Description
Full Package | |
Oculus Hardware | |
Personal Computer | |
VR headset | |
VR Sensor | |
Hand Held Controller | |
Simian Software online access: Radial Arm Maze; 2 Environments; 10 object pack | |
Online Configuration of experiment | |
Data Analysis Software: Path tracking; video replay; raw data |
Simian Only | |
Simian Software online access: Radial Arm Maze; 2 Environments; 10 object pack | |
Online Configuration of experiment | |
Data Analysis Software with path tracking; video replay; raw data |
Cardboard
Gear VR
Vive
Oculus
Windows 10
Desktop
-
Configure your Experiment Online
All configurations work as a drag and drop so your experiment is easy to configure, change, and collect data easily
-
Multivariable Isolation
Isolate Who, What, When, Where, Why & How. Simian VR is VR for scientists to experiment.
-
Collect Data
Pathway views, raw data, and first person views all for review
Introduction
The Radial Arm Maze (RAM) is a well-established tool for investigating spatial learning and memory in rodents. First introduced by Olton and Samuelson in 1976, it was designed to assess rodents’ ability to efficiently navigate and remember the locations of more than seven different arms during their initial eight choices. The maze capitalizes on rodents’ natural curiosity and their spatial memory, especially when motivated by rewards. Over the years, the Radial Arm Maze has become a cornerstone in behavioral neuroscience research due to its effectiveness in evaluating both working and reference memory, while minimizing stress on the subjects.
The challenge level of the Radial Arm Maze can be adjusted by altering the number of arms. The 3D Radial Arm Maze, an evolved version of the classic design, introduces complexity by removing safe spaces and incorporating adjustable, flexible arms. This version adds an aversive element through elevation and the absence of walled arms. Additionally, the water Radial Arm Maze merges features of the Morris Water Maze and the traditional RAM, creating a unique hybrid. The T-Maze and Y-Maze are other similar apparatuses used to study spatial learning and memory.
Review
The Radial Arm Maze serves as an ideal task for the assessment of learning and memory deficits and observation of brain function. The classical rodent’s radial arm maze task has been translated to humans using virtual radial arm mazes. The Virtual Radial Arm Maze has been used in studies relating to spatial learning and memory performances in individuals with neuropsychiatric illnesses. In their study of patients with Bulimia Nervosa using the virtual RAM, Cyr et al., 2016 observed that Bulimia Nervosa patients showed the abnormal functioning of the anterior hippocampus and frontostriatal regions. Another study evaluated the performance of Schizophrenics in a rewarded virtual Radial Arm Maze task. Spieker et al. (2016) tested Schizophrenic patients treated with antipsychotics on a desktop virtual RAM task. On comparison of maze performance with healthy controls, Schizophrenic participants were seen having decreased latencies to the rewards. The patients also made comparatively more working and reference errors.
The Virtual Radial Arm Task has also been used in understanding the role of gender and age in the navigational task performance. Levy et al. (2005) used a 12-arm virtual Radial Arm Maze to evaluate the spatial learning in men and women. Their investigation showed no difference in performance. The lack of difference was attributed to the superior object memory of women which, they believed, enabled them to associate the arms of the maze with specific extra-maze cues.
The Radial Arm Maze is also used in studying brain activity. In their investigation, Iglói et al. (2015) probed the role of the cerebellum in human spatial navigation. Another study by Demanuele et al. (2015) used a delayed win-shift virtual Radial Arm Maze task to investigate cognition and cognitive disturbances in humans. Investigation of brain activity in tasks such as the Radial Arm Maze allows understanding of how different parts of the brain operate and contribute to an individual’s learning and memory abilities.
Social Interactions
Researcher Manipulations
Tele research
Training Protocol
Participants are informed of the experimental process beforehand. Participants comfortability with the technology used for the investigation is also noted, as this could be a potential influencer on the performance. Ancillary tests may also be part of the investigation.
The general procedure of the virtual Radial Arm Maze can involve the following tasks.
- Exploration trial: This initial trial is performed to familiarize the participants with the technology and the virtual environment.
- Active-win shift task: In this task, all the maze arms are baited. The participants are instructed to retrieve all the rewards by visiting each arm only once without re-entering the arm. During this trial, the spatial cues remain unchanged.
- Active win-stay task: In these trials, a select number of arms are usually randomly selected and baited. In addition to unchanged spatial cues, additional hints may be given to the participants. These trials can be used to assess the navigational strategies used by the participants and other parameters relevant to the investigation.
Along with these trials, probe trials are also included. Often matched control trials also accompany these tasks. Control trials are designed to isolate a process of interest in the task performance. These trials may have a slight variation in spatial cues or may eliminate spatial cues altogether. They can also restrict the area of exploration. Further, these tasks could also be designed to include false hints or cues to test memory and strategy. The overall task, however, remains the same as the matched trials.
