Investigation of preference for local and global processing of Capuchin-monkeys (Sapajus spp.) in shape discrimination of mosaic arrangements.

Classical experiments using hierarchical stimuli to investigate the ability of capuchin monkeys to integrate visual information based on global or local clues reported findings suggesting a behavioral preference for local information of the image. Many experiments using mosaics have been conducted with capuchin monkeys to identify some of their perceptual phenotypes. As the identification of an image in a mosaic demands the integration of elements that share some visual features, we evaluated the discrimination of shapes presented in solid and mosaic stimuli in capuchin monkeys. Shape discrimination performance was tested in 2 male adult capuchin monkeys in an experimental chamber with a touchscreen video monitor, in three experiments: (i) evaluation of global and local processing using hierarchical stimuli; (ii) evaluation of target detection using simple discrimination procedures; (iii) evaluation of shape discrimination using simple discrimination and delayed matching-to-sample procedures. We observed that both monkeys had preferences for local processing when tested by hierarchical stimuli. Additionally, detection performance for solid and mosaic targets was highly significant, but for shape discrimination tasks we found significant performance when using solid figures, non-significant performance when using circle and square shapes in mosaic stimuli, and significant performance when using Letter X and Number 8 shapes in mosaic stimuli. Our results are suggestive that the monkeys respond to local contrast and partly to global contrast in mosaic stimuli.

Chromatic discrimination in fixed saturation levels from tufted capuchin monkeys with different color vision genotypes.

Recent research has proposed new approaches to investigate color vision in Old World Monkeys by measuring suprathreshold chromatic discrimination. In this study, we aimed to extend this approach to New World Monkeys with different color vision genotypes by examining their performance in chromatic discrimination tasks along different fixed chromatic saturation axes. Four tufted capuchin monkeys were included in the study, and their color vision genotypes were one classical protanope, one classical deuteranope, one non-classical protanope, and a normal trichromat. During the experiments, the monkeys were required to perform a chromatic discrimination task using pseudoisochromatic stimuli with varying target saturations of 0.06, 0.04, 0.03, and 0.02 u'v' units. The number of errors made by the monkeys along different chromatic axes was recorded, and their performance was quantified using the binomial probability of their hits during the tests. Our results showed that dichromatic monkeys made more errors near the color confusion lines associated with their specific color vision genotypes, while the trichromatic monkey did not demonstrate any systematic errors. At high chromatic saturation, the trichromatic monkey had significant hits in the chromatic axes around the 180° chromatic axis, whereas the dichromatic monkeys had errors in colors around the color confusion lines. At lower saturation, the performance of the dichromatic monkeys became more challenging to differentiate among the three types, but it was still distinct from that of the trichromatic monkey. In conclusion, our findings suggest that high saturation conditions can be used to identify the color vision dichromatic phenotype of capuchin monkeys, while low chromatic saturation conditions enable the distinction between trichromats and dichromats. These results extend the understanding of color vision in New World Monkeys and highlight the usefulness of suprathreshold chromatic discrimination measures in exploring color vision in non-human primates.

Differences in chromatic noise suppression of luminance contrast discrimination in young and elderly people.

Aging causes impairment of contrast sensitivity and chromatic discrimination, leading to changes in the perceptual interactions between color and luminance information. We aimed to investigate the influence of chromatic noise on luminance contrast thresholds in young and older adults. Forty participants were divided equally into Young (29.6 ± 6.3-year-old) and Elderly Groups (57.8 ± 6.6-year-old). They performed a luminance contrast discrimination task in the presence of chromatic noise maskers using a mosaic stimulus in a mosaic background. Four chromatic noise masking protocols were applied (protan, deutan, tritan, and no-noise protocols). We found that luminance contrast thresholds were significantly elevated by the addition of chromatic noise in both age groups (P < 0.05). In the Elderly group, but not the younger group, thresholds obtained in the tritan protocol were lower than those obtained from protan and deutan protocols (P < 0.05). For all protocols, the luminance contrast thresholds of elderly participants were higher than in young people (P < 0.01). Tritan chromatic noise was less effective in inhibiting luminance discrimination in elderly participants.

