Visual discrimination acquisition between compound stimuli and assessment of control by its components in bees (Melipona quadrifasciata)

• Grant number: 16/04834-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2016
• End date: July 31, 2017
• Field of knowledge: Humanities - Psychology
• Principal Investigator: Deisy das Graças de Souza
• Grantee: Natália Rodrigues Biscassi
• Host Institution: Centro de Educação e Ciências Humanas (CECH). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The expression control by elements refers to discriminative learning with limitations in the extent of discriminative control made by aspects of the stimulus correlated to reinforcement. Any stimulus owns several dimensions and when reinforcement is contingent on a response in presence of a compound stimulus (complex), the contingency will be attended even if the behavior occurs under the control of only one element of the compound stimulus, which would characterize as elementary control. This kind of phenomenon has been reported in studies with typical and atypical (autism and intellectual deficit) development individuals. Researches about elementary control in non-humans can help to determine variables involved in the occurrence of this phenomenon, with implications for its identification and control in natural situations. In a preliminary study with bees, conducted at this laboratory, all four subjects responded under discriminative control of all the elements of the compound visual stimulus, that is, without elementary control. However, the reduced number of subjects put in doubt the generalization of data. In a subsequent study, it was intended to replicate and extend the outcomes of the original study to a higher number of subjects, exposing each bee to a higher number of probe trials to assess the responses to each element of the compound stimulus. Twelve bees received the simple discrimination training (baseline) and elementary control test. The learning criteria in baseline was at least 90% of correct responses in two consecutive blocks with 20 trials, in a minimum of 80 training trials. Half of the bees had as positive stimulus (S+) a circle with white border and blue center and as negative stimulus (S-) a circle with a black border and a yellow center; to another half of bees, the stimuli's function was inverted. In the probe trials phase, the stimuli were decomposed into two positive elements and two negative elements (a circular border and a full circle which was the compound's center) and the landing frequency upon each component was analyzed. For each subject, 16 elementary control probe trials were conducted. Eight bees didn't present elementary control and four presented elementary control for the intern positive component of the compound stimulus. On average, it was observed general predominance in responding to a positive component located at the inner part of the disk (named as stronger S+ component). The positive component located at the extern part of the disk also controlled the bees' behavior, but to a lesser extent. In an analogous way, the negative component located at the inner part of the disk was the most rejected (stronger S- component). In the visual specter of this species of bees, the blue and yellow colors are better perceived than the black and white colors. Consequently, the pattern of the response observed might be due to a better perception of these colors by bees and not for the position of the elements in the compound. With the purpose to search a higher consistency in the interpretation of the result, the proposed study intends to replicate the procedure with twelve more bees, inverting the position of the colors in the disk, presenting a circle with a blue border and white center and a circle with yellow border and black center. Moreover, a preference test in extinction similar to probe trials phase will be added, with 16 trials to verify preference for the border or the center of positive and negative stimuli, interleaved by baseline trials. Such preference will be assessed by simultaneous presentation of the positive components in eight of 16 test trials foreseen; in the rest of test trials, the negative components will be presented simultaneously. (AU)