Jeanine M. I. Wessels's research while affiliated with Freie Universität Berlin and other places

The development of a lexicon critically depends on the infant's ability to identify wordlike units in the auditory speech input. The present study investigated at what age infants become sensitive to language-specific phonotactic features that signal word boundaries and to what extent they are able to use this knowledge to segment speech input. Experiment 1 showed that infants at the age of 9 months were sensitive to the phonotactic structure of word boundaries when word-like units were presented in isolation. Experiments 2 to 5 demonstrated that this sensitivity was present even when critical items were presented in context, although only under certain conditions. Preferences for legal over illegal word boundary clusters were found when critical items were embedded in two identical syllables, keeping language processing requirements and attentional requirements low. Experiment 6 replicated the findings of Experiment 1. Experiment 7 was a low-pass-filtered version of Experiment 6 that left the prosody of the stimulus items intact while removing most of the distinctive phonotactic cues. As expected, no listening preference for legal over illegal word boundary clusters was found in this experiment. This clearly suggests that the preferential patterns observed can be attributed to the infants' sensitivity to phonotactic constraints on word boundaries in a given language and not to suprasegmental cues.

Acquiring a native language involves learning about its phonetic elements and the constraints on their ordering. Our study explored this issue by examining infants′ listening preferences for unfamiliar words that either observe or violate native language phonetic and phonotactic patterns. American 9-month-olds, but not 6-month-olds, listened significantly longer to words with English, rather than Dutch, sound patterns. Dutch 9-month-olds showed the opposite pattern of preferences. No preferences occurred for low-pass-filtered versions of the words, suggesting that infants were responding to phonetic and phonotactic properties rather than to prosodic ones. However, when words fundamentally differed in their prosodic organization (e.g., English vs Norwegian), even American 6-month-olds listened significantly longer to English words.

The development of a lexicon critically depends on the infant’s ability to identify wordlike units in the auditory speech input. The present study investigated at what age infants become sensitive to language-specific phonotactic features that signal word boundaries and to what extent they are able to use this knowledgeto segment speech input. Experiment 1 showed that infants at the age of 9 months were sensitive to the phonotactic structure of word boundaries when wordlike units were presented in isolation. Experiments 2 to 5 demonstrated that this sensitivity was present even when critical items were presented in context, although only under certain conditions. Preferences for legal over illegal word boundary clusters were found when critical items were embedded in two identical syllables, keeping language processing requirements and attentional requirements low. Experiment 6 replicated the findings of Experiment 1. Experiment 7 was a low-pass-filtered version of Experiment 6 that left the prosody of the stimulus items intact while removing most of the distinctive phonotactic cues. As expected, no listening preference for legal over illegal word boundary clusters was found in this experiment. This clearly suggests that the preferential patterns observed can be attributed to the infants’ sensitivity to phonotactic constraints on word boundaries in a given language and not to suprasegmental cues.

The present study investigates Broca's aphasics' sensitivity to morphological information in an on-line task. German is used as the test language because it is highly inflected. Results from two word monitoring experiments show first that Broca's patients like normal controls are sensitive to the presence of a contextually incorrect inflection. Ćontrary to normals, they are, however, not sensitive to the absence of an obligatory inflection even when its presence is syntactically highly constrained. Second, they reveal that Broca's aphasics are only sensitive to the presence of an incorrect inflection when it functions as a marker of lexical category (noun vs. verb) and not when it functions as a diacritical marker (second person singular vs. third person singular). The results are taken as evidence for the claim that Broca's aphasics are impaired in the ability to process the full syntactic information encoded in closed class elements in a fast, automatic, and obligatory way.