Chromatic discrimination in fixed saturation levels from trichromats and subjects with congenital color vision deficiency.

Color vision tests use estimative of threshold color discrimination or number of correct responses to evaluate performance in chromatic discrimination tasks. Both approaches have advantages and disadvantages. In the present investigation, we compared the number of errors during color discrimination task in normal trichromats and participants with color vision deficiency (CVD) using pseudoisochromatic stimuli at fixed saturation levels. We recruited 28 normal trichromats and eight participants with CVD. Cambridge Color Test was used to categorize their color vision phenotype, and those with a phenotype suggestive of color vision deficiency had their L- and M-opsin genes genotyped. Pseudoisochromatic stimuli were shown with target chromaticity in 20 vectors radiating from the background chromaticity and saturation of 0.06, 0.04, 0.03, 0.02, 0.01, and 0.005 u'v' units. Each stimulus condition appeared in four trials. The number of errors for each stimulus condition was considered an indicator of the participant's performance. At high chromatic saturation, there were fewer errors from both phenotypes. The errors of the normal trichromats had no systematic variation for high saturated stimuli, but below 0.02 u'v' units, there was a discrete prevalence of tritan errors. For participants with CVD, the errors happened mainly in red-green chromatic vectors. A three-way ANOVA showed that all factors (color vision phenotype, stimulus saturation, and chromatic vector) had statistically significant effects on the number of errors and that stimulus saturation was the most important main effect. ROC analysis indicated that the performance of the fixed saturation levels to identify CVD was better between 0.02 and 0.06 u'v' units reaching 100%, while saturation of 0.01 and 0.005 u'v' units decreased the accuracy of the screening of the test. We concluded that the color discrimination task using high saturated stimuli separated normal trichromats and participants with red-green color vision deficiencies with high performance, which can be considered a promising method for new color vision tests based in frequency of errors.

Integrative Review of Developmental Behavior-Analytic Concepts.

We reviewed five behavior-analytic concepts related to development: behavioral trap, cumulative-hierarchical learning (CHL), basic behavioral repertoire (BBR), pivotal behavior, and behavioral cusp. We searched for terminological variations of the concepts in the CAPES Journals Portal and selected for analysis 31 peer-reviewed articles written in English or Portuguese, published between 1967 and 2021, that contained the search terms in the title, abstract, or keywords and contextualized in the main text. We analysed the conventional usage of the concepts, their conceptual limitations, and the relationships among them, declared or implied, and proposed a conceptual integration of the concepts under a CHL framework, following a path indicated by other authors. We considered BBR, pivotal behavior, and behavioral cusp nonsynonymous concepts of the same logical category, referring to prerequisites for important developmental outcomes and targets of CHL-inspired interventions but defined by different effects on subsequent behavioral development. The three concepts can be conflated in a superset-subset fashion, based on the specificity of their effects: BBR consists of a broad class of behaviors that may affect subsequent learning; the subclass of BBRs characterized by far-reaching collateral effects are classified as pivotal behavior, and the subclass of pivotal behaviors whose potential effects include contact with unprecedented environmental contingencies are classified as behavioral cusps. We propose that behavioral traps be explicitly incorporated in the CHL framework, to emphasize the environmental component of the cumulative-hierarchical learning process. Our formulation seems to organize the conceptual field in a way that respects the conventional use of concepts, preserving their strengths. Regardless of the specific formulation, we believe that integrating the various development-related concepts within a cumulative-hierarchical learning framework can encourage a more proactive integration of findings, questions, and practices informed by each concept, which could lead to the mutual refinement of the corresponding conceptual and methodological frameworks, as well as new research questions and practical applications. In particular, we expect that explicitly incorporating behavioral traps within the CHL framework will provide a useful heuristic model to guide research on how natural environmental contingencies influence the systematic transformation of behavior across the lifespan.

Effective use of the blank comparison procedure in simple discrimination by infant capuchin monkeys: A methodological note.

