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

1. Long-term working memory retention in aged rats in the radial maze

Chiaki Tanaka-Kanazawa University, Tohru Taniuchi-Kanazawa University

Crystal & Babb (2008) reported that rats could retain spatial memory in the eight-arm radial maze for 25 h. The present study examined long-term retention of spatial memory in the radial maze in aged rats of 21-months-old. A trial consisted of a learning phase, a retention interval and a test phase. In the learning phase, rats were given forced choices of randomly selected four arms of the radial maze. In the test phase after the retention interval, rats were required to choose the four arms of the eight-arm radial maze they had not visited in the learning phase. The retention interval was started for 1 minute, and then gradually extended to 1 h, 24 h, and 48 h, and finally 72 h. Rats’ performance in the test phase exceeded chance level of 50% correct in all the retention interval conditions. 95% confidence interval analysis revealed that the rats’ performance was reliably better than chance level, not only in the 48 h retention condition.


2. Long-term memory retention in young rats in the radial maze

Kanji Hayashida-Kanazawa University, Chiaki Tanaka-Kanazawa University, Tohru Taniuchi-Kanazawa University

Tanaka and Taniuchi (ISCP 2021) reports 72 h retention of spatial working memory in an eight-arm radial maze in aged rats. This 72 h is the longest retention interval that has been reported in an eight-arm radial maze in rats. However, Tanaka and Taniuchi (ISCP 2021) used aged rats of 21-months-old that have been reported to show relatively poorer memory retention in the radial maze. Therefore, the purpose of the present study to replicate the findings in Tanaka and Taniuchi (2021, ISCP) in young rats and to examine a possibility of longer retention of spatial working memory in the eight-arm radial maze. A trial consisted of a learning phase, a retention interval and a test phase. In the learning phase, forced choice of four arms of the radial maze was given by opening the doors of the arms in a designated order. In the test phase after the retention interval, a free choice test among the eight arms was give. The retention interval was started from 1 minute and gradually extended to 72 h. Rats’ performance in the 72 h retention condition significantly exceeded chance level of 50% correct replicating the findings of Tanaka and Taniuchi (ISCP 2021). We will report results in the 96 h or longer retention conditions at the meeting.


3. Conditional self-discrimination in zebrafish, in a spatial choice paradigm under positive reinforcement

Karen Gazca & Julio C. Penagos-Corzo Universidad de las Américas Puebla

In conditional self-discrimination a discriminative stimulus that is some aspect of the individual is associated with arbitrary stimuli. Because zebra fish is capable of perform recognition between conspecific, as well as locate an associated reward at a location, this study propose that probably it learn a conditional self-discrimination task in a paradigm spatial choice under positive reinforcement. For this purpose, a conditional self-discrimination model was tested on four male zebrafish of approximately one year old. The experimental subjects lived in a dark light cycle 14/10 and were fed with a fishmeal and fish protein concentrate enriched with vitamins and minerals. The experimental task was done in a square maze, submerged in water, of 10x10cm, with 1cm wide and 3.5cm high. Yellow and red, were used as comparator stimuli. The discriminative stimuli of the state itself were turn left (TL) and turn right (TR). The animals were exposed to a 16 conditioned sessions, divided in two conditions, one for TL and other for TR, interspersed for 12 hours. Each session consisted in a FR:1 program for five minutes. The results, although preliminary, indicated response rates in the direction of expected learning. The trend in the number of errors was towards a sustained decline, while that of hits showed an equally sustained increase. These findings are encouraging to continue research in an unexplored species in conditional self-discrimination.

4. Variability and exploration behavior in virtual mazes with humans

Idania Zepeda -Centro de Investigación en Conducta y Cognición Comparada Universidad de Guadalajara-Cuciénega Mitzi Salas -Centro de Investigación en Conducta y Cognición Comparada Universidad de Guadalajara-Cuciénega Dil Romero -Centro de Investigación en Conducta y Cognición Comparada Universidad de Guadalajara-Cuciénega

Environmental characteristics like shape, color, texture, size, affect velocity, acceleration, and variability behavior; that is, changes in layout environment imply changes in the routes that people or animals choose to reach a goal in a maze. Layout with more order allows precisely orientation and less variability, while layouts with less order can difficult orientation and produce more variability behavior. The goal of this research was to evaluate variability behavior in routes that choose participants in a virtual maze with different layouts. Four different mazes were created with Maze Suite software. Each maze was different in several routes to came to the goal. Forty university students participated in the experiment; they were assigned to two groups. Group 1was exposed to four mazes in ascendant order that is the first maze was less complex, and the finished maze was more complex than the previous one. Group 2 was the same exposition in inverse order. Both groups were exposed 20 trials, five per each maze. The results show different levels of variability behavior and execution time to reach the goal. The results are discussed considering variability or stereotyping in the route, exploratory behavior, and affordances in the mazes.

5. Probability, Feedback and Exploratory Behavior

Pablo Covarrubias-University of Guadalajara, Ma. Guadalupe Covarrubias Godínez-University of Guadalajara

It has been reported that exploratory behaviors (i.e., variations and repetitions) are distributed depending on the probabilistic structure of the task, which suggests that by these searching activities perceivers reveal the informative structure of the task. The feedback provided in that study was visual (i.e., the arrow’s trajectory) and verbal (i.e., a correct or incorrect label) as a compound. In the present study however we evaluated the way that feedback guides exploratory behaviors by providing visual and verbal feedback, separately. In two experiments we exposed participants to probabilistic structures in which the spatial relations between initial and final arrow’s trajectories were programmed under three probabilities (p= 1.0, 0.9, and 0.8). In the middle of the session, arrows’ trajectory shifted from straight to broken or vice versa. Results showed that with visual feedback (Experiment 1), variations increased and decreased under low and high values of probability, respectively. The opposite effect was observed in repetitions. Additionally, more variations and fewer repetitions were observed under broken than straight trajectories. With verbal feedback (Experiment 2), variations and repetitions were not distributed as a function of the probability nor the arrow’s trajectory. These results suggest that feedback guided the exploratory behaviors for detecting the probabilistic structure of the task when visual but verbal feedback was provided.


6. Rats (Rattus norvegicus) failed to show prospective information-seeking in an object exploration task

Sumie Iwasaki-Kanazawa University, Tohru Taniuchi-Kanazawa University

Information-seeking behavior is in line with research on metacognition in non-human animals; some species seek more information when they do not know the location of a food reward. Rats are also known to seek information in uncertain situations, but it is still unclear that they seek information prospectively depending on the availability of information in a later test. In the present study, we investigated rats’ information-seeking responses to two competitive areas. In one area, a memory task was required in the later test phase; rats were able to access a cue for a food reward in an information-seeking phase prior to the test, but the cue was removed in the subsequent test phase. In the other area, a discrimination task was required in the test phase; a cue was available in both the information-seeking and choice test phases so that it was not necessary to seek information prospectively in the information-seeking phase. The discrimination test and the memory test trials were given in quasi-random orders. Results showed that rats tended to stay longer in the discrimination task area than the memory task area during the information-seeking phase. The results show that rats failed to seek information effectively in the present task.