Abstract Learning to anticipate events based on the predictive relationship between an action and an outcome (operant conditioning) is a form of associative learning shared by humans and most of other living beings, including invertebrates. Several behavioral studies on the mechanisms of operant conditioning have included Melipona quadrifasciata, a honey bee that is easily manipulated due to lack of sting. In this work, brain proteomes of Melipona bees trained using operant conditioning and untrained (control) bees were compared by two-dimensional gel electrophoresis analysis within pI range of 3-10 and 4–7; in order to find proteins specifically related to this type of associative learning.One protein was detected with differential protein abundance in the brains of trained bees, when compared to not trained ones, through computational gel imaging and statistical analysis. This protein was identified by peptide mass fingerprinting and MS/MS peptide fragmentation using a MALDI-TOF/TOF mass spectrometer as one isoform of arginine kinase monomer, apparently dephosphorylated. Brain protein maps were obtained by 2-DE (Two-dimensional gel electrophoresis) from a total proteins and phosphoproteins extract of the bee Melipona quadrifasciata. One isoform of arginine kinase, probably a dephosphorylated isoform, was significantly more abundant in the brain of trained bees using operant conditioning. Arginine kinase has been reported as an important enzyme of the energy releasing process in the visual system of the bee, but it may carry out additional and unexpected functions in the bee brain for learning process.

This study established a simple simultaneous discrimination between a pair of two-element compound visual stimuli in children (Experiment 1) and bees (Melipona quadrifasciata, Experiment 2). The contingencies required discriminative control by the compound and the question was whether the accurate stimulus control reached at this level would hold for each individual element of the compound. After baseline reached stability, probe trials assessed stimulus control by each single element of both S+ and S-. Average data showed that children (Exp. 1) tended to show stimulus control by a single element of the S+ compound. In Experiment 2 three of four bees showed stimulus control by both elements of S+ and did not respond or responded only infrequently to the elements of the S-. The children's decline in discrimination accuracy in probe trials, along with its maintenance during the baseline, replicated previous findings showing the development of restricted stimulus control (RSC). The precise stimulus control shown by the bees indicated that all elements correlated with reinforcement acquired stimulus control over their behavior; this confirms the extensive literature on visual discriminative learning in bees, but due to the small number of subjects it is premature to say that bees do not develop RSC.

Two experiments evaluated an operant procedure for establishing stimulus control using auditory and electrical stimuli as a baseline for measuring the electrical current threshold of electrodes implanted in the cochlea. Twenty-one prelingually deaf children, users of cochlear implants, learned a Go/No Go auditory discrimination task (i.e., pressing a button in the presence of the stimulus but not in its absence). When the simple discrimination baseline became stable, the electrical current was manipulated in descending and ascending series according to an adapted staircase method. Thresholds were determined for three electrodes, one in each location in the cochlea (basal, medial, and apical). Stimulus control was maintained within a certain range of decreasing electrical current but was eventually disrupted. Increasing the current recovered stimulus control, thus allowing the determination of a range of electrical currents that could be defined as the threshold. The present study demonstrated the feasibility of the operant procedure combined with a psychophysical method for threshold assessment, thus contributing to the routine fitting and maintenance of cochlear implants within the limitations of a hospital setting.

O responder por "exclusão', que se supõe ser um dos mecanismos pelos quais crianças aprendem a relacionar palavras novas a objetos ou eventos, tem sido amplamente replicado em situação de laboratório. O presente estudo, conduzido com seis crianças, teve por objetivo investigar o responder por exclusão em um contexto de brincadeira, com estímulos manipuláveis, e verificar se este contexto favorece a aprendizagem da relação nome - objeto, após uma única tentativa de exclusão. Em cada tentativa o experimentador falava o nome de um brinquedo conhecido e a tarefa da criança era pegá-lo e jogá-lo dentro de uma caixa grande, disposta à frente da criança. Em meio a essas tentativas, eram introduzidas três sondas de exclusão (o nome falado era novo e havia um brinquedo novo exposto no ambiente); três outras sondas verificavam se a relação entre o nome e o brinquedo havia sido aprendida. Todas as crianças responderam por exclusão, mas somente uma mostrou aprendizagem após uma única tentativa.

Laboratory studies have repeatedly replicated the phenomenon of exclusion responding, which has been assumed as one of the mechanisms by which children learn to relate novel words to objects or events. The present study, conducted with six children, aimed to investigate exclusion responding in a play setting, with stimuli that could be manipulated, and to verify whether the play setting would favor learning of the relationships between names and objects after a single exclusion trial. In several trials the experimenter spoke the name of a familiar toy and the child's task was to pick this toy up and throw it into a box, placed in front of the child. Three exclusion probes were interspersed among these trials (the spoken name was novel and there was a novel toy available); three other probes verified whether the relationships between the novel name and the toy had been learned. All children responded by exclusion but only one of them demonstrated learning the relationships in a single trial.

Quatro estudantes com dificuldades na aquisição de leitura e escrita foram submetidos a um programa de ensino para o desenvolvimento de habilidades de consciência fonológica, com tarefas de identificação de rima e aliteração e análise e síntese silábica e fonêmica, enquanto continuavam sendo expostos a um programa individualizado para ensino de leitura, no qual não haviam obtido sucesso previamente. Todos os participantes apresentaram baixos escores no pré-teste da Prova de Consciência Fonológica, mas concluíram o programa com sucesso e apresentaram elevados escores no pós-teste. A aquisição de leitura e de escrita mostrou uma clara aceleração após o desenvolvimento das habilidades de consciência fonológica e o efeito foi replicado entre os quatro alunos. Os resultados confirmam descobertas prévias sobre a relação entre consciência fonológica e aquisição de leitura e escrita. Tendo em vista o baixo repertório de entrada dos participantes, mesmo após exposição prolongada ao ensino de leitura, estes resultados, aliados aos de pesquisas recentes, sugerem fortemente a importância de estratégias para promover o desenvolvimento de habilidades de consciência fonológica antes ou simultaneamente ao ensino de leitura e escrita. Essas estratégias são especialmente importantes para estudantes em risco para o fracasso na aquisição desses repertórios e que constituem o maior contingente de alunos que requerem procedimentos especiais de ensino.

Four elementary school children who had previously failed in the acquisition of reading and spelling were included in a teaching program designed to establish phonological awareness. Tasks required the identification of rhymes and alliteration, and syllabic and phonemic analysis and synthesis. All participants scored low on the pre-tests for assessment of phonological awareness, but were successful in completing the program and scored high on the post-test assessment. Reading and spelling acquisition showed a clear acceleration after the development of phonological awareness; the effects were reliably replicated among the four students. These results confirm previous findings on the relation between phonological awareness and reading and writing acquisition. Considering the participants' repertoires, after the long and unsuccessful initial exposure to teaching procedures, the present results, along with the conclusions of recent intervention studies, strongly suggest the relevance of teaching strategies to promote phonological awareness, either before or simultaneously with teaching reading and writing. This is especially important for students at risk of reading failure, the largest contingent of students who need special teaching procedures.