Operant theory and methodology in infant vocal conditioning

The numerous mechanisms of behavior change in infant development are sometimes difficult to distinguish. Although it is agreed that elicitation and reinforcement both influence infant learning, the distinction between these two learning mechanisms was clarified in response to K. Bloom's (1984, Journal of Experimental Child Psychology, 38, 93-102) commentary. The theoretical and methodological assumptions of an functional analysis of infant behavior were made explicit in the context of the C. L. Poulson study (1983, Journal of Experimental Child Psychology, 36, 471-489). The rationale for the use of DRO schedules to control for elicitation effects of continuous reinforcement and the inadequacy of noncontingent schedules for this purpose were also discussed.     

La construction sociale de la ressource en eau

This study deals with the way in which users represent water, how they perceive it, how they evaluate it (in terms of problem, in the space, and in the individuals–water relationship) and how they consume it according to the place where they live (Brittany vs. Paris Region; France), their attachment to this place and their level of personal involvement in relation to this resource. One hundred and ten semi-directive questionnaires, from both regions, were analyzed. The results show a social representation of the water based on two conceptions: the water is thought as vital natural resource or of consumption good. The study tends then to show the way in which these conceptions influence the evaluation of water quality and concerned practices.     

Dissociations in aphasia: A case report

This paper is a case study of an aphasic patient who displays two interesting characteristics, namely, (1) a dissociation between his oral and written disorders (i.e., oral Wernicke vs. written Broca); (2) an agraphia-alexia syndrome in which the picturability of the entities referred to by words plays an important role. Some of the characteristics shown by this patient have been well described concerning reading but never concerning writing. This second aspect is particularly emphasized.     

Play and cognition: Studies of pretence play and conservation of quantity

Study 1 examined the relative effectiveness of four different training conditions on the attainment of conversation of quantity. Subjects were 75 nonconserving preschoolers, ranging in age from 3.10 to 5.0 years. Treatment consisted of pretense play training, direct conservation training, a combination of pretense play and conservation training, mere exposure to the conservation tasks without the benefits of instruction, and a control condition which provided only conservation pre- and post-tests. The results of the two conservation post-tests indicated that a combination of pretense play and conservation training was the most effective condition, followed by the conservation training and then by the pretense play training. The data also suggested that the effects of the conservation-only training condition might be less stable than those attained with pretense play training. Study 2 compared the effectiveness of child initiated pretense play training with adult initiated play. Subjects were 47 nonconserving children ranging in age from 4.0 to 5.8. Treatment consisted of child initiated pretense play, adult initiated play, a condition which combined both treatments, and a control group. The results of the two conservation post-tests indicated that the child initiated pretense play training was most effective, followed by the combined condition and by the adult initiated training. The three pretense play training conditions induced significantly more conserving responses in previously nonconserving children than the control group.     

Differential reinforcement of other-than-vocalization as a control procedure in the conditioning of infant vocalization rate

The purpose of the present study is to demonstrate reinforcement control over infant vocalization rates using a DRO schedule to control for elicitation of social stimulation. Mothers of four 2 1/2- to 3-month-old infants provided social reinforcement for their infants' vocalization under two schedules: continuous reinforcement (CRF) and differential reinforcement of other-than-vocalization (DRO). In a repeated-reversal single-subject experimental design, all four infants produced systematically higher vocalization rates during CRF, even though densities of social stimulation during DRO were equal to or greater than densities provided during CRF. Thus, whatever its elicitation value, social stimulation may reinforce infant vocalization rates.