Standard behavioral apparatus for measuring locomotor activity, exploratory behavior, and anxiety-like responses in rodents through analysis of movement patterns and zone preferences.
CE MarkedBAA available
Scientist guidance
Louise Corscadden, PhD
Director of Science · ConductScience
Ask Louise about Open Field Test fit, setup, configuration, or quote prep.
The Open Field Test is a standard behavioral assay used to assess locomotor activity, exploratory behavior, and anxiety-like responses in rodents. The apparatus consists of a square arena where animals are placed to freely explore while their movement patterns, zone preferences, and behavioral metrics are recorded. This test is fundamental to neuroscience and behavioral pharmacology research, providing quantitative measures of spontaneous locomotion, thigmotaxis (wall-seeking behavior), and center zone exploration.
The Open Field Test serves dual purposes in research protocols. When configured with clear walls, it effectively measures anxiety-like behaviors through analysis of center versus periphery time allocation. When equipped with opaque walls, it supports novel object recognition studies and general locomotor assessment. The apparatus accommodates both mouse and rat subjects with species-appropriate dimensions, featuring removable bases for efficient cleaning and optional grid floor inserts for enhanced video tracking compatibility.
How It Works
The Open Field Test operates on the principle that rodents exhibit measurable behavioral responses when placed in a novel, open environment. Animals naturally display thigmotaxis (preference for wall proximity) as an anxiety-related behavior, while exploration of the center zone indicates reduced anxiety or increased exploratory drive. The square arena design eliminates corner preferences that could confound behavioral measurements in alternative configurations.
Movement tracking relies on the contrast between the animal and the arena floor, with optional grid markings facilitating manual scoring or automated video analysis. Clear walls allow researchers to observe natural anxiety responses, as animals can see beyond the immediate testing environment. Opaque walls eliminate external visual cues, focusing attention on objects placed within the arena for recognition studies. The matte finish reduces reflective glare that could interfere with video tracking systems or alter animal behavior.
Features & Benefits
Removable base design
Enables rapid cleaning between subjects and easy maintenance without dismantling the entire apparatus.
Species-specific dimensions
Optimized arena sizes for mouse (40x40x30 cm) and rat (60x60x40 cm) provide appropriate spatial contexts for natural exploration behaviors.
Interchangeable wall types
Clear and opaque wall options support both anxiety assessment and novel object recognition protocols within the same apparatus.
Matte finish surfaces
Eliminates reflective glare that could interfere with video analysis or create visual artifacts affecting animal behavior.
Grid floor insert compatibility
Supports automated tracking systems by providing visual reference points for precise movement quantification.
70% ethanol compatibility
Withstands standard laboratory disinfection protocols without surface degradation or odor retention.
Detachable wall system
Facilitates thorough cleaning of all surfaces and allows compact storage when not in use.
Add-ons and modifications
Add-on
Size
Price
Details
Grid Lines
Mouse - 40x40cm to fit Rat - 60x60cm to fit
$150
Polypropylene
$200
Suitable for autoclaving (wet 121°C, 15PSI for 30 minutes). Prior to insertion of the open field, be sure to carefully clean the items with distilled water, as
Add any of these to your quote request.
Sizes by model
Measurement
Mouse
Rat
XS (Stroke)
Mouse (Set of 4)
Rat (Set of 4)
XS (Stroke - Set of 4)
Length
40 cm
60 cm
25 cm
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Width
40 cm
60 cm
25 cm
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Height
30 cm
40 cm
25 cm
30 cm
40 cm
25 cm
Mouse: Removable base for easy clean
Mouse: Acrylic
Mouse: Easy clean with 70% Ethanol
Mouse: Matte Finish for non-shine
Mouse: No odors
Rat: Removable base for easy clean
Rat: Acrylic
Rat: Easy clean with 70% Ethanol
Rat: Matte Finish for non-shine
Rat: No odors
XS (Stroke): Removable base for easy clean
XS (Stroke): Large singular box can serve as large Open Field
XS (Stroke): Separator included dividing into 4 individual mouse/rat boxes
XS (Stroke): Acrylic
XS (Stroke): Easy clean with 70% Ethanol
XS (Stroke): Matte Finish for non-shine
XS (Stroke): No odors
Mouse (Set of 4): Total size: 80cm x 80cm
Mouse (Set of 4): With wall insert
Rat (Set of 4): Total size: 120cm x 120cm
Rat (Set of 4): With wall insert
XS (Stroke - Set of 4): Total size: 50 x 50cm
XS (Stroke - Set of 4): With wall insert
Shipping weight
109.0 lb
Shipping box
L: 88.9 cm
W: 88.9 cm
H: 40.0 cm
Feature
This Product
Typical Alternative
Advantage
Arena Dimensions
Species-optimized sizes: 40x40 cm (mouse), 60x60 cm (rat), 25x25 cm (XS)
Many alternatives offer fixed dimensions regardless of species
Proper sizing ensures natural exploration behaviors and appropriate center-periphery zone ratios for each species.