In studies of simple and conditional discrimination, procedures are needed to measure those aspects of stimuli that control behavior. The blank comparison procedure is one such procedure. It was designed explicitly for assessing S+ and S- functions when discriminative stimuli are presented simultaneously. In this procedure, a neutral stimulus serves sometimes as S+ and sometimes as S-. Its discriminative function is defined in relation to other stimuli in the display. The present study aimed to prepare 2 infant female capuchin monkeys for the effective use of the blank comparison procedure in a simple discrimination task. First, simple discrimination training was applied up to a stable accuracy criterion of ≥90%. This training was followed by the replacement of S+ and then of S- stimuli with new stimuli. Ultimately, trials with the blank comparison were introduced. Following this sequence, both monkeys immediately displayed highly accurate blank-comparison performances without the need for stimulus control shaping or other preparatory discrimination training. Thus, this procedure sequence may be an efficient, effective method for establishing blank-comparison baselines for experimental analyses of S+/S- discriminative functions and perhaps for other applications in teaching simple and conditional discrimination performances to this species and others.

Uniform trichromacy in Alouatta caraya and Alouatta seniculus: behavioural and genetic colour vision evaluation.

Primate colour vision depends on a matrix of photoreceptors, a neuronal post receptoral structure and a combination of genes that culminate in different sensitivity through the visual spectrum. Along with a common cone opsin gene for short wavelengths (sws1), Neotropical primates (Platyrrhini) have only one cone opsin gene for medium-long wavelengths (mws/lws) per X chromosome while Paleotropical primates (Catarrhini), including humans, have two active genes. Therefore, while female platyrrhines may be trichromats, males are always dichromats. The genus Alouatta is inferred to be an exception to this rule, as electrophysiological, behavioural and molecular analyses indicated a potential for male trichromacy in this genus. However, it is very important to ascertain by a combination of genetic and behavioural analyses whether this potential translates in terms of colour discrimination capability. We evaluated two howler monkeys (Alouatta spp.), one male A. caraya and one female A. seniculus, using a combination of genetic analysis of the opsin gene sequences and a behavioral colour discrimination test not previously used in this genus. Both individuals completed the behavioural test with performances typical of trichromatic colour vision and the genetic analysis of the sws1, mws, and lws opsin genes revealed three different opsin sequences in both subjects. These results are consistent with uniform trichromacy in both male and female, with presumed spectral sensitivity peaks similar to Catarrhini, at ~ 430 nm, 532 nm, and 563 nm for S-, M- and L-cones, respectively.

Specificity of the chromatic noise influence on the luminance contrast discrimination to the color vision phenotype.

Many studies have examined how color and luminance information are processed in the visual system. It has been observed that chromatic noise masked luminance discrimination in trichromats and that luminance thresholds increased as a function of noise saturation. Here, we aimed to compare chromatic noise inhibition on the luminance thresholds of trichromats and subjects with severe deutan or protan losses. Twenty-two age-matched subjects were evaluated, 12 trichromats and 10 with congenital color vision impairment: 5 protanopes/protanomalous, and 5 deuteranopes/deuteranomalous. We used a mosaic of circles containing chromatic noise consisting of 8 chromaticities around protan, deutan, and tritan confusion lines. A subset of the circles differed in the remaining circles by the luminance arising from a C-shaped central target. All the participants were tested in 4 chromatic noise saturation conditions (0.04, 0.02, 0.01, 0.005 u'v' units) and 1 condition without chromatic noise. We observed that trichromats had an increasing luminance threshold as a function of chromatic noise saturation under all chromatic noise conditions. The subjects with color vision deficiencies displayed no changes in the luminance threshold across the different chromatic noise saturations when the noise was composed of chromaticities close to their color confusion lines (protan and deutan chromatic noise). However, for tritan chromatic noise, they were found to have similar results to the trichromats. The use of chromatic noise masking on luminance threshold estimates could help to simultaneously examine the processing of luminance and color information. A comparison between luminance contrast discrimination obtained from no chromatic and high-saturated chromatic noise conditions could be initially undertaken in this double-duty test.

