Zone Preference in the Visual Water Maze
June 26, 2025
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Magnifiers are defined as instruments that enlarge the size of images. Interestingly, the phenomenon of magnification was highly valued in the ancient world. In Ancient Egypt and Rome, for instance, people used crystals and gemstones to view small objects or images; the magnifying glass was also used to ignite paper. Note that the first magnifier used as a scientific tool was invented in the 13th century, followed by the notable work of philosopher Roger Bacon. The basic principles of the magnifying glass laid the foundations of spectacle-making, microscopy, and modern lens technology.
Lens technology has evolved significantly over the centuries, resulting in different types of contemporary magnifiers, microscopic and telescopic devices, and digital units. Some of the most popular types of magnifiers include handheld, stand, and electronic units, as well as magnifying mirrors. Also, there’s a range of specialized tools, such as magnifying tweezers and syringes, credit card magnifiers, and cell phone magnifiers.
Magnifiers are popular tools, so it’s no surprise that the magnifying glass is an icon of detective stories and a popular Internet search and zoom symbol. Magnifiers are preferred tools by scientists, collectors, historians, craftsmen, teachers, people with poor vision, and outdoor enthusiasts. Note that there are three major factors to consider when choosing a magnifier:
Requirements: The duration and distance of use are crucial criteria for purchasing. While handheld magnifiers are suitable for short-term tasks, stand and head-mounted magnifiers are ideal for prolonged use. Note that short-term spotting tasks can include reading menus, price tags, and signs, while extended viewing refers to writing, reading books, and watching TV. When it comes to distance, distance refers to the space between the user and the object. Near tasks are categorized as those at a reading distance of less than 20 inches; intermediate tasks are those at arm’s length and can include activities, such as playing cards and using a computer; distance tasks can be watching TV, watching sporting events, or reading signs.
Depending on the purpose of usage, users should also consider design and portability. There’s a wide variety of units, such as spectacles, telescopic devices, stand magnifiers, and electronic units, with handheld units being one of the most common types.
Specifications: Magnification is one of the most important specifications that should determine purchasing choices. The usual power of magnifiers varies between 2X and 20X; low-power units vary between 1X and 10X magnification, while electronic and video devices can provide magnification from 5X to 60X. However, purchasing decisions should be determined not only by the magnification rates but by the user’s diopter. For people without visual problems, for instance, a unit with a magnification range of 2X will be enough for everyday tasks, such as reading. Note that age is another individual characteristic to consider as it can affect the near point of accommodation or the closest point to the eye where the object is focused on the retina.
Interestingly, magnification ranges are often determined by the types of lenses, with glass lenses being better quality than acrylic lenses. Note that biconvex lenses are used in low-power reading units, usually with a magnification level of up to 4X. Aspheric lenses allow magnification rates of up to 12X, while aplanatic lenses provide crisp imaging and power of up to 20X. Achromatic lenses, on the other hand, are the highest-quality lenses that allow magnification of up to 25X. Most magnifying glasses consist of double-convex lenses that make objects appear bigger.
Total cost: Prices can vary between low and high-power products and vendors. Optical quality, power levels, and design types can affect the total cost of a unit. Additional features, such as built-in lighting and stands to facilitate adaptability, can also increase the price of a magnifier. To provide an example, units with big lenses that come with a mounting system can be more costly than low-power portable units. A built-in light system that provides a greater level of detail and facilitates reading in dark environments can also increase costs.
Last but not least, we should note that electronic magnifiers (e.g., desktop electronic devices, portable video units) are usually more costly than other optical magnifiers.
Magnifiers are invaluable tools in day to day life. From handheld magnifiers to magnifying mirrors, users can choose from a wide range of products. Based on different specifications and user reviews, here’s a list of the best magnifiers on the market:
1. Handheld Magnifiers: Handheld magnifiers are among the most popular types of magnifiers. They are compact, practical, and light. Note that aluminum is good material as it is light and sturdy at the same time. Handheld magnifiers can be either illuminated or non-illuminated. They provide flexible working distances and are ideal for short-term tasks, such as reading a menu.
