Marie-Germaine Pêcheux

Tactual habituation and discrimination of form in infancy: A comparison with vision.

Tactual discriminative abilities out of the control of vision are studied in 5-month-old infants, and compared with their visual discriminative abilities. The relevance of a habituation/reaction to novelty procedure in the tactual modality is tested. An infant control procedure is used in both modalities on 2 independent samples of 32 infants each. Habituation and discrimination occur tactually as well as visually, the duration of holds decreasing more than the duration of looks. Accumulated holding time is 3 times longer than accumulated looking time. Analogies and discrepancies between tactual and visual habituations are discussed, and the problem of sensory dominance is raised. Such results are basic to studies on cross-modal transfer, from vision to touch as well as from touch to vision.

Habituation Rate and Free Exploration Tempo in 4-Month-Old Infants

If rate of habituation reflects information processing speed and is a stable individual characteristic, fast habituators should habituate relatively quickly to any stimulus, and slow habituators relatively slowly. Moreover, rate of habituation should be related to the babys tendency to explore in any common situation. To examine these inferences, 24 four-month-old infants were habituated to four stimuli (two geometric patterns and two faces) successively, in two sessions, and observed in a free-exploration situation. The number of trials required to reach criterion in the habituation situations were not correlated, but total looking times to criterion were. Also, slow habituators stayed in the exploration situation for a relatively longer time and also explored a new toy for a longer time. Methodological aspects of habituation are discussed, and an interpretation of habituation sequences in terms of cognitive style is suggested.

Maternal scaffolding of attention between 5 and 8 months

Infants’ abilities to focus attention on objects and mothers’ behaviors mobilizing the attention of their child were studied in a sample of 30 dyads, at 5 and 8 months of age. It was hypothesized that at the younger age infants need their mothers’ scaffolding to explore their environment, and that the frequency of mothers’ encouragements at that age is related with their attentional capacities at 8 months; at this later age, mother’s and infant’s behaviors should no more be correlated. Data concerning both the total frequency of the target behaviors and the length of individual occurrences strongly confirm the hypotheses. They imply that in the mother attention getting should be distinguished from attention holding, and are discussed in terms of educational consequences.

Dyadic activities and attention in the infant: A developmental study

Infants’ abilities to focus attention on objects are known to be related to mothers’ mobilizing behaviors. As delayed effects of maternal behaviors at 5 months may be observed in 8-month-olds, mothers may be considered as scaffolding their infant’s attention. However, all dyadic activities are probably not equally propitious to attention mobilizing. In a sample of 30 dyads, studied at 5 and 8 months of age, whole observations were split in four broad categories: care, dyadic play with objects, dyadic play without objects and infant alone. The duration of maternal mobilizing and infant attention focussing were studied within categories. Inter-dyads variability is high, while dyads are stable across ages. Even within the dyadic play with objects, mothers differ widely in the duration and way they mobilize attention. Five-month-olds still need their mother’s support, as they explore less when they are alone, while 8-month-olds are more autonomous. The impact and importance of the various types of dyadic activities on cognitive development are discussed.

A continuous performance task in preschool children: Relations between attention and performance

The continuous performance task is currently used to detect attention disorders in school-age children. However, its use with younger children is problematical, because indices measuring attention indirectly (omissions, commissions, reaction time) may be distorted by difficulties in following instructions: the ability to maintain and manipulate instructions in working memory, and to inhibit inappropriate actions increases with age. In the present research, we adapted such a task for children between 2 years 6months and 5 years 6 months, and recorded visual activity in order to measure directly visual attention and to relate it to performance. Even very young children spend most of the time looking at the screen, but they display poor performances and are unable to re-engage in the task after a gap (2 consecutive omissions). At a medium level (age 3 years 6 months to 4 years) endogenous control of attention increases, children come back to the task, off-task looks shorten and reach the short values observed in older children. After 4 years 6 months no more gaps are observed, the consistency of reaction times shows that a controlled strategy, including shifts from and to the screen, is now adopted. The discussion suggests that only at this upper level do indirect performance indices evaluate attention.

Catégoriser à 13 et 16 mois : comparaison de deux méthodes

Two common tasks evaluating categorisation in infancy, examining and sequential touching, are compared in 13- and 16-month-olds. Various kinds of categorisation were suggested using plastic replicas of animals and vehicles: basic, superordinate and subordinate taxonomical categories (Rosch et al., 1976) and contextual categories (Mandler et al., 1988). Examining followed the design used by Oakes et al. (1996), i.e. habituation on 4 items with 12 trials, then reaction to novelty to a within-category and two out-category new stimuli. The same items were presented in the sequential touching task, each tray involving 4 items of two contrasted categories. Results confirm that success in categorisation appears earlier in the examining task than in the sequential touching task for all categories. The order of difficulty of categories is the same in both tasks and at both ages: superordinate, then subordinate, then basic and contextual. Last, no strong effect of age is observed. The discussion mentions the question of previous knowledge mobilised in both tasks; it further suggests that, as both tasks involve attention as a mean to evaluate cognitive activity, the characteristics of attention at the beginning of the second year need to be taken into account as well.

Attention visuelle et distractibilité chez des bébés de 3 à 5 mois

Development of sensitivity to distractors is explored in 3- to 5-month-old infants. A peripheral distractor was presented when infants sustained attention on a central stimulus for 4 seconds, and both targets remained present for 10 seconds. A session involved 5 trials, with the central stimulus changing from trial to trial, while the distractor remained the same. Moreover, infants were observed in an habituation situation. Two hypotheses were studied : first, as 3 months is a transition point concerning the development of the oculomotor system, important interindividual differences are expected. Second, such problems no longer occur in 5-month-old infants, thus no links between ages are expected, whereas habituation with trials should be observed. For 3-month-old infants, long latences were observed, which may correspond to difficulties in disengaging fixations. Two months later such long latencies were rare, and no individual stability was observed. Moreover habituation to the distractor appeared only in 5-month olds. Finally, correlations between fixation durations in both situations, distractor and habituation, were significant in 3-month olds. Results are discussed in relation to Colombos, Richardss and Ruffs data.