Arianna Bello

Hand action preparation influences the responses to hand pictures

The relations between stimuli triggering a hand grasping movement and the subsequent action were studied in normal human participants. Participants were instructed to prepare to grasp a bar, oriented either clockwise or counterclockwise, and to grasp it as fast as possible on presentation of a visual stimulus with their right hand. The visual stimuli were pictures of the right hand as seen in a mirror. In Experiment 1, they represented the mirror image of the hand final posture as achieved in grasping the bar oriented either clockwise or counterclockwise. In Experiment 2, in addition to the pictures of Experiment 1, another two pictures, obtained rotating the hands represented in the previous ones of 90 degrees, were also used. Both experiments showed that the reaction times were faster when there was a similarity between hand position as depicted in the triggering visual stimulus and the grasping hand final position, the fastest responses being those where this similarity was the closest. In addition, Experiment 2 showed that reaction times to not rotated stimuli were faster than reaction times to the rotated stimuli, thus excluding a simple stimulus-response compatibility explanation of the findings. The data are interpreted as behavioral evidence that there is a close link between specific visual stimuli and specific motor actions. A neurophysiological model for this visuo-motor link is presented.

Lexical production in children with Williams syndrome: spontaneous use of gesture in a naming task.

This study investigates lexical organization and lexical retrieval in children with Williams syndrome (WS), by examining both naming accuracy and accompanying use of gestures in a picture-naming task. Ten children with the genetic disorder of Williams syndrome (age range: 9.5-12.9) were compared with 20 typically developing children, 10 matched for chronological age (CA) and 10 for mental-age (MA). Lexical production was measured by administering the Boston Naming test (BNT). Older typically developing children performed significantly better than the other two groups. No differences in accuracy were found between the children with WS and the typically developing children matched for mental-age. The overall distribution of error types displayed by children with WS indicate that the lexical-semantic organization is similar to that of typically developing children. However, compared to controls, the WS group produced more iconic gestures during the task, in patterns that suggest the existence of specific word-finding difficulties in these children. Results are discussed within the framework of recent theories on the role of gesture in speech production.

Co-speech gestures in a naming task: Developmental data

Few studies have explored the development of the gesture-speech system after the two-word stage. Aim of the present study is to examine developmental changes in speech and gesture use, in the context of a simple naming task. Fifty-one children (age range: 2;3–7;6) were divided into five age groups and requested to name pictures representing objects, actions, or characteristics. In the context of a naming task that requires only the production of a single word, children produced pointing and representational gestures together with spoken responses. Pointing was the most frequent gesture produced by all groups of children. Among representational gestures, action gestures were more frequent than size and shape gestures. In addition, gesture production declined as a function of increasing age and spoken lexical competence. Results are discussed in terms of the links between action, gesture, and language, and the ways in which these may change developmentally.

Nouns and predicates comprehension and production in children with Down syndrome.

Our study investigated the lexical comprehension and production abilities as well as gestural production taking into account different lexical categories, namely nouns and predicates. Fourteen children with DS (34 months of developmental age) and a comparison group of 14 typically developing children (TD) matched for gender and developmental age were assessed through a test of lexical comprehension and production (PiNG) and the Italian MB-CDI. Children with DS showed a general weakness in lexical comprehension and production that appeared more evident when the lexicon was assessed through a structured test such as the PiNG that requires general cognitive skills that are impaired in children with DS. As for the composition of the lexical repertoire, for both groups of children, nouns are understood and produced in higher percentages compared to predicates. Children with DS produced more representational gestures than TD children in the comprehension tasks and above all with predicates; on the contrary, both groups of children exhibited the same number of gestures on the MB-CDI and during the subtests of PiNG production. Children with DS produced more unimodal gestural answers than the control group. Theoretical implications of these results are discussed.

Noun and predicate comprehension/production and gestures in extremely preterm children at two years of age: Are they delayed?

