Lightning talk - Room D (12:15 P.M.)

17. Matching-to-sample learning and transfer with patterned visual stimuli in rats

Makiko Kamijo-The University of Tokyo, Kazuo Okanoya-The University of Tokyo

Abstract concepts, rules about relations between stimuli, have been argued to be unique to limited species and the set size of training stimuli is important to form the abstract concept. For example, pigeons learn stimulus-response chains on matching-to-sample (MTS) tasks with a small set size of stimuli whereas they show abstract concept learning as the set size is increased. Here, we examined whether rats could learn the MTS task with visual stimuli and transfer their learning to novel stimuli. Four Long-Evans rats were trained on MTS procedure with patterned black-and-white visual stimuli in an operant chamber attached with an LCD. A trial began with the presentation of a sample, and response to the sample resulted in the appearance of the two comparisons. A response to the identical stimulus with the sample was reinforced with pellets. The acquisition training was started with one stimulus-set (sample: A, comparisons: A and B), and another stimulus-set (sample: C, comparisons: C and D) was added after rats accomplished the learning criteria. When rats reached the criteria with two stimulus sets, they were tested with novel stimuli and repeated the tests as training stimuli were increased. All rats accomplished the criteria and three rats showed the significant transfer to novel stimuli after the training with two or four stimulus sets in test sessions. And the accuracy of two rats out of three was equivalent to the training trials. These results suggest rats could acquire the abstract MTS concept. Supported by JSPS grant #4903, 17H06380.

18. Human Perceptual Learning: discrimination based on different rules

Marcela Lugo Hernández y Rosalva Cabrera Castañón Facultad de Estudios Superiores Iztacala-UNAM

The pre-exposition with compound stimuli had demonstrated that humans participants can to do more accurate discriminations in later tests as function of physical properties of the stimuli (Wang, Lavis, Hall & Mithell, 2008; Hall & Mitchell, 2014); nevertheless, it hasn´t demonstrated the rules abstracction with only to observe perceptual arrays that involved it. The purpose of this study is to evaluate in humans the perceptual learning of relations with compound visual stimuli. University students (n = 10) were randomly assigned to four groups. The stimuli, big white square (X) with a small square into (red or blue as distinctive characteristics A or B). During pre-exposition stimuli were arranged to exemplify two rules, which involved Colour and Position. Experimental group (EUD), was pre-exposed to arrays color 1-up position vs color 2-down-position; Experimental group (ELR) was pre-exposed to colour 1-left position vs colour 2-right position; the Control groups (CUD and CLR) were no pre-exposed. Later, in the test the four groups were exposed to choice multiple task in which they had to select three from six items, three of them (correct) exemplified the pre-exposed colour-position relation. The mean percent of correct responses was better to experimental groups (72%) that the control groups (45%), additionally, experimental groups showed an accuracy of 73% in their first choice. These results allow us to conclude that this experimental preparation of Perceptual Learning was effective to promoting the colour-position relationships learning. Key words: perceptive learning, rules, discrimination, colour-position, abstraction.

19. Two-item same/different categorization in pigeons

Francisca Diaz - University of Iowa Ellen O’Donoghue - University of Iowa Edward Wasserman - University of Iowa

The ability to determine if two or more items are the same as or different from each other is key for cognitive and behavioral adaptation. Research on same/different categorization has shown that abstract learning of these twin concepts can be affected by the number of items in the array to be categorized. Two-item categorization seems to be especially hard to learn for pigeons. This effect suggests that pigeons might base their categorization behavior on lower level strategies, such as relying on perceptual cues, instead of resorting to the abstract concepts of same and different. We trained 4 pigeons in a same/different categorization task using pairs of randomly generated color patches which were never repeated during training. Birds were simultaneously presented with two pairs of stimuli, and were reinforced for pecking the pair that consisted of two identical or different items depending on the color of the surrounding frame. Results provide evidence that pigeons can in fact learn the same/different categorization after training with pairs of stimuli that are never repeated during training.