O Trabalho do Futuro? Motivações para o trabalho na economia compartilhada / The work of the future? Work motivations in the sharing economy / ¿El trabajo del futuro? Motivaciones para trabajar en la economía compartida

Os aplicativos de economia compartilhada impulsionaram um novo modelo de trabalho e um novo perfil de trabalhador. Considerando tal realidade, o presente estudo buscou identificar os principais motivadores de engajamento como trabalhador em plataformas de mobilidade urbana, mais especificamente de compartilhamento de carona (ridesharing). Em concomitância, investigou-se a influência de fatores socioeconômicos na relevância dos diferentes motivadores. Participaram da pesquisa quarenta e três motoristas de aplicativos, por meio online, a partir do aplicativo denominado Google Formulários. Para a análise de dados foi utilizado o modelo estatístico de regressão múltipla. Nos resultados encontrados, os motivadores considerados os mais relevantes para a escolha dos participantes foram Autonomia, Renda e Horário Flexível. Dos catorze motivadores investigados, dez apresentaram interações estatisticamente significativas com aspectos socioeconômicos. Os resultados também apontam diferenças entre os motivadores considerados como mais relevantes pelos participantes, quando comparados com estudos realizados em outros países. Salienta-se, portanto, a necessidade de um olhar diferenciado para a realidade brasileira.

Sharing economy applications have boosted a new work model and worker profile. The present study aimed to identify the main worker's motivators for engagement in urban mobility platforms, specifically in ridesharing applications. The influence of socioeconomic factors on the relevance of motivators was also investigated. Data was collected using an online survey from 43 drivers who work through applications. A multiple regression model was used for data analysis. The results showed that the most important motivators indicated by the participants were autonomy, income, and having flexible schedules. 10 out of the 14 motivators studied had significant interactions with socioeconomic aspects. The results also point out differences between the motivators considered most relevant by the participants, when compared to studies carried out in other countries. Therefore, a specific approach to this topic which is compatible with the Brazilian reality is needed.

Los aplicativos de movilidad urbana impulsaron un nuevo modelo de trabajo y un nuevo perfil de trabajadores. Considerando tal realidad, este estudio buscó identificar los principales motivadores de la participación como trabajador en plataformas de movilidad urbana, más específicamente de viajes compartidos. En concomitancia, fue investigada la influencia de los factores socioeconómicos en la relevancia de los diferentes motivadores. Participaron de la pesquisa cuarenta y tres conductores de aplicativos, por medio on line, a través del aplicativo denominado Google Formulários. Para el análisis de datos, se utilizó el modelo estadístico de regresión múltiple. Según los resultados, los motivadores considerados más relevantes para los participantes fueron Autonomía, Ingresos y Horas Flexibles. De los catorce motivadores investigados, diez tuvieron interacciones estadísticamente significativas con aspectos socioeconómicos. Comparado con estudios realizados en otros países, los resultados mostraron diferencias entre los motivadores mas relevantes. Por lo tanto, se enfatiza la necesidad de una mirada diferente, ajustada a la realidad brasileña.

Spatial frequency selectivity of the human visual cortex estimated with pseudo-random visual evoked cortical potential (VECP).

Single-cell recordings in the primary visual cortex (V1) show neurons with spatial frequency (SF) tuning, which had different responses to chromatic and luminance stimuli. Visually evoked cortical potential (VECP) investigations have reported different spatial profiles. The current study aimed to investigate the spatial selectivity of V1 to simultaneous stimulus of chromatic and luminance contrasts. Compound stimuli temporally driven by m-sequences at 8 SFs were utilized to generate VECP records from thirty subjects (14 trichromats and 16 colorblind subjects). We extracted the second-order kernel, first and second slices (K2.1 and K2.2, respectively). Optimal SF, SF bandwidth, and high SF cut-off were estimated from the best-fitted functions to the VECP amplitude vs SF. For trichromats, K2.1 waveforms had a negative component (N1 K2.1) at 100 ms followed by a positive component (P1 K2.1). K2.2 waveforms also had a negative component (N1 K2.2) at 100 ms followed by a positive deflection (P1 K2.2). SF tuning of N1 K2.1 and N1 K2.2 had a band-pass profile, while the P1 K2.1 was low-pass tuned. P1 K2.1 optimal SF differed significantly from both other negative responses and from P1 K2.2. We found differences in the optimal SF, SF tuning and high SF cut-off among the VECP components. Dichromats had little or no response for all stimulus conditions. The absence of the responses in dichromats, the similarity between the high SF cut-off of the pseudorandom VECPs and psychophysical chromatic visual acuity, and presence of multiple SF tunings suggested that pseudorandom VECPs represented the activity of cells that responded preferentially to the chromatic component of the compound stimuli.

