Description

The visual cliff test is used for the depth perception and the visualization of perceived barriers. The visual cliff test comprises a chamber with a checkered pattern insert. Additional patterns and colors are available upon request.

Many behavioral assessments utilize heights as an integral part of their apparatuses and protocols. A few such apparatuses include the Ladder Rewarded Plus Maze, Asymmetric Elevated Plus Maze and 3D Radial Arm Maze. Visual depth perception is used in combination with other systems and cues, such as the use of vibrissae (whiskers) by rodents to navigate areas and in performing visual assessments of a scene.

Our Visual Cliff is compatible with our video tracking and analysis package ConductVision.

Modification

Documentation

Introduction

The visual cliff was created and used for depth perception experiments by Eleanor J. Gibson and Richard D. Walk (Gibson & Walk, 1960) at Cornell University. In their experiments, Gibson and Walk assessed stereopsis in humans and animal species by creating a false cliff. They concluded that depth perception was innate rather than a learned behavior. Their experiment of visual depth assessment with human babies became one of the most prevalent developmental psychological experiments.

The initial design of the visual cliff used by Gibson and Walk was a sturdy plexiglass slab supported approximately a foot above the floor. One end of the slab had a high-contrast checkered patterned wallpaper pressed underneath it to create the shallow end. The remaining surface had the same wallpaper on the floor underneath it to create the illusion of a cliff. The apparatus since then has seen further refinements in construction.

Apparatus and Equipment

The Visual Cliff test apparatus is a single chamber, clear plexiglass box. The box is positioned in a way that it partially overhangs from the edge of the support surface. To create the illusion of depth, the part of the floor in contact with the support surface is lined with a pattern paper (usually checkered patterned) and the same paper is placed on the floor with an overhang.

Observation of the Visual Cliff can be done using tracking software such as ConductVision, Noldus Ethovision XT,and ANY-Maze. mounted above the apparatus. Live scoring is also possible.

Training Protocol

Before beginning the experiments, the apparatus must be thoroughly cleaned and well-lit. The task does not require any familiarization; thus, testing can be initiated immediately.

Begin the experiment by placing the subject in the central neutral area between the shallow and deep ends of the apparatus floor. Ensure that there is minimal interference during the testing process. Observe the performance of the subject for 20 minutes. Repeat trials as necessary with appropriate inter-trial intervals.

Evaluation of regenerated RGC connections in supporting visual function

Lim et al., 2016 tested if regenerated retinal ganglion cell (RGC) would restore visual function in mammals with optic nerve injuries. In the visual cliff test performed by the mice that received RGC axon regeneration treatment, it was observed that they were unable to perceive visual depth, just as the non-treated lesioned mice. The result suggested the failure of the restoration of visual abilities, by regeneration resulting from biased-visual-stimulation/AAV2-cRheb1 treatment, required for visual cliff avoidance behavior. In conclusion, however, the study was able to conclude, based on other assessments, that biased-visual-stimulation/cRheb1 treatments lead to the regrowth of RGC axons resulting in partial recovery of certain visual functions and vision-driven behaviors.

Evaluation of long-term EMF treatment effects on visual acuity

Arendash et al., 2012 suggested the use of the high-frequency electromagnetic field (EMF) as a treatment for Alzheimer’s disease. In their study transgenic Alzheimer’s mice, APPsw and NT mice were treated with two 2-hour periods of EMF treatment per day for 2 months which also included the behavioral testing period. The visual cliff test was the last behavioral test performed to assess visual depth perception. No negative impact of EMF treatment was observed in the visual acuity test in either Tg and NT mice.

High-precision mapping of behavioral traits

Logan et al., 2013 characterized the behavioral variations in the newly developed Diversity Outbred (DO) mice and performed behavioral assessments to assess their efficacy for quantitative genetic analysis. The visual cliff test was one of the behavioral assays used in the investigation. The results from the visual cliff test showed a significant effect of strain on the progenitor strains’ locomotor activity in the bottom (cliff) arena. Quantitative trait loci mapping showed that 129S1/SvlmJ and NOD/ShiLtJ progenitor strains traveled the shortest and longest distance at the bottom of the visual cliff test, respectively.

Sample Data

Data that is obtained using the visual cliff test includes the following.

• Avoidance behaviors
• Crossing time
• Distance traveled in each region
• Duration of exploration of the regions
• Mean velocity
• Number of entries into each region
• Number of transitions between regions
• Percentage duration in each region
• Response latencies
• Time spent immobile
• Time spent in the neutral area
• Total distance traveled

Other data that can also be recorded during the test, as per investigation needs, include neural activity scans, cortisol levels, and heart rate.

Strengths & Limitations

Strengths

The visual cliff test is a simple and inexpensive apparatus to test visual acuity and depth perception. The apparatus can be easily adapted for other animals. The visual cliff test utilizes the fear of heights using the illusion of a cliff drop. The apparatus tests the animal’s depth perception abilities by allowing observation of the subject’s explorative behavior in the cliff region.

Limitations

Although a simple assessment of visual depth perception, the Visual Cliff test has its fair share of criticism. It is argued that the subject can sense the solid plexiglass under its touch which can influence its decision to crossover the “cliff” region. The presence of experimenters can also influence the performance. Residual olfactory cues or the presence of any visual cues could potentially lead the subject to explore the “cliff” area. The test can also be quite stressful for the subject as it incorporates the fear of heights into the assessment. Repeated trials may lead to learned behaviors resulting in the novelty of the “cliff” aspect to decline, thus leading to incorrect observations.

Summary and Key Points

• The visual C=cliff was created by Eleanor J. Gibson and Richard D. Walk.
• The use of the visual cliff by Gibson & Walk was to investigate the hypothesis that depth perception is an innate rather learned behavior.
• The visual cliff apparatus uses a clear plexiglass base that is divided into shallow and cliff regions using patterned paper.

References

Arendash GW, Mori T, Dorsey M, Gonzalez R, Tajiri N, Borlongan C (2012). Electromagnetic treatment to old Alzheimer’s mice reverses β-amyloid deposition, modifies cerebral blood flow, and provides selected cognitive benefit. PLoS One. 7(4): e35751. doi: 10.1371/journal.pone.0035751.

Fox MW (1965). The visual cliff test for the study of visual depth perception in the mouse. Anim Behav. 13(2):232-3.

Gibson, E.J. & Walk, R.D. (1960). The “Visual Cliff”. Scientific American. 202 (4):64. doi:10.1038/scientificamerican0460-64

Lim JH, Stafford BK, Nguyen PL, Lien BV, Wang C, Zukor K4, He Z, Huberman AD (2016). Neural activity promotes long-distance, target-specific regeneration of adult retinal axons. Nat Neurosci. 19(8):1073-84. doi: 10.1038/nn.4340.

Logan RW, Robledo RF, Recla JM, Philip VM, Bubier JA, Jay JJ, Harwood C, Wilcox T, Gatti DM, Bult CJ, Churchill GA, Chesler EJ (2013). High-precision genetic mapping of behavioral traits in the diversity outbred mouse population. Genes Brain Behav. 12(4):424-37. doi: 10.1111/gbb.12029.