Appetitive latent inhibition: impact of preexposure on the formation of conditioned reinforcers in rats

• Grant number: 20/11141-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): June 01, 2021
• Effective date (End): March 31, 2023
• Field of knowledge: Humanities - Psychology - Experimental Psychology
• Principal Investigator: Fábio Leyser Gonçalves
• Grantee: Victor Bastos Ventura
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

The various Latent Inhibition (LI) procedures are widely used to investigate positive symptoms of schizophrenia, especially dysfunctional selective attention processes. Understanding the selective attention deficit as the persistence of the control of a response by irrelevant stimuli. Thus, the repeated presentation of a stimulus without signaling a significant consequence, subsequently, reduces the conditioning of that stimulus to an unconditioned stimulus. Different conditioning protocols are used to assess the strength of conditioning between conditioned stimulus (CS) and unconditioned stimulus (US). Very commonly, they are protocols that use aversive stimuli, such as the procedure of conditioned aversion to taste (CTA) and conditioned emotional response (CER). Appetitive respondent conditioning protocols are also found, although little explored. The wide variety of aversive procedures with different measures in checking the interference of CS pre-exposure on an operating baseline, often results in evaluations of different stimulus functions, such as the consequence, in the case of CTA, and the conditioned suppression in the CER protocol. In appetitive procedures, the function linked to the CS is antecedent, guiding a response, different from interference on an operating baseline or the consequence function. We verified that one possibility would be to use the CS stimulus as a consequence of a class of responses operating in the elaboration of an appetitive protocol that approximates aversive LI protocols. The present study has as main objective to evaluate the impact of pre-exposure in a latent inhibition protocol on the formation of conditioned reinforcers. The protocol will use 20 male Wistar rats manipulated in four Skinner boxes controlled by a PC computer. The procedure involves 4 phases: in the baseline, two bars will be displayed, one bar turns on the light and the other bar emits a tone, both responses will be counted. In the pre-exposure phase, half of the subjects will be presented with a light stimulus (PE group), while the other half will not be presented with any stimulus (NPE group). In the conditioning phase, all rats received presentations of the light stimulus immediately followed by a pellet of food. The test phase will be identical to the baseline phase. The responses in each bar will be counted and compared to the baseline and across groups. (AU)