Behavioural Processes May 2018

To understand the interest in Amd et al. (2018: Effects of orientation and differential reinforcement II: transitivity and transfer across five-member sets), I need to summarize the Amd et al. (2017) part-1 study. People were trained on three-item equivalence classes and then tested for transitivity (e.g., A1-B1, B1-C1 were trained and A1-C1 was tested). Four training procedures were compared, but the two of interest were an operant one (symbolic MTS with reward--the same way that we've generally trained equivalence categories) and a Pavlovian one in which the A1 and B1 stimuli, for instance, just appeared after one another on the screen. For the key comparison, the participants had to make an orienting response (click a spot on a corner of the screen)--that is what 'orientation' means in the article title--to see the two stimuli. '''The interesting finding is that performance on transitivity tests was better for this orientation+S-S training than for the differentially rewarded S-R MTS training. '''The 2018 paper replicated and extended this effect to five-member sets (A1-B1-C1-D1-E1) and also demonstrated that affective responses associated with the A1 stimulus (an emotion-inducing face) became associated by transitivity with the other members of the equivalence class. ''I'm skeptical that you'd find this same orientatiion+contiguity > consequence effect with monkeys. If we didn't, it would be an interesting insight into how humans viewed the S-S presentation. But if we did replicate the effect, maybe this would provide an avenue into the other, elusive aspect of stimulus equivalence: symmetry. When we've studied stimulus equivalence in the past, using symbolic MTS training and testing, monkeys readily pass the transitivity test but reliably fail the (simpler) symmetry test (e.g., if A1-B1 then B1-A1)).''

If interested, see paper at https://www.sciencedirect.com/science/article/pii/S0376635717306046#bib0010

Other papers in the May 2018 issue of BP: aggressive b'ior by kittens during feeding; aggression in sows; a concurrent-conditioning study with pigeons; female-limited polymorphism in butterflies; ethanol consumption by rats in a maze; social structure of flamingos; social behavior of blackface sheep