Wall Configuration
Interchangeable clear and opaque walls with detachable design
Fixed wall types require separate apparatus for different protocols
Single apparatus supports both anxiety assessment and novel object recognition studies.
Cleaning System
Removable base with 70% ethanol compatibility and odor-resistant materials
Integrated bases often require more complex cleaning procedures
Rapid turnaround between subjects minimizes olfactory contamination and experimental delays.
Multi-Chamber Option
XS model converts between single arena and four-chamber configuration
Separate apparatus required for individual versus group paradigms
Flexible testing configurations maximize experimental throughput and protocol versatility.
Surface Finish
Matte finish acrylic construction eliminates reflective glare
Standard acrylic often creates visual artifacts during recording
Improved video analysis quality and reduced visual stimuli that could confound behavioral responses.
This Open Field Test apparatus offers species-specific sizing, interchangeable wall configurations, and modular design features that support multiple behavioral paradigms within a single system. The emphasis on cleaning efficiency and video-compatible surfaces addresses common practical challenges in high-throughput behavioral testing.
Model
Size
SKU
Listed price
Status
Shipping box
Mouse
Length 40 cm · Width 40 cm · Height 30 cm
ME-3201-02-CLEAR (+5)
$650.00
Available
88.9 x 88.9 x 40.0 cm
Rat
Length 60 cm · Width 60 cm · Height 40 cm
ME-3201-03-CLEAR (+5)
$790.00
Available
88.9 x 88.9 x 40.0 cm
XS (Stroke)
Length 25 cm · Width 25 cm · Height 25 cm
ME-3201-04-CLEAR (+5)
$540.00
Available
88.9 x 88.9 x 40.0 cm
Mouse (Set of 4)
Height 30 cm
ME-3201-05-CLEAR (+4)
$2,090.00
Available
88.9 x 88.9 x 40.0 cm
Rat (Set of 4)
Height 40 cm
ME-3201-06-CLEAR (+4)
$2,890.00
Available
88.9 x 88.9 x 40.0 cm
XS (Stroke - Set of 4)
Height 25 cm
ME-3201-01-CLEAR (+4)
$1,790.00
Available
88.9 x 88.9 x 40.0 cm
Neuroscience
Quantifying baseline locomotor activity and exploratory behavior in transgenic mouse models to characterize behavioral phenotypes associated with neurological conditions.
Behavioral Pharmacology
Screening anxiolytic and anxiogenic compounds by measuring changes in center zone exploration and thigmotactic behavior following drug administration.
Anxiety and Depression
Assessing anxiety-like behaviors through analysis of time spent in center versus peripheral zones and overall locomotor activity patterns.
Learning and Memory
Establishing baseline locomotor function before cognitive testing and measuring exploratory drive in novel object recognition paradigms.
Aging Research
Documenting age-related changes in spontaneous locomotion and exploratory motivation across different life stages in rodent models.
Motor Function
Evaluating gross motor coordination and ambulatory capacity following neurological interventions or in disease models.
Practical Tips
Best Practices
Maintain consistent ambient lighting conditions across all testing sessions to avoid confounding variables in exploratory behavior.
Why: Light level changes can significantly alter anxiety responses and locomotor activity patterns.
Maintenance
Inspect wall attachment points regularly and ensure secure connections before each testing session.
Why: Loose walls can create noise or movement that disrupts natural exploration behaviors.
Data Quality
Allow animals to acclimate to the testing room for at least 30 minutes before behavioral assessment.
Why: Transportation stress and novel environment exposure can temporarily alter baseline locomotor activity.
Calibration
Verify video tracking software calibration using known distance measurements on the grid floor insert.
Why: Accurate spatial calibration ensures reliable quantification of distance traveled and velocity measurements.
Troubleshooting
If animals show excessive corner-seeking behavior, check for external visual or auditory stimuli that may be increasing anxiety responses.
Why: Environmental distractors can override natural exploration patterns and confound behavioral measurements.
Safety
Ensure all acrylic edges are smooth and free from cracks that could injure animals during active exploration.
Assemble the acrylic walls onto the removable base, ensuring all joints are secure and the arena forms a complete square enclosure.
Wall Configuration
Select clear walls for anxiety assessment or opaque walls for novel object recognition studies based on your experimental protocol.
Floor Preparation
Install grid floor inserts if using video tracking analysis, or use the plain floor for manual observation and scoring.
Environmental Setup
Position the apparatus in a quiet testing room with consistent ambient lighting and minimal external visual cues.
Cleaning Protocol
Clean all surfaces with 70% ethanol between subjects to eliminate olfactory cues that could influence subsequent behavioral responses.
Recording System
Position video camera directly overhead to capture the entire arena floor for comprehensive movement analysis.
Subject Placement
Place the animal in the center of the arena or consistently in the same corner to begin each testing session.