Effect of the Decrease in Luminance Noise Range on Color Discrimination of Dichromats and Trichromats.

Color vision assessment can be done using pseudoisochromatic stimuli, which has a luminance noise to eliminate brightness differences between the target and background of the stimulus. It is not clear the influence of the luminance noise on color discrimination. We investigated the effect of change in the luminance noise limits on color discrimination. Eighteen trichromats and ten congenital dichromats (eight protans, two deutans) had their color vision evaluated by the Cambridge Colour Test, and were genetically tested for diagnostic confirmation. The stimuli were composed of a mosaic of circles in a 5° circular field. A subset of the circles differed in chromaticity from the remaining field, forming a letter C. Color discrimination was estimated in stimulus conditions differing in luminance noise range: (i) 6-20 cd/m2; (ii) 8-18 cd/m2; (iii) 10-16 cd/m2; and (iv) 12-14 cd/m2. Six equidistant luminance values were used within the luminance noise limits with the mean stimulus luminance maintained constant under all conditions. A four-alternative, forced-choice method was applied to feed a staircase procedure to estimate color discrimination thresholds along eight chromatic axes. An ellipse model was adjusted to the eight color discrimination thresholds. The parameters of performance were threshold vector lengths and the ellipse area. Results were compared using the Kruskal-Wallis test with a significance level of 5%. The linear function model was applied to analyze the dependence of the discrimination parameters on the noise luminance limits. The first derivative of linear function was used as an indicator of the rate of change in color discrimination as a function of luminance noise changes. The rate of change of the ellipse area as a function of the luminance range in dichromats was higher than in trichromats (p < 0.05). Significant difference was also found for individual thresholds in half of the axes we tested. Luminance noise had a greater effect on color discrimination ability of dichromats than the trichromats, especially when the chromaticities were close to their protan and deutan color confusion lines.

The Adventures of Amaru: Integrating Learning Tasks Into a Digital Game for Teaching Children in Early Phases of Literacy.

In low-income countries, the history of academic failure is a liability for children acquiring literacy skills. It is thus important to develop strategies that motivate and focus these students on specific strategies to learn to read. Digital games can be useful in motivating students and assisting teachers in the teaching-learning process, but there are few interactive tools that effectively integrate tasks of direct instruction and good gameplay. This technical report describes an interactive digital game to engage students in the initial phase of reading skills acquisition, whose design incorporates evidence-based procedures. The game, called "The Adventures of Amaru," aims to promote word coding-decoding skills and vocabulary growth through teaching trials. We discuss the adaptation of reading teaching curricula, their limitations and future implications of the use of this game by children from a low-income background.

Color discrimination in the tufted capuchin monkey, Sapajus spp.