1.1. Fancii Extra Large LED Handheld Magnifying Glass with Light
Fancii Extra Large LED Handheld Magnifying Glass with Light is a great product with three sets of magnification (2X, 4X, and 10X) and three built-in LED lights to improve the quality of the images. Interestingly, this oversized product (5.5 inches) is one of the lightest oversized instruments with LED. With its ergonomic handle, Fancii Extra Large LED Handheld Magnifying Glass is ideal for reading, jewelry-making, and crafts.
1.2. Jumbo Rectangular Handheld Magnifying Glass
Jumbo Rectangular Handheld Magnifying Glass is a lightweight model that provides a magnification rate of 3X. The unit comes with a high-quality optical grade glass lens. This magnifier has a versatile design and can be used both vertically and horizontally. Thus, Jumbo Rectangular Handheld Magnifying Glass is ideal for both hobbyists and specialists.
1.3. Carson SureGrip Rubberized Soft Grip Handheld Magnifier
Carson SureGrip Rubberized Soft Grip Handheld Magnifier is a great magnifying tool that comes with two power lenses (with magnifications of 2X and 10X, respectively). This SG-10 model is equipped with a rubberized ergonomic handle and comes with a zipper pouch. With a variety of features, Carson SureGrip Rubberized Soft Grip Handheld Magnifier is perfect for reading, crafts, and inspection.
1.4. Landincs Antique 10X Handle Magnifier
Landincs Antique 10X Handle Magnifier is a beautiful vintage product with a 138 mm (5.43 inches) handle made of sandalwood and high-quality optical glass lenses. It provides magnification of 10X and distortion-free viewing. The unit comes in an elegant box, which makes it a chic gift choice, especially for detective fiction lovers. Landincs Antique 10X Handle Magnifier is ideal for reading, crafts, coin analysis, engraving, and inspection.
2.1. Carson 5X LumiLoupe Ultra LED Lighted Stand Magnifier Loup
Carson 5X LumiLoupe Ultra LED Lighted Stand Magnifier Loup is a powerful stand magnifier that provides magnification of 5X. This LL-88 model comes with six LEDs and three brightness levels to facilitate viewing. Note that the unit requires three AAA batteries. With a variety of features, Carson 5X LumiLoupe Ultra LED Lighted Stand Magnifier Loup is ideal for observing coins, stamps, and miniatures.
2.2. Carson 2X LumiDome Polished Ball Loupe with 75 mm Base
Carson 2x LumiDome Polished Ball Loupe with 75 mm Base is a sophisticated unit with a unique design. This LD-75 model features 2X magnification, a viewing area of 2.5 inches, and a shatterproof acrylic base. The unit provides a good grip and is ideal for crafts and reading. Moreover, Carson 2X LumiDome Polished Ball Loupe with 75mm Base comes with a microfiber cloth pouch to ensure safety.
2.3. Carson 10X LumiLoupe Stand Magnifier Loupe
Carson 10X LumiLoupe Stand Magnifier Loupe is one of the most popular stand magnifiers on the market. The unit is compact and portable, which makes it ideal for people with an active lifestyle. At the same time, it provides high magnification (10X) suitable for both professionals and amateurs. Note that Carson 10X LumiLoupe Stand Magnifier Loupe has a transparent base that allows ambient light to be caught to improve visibility.
3.1. Carson DeskBrite200 LED Lighted 2X Magnifier and Desk Lamp
Carson DeskBrite200 LED Lighted 2x Magnifier and Desk Lamp is a versatile dual-powered set; the unit includes a 2X magnifying desk lamp and a 5X power spot lens. It’s equipped with a flexible neck and LED illumination. Carson DeskBrite200 LED Lighted 2X Magnifier, and Desk Lamp is ideal for office work, soldering, sewing, reading, and a whole range of hobbies.