What’s in the Box
Open field arena with acrylic walls (size specific)
Removable base platform
Wall attachment hardware
Grid floor insert (if specified)
Separator dividers (XS model only)
Cleaning protocol instructions (typical)
User manual with setup guidelines (typical)
Warranty
ConductScience provides a standard one-year manufacturer warranty covering defects in materials and workmanship, with technical support for setup and protocol optimization.
Compliance
ARRIVE Guidelines 2.0Open field testing protocols commonly reference these guidelines for reporting animal research methodology and behavioral outcome measures.
NIH Guidelines for Animal ResearchBehavioral testing apparatus used in facilities subject to these guidelines for humane animal care and use in research.
AAALAC StandardsEquipment used in accredited research facilities following these standards for laboratory animal care and behavioral assessment.
References
Background reading relevant to this product:
1.L. Prut et al. (2003) “The open field as a paradigm to measure the effects of drugs on anxiety-like behaviors: a review” European Journal of Pharmacologydoi:10.1016/s0014-2999(03)01272-x
2.M. Lamar Seibenhener et al. (2015) “Use of the Open Field Maze to Measure Locomotor and Anxiety-like Behavior in Mice” Journal of Visualized Experimentsdoi:10.3791/52434
3.Ann-Katrin Kraeuter et al. (2018) “The Open Field Test for Measuring Locomotor Activity and Anxiety-Like Behavior” Methods in molecular biologydoi:10.1007/978-1-4939-8994-2_9
4.Natalia Kulesskaya et al. (2014) “Assessment of mouse anxiety-like behavior in the light–dark box and open-field arena: Role of equipment and procedure” Physiology & Behaviordoi:10.1016/j.physbeh.2014.05.006
the open field test is a simple apparatus used in the assessment of locomotion, exploration, and anxiety. The open field task explores the innate responses of the subject to open spaces apart from their explorative drive. Thigmotaxis is often seen in rodents such as rats and mice. This behavior is characterized by avoiding brightly lit open spaces and is believed to be an evolutionary adaptive behavior that can be observed in many species. The open field test exploits this fear in species to evaluate the different aspects of anxiety-related behaviors. Animals with a decreased level of anxiety are more likely to explore the central area of the open arena than animals with high levels of anxiety. Animals with high levels of anxiety will display reduced locomotion and exploration, with a preference to stay close to the walls of the open field arena. However, despite the fear, animals have also been known to explore threatening stimuli as part of their exploratory drive.
The apparatus was developed in the early 1930’s by Calvin S. Hall to observe rat behavior in an open arena (Hall & Ballechey 1932). Hall and Ballachey’s experiment used a square arena that was marked into a grid. The experiment involved the observation of the rats to food stimulus placed within a barrier in the center of the arena. This experiment allowed observation of the influence of a positive stimulus on the thigmotaxic behaviors of the rats and their emotionality. Though the apparatus is useful in the assessment of anxiety and explorative behaviors, it is debated that the task does not provide a specific measure of anxiety. To overcome these shortcomings, the 3-D Open Field apparatus can be used to allow a more precise measure of anxiety and fear-related behaviors.
The open field test is usually used alongside other mazes that measure anxiety, such as the Elevated Plus Maze, Elevated Zero Maze, and Elevated Y-Maze (see also T-Maze), following anxiolytic and anxiogenic treatments. The Ziggurat task is a variation of the open field apparatus that uses ziggurats in the open space to create a complex environment. Another task that uses a similar apparatus to the open field task is the Novel Object Recognition task used to evaluate the subject’s responses to novel objects.
The open field apparatus has a simple construct. Usually, a square arena that is surrounded by high walls to prevent escaping is used, though circular arenas are also used. These walls can be transparent to allow the subject to view any visual stimuli placed around them or can be opaque to limit observation of behaviors in response to brightly lit open spaces. The floors are often marked with square grid crossings, and the center of the arena is marked with a square. In addition, the apparatus can have additions and modifications to test different behaviors and responses.
History
Origin
The first use of an open field was described in Hall and Ballechey’s 1932 paper, “A study of the rat's behavior in a field: a contribution to method in comparative psychology.” In their experiment, they utilized a 7 x 7-foot walled arena that had been marked into 49 square grids. In the center, a cylinder wire mesh covering 25 squares was placed to contain a food reward. When the animals were introduced into the arena from a start point, it was observed that the presence of a food reward resulted in animals circling the wire-mesh barrier more than when no food reward was present. A similar set-up was once again used by Hall in his 1934 experiment to highlight “the importance of needs or drives and emotionality as factors determining adjustment or maladjustment” (Hall, 1934a). In the same year, Hall published a paper aimed at validating the correlation between defecation and urination and the individual emotionality of the rats in an open-field task (Hall, 1934b). Although, it has been argued that a measure of defecation or urination simply measures timidity in a controlled environment.