20. Abstract oddity discrimination learning in rats

Qi Wang-Kanazawa University, Tohru Taniuchi-Kanazawa University

The present study examined oddity discrimination learning of visual stimuli and its cross-modal transfer to olfactory stimuli in rats. LE rats were trained to choose an odd stimulus among three identical visual stimuli presented simultaneously on a LCD screen. A well filled with sand was set as a goal in front of each visual stimulus. Positions of the odd and identical stimuli were changed trial to trial. Food rewards were set at the bottom of the wells, but rats were removed from the apparatus when they started to dig at an incorrect well. Therefore, possible odor cues from food rewards could not serve as an effective discriminative cue. Rats were concurrently trained with 30 oddity problems derived from six different visual stimuli A, B, C, D, E, or F. After rats achieved learning criterion of the training, six novel test problems of GGGH, GGGI, HHHG, HHHI, IIIG, and IIIH were inserted to the training trials. Although rats’ responses were rewarded non-differentially regardless of the stimuli in the test trials, test performance was significantly better than chance. After the first transfer test, six novel test problems derived from three different odors O1, O2, and O3 were inserted to the training trials with visual stimuli. Odor substances were applied to the edge of the goal wells. Four identical visual stimuli were presented in the odor trials. Rats also showed significant oddity performance to the odor stimuli. These results suggest that rats acquired the oddity discrimination at an abstract level.

21. Effect of variations on absolute and relative values of composed stimuli on perceptual learning

Bernardo Jiménez Santa Cruz y Rosalva Cabrera Castañón - Facultad de Estudios Superiores Iztacala-UNAM

The intermixed pre-exposure to composed stimuli produce better subsequent discrimination between them. Hall & Rodriguez (2019) had argued that intermixed presentation promotes the restore of the salience of the distinctive elements of composed stimuli. Variables such as the composition of the stimulus elements in different arrangement had received little attention. The purpose of present study was to evaluate the effect of changes on the configuration of the elements of stimuli, using an asterisk composed by four pairs of lines. Groups of students (n=10) were pre-exposed to intermixed presentations of AX/BX or CX/DX stimuli. For EGMM group, A was composed by two lines with minimum values of a continuous and B was composed by two lines of maximum values, whereas the common feature X was composed by intermediate values. For EGII group, C was composed by two lines, first line with minimum value and second line with intermediate value, while D had lines with a maximum and an intermediate value, X was composed by the remaining values. Groups CGMM and CGII were no pre-exposed. Later, four groups were exposed to discrimination task Same-Different. The results indicate a better performance in the group EGMM, whereas discrimination of EGII group was poor. These data allows us to suggest that salience of distinctive features is thoroughly based in the absolute values (minimum vs maximum) and relative values (different arrangements of same elements). Thus, composed stimulus in which the distinctive features have neutral values aren´t promoting the restore of the salience under intermixed pre-exposure. Key words: perceptual learning, absolute values, relative values, arrangement, salience.

22. Mental enumeration of object stimuli in rats

Tohru Taniuchi-Kanazawa University, Yuka Kurachi-Kanazawa University

We trained rats to respond to a “third” stimulus among six same objects arranged in a row. The objects were put on one of ten goal wells filled with sand in a rectangular open field. Food rewards were given at the bottom of a correct well (under the third object). Since the assignment of objects to the wells was changed trial to trial (third to seventh well could be the correct goal), rats could identify the correct stimulus based on neither location of specific goal box nor distance from start point. Additionally, inaccessible food rewards put in wire mesh tea strainers were set in the incorrect wells to control possible odor cues. Rats learned the numerical discrimination task reliably. In the next phase, partitions with openings were inserted between the goal wells and thus rats could encounter the object stimuli only sequentially. Although rats’ performances were deteriorated initially, they recovered rapidly and reached reliable levels. When different types of objects were introduced to the task, rats kept their good performance. These results suggest that rats can mentally enumerate the number of object stimuli in an abstract manner.