3.2. Brightech LightView Pro LED Magnifying Glass
Brightech LightView Pro LED Magnifying Glass is one of the most popular products. It has a magnification of 2.25X and a flexible neck. Note that the height can be modified from 4 inches to 33 inches over the surface of use, with an outward reach of up to 42 inches. The unit comes with a built-in LED system that has nine watts, 800 Lumens, and a cool white color temperature of 6,000 Kelvin. Brightech LightView Pro LED Magnifying Glass is a great tool for both amateurs and professionals.
3.3. Carson Desk Brite Mini 3X LED Lighted Magnifier
Carson Desk Brite Mini 3X LED Lighted Magnifier is an appealing product with a 3X power acrylic lens, and built-in LED illumination. This LM-10 model has an extendable neck and an ergonomic collapsible design (when collapsed, it measures 3.4 inches (L) x 3.0 inches (W) x 1.5 inches (H)). Note that the unit is powered by three AAA batteries. Carson Desk Brite Mini 3X LED Lighted Magnifier is suitable for reading, inspection, and a wide variety of hands-free activities.
4. Pocket Magnifiers: Pocket magnifiers are excellent tools for people with an active lifestyle. They are small, compact, and versatile. Note that pocket magnifiers can be either illuminated or non-illuminated. Such units often come with protective cases to ensure safety.
4.1. Carson MiniBrite 5X Pocket Magnifier with Built-in LED Light
Carson MiniBrite 5X Pocket Magnifier with Built-in LED Light is a popular pocket magnifier that comes with a 5X aspheric lens, LED lighting, and a built-in sliding protective case. With its lightweight and small dimensions, this unit can fit in a pocket, which makes it ideal for people with an active lifestyle and a love for outdoor adventures.
4.2. Dreame LED Lighted Illuminated Jewelers Eye Loupe
Dreame LED Lighted Illuminated Jewelers Eye Loupe is a wonderful pocket model. It features two lenses and magnification ranges of 30X and 60X. Additionally, the unit is equipped with an illumination system. The model has a unique foldable design, which makes it a great choice for anyone interested in analyzing things that cannot be seen with the naked eye.
4.3. SE Glass Lens Folding Magnifier with Leather Pouch
SE Glass Lens Folding Magnifier with Leather Pouch is a practical pocket folding unit, ideal for reading, traveling, and everyday use. It has a magnification rate of 5X. Note that the unit comes with a carrying case made of leather to ensure safety. SE Glass Lens Folding Magnifier with Leather Pouch is one of the most convenient pocket magnifiers on the market.
5.Magnifying Mirrors: Magnifying travel mirrors are essential tools for artists, celebrities, ambassadors, and anyone with an active lifestyle who needs to look flawless 24/7. Such units are small enough to be transported, and at the same time, they can be mounted on a table to provide a high level of comfort – similar to seating down at a vanity table. Some models have an LED light system that resembles sunlight to improve usability (e.g., help users apply make-up or put in contact lenses). Interestingly, there is a variety of magnifying units, such as make-up mirrors, magnified fogless shower mirrors, vanity mirrors, and car rearview mirrors.
5.1. Terresa Lighted Travel Makeup Mirror
Terresa Lighted Travel Makeup Mirror is a wonderful tool with 1X/7X magnification. The unit comes with a LED light ring that simulates natural sunlight to support high-quality viewing. With its folding and lightweight design, Terresa Lighted Travel Makeup Mirror is ideal for tweezing, applying makeup, and personal grooming.
5.2. 7X Magnifying Lighted Makeup Mirror
7X Magnifying Lighted Makeup Mirror is another wonderful portable product. It provides magnification of 7X. This unit can be fixed to flat surfaces (e.g., mirrors), and with its 360-degree swivel, it can be adjusted easily. Additionally, this 7X Magnifying Lighted Makeup Mirror comes with LED illumination and a padded neoprene bag with a zippered pouch for batteries.
5.3. Magnifying Compact Mirror for Purses with 10X Magnification
Magnifying Compact Mirror for Purses with 10X Magnification is an ideal product for anyone who wants to look flawless 24/7. This Mavoro unit is a powerful two-sided magnifying glass with anti-distortion 1X and 10X magnification. Magnifying Compact Mirror for Purses with 10X Magnification comes with a plush pouch, which makes it a chic present choice for people who value aesthetics.