UNLABELLED Extremely low gestational age (ELGA, GA<28 weeks) preterm children are at high risk for linguistic impairments; however, their lexical comprehension and production as well as lexical categories in their early language acquisition have not been specifically examined via direct tools. Our study examines lexical comprehension and production as well as gestural production in ELGA children by focusing on noun and predicate acquisition. Forty monolingual ELGA children (mean GA of 26.7 weeks) and 40 full-term (FT) children were assessed at two years of corrected chronological age (CCA) using a test of noun and predicate comprehension and production (PiNG) and the Italian MB-CDI. Noun comprehension and production were delayed in ELGA compared with FT children, as documented by the low number of correct responses and the large number of errors, i.e., incorrect responses and no-response items, and by the types of incorrect responses, i.e., fewer semantically related responses, in noun production. Regarding predicate comprehension and production, a higher frequency of no responses was reported by ELGA children and these children also presented a lower frequency of bimodal spoken-gestural responses in predicate production than FT children. A delayed vocabulary size as demonstrated by the MB-CDI, was exhibited by one-fourth of the ELGA children, who were also unable to complete the predicate subtest. These findings highlight that noun comprehension and production are delayed in ELGA children at two years of CCA and are the most important indexes for the direct evaluation of their lexical abilities and delay. The types of incorrect responses and bimodal spoken-gestural responses were proven to be useful indexes for evaluating the noun and predicate level of acquisition and to plan early focused interventions. LEARNING OUTCOMES After reading this manuscript, the reader will understand (a) the differences in noun and predicate comprehension and production between ELGA and FT children and the indexes of lexical delays exhibited by ELGA children at 2;0 (CCA); (b) the relevance of evaluating errors (incorrect response and no response), the types of incorrect responses (semantically related and unrelated) and the modality of the responses (unimodal spoken and bimodal spoken-gestural) in noun and predicate production to understand the difficulties experienced by ELGA children in representing and expressing meanings; and (c) the need to plan specific interventions to support spoken and gestural modalities in lexical comprehension and production in ELGA children by focusing on noun and predicate acquisition.

A Developmental Study on Children's Capacity to Ascribe Goals and Intentions to Others.

The capacity to ascribe goals and intentions to others is a fundamental step in child cognitive development. The aim of the present study was to assess the age at which these capabilities are acquired in typically developing children. Two experiments were carried out. In the first experiment, 4 groups of children (age range = 3 years 2 months-7 years 11 months) were shown pictures representing hand-object interactions and asked what the individual was doing (what task) and why (why task). In the why task, observed handgrip could be either congruent with the most typical action performed with that object (e.g., to drink in the case of a mug) or corresponding to the act of putting away the object. In the second experiment, children saw pictures showing a handgrip either within a context suggesting the most typical use of the object or its being put away. Results showed that by 3-4 years, children are able to state the goal relatedness of an observed motor act (what understanding), whereas the ability to report the intention underlying it (why understanding) is a later and gradual acquisition, reaching a high performance by 6-7 years. These results, besides their intrinsic value, provide an important baseline for comparisons with studies on developmental disorders, also highlighting the relevance of distinguishing what and why understanding.

Gesture and Symbolic Representation in Italian and English-Speaking Canadian 2-Year-Olds.

Analyses of elicited pantomime, primarily of English-speaking children, show that preschool-aged children are more likely to symbolically represent an object with gestures depicting an objects form rather than its function. In contrast, anecdotal reports of spontaneous gesture production in younger children suggest that children use multiple representational techniques. This study examined the spontaneous gestures of sixty-four 2-year-old Italian children and English-speaking Canadian children, primarily from middle-class Caucasian families. The Italian children produced twice as many gestures as Canadian children in a picture-naming task but produced a similar range of representational techniques. Two-year-olds were equally likely to produce gestures depicting function as form. These data suggest young childrens communicative skills are supported by a symbolic capacity that reflects contextual communicative demands.

Types of prehension in children with Williams–Beuren syndrome: A pilot study

As part of a more extensive research program investigating cognitive, linguistic and motor skills in children with Williams – Beuren syndrome (WBS) we made some preliminary observations of prehension movements. Eight children, in a restricted age range (9 – 11 years), took part in the pilot study. We individuated and classified three types of prehension in two different tasks: the Developmental Test of Visual-Motor Integration (VMI) for assessing perceptual and motor skills, and the Movement Assessment Battery for Children (M-ABC) for assessing manual dexterity. Sixteen typically developing children, individually matched with WBS children, were also assessed, resulting in two different comparison groups: 8 children were matched for mental age and 8 for chronological age. A peculiar type of prehension (referred to as the “lateral grip”) was used by all children with WBS, but was only rarely observed in the comparison groups. These findings can contribute to a better description of motor development in children with WBS and to a better understanding of their visuospatial difficulties.