Annual Activity Report 2010

Populations with Developmental and/or Acquired Limitations in Symbolic Functioning

4: Perception, Discrimination, and Equivalence

4.1. The cumulative results aiming at understanding the development of processes of stimulus classification in human babies has produced the identification of optimal (or at least much improved) conditions and parameters of reinforcement, session duration, number of trials, and mastery criteria. Implementation of these conditions diminished experimental variability and yielded systematic and replicable data in the study of simple discrimination, discrimination reversal, identity conditional discrimination, generalized identity, and arbitrary conditional discrimination, in children in the age range of 15 to 24 months. The maintenance of the babies engaged in experimental sessions has been a fundamental conquest for the development of this line of investigation.

4.2. Studies on learning by exclusion advanced in several respects, including the demonstration of exclusion with children younger than those of previous studies.

4.2 (1) Babies with ages from 15 to 18 months showed exclusion responding, or fast mapping (rapid acquisition and retention of vocabylary, evidenced by emergent selections of an unfamiliar item in response to an unfamiliar item, concomitant with reliable selections of familiar items in response to familiar names), demonstrating, in new experimental preparations, the precociousness of this basic behavioral process in the human species. Animal studies of exclusion with Cebus and dogs also produced positive results, revealing an instigating prospect for data integration.

4.2 (2) Children with ages from 24 to 30 months learned by exclusion in the presence of new nonsense words simulating adjectives (properties), verbs (actions) and names, extending the generality of previously obtained data, which been described almost exclusively for names. This confirms the hypothesis that behavioral processes underlying exclusion with grammatical categories other than names are basically similar to those underlying names. This is an important contribution for the scientific analysis of processes of language acquisition in children with typical development, and may also be useful for planning preventive interventions with children at risk for delays in language acquisition.

4.3 Results on relational learning involving auditory stimuli, with children that recently received cochlear implant were extended and amplified. The institute demonstrated learning of auditory-visual conditional discriminations in this population, with various systematic replications. Results showed the incorporation of auditory stimuli into previously formed equivalence classes of visual stimuli, and the formation of new auditory-visual equivalence classes. A learning set effect (faster and more precise learning for successive problems) was also demonstrated. Children showed improvement in auditory tasks along a “curriculum” for teaching auditory-visual conditional discriminations with successive sets of words, and they also showed learning of auditory-visual conditional discrimination and recombinative generalization in matching-to-sample tasks with dictated sentences as samples.
Another advancement has been the improvement of a non-verbal operant procedure to obtain auditory tresholds with children with very recent implantation (who are not yet verbal). This procedure is been used not only in scientific research but also in clinical routines of implant adjustment.

5: Relational Learning in Basic Academics

5.1 The efficacy of a computerized individualized program to teach rudimentary reading skills, previously demonstrated with single subject designs, proved to be also robust in a group design. New studies explored variations in the basic procedure, such as specific differential consequences, adaptation of the program to a game setting, and access to games as a motivating condition to keep the student engaged in a longer teaching session.

5.2 (1) The Institute developed and evaluated a battery of tasks for assessment of pre-arithmetic behaviors, which will be important as a diagnostic tool.
5.2 (2) Studies demonstrated the efficacy of equivalence based instruction for the emergence of mathematical relations such as in teaching fractions.

6: Extensions to Neurobehavioral Science

6.1. Laboratory-Derived Neuropsychological Methodology. Researchers at the University of Massachusetts Medical School (UMMS, McIlvane, Dube) are in the late stage of a project designed to develop a mini-battery of neuropsychological tests for children with developmental limitations (e.g. preschool children, children with intellectual disabilities, etc.) that does not rely on syntactically-complex verbal instructions. The battery is designed also for adaptation to nonhuman primates, an extension that will be useful also in collaborations between the University Federal do Pará and the UMMS. The battery has tests for 1) sustained attention, 2) shifts in attention (executive functioning), 3) immediate and delayed memory, and 4) matching- and nonmatching to sample. There are two phases to the validation testing: 1) usability tests for psychologists and educators to assure that the test methods can be used appropriately by persons administering the tests and 2) tests of efficacy with children. The usability tests with professionals are underway, and the data to date indicate that the tests are both useful and desired by the target audience. The tests with children are also underway. Data thus far show that these tests can be used effectively with typically developing children in the 3-5 year age range. Data from the children with intellectual disabilities are also promising, but further work is indicated to adapt the methods for use with totally nonverbal children. We hope to complete the main phases of the project by December 2010, including efficacy evaluations on all of the neuropsychological tests with the children. Subsequent work will be targeted at reaching nonverbal children reliably via implementing a variety of stimulus control shaping methods that have been developed for this population in laboratory research conducted at UMMS and collaborating universities within the INCT-ECCE network.

6.2 Translational Studies of Neurobehavioral Effects of Mercury Exposure. This project is a collaboration between UMMS and UFPA researchers who will study the effects of mercury exposure on children in gold-mining areas of Brasil and in a nonhuman primate model. The work will be funded by the US National Institute of Environmental Health Sciences. Although this project was approved by the relevant Ethics Committees at UMMS and UFPA more than 16 months ago, securing the necessary approvals from the Brasilian and US governments required much more time than was anticipated. Approvals in Brasil were finalized in February 2010 and those in the US were finalized only in mid-April 2010. The US NIEHS is now in the process of issuing a “notice of grant award” (NOGA) to UMMS, which will allow the release of the financial support for the project. The NOGA is expected on or about May 1, 2010, which will permit the project to go forward. The initial planning meetings for the project will occur in late May 2010 when US and Brasilian researchers will meet at the meeting of the Association for Behavior Analysis in San Antonio (the end of May 2010) and in a follow-up at the ANPEPP meeting in Fortaleza in June 2010. We hope to have the funding subcontract issued to UFPA by July 1, 2010 to support the Brasilian collaborators working on the project.