Influence of distal and proximal cues in encoding geometric information

Vertebrates use geometric and featural information for spatial navigation. When both geometric and featural cues are available, animals can use a variety of spatial strategies based on this information. To examine the nature of these strategies, we manipulated the spatial relationship between a conspicuous cue and the position of the goal when goldfish (Carassius auratus) were searching for the exit of a rectangular environment with one distinctive wall. Two groups of fish were used, one with the distinctive wall close to the goal and the other with the distinctive wall on the other end of the enclosure. Results showed that fish encoded featural and geometric information in both conditions but the spatial relationship between the goal and the distinctive wall influences the characteristics of the encoding of the spatial cues and the strategy used to locate the goal. These results suggest that fish in both procedures use the local featural cues associated with the goal instead of the whole set of spatial cues as previous studies propose.