Hall’s experiment for determining the relationship between emotional behavior and the speed of ambulatory activity in an open field task suggested that emotional rats tended to be less active than their non-emotional counterparts (Hall, 1936). This behavior was further observed by Hall in the “The inheritance of emotionality” paper published in 1938. In the experiment, it was observed that males were more likely to be emotional than females and the quality of emotionality was inheritable as evident from the higher defecation and urination rates of the progeny of most emotional males and females compared with the progeny of least emotional males and females (Hall, 1938).
Development
Since its initial use as a test for emotionality by Hall (1938), the open field task has seen different modifications and adaptations and a wider range of applications. In 1945, Anderson utilized the open-field task to assess timidity and the role of gender in timidity in normal and gonadectomized rats. The results of the investigation showed that the females were less timid than their male counterparts and that gonadectomy before puberty did not affect the sex difference in timidity,
Stern (1957) evaluated the effect of frontal area lesions on the behavioral performances of male albino rats in an open-field task. The author found that the subjects with frontal lesions showed similar and long-lasting behavioral changes in the open field as animals subjected to a series of electroconvulsive seizures (ECS). Subjects showed an increase in emotionality and changes in behavior were more gradual than in the ECS animals.
The effect of aging on the open field behavior was evaluated by Werboff and Havelena in their 1962 paper. Their test assessed the performances of both sexes of Sprague-Dawley at ages 90, 180, 360, and 540 days. The evaluation of age and gender-based performance in the open field concluded that activity and emotionality declined with increasing age and that the females exhibited higher activity and emotionality scores than the males.
Levine et al. (1967) evaluated the relationship between open-field behavior and changes in adrenal corticoid in male Purdue-Wistar rats. The animals were grouped into two groups based on if they had been handled in infancy or not. The animals were tested on the open field for 4 days in their adulthood and were immediately killed at the termination of the test. As expected animals that were handled in their infancy were more active in the open field task, defecated less on all days of testing and had lesser corticosterone response throughout the testing period.
Recent Developments
Itoh et al. (1994) investigated the behavioral effects of neuromedin B (NMB) and neuromedin C (NMC) in an open field task using male Wistar rats. Subjects were intracerebroventricularly (ICV) administered either 5 μl peptide or saline and tested at 1 and 30 minutes after administration in the open field. At both evaluation points a decrease in the duration of locomotion, the distance moved, and rearing behavior was observed with an increase in excessive grooming and violent scratching. However, the pronounced behavioral changes after 30 minutes was only observed in NMC-administered rats.
Brotto's et al. (2000) experiment assessed the effect of chronic melatonin administration and sex differences in forced-swim test and open field task. Results from both tests showed that females displayed higher activity than males. Melatonin administration led to decreased activity in the forced-swim test while increasing ambulatory behavior in the open field task for both genders. The study concluded based on both the tests results that melatonin, in general, did not have an inhibitory effect on the motor activities of the subjects.
Popović et al. (2014) tested the effects of low and high doses of anti-nausea medication on the open field habituation task using male Wistar rats. Subjects were administered either 1 mg/kg (low dose) or 30 mg/kg (high dose) of anti-nausea medication soon after their acquisition task in the open field. Behavioral observation of the subjects after reintroduction to the open field after 48 hours showed that subjects treated with a low dose significantly decreased grooming while the opposite was true for subjects treated with a high dose of anti-nausea medication. Further, the defecation rate was maintained in the low-dose group while it increased significantly in the high-dose group. Based on the data it was concluded that post-training anti-nausea medication administration increased defecation and grooming, behaviors that are associated with fear and stress.
Apparatus and Equipment
The open field apparatus is a square arena that is available in default small mouse, mouse, and rat sizes but can be customized in dimensions. The arena is surrounded by high walls to prevent the subjects from escaping the apparatus. In general, the walls are clear. However, opaque colors and matte finishes are also available. Floor inserts for the apparatus are available with or without gridlines. These gridlines divide the area into equal smaller squares and can be helpful for both manual scoring, as well as video recording and scoring with tracking software. A square area in the very center of the area may also be outlined.
Training Protocol
The open field test is used in the assessment of exploration, locomotion, and anxiety. The test can be used to compare animals in a control group to animals in a treatment or disease model group by observing their behaviors and tracking their movements in the open field. Animals with minimal anxiety are likely to move about the area and perform other behaviors such as grooming and rearing, while animals with increased anxiety may freeze or exhibit stretch-attend postures.
Prior to beginning the experiment, the apparatus should be thoroughly cleaned to prevent the influence of any lingering stimuli. Overhead lighting set-up is recommended to prevent shadows. The arena should be sufficiently, but dimly, lit to allow subjects to see and explore their surroundings while avoiding stress from bright lights. Observation of the Open-Field task can be done using tracking software and video camera, such as Noldus EthoVision® XT or ANY-Maze video tracking system mounted above the apparatus. Live scoring is also possible.
