What makes a landmark effective? Sex differences in a navigation task

Abstract

In Experiment 1, two groups of female rats were trained in a triangular pool to find a hidden platform whose location was defined in terms of a single a landmark, a cylinder outside the pool. For one group, the landmark had only a single pattern (i.e., it looked the same when approached from any direction), while for the other, the landmark contained four different patterns (i.e., it looked different when approached from different directions). The first group learned to swim to the platform more rapidly than the second. Experiment 2 confirmed this difference when female rats were trained in a circular pool but found that male rats learned equally rapidly (and as rapidly as females trained with the single-pattern landmark) with both landmarks. This second finding was confirmed in Experiment 3. Finally, in Experiment 4a and 4b, male and female rats were trained either with the same, single-pattern landmark on all trials or with a different landmark each day. Males learned equally rapidly (and as rapidly as females trained with the unchanged landmark) whether the landmark changed or not. We conclude that male and female rats learn rather different things about the landmark that signals the location of the platform.

Navigation with two landmarks in rats (Rattus norvegicus): The role of landmark salience.

“…Only when the landmark looks the same from different perspectives (like a plain cone, but not a pyramid), females show a preference for it. In addition, male and female rats can learn rather different things about a single landmark that signals the location of a hidden platform (Chamizo, Rodríguez, Torres, Torres, & Mackintosh, 2014). We believe that such differences between males and females could have many important implications and deserve further research.…”

What makes a landmark effective in adolescent and adult rats? Sex and age differences in a navigation task

“…When rats are trained in a circular pool to find a hidden platform whose location is defined in terms of a single landmark outside the pool, Chamizo et al (2014) have shown that adult male and female rats do not seem to learn the same things about the landmark (for a similar result, see also Torres et al, 2014). Chamizo et al found that the nature of the landmark affected only the behavior of females, and not that of males.…”

Geometry learning while navigating: The importance of task difficulty and sex differences.

“…They were located at positions A, B, C, and D as follows: at A, a 6.5-cm diameter white can, 12 cm high; at B, a white ninepin, 6 cm in diameter at the base and 16.5 cm in height, with the wider part measuring 26 cm in circumference; at C, a white funnel, 10 cm in diameter at the top and 14 cm in height, with the narrowest part at the base measuring 1 cm in diameter; and at D, an 8-cm diameter white cup, 9 cm high. Importantly, all four landmarks (as well as those used in Experiment 2) looked the same from all perspectives in order to avoid unwanted problems in the females (Chamizo et al, 2014; Torres, Rodríguez, Chamizo, & Mackintosh, 2014).…”

“…Answering this question is important because it has been shown, in rodents and in humans, that when trained to find a hidden goal in the presence of geometrical and nongeometrical cues, in the two species mentioned, males seem more likely to rely on geometrical information to reach the goal, while females are more likely to use landmarks (in rats, see Rodríguez, Torres, Mackintosh, & Chamizo, 2010; Williams, Barnett, & Meck, 1990; in humans, Sandstrom, Kaufman, & Huettel, 1998; Ward, Newcombe, & Overton, 1986). Moreover, even when only landmark learning is addressed, males seem to learn different things than females about a single landmark that signals the location of a hidden platform (Chamizo, Rodríguez, Torres, Torres, & Mackintosh, 2014; Chamizo, Torres, Rodríguez, & Mackintosh, 2019).…”