of a frequency manipulation on 1st but not 2nd syllables, in our study English speakers were sensitive to the frequency of both syllables. We interpret this sensitivity as an indication that the production of English has more extensive planning scopes at the interface of phonetic encoding and articulation.

Abstract

The process of speaking is traditionally regarded as a mapping of thoughts (intentions, feelings, etc.) onto language. One requirement that this mapping has to meet is that the units of information to be expressed be strictly ordered. The channel of speech largely prohibits the simultaneous expression of multiple propositions: the speaker has a linearization problem - that is, a linear order has to be determined over any knowledge structure to be formulated. This may be relatively simple if the informational structure has itself an intrinsic linear arrangement, as often occurs with event structures, but it requires special procedures if the structure is more complex, as is often the case in two- or three-dimensional spatial patterns. How, for instance, does a speaker proceed in describing his home, or the layout of his town? Two powerful constraints on linearization derive, on the one hand, from 'mutual knowledge' and, on the other, from working memory limitations. Mutual knowledge may play a role in that the listener can be expected to derive different implicatures from different orderings (compare 'she married and became pregnant' with 'she became pregnant and married'). Mutual knowledge determinants of linearization are essentially pragmatic and cultural, and dependent on the content of discourse. Working memory limitations affect linearization in that a speaker's linearization strategy will minimize memory load during the process of formulating. A multidimensional structure is broken up in such a way that the number of 'return addresses' to be kept in memory will be minimized. This is attained by maximizing the connectivity of the discourse, and by backtracking to stored addresses in a first-in-last-out fashion. These memory determinants of linearization are presumably biological, and independent of the domain of discourse. An important question is whether the linearization requirement is enforced by the oral modality of speech or whether it is a deeper modality-independent property of language use.