Since the open field task is based on the novelty of the environment, the test does not require any pre-training. The subject is placed in the center of the arena, and its behaviors are observed for a period of at least 5 minutes without any interference.
Modifications
The simplicity of the open field apparatus makes it a highly modifiable apparatus. Simple modifications include using opaque walls, different lights, different floor inserts (shock floor inserts) and varying the size of the arena. Each modification can be tailored to the needs of the research with the open field apparatus.
The Ziggurat task apparatus is a modification of the open field that uses ziggurats to create a complex environment for the subject to explore. The task involves assessment of the subject’s spatial memory and navigation (Faraji et al., 2008). The novel object recognition task is another battery that uses apparatus similar to the open field task. This task is commonly used in the assessment of memory and response to novel objects (Bevins & Besheer 2006Leger et al., 2013).
Modification of the protocol can also be of interest in research. Repeated exposure to the open field apparatus can be used to evaluate habituation behaviors of animals.
Data Analysis
The primary observation made using the open field apparatus is the behavioral response of the subjects to the open space. Subjects with less anxiousness in the open arena usually will explore the entire space. However, subjects treated with anxiogenics or disease models such as stress, will avoid the central arena and stay close to the walls. The following parameters can be measured using the open field task,
Frequency of line crossing: The number of times the subject crosses the grid lines on the grid floor insert with all four of its paws.
Frequency of central square entries: The number of times the subject enters the center of the arena marked by the square on the grid floor insert.
Time spent in the center of the arena: The duration of time spent in the center of the arena.
Time spent close to the walls: The duration of time spent staying close to the walls of the arena.
Frequency of rearing behavior: The number of times the subject stands on its hind paws. In general, unsupported rearing (the subject does not rest its front paws on the walls) is a better measure of anxiety.
Frequency of stretch attend postures: The number of times the subject elongates forward its head and shoulders and retracts it.
Other observable behaviors can include urination/defecation, grooming and climbing behaviors using video tracking packages such as Noldus EthoVision® XT or ANY-Maze.
Translational Research
The open field test has also been directly applied in human studies. Walz et al. (2016) utilized a soccer field to evaluate thigmotaxic behaviors in human participants with agoraphobia or high anxiety sensitivity. Participants' behavior data were recorded using GPS and heat maps in addition to visual analyses. It was observed that participants with agoraphobia and high anxiety sensitivity showed enhanced thigmotaxis as evident from the long durations spent close to the walls and reluctance to explore the central area. This behavior was further observed in the city walk experiment; wherein, the participants walked through a market area to allow observation of real-life behavior. Observations of both experiments, open field task and real-life scenario, strongly suggested that thigmotaxis is related to agoraphobia and anxiety sensitivity.
The availability of the latest technology also makes execution of the open-field task using virtual reality a possibility. With virtual reality, the setting up of different open-field environments with varying levels of complexity can be easily accomplished. Environments can include an apartment room, a closed room, a cityscape, or an outdoor nature set-up. The benefit of virtual environments is that they are easily modifiable, cost-effective, and provide a safe environment for the participants.
Strength and Limitations
The open field task is a simple apparatus that is both easy to construct and use. Since the apparatus does not require any pre-training, the evaluations can be performed in a much shorter time in comparison to other tests of anxiety. The simplicity of the apparatus makes it easy to adapt it for different investigations such as the assessment of the effects of aging, substances, and lesions on the behaviors of the animals. Open field apparatus can also be used to evaluate social defeat and in novel object recognition tasks.
Using the open-field task behaviors of treatment or disease model animal groups can be compared with control and a normal group of animals to help understand the behaviors of the former group and develop and improve treatments. Apart from testing the animals to the novelty of the open arena, animals can also be subjected to habituation tasks by reintroduction to the arena. This allows improvement in the understanding of the habitation behaviors of animals. The availability of virtual open-field tasks also allows direct application of the assay in human subjects, with the capability of easy modification of virtual environments.
Though the open field task is a straightforward and simple assay, it is debated that it does not differentiate between anxiety and fear-induced behaviors. This can be remedied by using a 3D Open-Field apparatus that does not provide any safe regions, unlike the open-field arena's walls. Further, since the open-field task does not provide a specific measure of anxiety, it is recommended that it should be used in combination with other behavioral assays. It is also important to remember that many different processes play into the behaviors observed during the task.
Apart from these limitations, the handling of the animal, gender, and the intensity of the light used can also influence the outcome of the open-field test. Further, the apparatus must be cleaned before every use to prevent the influence of any lingering stimuli.
Summary
The open field test was developed by C. S. Hall in the early 1930’s.
The open field task is used in the assessment of locomotion, exploratory and anxiety-related
The open field task explores the innate thigmotaxic responses and exploratory drive.
Hall’s used the rate of defecation and urination as a measure of emotionality.
The open field test is a simple and easily modifiable apparatus with a wide range of research applications including aging, treatment effects, and lesions.
