Use of slope and feature cues in pigeon (Columba livia) goal-searching behavior.

Abstract

Terrain slope provides a directional frame of reference for reorientation and navigation, similar to cardinal directions. Previous studies have shown that, in a goal location task, slope is a very salient cue and that pigeons tend to rely on it even if it is not the most informative cue. Such a strong dependence on one type of information, when there are more effective predictors of reward, is a key premise for a modular view of information processing. Here we tested the provocative hypothesis of a “slope module” for reorientation in slanted environments. Pigeons had to solve a goal location task using slope or another, theoretically salient cue: a beacon feature. Overall, searching behavior was controlled almost equally by the two cues. The fact that, for the first time, slope failed to capture most of the associative strength allows us to reject a strong modularity view and suggests instead that there is competition between cues based on salience. As an interesting additional finding, the reliance on slope and the feature was affected by training location (uphill vs. downhill), suggesting the possibility of a modulatory role of effort on the cue-weighting mechanism of reorientation.

Two fields are better than one: Developmental and cognitive perspectives on underatnding spatial reorientation

“…Pigeons readily learned the reorientation task (Nardi, Mauch, Klimas, & Bingman, 2012). Post training tests indicated that the pigeons had encoded both cues.…”

Does terrain slope really dominate goal searching?

“…However, for the first time in this series of experiments, slope failed to capture most of the associative strength, and pigeons chose almost equally the two correct corners (see Fig. 2; Nardi et al 2012). Nardi et al (2012).…”

“…2; Nardi et al 2012). Nardi et al (2012). b Mean percentage of choices (± SEM) to each corner in the conflict test in Nardi et al (2012); overall, the two correct corners were chosen approximately equally Conclusions The finding from Nardi et al (2012) substantially weakens the claim of slope having a special status-driving searching behavior irrespective of other task--relevant cues.…”

“…Nardi et al (2012). b Mean percentage of choices (± SEM) to each corner in the conflict test in Nardi et al (2012); overall, the two correct corners were chosen approximately equally Conclusions The finding from Nardi et al (2012) substantially weakens the claim of slope having a special status-driving searching behavior irrespective of other task--relevant cues. Instead, considering this whole line of research on pigeons, slope seems to obey the principles of associative learning, because the associative strength it gained depended on the salience of the competing stimulus: when paired with a less salient cue (the geometry of the environment), slope guided behavior, but when paired with a more salient cue (a beacon), slope gained a comparable amount of associative strength as the other cue.…”

“…However, in order to ascertain whether slope is really a privileged cue, exerting strong dependence for goal searching, this has to generalize also when tested with other cues. Nardi et al (2012) trained pigeons to locate a goal in a square, tilted arena (20°) with colored cards placed in each corner; the baited corner was associated with a card of different color from the other 3 corners (see Fig. 2).…”