The theory of mental models explains the differences in effectiveness when deriving modus ponens (MP) and modus tollens (MT) conclusions. That differences arise from different numbers of mental modes that need to be constructed for a valid conclusion. However, directionality of the conditionals also affects the effectiveness of conclusions besides the number of models. Previous research has shown that the direction of conclusion can affect the response time. Also, contemporary studies have shown that many of cognitive processes (e.g. understanding of sentences) had a significant perceptual basis. This research tested the possibility of perceptual grounding of deductive reasoning. Direction of conditionals, as well as spatial orientation of antecedent and consequent content has been used as critical perceptual feature. Three-factor experiment was carried out. Perceptual priming, conditional direction and conclusion type were manipulated as independent factors. Participants’ task was to decide as quickly as possible whether the presented conditional conclusion was right or wrong. Perceptual priming, as well as conditional directionality, showed significant effect on MP conclusions. It is interesting that the clear effect of perceptual priming (which was also reversed when compared to MP one) was obtained for wrong MT conclusions where participants were supposed to press *No* as a corrrect answer. These findings supported the claim for perceptual grounding of mental models that are needed for deriving valid conclusions.

Psihologija