The open field task may not provide a specific measure of anxiety. Hence, it should be used in conjunction with other behavioral batteries.
The open field task may also not satisfactorily differentiate anxiety from fear.
From the Maze Engineers documentation for this apparatus.
Q
What is the Open Field Test?
A
The Open Field Test is a behavioral assay that measures locomotor activity, exploration, and anxiety-like behavior in rodents. Animals are placed in a square or circular arena and their movement is tracked over a set period.
Q
How does the Open Field Test work?
A
A rodent is placed in an open arena and its movement is recorded via video tracking. Metrics include total distance traveled, time in center versus periphery, rearing frequency, and velocity - providing a comprehensive locomotor and anxiety profile.
Q
What research applications use the Open Field Test?
A
The Open Field Test is used in psychopharmacology for drug screening, assessment of motor function in neurological disease models, and baseline activity profiling. It is essential in ADHD, Parkinson's, and general behavioral phenotyping studies.
Have a question about this product?
Each paper below used this product. Under each title is the paper’s own sentence naming the equipment it used.
Andrea Verdugo-Meza, Jessica K. Josephson, Hansika Dadlani et al. · Preprint on bioRxiv · 2026
From the methods
Open field maze (OF) and novel object recognition (NOR) behavioural assessments were performed in this study using mazes from Maze Engineers (60077, Skokie, Illinois, USA).
Mice were placed in the center of a chamber measuring 40 cm (length) × 40 cm (width) × 40 cm (height) (Maze Engineers) and allowed to explore the chamber for 5 min freely (500 lx throughout the chamber).
Sydney M Bonauto, Kaya A Patel, Jennifer A Honeycutt · Behavioural Brain Research · 2025
From the methods
On testing day, a single animal was transported to the testing room in a clean transport cage and placed in the corner of a 100 × 100 cm × 40 cm open field (Maze Engineers, Skokie, IL).
Brittany Monte, Judianne Davis, Xiaoyue Zhu et al. · Cerebral Circulation - Cognition and Behavior · 2025
From the methods
A total of n = 11 CRHTRA1 and n = 13 WT rats aged to 12 M were used. The open field (Maze Engineers, Skokie, IL) measures 60 cm x 60 cm and is constructed with matte black acrylic floor and walls.
Sangbhin Lee, Young-Hwan Jo · Frontiers in Neural Circuits · 2025
From the methods
...were placed in the center of a chamber measured 40 cm (length) × 40 cm (width) × 40 cm (height) (Maze Engineers) and allowed to explore the chamber for 5 min freely (750 lux throughout the chamber).
Sushma Narayan, Kai Mao, Alberto R Williams-Medina et al. · Scientific Reports · 2025
From the methods
...in the corner of an evenly lit square arena (80 cm × 80 cm, 41 cm height) without visual cues (Maze Engineers; Skokie, IL), and average velocity, track length, activity level, and time spent in the central...
Haven Tillmon, Breeanne M. Soteros, Liang Shen et al. · Nature Communications · 2024
From the methods
TOR was conducted in an 80 × 80 × 30 cm white acrylic open field arena, with white opaque wall inserts separating the arena into (4) 40 × 40 × 30 cm height square chambers (Conduct Science).
Rafiad Islam, Jordon D White, Tanzil M Arefin et al. · Biology of Sex Differences · 2024
From the methods
Briefly, mice were allowed to explore a 40 × 40 cm arena (Maze Engineers, # 3201) illuminated at 60 l × for 5 min during which the distance traveled and the time spent in the inner 15 cm-area were measured using the EthoVision tracking system (XT 17, Noldus Information Technology).
Sarah A Lechner, Cynthia A Kelm-Nelson, Michelle R Ciucci · Behavioral Neuroscience · 2024
From the methods
An open-field arena (a square, empty arena, 60 cm × 60 cm surrounded by walls 40 cm in height, Maze Engineers, Illinois) was used to assess anxietylike behavior in this study (Seibenhener and Wooten, 2015).
Janise N Kuehner, Nevin R Walia, Rachel Seong et al. · G3: Genes, Genomes, Genetics · 2023
From the methods
...toward an unfamiliar CD1 target animal. The arena was a white open field (40 × 40 cm height; Maze Engineers) maintained in complete darkness supplemented with red lamp lights.
Kathryn J. Bjornson, Amanda M. Vanderplow, Yezi Yang et al. · iScience · 2023
From the methods
...were allowed to explore four novel objects in a square open field box purchased from Maze Engineers (40cm long, 40cm wide, 30cm tall) for 7 minutes (mice not exposed to the novel objects were used...
Ming Li, Jing Zhang, Wendi Chen et al. · Journal of Neuroinflammation · 2023
From the methods
...field test consisted of 5 min trial in a white opaque arena of 45 cm × 45 cm × 30 cm in size (Maze Engineers, Boston, USA). The test arena was divided equally into nine square quadrants.
