Using visual strategies to support verbal comprehension in an adolescent with Down syndrome
International audience; It has been frequently reported that children with Down syndrome have deficits in verbal short-term memory while having relatively good performance in visual short-term memory tasks. Such verbal deficits have a detrimental effect on various high-level cognitive processes, most notably language comprehension. In this study, we report the case of an adolescent with Down syndrome whose verbal short-term memory and comprehension capacities are impaired. Noting that his visual memory remained relatively well preserved, we developed a remediation strategy based on his visual abilities to support his verbal memory deficit. This remediation led to significant improvements in…
Centre-embedded structures are a by-product of associative learning and working memory constraints: Evidence from baboons (Papio Papio)
International audience; Influential theories have claimed that the ability for recursion forms the computational core of human language faculty distinguishing our communication system from that of other animals (Hauser, Chomsky, & Fitch, 2002). In the present study, we consider an alternative view on recursion by studying the contribution of associative and working memory processes. After an intensive paired-associate training with visual shapes, we observed that baboons spontaneously ordered their responses in keeping with a recursive, centre-embedded structure. This result suggests that the human ability for recursion might partly if not entirely originate from fundamental processing cons…
A case of normal word reading but impaired letter naming
A case of a word/letter dissociation is described. The present patient has a quasi-normal word reading performance (both at the level of speed and accuracy) while he has major problems in nonword and letter reading. More specifically, he has strong difficulties in retrieving letter names but preserved abilities in letter identification. This study complements previous cases reporting a similar word/letter dissociation by focusing more specifically on word reading and letter naming latencies. The results provide new constraints for modeling the role of letter knowledge within reading processes and during reading acquisition or rehabilitation.
Does the mastery of center-embedded linguistic structures distinguish humans from nonhuman primates?
In a recentScience article, Fitch and Hauser (2004; hereafter, F&H) claimed to have demonstrated that cotton-top tamarins fail to learn an artificial language produced by a phrase structure grammar (Chomsky, 1957) generating center-embedded sentences, whereas adult humans easily learn such a language. We report an experiment replicating the results of F&H in humans but also showing that subjects learned the language without exploiting in any way the center-embedded structure. When the procedure was modified to make the processing of this structure mandatory, the subjects no longer showed evidence of learning. We propose a simple interpretation for the difference in performance observed in F…
Graphemic complexity and multiple print-to-sound associations in visual word recognition
Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands It has recently been reported that words containing a multiletter grapheme are processed slower than are words composed of single-letter graphemes (Rastle & Coltheart, 1998; Rey, Jacobs, Schmidt-Weigand, & Ziegler, 1998). In the present study, using a perceptual identification task, we found in Experiment 1 that this graphemic complexity effect can be observed while controlling for multiple print-to-sound associations, indexed by regularity or consistency. In Experiment 2, we obtained cumulative effects of graphemic complexity and regularity. These effects were replicated in Experiment 3 in a naming task. Overall, these r…
Do distractors interfere with memory for study pairs in associative recognition?
In an associative recognition task, distractors generally consist of a rearrangement of the items composing the study pairs. This makes it possible that processing the distractors generates retroactive interference on memory for the study pairs. In Experiment 1, we explored this possibility in a yes/no recognition test concerning previously learned arbitrary associations between visual symbols and auditory syllables. Rearranged pairs had a deleterious impact on the accuracy and the speed of responses to related correct pairs. This effect did not vary as a function of the number of training blocks, and furthermore, in Experiment 2, the same effect was observed for overlearned small multiplic…
Lexical and sublexical units in speech perception.
Saffran, Newport, and Aslin (1996a) found that human infants are sensitive to statistical regularities corresponding to lexical units when hearing an artificial spoken language. Two sorts of segmentation strategies have been proposed to account for this early word-segmentation ability: bracketing strategies, in which infants are assumed to insert boundaries into continuous speech, and clustering strategies, in which infants are assumed to group certain speech sequences together into units (Swingley, 2005). In the present study, we test the predictions of two computational models instantiating each of these strategies i.e., Serial Recurrent Networks: Elman, 1990; and Parser: Perruchet & Vint…
Where is the syllable priming effect in visual word recognition?
Recent studies using the masked priming paradigm have reported facilitating effects of syllable primes in French and English word naming (Ferrand, Segui, & Grainger, 1996; Ferrand, Segui, & Humphreys, 1997). However, other studies have not been able to replicate these effects in Dutch and English (Schiller, 1998, 1999, 2000). In Experiment 1, using the same stimuli and procedure as Ferrand et al. (1996), we did not replicate the syllable priming effect in French. In Experiments 2a and 2b, when prime duration was increased (from 30 to 45 and 60 ms), we did not obtain a syllable priming effect. In Experiment 3, with 60 participants and exactly the same procedure as Ferrand et al. (1996), we a…
Syllable onsets are perceptual reading units
Syllable onsets are defined as the initial consonant or consonant cluster in a syllable (e.g., BR in BREAD). In the present study, using a letter detection paradigm and French words, we tested whether syllable onsets are processed as units by the reading system. In Experiment 1, we replicated Gross, Treiman, and Inman's (2000) result of observing no difference between the detection latencies of letters embedded in a multi-letter syllable onset (e.g., c in ECLATER) relative to a single-letter syllable onset (e.g., C in ECARTER). In Experiment 2, participants took longer to detect the target letter when it was in the second position of a multi-letter onset (e.g., L in TABLIER) than when it wa…