Related Experiment Video
Updated: Aug 8, 2026
08:44
Assessing Spatial Learning and Memory in Small Squamate Reptiles
Published on: January 3, 2017
Evolution of spatial cognition: sex-specific patterns of spatial behavior predict hippocampal size
L F Jacobs1, S J Gaulin, D F Sherry
1Department of Anthropology, University of Pittsburgh, PA 15260.
Summary
In polygamous voles, males have larger hippocampi relative to brain size than females, linked to spatial cognition differences. This sex difference in the hippocampus is absent in monogamous voles, suggesting adaptive evolution.
Area of Science:
- Neuroscience
- Evolutionary Biology
- Behavioral Ecology
Background:
- Hippocampal size correlates with spatial memory and maze performance across species.
- Sex-specific spatial cognition patterns are observed in some rodent species, particularly voles.
- Polygamous species often exhibit greater sex differences in spatial behavior than monogamous ones.
Purpose of the Study:
- To investigate sex differences in hippocampal size in relation to spatial cognition in two congeneric vole species.
- To determine if evolutionary pressures on spatial behavior translate to neural substrate differences between sexes.
- To compare hippocampal-to-brain volume ratios in polygamous versus monogamous vole species.
Main Methods:
- Studied meadow voles (M. pennsylvanicus, polygamous) and pine voles (M. pinetorum, monogamous).
- Collected ten males and ten females from natural populations of each species.
- Measured hippocampal and brain volumes, calculating the ratio of hippocampal volume to brain volume.
Main Results:
- Males had larger hippocampi relative to brain volume than females, but only in the polygamous meadow vole.
- A two-way analysis of variance revealed a significant interaction between sex and species for hippocampal-to-brain volume ratio.
- No significant sex difference in hippocampal-to-brain volume ratio was found in the monogamous pine vole.
Conclusions:
- Adaptive sex differences in behavior, driven by evolutionary pressures, can manifest in the neural substrate (hippocampus).
- The study provides evidence linking evolutionary history, spatial cognition, and brain morphology in voles.
- This research highlights the role of mating systems in shaping sex-specific brain adaptations.
Related Concept Videos
01:30Biological Influences on Intelligence
Intelligence is often thought to be linked to brain size, but the relationship is more complex than that. While brain size does correlate modestly with some abilities, like verbal skills, the connection is weaker for others, such as spatial reasoning. Other factors, like brain structure, also play crucial roles. For instance, despite Einstein's smaller-than-average brain, his parietal cortex, which is involved in spatial reasoning, was 15% wider, suggesting that neural density might matter more...
01:19Role of Hippocampus in Memory
The hippocampus, a critical brain structure, plays an essential role in memory processing, particularly in the formation and retrieval of memory. This small, seahorse-shaped region is located within the medial temporal lobe, with one hippocampus in each brain hemisphere. Experimental studies involving lesions in the hippocampi of rats have demonstrated significant impairments in tasks such as object recognition and maze navigation, indicating the hippocampus involvement in both recognition and...