Mice recognize 3D objects from recalled 2D pictures, support for picture-object equivalence

Sarah J Cohen,David A Cinalli,Brandon Hindman,Robert W Stackman,Elan Barenholtz,Herborg N Ásgeirsdóttir

doi:10.1038/s41598-022-07782-4

Abstract

Picture-object equivalence or recognizing a three-dimensional (3D) object after viewing a two-dimensional (2D) photograph of that object, is a higher-order form of visual cognition that may be beyond the perceptual ability of rodents. Behavioral and neurobiological mechanisms supporting picture-object equivalence are not well understood. We used a modified visual recognition memory task, reminiscent of those used for primates, to test whether picture-object equivalence extends to mice. Mice explored photographs of an object during a sample session, and 24 h later were presented with the actual 3D object from the photograph and a novel 3D object, or the stimuli were once again presented in 2D form. Mice preferentially explored the novel stimulus, indicating recognition of the “familiar” stimulus, regardless of whether the sample photographs depicted radially symmetric or asymmetric, similar, rotated, or abstract objects. Discrimination did not appear to be guided by individual object features or low-level visual stimuli. Inhibition of CA1 neuronal activity in dorsal hippocampus impaired discrimination, reflecting impaired memory of the 2D sample object. Collectively, results from a series of experiments provide strong evidence that picture-object equivalence extends to mice and is hippocampus-dependent, offering important support for the appropriateness of mice for investigating mechanisms of human cognition.

Highlights

Picture-object equivalence or recognizing a three-dimensional (3D) object after viewing a twodimensional (2D) photograph of that object, is a higher-order form of visual cognition that may be beyond the perceptual ability of rodents
We confirmed that under our conditions, naïve mice could successfully perform a 2D picture recognition memory task and demonstrated that consolidation of such picture memory was dependent upon neuronal activity from the CA1 region of dorsal hippocampus (Fig. 1b), as previously reported[7,12]
The post-sample saline-treated mice (n = 9) explored the novel picture significantly more than they did the familiar picture during the test session [t(8) = − 4.97, P < 0.01, d = 2.02]; behavior consistent with visual recognition memory

Summary

Introduction

Picture-object equivalence or recognizing a three-dimensional (3D) object after viewing a twodimensional (2D) photograph of that object, is a higher-order form of visual cognition that may be beyond the perceptual ability of rodents. Photographs or pictures representing real-world physical items have traditionally been used to study visual recognition memory in primates, birds, and rodents because such images provide a consistent stimulus presentation regardless of viewing angle or orientation of the subject. It is unclear, in all species studied, whether these testing procedures elicit the perceptual inference required to fully relate a pictured object to its 3-dimensional (3D) physical form—a process known as picture-object e quivalence[1]. Relating a 2D image from memory to an actual 3D object in view represents a higher-order, flexible use of memory akin to the transitive inference demonstrated in r ats[25–28], in which rats infer the relationship between items that are not presented together, but are directly related

Methods

Results

Conclusion