Sophia C. Noel, Liana Fortin-Hamel, Manjurul Haque et al. · Scientific Reports · 2022
From the methods
The OFT/OLT arena (Maze engineers, 412 Wilmette Ave, Glenview, IL 60025, USA) (80 × 80 × 30 cm) had four opaque plexiglass compartments (40 × 40 × 30 cm) that allowed us to test the four pups per litter at the same time (Fig. 6a).
Amanda M Vanderplow, Andrew L Eagle, Bailey A Kermath et al. · Neuron · 2021
From the methods
...plastic open field box with dimensions of 40cm wide, 40cm long, and a 30cm height was purchased (Maze Engineers), and the box surrounded by distal spatial cues.
The same license also scores standard tests such as the elevated plus maze, the Y-maze, the Morris water maze and the Barnes maze. Results export as CSV files.
CSCalvin S. HallIntroduced the open field test (1934)Western Reserve University (now Case Western Reserve University)
About the Creator
Calvin S. Hall was an American psychologist at Western Reserve University (now Case Western Reserve University), where he carried out foundational research on animal emotionality. His 1934 paper introduced the open field test, proposing that a rat’s defecation and urination in a novel arena provide a quantifiable measure of emotional reactivity. The paradigm became one of the first systematized assays of emotionality in rodents and established the open-arena template still used today to measure locomotion, thigmotaxis and anxiety-like behavior. Hall later became widely known for his content-analysis approach to the psychology of dreams.
To view Calvin S. Hall’s publications, visit PubMed.
Did you work with Calvin S. Hall? to suggest corrections or share material for these Creator Insights.
ConductScience celebrates method creators: researchers who, through rigorous and often ingenious experiments, develop the tools that reveal how the brain and body work. These are real scientific discoveries that become everyday instruments for the labs that follow.
Foundational paper
Hall, C. S. (1934). Emotional behavior in the rat. I. Defecation and urination as measures of individual differences in emotionality. Journal of Comparative Psychology, 18(3), 385–403. doi:10.1037/h0071444
The Open Field Test measures spontaneous locomotion and exploration in a novel arena. It is used as a baseline activity assay, an anxiety-like behavior screen based on center avoidance, and a control for interpreting other behavioral tasks. 1
The classic readout is the tradeoff between exploration of the exposed center and thigmotaxis near the walls. Because total distance, immobility, and velocity can shift for non-anxiety reasons, open-field interpretation depends on reporting both affective and locomotor endpoints. 1
Open field is often paired with EPM, light-dark box, rotarod, fear conditioning, or spatial learning assays so researchers can separate general activity from task-specific performance. 1
§ 2
Methods
2.1 Procedure
Single-session or repeated-session arena exploration, typically 5 to 30 minutes.
Pre-test setup
1.Arena zones: Define center, wall, corner, and full-arena zones before acquisition. Use the same center-zone dimensions for all animals.
2.Lighting: Set and record illumination at the arena center and corners. Keep lighting consistent across groups.
3.Cleaning: Clean floor and walls between animals, then allow odor and liquid residue to dissipate.
4.Camera: Calibrate the overhead camera to arena boundaries and confirm tracking contrast for the chosen floor and animal color.
Trial sequence
1.Place subject: Place the animal in the same start zone for all subjects, commonly the center or one fixed corner.
2.Record session: Record a fixed session duration. Five to ten minutes captures anxiety-like center avoidance; longer sessions support habituation curves.1
3.Return animal: Return the animal to the home cage and log grooming, freezing, jumping, or escape attempts.
4.Clean arena: Clean and dry the full arena before the next subject.
5.Counterbalance: Interleave groups through the same time window to avoid circadian and order effects.
Critical methodological constraints
Activity confound. Center time falls when animals are sedated or hypoactive. Always interpret center ratio alongside distance and velocity.2
Lighting sensitivity. Bright light increases wall preference. Report lux levels so center avoidance can be compared across labs.
Arena geometry. Square arenas create corners that attract shelter-seeking behavior; circular arenas change the zone structure and should not be pooled with square data.
Habituation. Repeated sessions change novelty drive. Analyze habituation separately instead of mixing first-exposure and repeat-exposure data.
2.2 Measurement & Analysis
Core open-field endpoints ConductVision scores from arena trajectories.
Center Time
Anxiety-like behavior
Time in the exposed center zone. Higher center time is usually interpreted as lower anxiety-like avoidance.1
Wall Time
Thigmotaxis
Time spent near the arena wall. Increased wall preference can reflect anxiety-like behavior or low exploration.
Total Distance
Locomotor control
Whole-session path length. Essential for separating anxiety-like changes from hypoactivity or hyperactivity.2
Center Entries
Exploration frequency
Number of center-zone transitions. Useful when center dwell time is skewed by freezing.
Velocity and Immobility
Activity state
Speed and immobility time identify sedation, freezing, or stimulant effects.