The present study evaluated the efficacy of an adapted version of the Mollon-Reffin test for the behavioral investigation of color vision in capuchin monkeys. Ten tufted capuchin monkeys (Sapajus spp., formerly referred to as Cebus apella) had their DNA analyzed and were characterized as the following: one trichromat female, seven deuteranope dichromats (six males and one female), and two protanope males, one of which was identified as an "ML protanope." For their behavioral characterization, all of the subjects were tested at three regions of the Commission International de l'Eclairage (CIE) 1976 u'v' diagram, with each test consisting of 20 chromatic variation vectors that were radially distributed around the chromaticity point set as the test background. The phenotypes inferred from the behavioral data were in complete agreement with those predicted from the genetic analysis, with the threshold distribution clearly differentiating between trichromats and dichromats and the estimated confusion lines characteristically converging for deuteranopes and the "classic" protanope. The discrimination pattern of the ML protanope was intermediate between protan and deutan, with confusion lines horizontally oriented and parallel to each other. The observed phenotypic differentiation confirmed the efficacy of the Mollon-Reffin test paradigm as a useful tool for evaluating color discrimination in nonhuman primates. Especially noteworthy was the demonstration of behavioral segregation between the "classic" and "ML" protanopes, suggesting identifiable behavioral consequences of even slight variations in the spectral sensitivity of M/L photopigments in dichromats.

Restricted stimulus control in stimulus control shaping with a capuchin monkey

Teaching the first instances of arbitrary matching-to-sample to nonhumans can prove difficult and time consuming. Stimulus control relations may develop that differ from those intended by the experimenter-even when stimulus control shaping procedures are used. We present, in this study, efforts to identify sources of shaping program failure with a capuchin monkey. Procedures began with a baseline of identity matching. During subsequent shaping trials, compound comparison stimuli had two components-one identical to and another different from the sample. The identical component was eliminated gradually by removing portions across trials (i.e., subtracting stimulus elements). The monkey performed accurately throughout shaping. At a late stage in the program, probe tests were conducted: (1) arbitrary matching trials that had all elements of the identical comparison removed and (2) other trials that included residual elements. During the test, the monkey performed at low levels on the former trials and higher levels on the latter. These results suggested that higher accuracy was due merely to continued control by the residual elements: the target arbitrary matching relations had not been learned. Thus, it appears that procedures that gradually transform identity matching baselines into arbitrary matching can fail by inadvertently shaping restricted control by residual elements. Subsequent probes at the end of the shaping series showed a successful transfer of stimulus control from identity to arbitrary matching after further programming steps apparently overcame the restricted stimulus control.

Testes de identidade generalizada com objetos em macaco-prego (Cebus apella) / Generalized identity tests with objects in capuchin monkeys (Cebus apella)

Macacos-prego demonstram identidade generalizada (IG) quando os testes são precedidos de treino de discriminações simples com mudanças sucessivas (DSMS) da função dos estímulos usados nos testes. O presente estudo avaliou se esse efeito facilitador deve-se exclusivamente ao contato prévio com os estímulos. Submeteu-se um macaco-prego a quatro testes de IG com objetos: Teste 1 - diretamente com estímulos novos em uma tarefa de discriminação condicional por identidade; Teste 2 - com os mesmos estímulos do teste anterior após o treino de indução de controle condicional via DSMS; Teste 3 - com estímulos novos previamente manipulados livremente pelo sujeito; e Teste 4 - com os mesmos estímulos do Teste 3 após terem sido apresentados em treino de DSMS. O desempenho do sujeito atingiu o critério de aprendizagem nos testes 2 e 4. O treino de indução de controle condicional via DSMS com os estímulos de teste foi mais efetivo para produzir IG do que a livre manipulação.

Capuchin monkeys show generalized identity (GI) when tests are preceded by repeated shifts of simple discrimination training (RSSD) with stimuli used in tests. The present study evaluated if that facilitating effect of RSSD training could be due exclusively to the previous contact with the testing stimuli. It was given to a male capuchin monkey four GI tests with objects: Test 1 - an identity conditional discrimination task with new stimuli; Test 2 - with the same stimuli used in Test 1 after RSSD training to induce conditional control; Test 3 - with new stimuli, freely manipulated by the subject previously; and Test 4 - with the same stimuli used in Test 3 after RSSD training. The subject's performance reached the learning criterion in Tests 2 and 4. RSSD training was more effective than free manipulation to produce immediate matching to sample with new stimuli.