6.1. iMagniphy LED Illuminated Magnifying Glass Set
iMagniphy LED Illuminated Magnifying Glass Set is a wonderful set that can help people with poor vision. The unit is equipped with two interchangeable lenses with a magnification of 10X and 5X, respectively. It comes with a carrying pouch and cleaning cloths. iMagniphy LED Illuminated Magnifying Glass Set is ideal for everyday activities, such as knitting, reading, crafts, and writing.
6.2. Fancii LED Light 2X Large Rectangular Handheld Magnifier
Fancii LED Light 2X Large Rectangular Handheld Magnifier is a great rectangular unit with a 2X crystal-clear lens (58mm (L) x 102mm (W)). With bright LED lights, Fancii LED Light 2X Large Rectangular Handheld Magnifier can help elderly people read small prints, documents, maps, and much more.
6.3. Magnifier Bundle Quality Magnifying Glass with Light
Magnifier Bundle Quality Magnifying Glass with Light is a powerful set of three magnifiers. It includes 1) a handheld magnifying glass with bright lights and a set of 2X, 4X, and 10X lenses; 2) a pocket-size unit with 3X and 6X lenses; 3) a credit card size 3X tool. Magnifier Bundle Quality Magnifying Glass with Light is simply great for people with impaired vision.
6.4. Magnifier for Reading with Bright LED Lights
Magnifier for Reading with Bright LED Lights is another rectangular model with a large field of viewing to reduce eyestrain. It has two lenses in one – a main 2.5X lens and a 4X bifocal insert. With its compact design, Magnifier for Reading with Bright LED Lights is ideal for reading and people with poor vision.
From page and screen magnifiers to bar and pocket magnifiers, magnifiers come in all shapes and sizes to offer different benefits to users. With the increasing use of technology, electronic magnifiers are also increasing in popularity. Note that two of the most popular types are electronic desktop magnifiers and portable digital magnifiers. Electronic desktop magnifiers or closed-circuit television systems consist of a camera that displays a magnified image on a monitor. Some of these units come with cameras that rotate 360 degrees to improve visibility; other systems come with optical character recognition and speech output that enables users to hear texts. Additionally, some systems offer reverse polarity. Electronic desktop magnifiers can support reading, seeing a prescription, doing crosswords, and crafts.
Portable digital magnifiers, on the other hand, are portable units that come with a camera and a display. Note that monitor sizes can range from 3.5 inches to 13 inches. Such units are rechargeable and can be taken anywhere. Interestingly, Smartphones and applications are also increasingly popular as an alternative to electronic magnifiers. Note that some smart devices come with cameras with high resolution and additional features.
Given the wide range of magnifying products on the market, choosing a magnifier can be tricky. Distance, duration of use, portability, magnification, illumination, and types of lenses are all factors that can determine purchasing decisions. For instance, while pocket magnifiers are ideal for an active lifestyle, oversized magnifiers provide large viewing to reduce eyestrain.
At the same time, taking care of a magnifier is essential. Lenses should be kept safely and cleaned with soft material (e.g., cloths, wipes). To prevent accidents, such as scratching, and to ensure a long life, magnifiers should be handled with care. Pocket magnifiers, for instance, can be carried in resistant cases made of plastic or leather.
From pocket magnifiers to electronic units, magnifiers are invaluable instruments in a variety of settings, such as crafts, entertainment, inspection, medicine, and forensics. Magnifying glasses can be used to ignite paper, which makes them ideal for outdoor enthusiasts. While each model has its advantages, choosing a magnifier should be based on three major factors: requirements, specifications, and budget. Some of the most popular types of magnifiers include handheld units, stand magnifiers, magnifying glasses, pocket models, and electronic devices.
As stated above, taking care of magnifiers is also essential. To prevent accidents, for instance, users can purchase a protective case for their unit. With a variety of settings, magnifiers are essential in life and an invaluable aid for people with impaired vision.