+ Additional metrics: corner time, rearing, grooming, path entropy, turn angle, zone transitions, and habituation slope.
2.3 center time ratio (analysis)
A normalized center preference endpoint for comparing animals with different activity levels.
Formula: center time / (center time + periphery time) x 100. Interpret with total distance and velocity because low activity can reduce both center entries and center time. 1
§ 3
Results
3.1 Sample apparatus output
Representative center-periphery and locomotor endpoints.
Table 1 · Per-animal Open Field Test scoring output
Animal
Group
Center (s)
Periphery (s)
Distance (m)
Center ratio (%)
OF-001
Control
61
239
38.2
20.3%
OF-002
Control
55
245
36.7
18.3%
OF-003
Control
64
236
39.1
21.3%
OF-004
Anxiety-like
24
276
35.4
8.0%
OF-005
Anxiety-like
29
271
34.8
9.7%
OF-006
Anxiety-like
21
279
33.9
7.0%
Synthetic example for illustration only. Low center ratio should be interpreted with total distance and velocity.
§ 4
Discussion
Limitations of the paradigm, methodological caveats, and current directions.
4.1 Common confounds
Variables that can shift Open Field Test results apart from the effect under study.
Sedation and hyperactivity
Distance and velocity can change center time independent of anxiety-like behavior.2
Lighting
Illumination intensity strongly changes center avoidance and must be reported.
Arena cleaning
Residual odor changes exploration and wall preference. Keep cleaning and drying intervals consistent.
Prior handling
Handling, injection, and transport stress can shift center behavior before the session begins.
Repeated exposure
Habituation changes novelty-driven locomotion. First exposure and repeated exposure answer different questions.
4.2 Construct validity caveats
Open field is a broad screen, not a standalone anxiety diagnosis. Center avoidance can reflect anxiety-like behavior, low activity, visual impairment, freezing, or altered novelty seeking. 1 Strong designs pair center endpoints with locomotor controls and, when needed, another anxiety assay such as EPM or light-dark box. 2
4.3 Special considerations
Should I use center time or center entries?
Report both when possible. Center time captures dwell behavior, while entries capture approach frequency and can be less sensitive to one long center visit.
Can open field be repeated?
Yes, but repeated sessions measure habituation and activity adaptation. Do not pool repeat sessions with first-exposure anxiety-like behavior.
Does arena shape matter?
Yes. Square arenas introduce corner zones, while circular arenas emphasize wall distance. Treat shape as a protocol factor.
4.4 Current directions
Quarterly editorial review of emerging Open Field Test methodology. Q2 2026
Emerging
Home-cage to open-field transitions
Studies increasingly compare home-cage baseline with novelty-evoked open-field behavior.
Methods
Zone-free path features
Path entropy, turn angle, and wall-distance distributions supplement center-periphery scoring.
Emerging
Disease-model baseline controls
Open field remains a standard control before memory, depression-like, and sensorimotor tasks.
Methods
Automated behavior states
Pose-based scoring is adding rearing, grooming, freezing, and stretch-attend states to basic zone data.
§ 5
References
10 selected methods and validation references for Open Field Test.
Hall CS. Emotional behavior in the rat. I. Defecation and urination as measures of individual differences in emotionality. J Comp Psychol. 1934;18(3):385-403.Find source
Prut L, Belzung C. The open field as a paradigm to measure the effects of drugs on anxiety-like behaviors: a review. Eur J Pharmacol. 2003;463(1-3):3-33.Find source
Walsh RN, Cummins RA. The Open-Field Test: a critical review. Psychol Bull. 1976;83(3):482-504.Find source
Gould TD, Dao DT, Kovacsics CE. The open field test. Mood and Anxiety Related Phenotypes in Mice. 2009:1-20.Find source
Carola V, D'Olimpio F, Brunamonti E, Mangia F, Renzi P. Evaluation of the elevated plus-maze and open-field tests for the assessment of anxiety-related behaviour in inbred mice. Behav Brain Res. 2002;134(1-2):49-57.Find source
Seibenhener ML, Wooten MC. Use of the Open Field Maze to measure locomotor and anxiety-like behavior in mice. J Vis Exp. 2015;(96):e52434.Find source
Denenberg VH. Open-field behavior in the rat: what does it mean? Ann N Y Acad Sci. 1969;159(3):852-859.Find source
Archer J. Tests for emotionality in rats and mice: a review. Anim Behav. 1973;21(2):205-235.Find source
Choleris E, Thomas AW, Kavaliers M, Prato FS. A detailed ethological analysis of the mouse open field test: effects of diazepam, chlordiazepoxide and an extremely low frequency pulsed magnetic field. Neurosci Biobehav Rev. 2001;25(3):235-260.Find source
Bailey KR, Crawley JN. Anxiety-related behaviors in mice. Methods of Behavior Analysis in Neuroscience. 2009.Find source