Pode o comportamento do ouvinte ser considerado verbal? / Should the behavior of the listener be deemed verbal

O objetivo deste trabalho é demonstrar, a partir de uma análise da noção de “comportamento de ouvinte” na obra de Skinner, que afirmar que o comportamento do ouvinte não é verbal é incoerente com a própria definição de comportamento verbal do autor. Aos resultados dessa análise conceitual, seguem-se considerações sobre a complementação do tratamento do ouvinte feita por Skinner em 1989. Em seguida, são apresentadas outras propostas para o estudo do comportamento verbal, nas quais se avalia que o comportamento do ouvinte recebeu tratamento aparentemente mais coerente com sua relevância para o episódio verbal. A presente discussão visou a fomentar uma apropriação mais crítica da terminologia proposta por Skinner para o tratamento do comportamento verbal. Tal esforço se alicerça na percepção de que quaisquer incoerências no tratamento conceitual de um fenômeno fatalmente levarão a incoerências em todos os níveis do empreendimento científico relacionado com este fenômeno.

The present paper aims to show that, based on an analysis of the notion of “behavior of the listener” in Skinner’s work, the claim that the behavior of the listener is not verbal is inconsistent with the definiton of verbal behavior. Following the results of such conceptual analysis, some considerations are made on Skinner’s revision of the behavior of the listener. Also presented are some alternative approaches for the study of verbal behavior, in which the behavior of the listener seems to have received a treatment more coherent with its importance for the verbal episode. The discussion presented here seeks to encourage a more critical use of the terminology proposed by Skinner, based on the realization that any inconsistence in the conceptual treatment of a given phenomenon will inevitably lead to inconsistency in every level of the scientific enterprise related to that phenomenon.

Busca de formação de classes de estímulos via procedimento de reversões repetidas de discriminações simples combinadas em macaco-prego (Cebus apella) / Search for stimulus class formation via repeated reversals procedure of matched simple discriminations in a capuchin monkey (Cebus apella)

Classes funcionais e classes de equivalência são obtidas com dificuldade com sujeitos não-humanos e podem refletir os mesmos processos comportamentais. O presente trabalho explorou o uso do procedimento de reversões repetidas de discriminações simples (RRDS) para a formação de classes funcionais com um macaco-prego como sujeito. Foram conduzidos três experimentos. Os Experimentos 1 e 2 tiveram como objetivo o estabelecimento de classes funcionais, por meio do treino de RRDS combinadas, com três conjuntos de dois estímulos. Os desempenhos do sujeito em testes subseqüentes não apresentaram as evidências esperadas de formação das duas classes de três membros. O Experimento 3 consistiu da utilização de dois conjuntos de dois estímulos, ao invés de três conjuntos, no treino de RRDS combinadas. Os resultados dos testes de formação de classes não foram conclusivos. É provável que o desenvolvimento de topografias de controle de estímulos diferentes daquelas previstas pelo experimentador tenham dificultado o estabelecimento de classes funcionais. Atualmente estão em andamento experimentos para averiguar esta hipótese

Escola experimental de primatas / Experimental school for primates

Aproximando, metaforicamente, os termos "laboratório" e "escola", o presente trabalho apresenta um programa de pesquisa experimental que visa desenvolver procedimentos para a construçäo de repertório simbólico em macacos-prego (Cebus apella). A metáfora "laboratório-escola" justifica-se pela semelhança dos procedimentos de treino de discriminaçöes ou relaçöes com programas de ensino de tarefas gradualmente mais complexas. O desafio tem sido o de manter o comportamento dos "aprendizes" sob controle das propriedades da tarefa programadas pelo experimentador. Os procedimentos säo permanentemente avaliados em funçäo da efetividade para produzir a planejada formaçäo de relaçöes näo diretamente treinadas entre estímulos. Os resultados obtidos demonstram a aquisiçäo do conceito de identidade e indicam a possibilidade de ensino de repertórios mais complexos, que säo pré-requisitos para o comportamento simbólico e o possível aproveitamento de tecnologia para ensino desse tipo de repertório a pessoas com dificuldades no desenvolvimento de funcionamento simbólico convencional.