Frans Zwarts

Localizing components of a complex task: sentence processing and working memory

THREE areas of the left hemisphere play different roles in sentence comprehension. An area of posterior middle and superior temporal gyrus shows activation correlated with the structural complexity of a sentence, suggesting that this area supports processing of sentence structure. The lateral anterior temporal gyrus is more activated bilaterally by all sentence conditions than by word lists; thus the function of the area probably does not directly support processing of structure but rather processing of words specific to a sentence context. Left inferior frontal cortex also shows activation related to sentence complexity but is also more activated in word list processing than in simple sentences; this region may thus support a form of verbal working memory which maintains sentence structural information as well as lexical items.

Weak islands and an algebraic semantics for scope taking

Modifying the descriptive and theoretical generalizations of Relativized Minimality, we argue that a significant subset of weak island violations arise when an extracted phrase should scope over some intervener but is unable to. Harmless interveners seem harmless because they can support an alternative reading. This paper focuses on why certain wh-phrases are poor wide scope takers, and offers an algebraic perspective on scope interaction. Each scopal element SE is associated with certain operations (e.g., not with complements). When a wh-phrase scopes over some SE, the operations associated with that SE are performed in its denotation domain. The requisite operations may or may not be available in a domain, however. We present an empirical analysis of a variety of wh-phrases. It is argued that the wh-phrases that escape all weak islands (i.e., can scope over any intervener) are those that range over individuals, the reason being that all Boolean operations are defined for their domain. Collectives, manners, amounts, numbers, etc. all denote in domains with fewer operations and are thus selectively sensitive to scopal interveners—a “semantic relativized minimality effect”.

Sentence comprehension and word repetition: A positron emission tomography investigation

Using positron emission tomography, visual presentation of sentences was shown to cause increased regional cerebral blood flow relative to word lists in the left lateral anterior superior and middle temporal gyri, attributable to cognitive processes that occur during sentence comprehension in addition to those carried out during word comprehension. Additional comparisons showed that repeating words (in a different context, when subjects did not attempt to learn the initial lists) led to significant patterns of both increased blood flow (left putamen and right caudate) and decreased blood flow (left posterior temporal lobe). Increases are argued to reflect retrieval of memory traces, whereas decreases reflect diminished necessity for processing of input. A decrease in the left inferior parietal lobe was attributable to other factors.

Differences in AERP responses and atypical hemispheric specialization in 17-month-old children at risk of dyslexia

To determine the auditory event-related potential (AERP) correlates of phoneme perception in 17-month-old children at risk of dyslexia and controls, AERPs were elicited by standard (/bAk/) and deviant (/dAk/) word stimuli presented in an oddball paradigm. The at-risk children tended to show delayed P1 and P2 peaks for standard stimuli. Hemispheric group differences were observed for N2 amplitude and P1 latency, suggesting atypical processing of spoken words in at-risk children. Larger P2 and to a lesser extent P1 amplitudes following deviant words occurred in the control but not in the at-risk group, this may signal poorer phoneme discrimination in at-risk children. The present AERP results offer clues to where to look for a marker to identify children at high risk of reading and writing problems at an early age to facilitate early intervention.

Cortical categorization failure in 2-month-old infants at risk for dyslexia.

Cortical auditory categorization was assessed in 2-month-old infants at genetic risk for dyslexia and controls. Manipulated /bAk/ and /dAk/ speech stimuli were used as frequently presented standards. The neuroelectric brain responses of the control infants were highly sensitive to the phoneme boundary that separated these stimuli, but the infants at risk showed no signs of cortical categorical perception. Cortical sources of the responses were predominantly found in the left hemisphere for the control infants, but mainly in the right hemisphere for the infants at risk. The results demonstrate that impaired categorical perception in dyslexia is already present in infants at risk for the disorder.

Auditory P2 is Reduced in 5 Month old Infants From Dyslexic Families

In this ERP study we examined the auditory processing of 5-month-old infants from dyslexic families (n=121) and controls (n=73) as part of a national longitudinal research program in The Netherlands on developmental dyslexia. A natural manipulated speech stimulus /bak/ was presented to these infants as the standard stimulus (about 400 repetitive presentations) in an oddball paradigm. Infants were either awake, watching a silent video, or asleep during the repetitive presentation of the stimulus. In this study we tested the prediction from a dynamic neuronal model study that the P2 should be reduced in infants from dyslexic families. The data indicates that infants from dyslexic families have a reduced P2 in the frontal-central-parietal regions in both hemispheres. During sleep the P2 amplitude was reduced compared with the awake state, but there was no difference between sleeping stages. Somewhat unexpectedly we did not find gender differences in this study. Cortical generators of the P2 were found in the auditory cortex and in Wernicke’s and Broca’s area. P2 amplitude explains 18% of the variance in verb production of the same infants at the age of 17 months. A discriminant analysis shows that infants are classified as deficient in auditory processing in 10% of the controls and 35% of the infants from dyslexic families. These numbers are well in line with the normal population risk and the elevated risk in infants from dyslexic

Measuring orthographic transparency and morphological-syllabic complexity in alphabetic orthographies: a narrative review

This narrative review discusses quantitative indices measuring differences between alphabetic languages that are related to the process of word recognition. The specific orthography that a child is acquiring has been identified as a central element influencing reading acquisition and dyslexia. However, the development of reliable metrics to measure differences between language scripts hasn’t received much attention so far. This paper therefore reviews metrics proposed in the literature for quantifying orthographic transparency, syllabic complexity, and morphological complexity of alphabetic languages. The review included searches of Web of Science, PubMed, PsychInfo, Google Scholar, and various online sources. Search terms pertained to orthographic transparency, morphological complexity, and syllabic complexity in relation to reading acquisition, and dyslexia. Although the predictive value of these metrics is promising, more research is needed to validate the value of the metrics discussed and to understand the ‘developmental footprint’ of orthographic transparency, morphological complexity, and syllabic complexity in the lexical organization and processing strategies.

The aspectual significance of event particles

Several linguists and philosophers have argued that natural language-predicates are Davidsonian in that they have an extra argument position for eventualities. In what follows, we explore the idea that the Dutch particle eens and its German counterpart mal are overt manifestations of this Davidsonian argument.