In behavioral neuroscience, the Open Field Test (OFT) remains one of the most widely used assays to evaluate rodent models of affect, cognition, and motivation. It provides a non-invasive framework for examining how animals respond to novelty, stress, and pharmacological or environmental manipulations. Among the test’s core metrics, the percentage of time spent in the center zone offers a uniquely normalized and sensitive measure of an animal’s emotional reactivity and willingness to engage with a potentially risky environment.
This metric is calculated as the proportion of time spent in the central area of the arena—typically the inner 25%—relative to the entire session duration. By normalizing this value, researchers gain a behaviorally informative variable that is resilient to fluctuations in session length or overall movement levels. This makes it especially valuable in comparative analyses, longitudinal monitoring, and cross-model validation.
Unlike raw center duration, which can be affected by trial design inconsistencies, the percentage-based measure enables clearer comparisons across animals, treatments, and conditions. It plays a key role in identifying trait anxiety, avoidance behavior, risk-taking tendencies, and environmental adaptation, making it indispensable in both basic and translational research contexts.
Whereas simple center duration provides absolute time, the percentage-based metric introduces greater interpretability and reproducibility, especially when comparing different animal models, treatment conditions, or experimental setups. It is particularly effective for quantifying avoidance behaviors, risk assessment strategies, and trait anxiety profiles in both acute and longitudinal designs.
This metric reflects the relative amount of time an animal chooses to spend in the open, exposed portion of the arena—typically defined as the inner 25% of a square or circular enclosure. Because rodents innately prefer the periphery (thigmotaxis), time in the center is inversely associated with anxiety-like behavior. As such, this percentage is considered a sensitive, normalized index of:
Critically, because this metric is normalized by session duration, it accommodates variability in activity levels or testing conditions. This makes it especially suitable for comparing across individuals, treatment groups, or timepoints in longitudinal studies.
A high percentage of center time indicates reduced anxiety, increased novelty-seeking, or pharmacological modulation (e.g., anxiolysis). Conversely, a low percentage suggests emotional inhibition, behavioral avoidance, or contextual hypervigilance. reduced anxiety, increased novelty-seeking, or pharmacological modulation (e.g., anxiolysis). Conversely, a low percentage suggests emotional inhibition, behavioral avoidance, or contextual hypervigilance.
The percentage of center time is one of the most direct, unconditioned readouts of anxiety-like behavior in rodents. It is frequently reduced in models of PTSD, chronic stress, or early-life adversity, where animals exhibit persistent avoidance of the center due to heightened emotional reactivity. This metric can also distinguish between acute anxiety responses and enduring trait anxiety, especially in longitudinal or developmental studies. Its normalized nature makes it ideal for comparing across cohorts with variable locomotor profiles, helping researchers detect true affective changes rather than activity-based confounds.
Rodents that spend more time in the center zone typically exhibit broader and more flexible exploration strategies. This behavior reflects not only reduced anxiety but also cognitive engagement and environmental curiosity. High center percentage is associated with robust spatial learning, attentional scanning, and memory encoding functions, supported by coordinated activation in the prefrontal cortex, hippocampus, and basal forebrain. In contrast, reduced center engagement may signal spatial rigidity, attentional narrowing, or cognitive withdrawal, particularly in models of neurodegeneration or aging.
The open field test remains one of the most widely accepted platforms for testing anxiolytic and psychotropic drugs. The percentage of center time reliably increases following administration of anxiolytic agents such as benzodiazepines, SSRIs, and GABA-A receptor agonists. This metric serves as a sensitive and reproducible endpoint in preclinical dose-finding studies, mechanistic pharmacology, and compound screening pipelines. It also aids in differentiating true anxiolytic effects from sedation or motor suppression by integrating with other behavioral parameters like distance traveled and entry count (Prut & Belzung, 2003).
Sex-based differences in emotional regulation often manifest in open field behavior, with female rodents generally exhibiting higher variability in center zone metrics due to hormonal cycling. For example, estrogen has been shown to facilitate exploratory behavior and increase center occupancy, while progesterone and stress-induced corticosterone often reduce it. Studies involving gonadectomy, hormone replacement, or sex-specific genetic knockouts use this metric to quantify the impact of endocrine factors on anxiety and exploratory behavior. As such, it remains a vital tool for dissecting sex-dependent neurobehavioral dynamics.
The percentage of center time is one of the most direct, unconditioned readouts of anxiety-like behavior in rodents. It is frequently reduced in models of PTSD, chronic stress, or early-life adversity. Because it is normalized, this metric is especially helpful for distinguishing between genuine avoidance and low general activity.
Environmental Control: Uniformity in environmental conditions is essential. Lighting should be evenly diffused to avoid shadow bias, and noise should be minimized to prevent stress-induced variability. The arena must be cleaned between trials using odor-neutral solutions to eliminate scent trails or pheromone cues that may affect zone preference. Any variation in these conditions can introduce systematic bias in center zone behavior. Use consistent definitions of the center zone (commonly 25% of total area) to allow valid comparisons. Software-based segmentation enhances spatial precision.
Evaluating how center time evolves across the duration of a session—divided into early, middle, and late thirds—provides insight into behavioral transitions and adaptive responses. Animals may begin by avoiding the center, only to gradually increase center time as they habituate to the environment. Conversely, persistently low center time across the session can signal prolonged anxiety, fear generalization, or a trait-like avoidance phenotype.
To validate the significance of center time percentage, it should be examined alongside results from other anxiety-related tests such as the Elevated Plus Maze, Light-Dark Box, or Novelty Suppressed Feeding. Concordance across paradigms supports the reliability of center time as a trait marker, while discordance may indicate task-specific reactivity or behavioral dissociation.
When paired with high-resolution scoring of behavioral events such as rearing, grooming, defecation, or immobility, center time offers a richer view of the animal’s internal state. For example, an animal that spends substantial time in the center while grooming may be coping with mild stress, while another that remains immobile in the periphery may be experiencing more severe anxiety. Microstructure analysis aids in decoding the complexity behind spatial behavior.
Animals naturally vary in their exploratory style. By analyzing percentage of center time across subjects, researchers can identify behavioral subgroups—such as consistently bold individuals who frequently explore the center versus cautious animals that remain along the periphery. These classifications can be used to examine predictors of drug response, resilience to stress, or vulnerability to neuropsychiatric disorders.
In studies with large cohorts or multiple behavioral variables, machine learning techniques such as hierarchical clustering or principal component analysis can incorporate center time percentage to discover novel phenotypic groupings. These data-driven approaches help uncover latent dimensions of behavior that may not be visible through univariate analyses alone.
Total locomotion helps contextualize center time. Low percentage values in animals with minimal movement may reflect sedation or fatigue, while similar values in high-mobility subjects suggest deliberate avoidance. This metric helps distinguish emotional versus motor causes of low center engagement.
This measure indicates how often the animal initiates exploration of the center zone. When combined with percentage of time, it differentiates between frequent but brief visits (indicative of anxiety or impulsivity) versus fewer but sustained center engagements (suggesting comfort and behavioral confidence).
The delay before the first center entry reflects initial threat appraisal. Longer latencies may be associated with heightened fear or low motivation, while shorter latencies are typically linked to exploratory drive or low anxiety.
Time spent hugging the walls offers a spatial counterbalance to center metrics. High thigmotaxis and low center time jointly support an interpretation of strong avoidance behavior. This inverse relationship helps triangulate affective and motivational states.
By expressing center zone activity as a proportion of total trial time, researchers gain a metric that is resistant to session variability and more readily comparable across time, treatment, and model conditions. This normalized measure enhances reproducibility and statistical power, particularly in multi-cohort or cross-laboratory designs.
For experimental designs aimed at assessing anxiety, exploratory strategy, or affective state, the percentage of time spent in the center offers one of the most robust and interpretable measures available in the Open Field Test.
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