Spriggs et al., 2018 designed a virtual analog 6-arm Radial Arm Maze called the Hex maze to distinguish between allocentric, egocentric-cue and egocentric-response strategies. The maze was also capable of indexing strategy aspects such as preference, acquisition, stability, and competence. The Hex maze consisted of a large circular arena (approx. 60m diameter) that was enclosed within a round room twice as large as the arena. The arms of the maze had low stone walls and tiled floor, and the ends of each arm had a floating whitish-grey sphere. Ends of the north and south arms (arbitrarily chosen) had large windows that allowed a view of mountain range and a large water body with an island, respectively. The east and west arms had narrower windows with the view of mountain range meeting the water body. Participants performed learning and probe trials, and other ancillary tests to allow assessment of navigational strategies used.
Bauer et al. (2017) investigated the sex-specific susceptibility of children (aged 10 to 14) to manganese-related neurobehavioral abilities. Estimation of prenatal and early postnatal Mn exposure was done using participants naturally shed deciduous teeth. A virtual Radial Arm Maze task was administered using a laptop and joystick to evaluate visuospatial learning, working memory and reference memory. The 3D virtual environment consisted of a Radial Arm Maze that was placed in an asymmetrical room that had plenty of visual cues such as doors, windows, and other landmarks. The arms of the maze, each had a well of which only four of the eight were baited with a reward. Result analysis showed that females were more prone to visuospatial decrements leading from prenatal Mn overexposure. Prenatal Mn exposure in females resulted in worse scores in task performance for both high and low concentrations.
Cyr et al., 2016 used a virtual Radial Arm Maze to evaluate the spatial learning abilities of participants with Bulimia Nervosa. The virtual RAM had 8-arms surrounded by landscape elements that served as spatial cues. The participants navigated the maze using a joystick and were provided with reward stimuli hidden in the arm ends. The task utilized reward-based spatial learning paradigm and consisted of learning and control conditions to assess the learning abilities. The task results and MRI scan data revealed that, although behavioral performance did not differ between healthy controls and the bulimic participants, abnormal functioning in the hippocampus and frontostriatal regions was observed in the latter group. The bulimic participants showed activation of the right anterior hippocampus when they received unexpected rewards (control condition), and deactivation of the left superior frontal gyrus and right anterior hippocampus during learning condition trial.
Migo et al. (2016) evaluated participants with amnestic mild cognitive impairments using spatial navigation task in conjunction with fMRI. Participants aged between 61 and 80 years performed the task in an analog virtual Radial Arm Maze that used platforms instead of arms. The maze was constructed in a virtual open green arena that had plenty of landmarks (visual cues) such as cottage, car, wind turbine, bus. To avoid simple egocentric strategies, participants were only allowed to select a platform if it was yellow. Task difficulty was managed by changing the number of platforms the participants could choose to 4 or 6. Task performance between the aMCI group and control group was comparable. However, fMRI data revealed that aMCI patients showed increased activity in the right dorsolateral prefrontal cortex, which plausibly was in compensation of reduced bilateral activity in the hippocampus, retrosplenial cortex, and left dorsolateral prefrontal cortex.
In a virtual Radial Arm Maze, Spieker et al., 2016 evaluated the learning and memory impairments of schizophrenic patients. The virtual maze was placed in the center of a virtual room. The room consisted of visual cues such as chairs, bookshelf, and textured walls. The room was roofed with lighting arrangements. The Radial Arm Maze had 8-arms extending from a central platform. The ends of each arm were equipped with wells of which four were baited. Schizophrenic patients took longer to complete the trials and traveled more distance when compared to healthy controls. They also made more working and reference memory errors.
Iglói et al., 2015 used functional magnetic resonance imaging to observe brain activity while participants performed spatial navigation task in a virtual 5-arm Radial Arm Maze. The maze design consisted of a central pentagonal ring, as opposed to a platform, and had five arms radiating out from its angles. The virtual environment flaunted natural scenery that provided spatial cues to the participants. Participants performed trials that were interleaved with probe trials. Participants also performed control trials wherein they were limited to a certain part of the maze and were forced to choose without any environmental cues. Brain activity analysis was performed for activation before the first-choice point of the trials to enable strategy-based analysis.
Demanuele et al., 2015 used the performance in a virtual 12-arm Radial Arm Maze to study human cognition and its disturbances. By utilizing fMRI blood oxygenation level dependent (BOLD) time series, they distinguished different cognitive stages (encoding/retrieval, choice, reward and delay stages) in a win-shift task. The virtual maze consisted of a park that had 12 pathways radiating from a central area. The maze was surrounded by 5 landmarks (houses, church, tree, telephone booth, and tractor) and the participants used them as visual cues to find the hidden gold coins.
Data Analysis
The Radial Arm Maze offers a range of choices and its difficulty can be adjusted by changing the number of arms or the type and number of cues provided. This maze is primarily employed to investigate spatial memory and learning, utilizing various protocols like the win-shift or win-stay tasks. To boost participant motivation, virtual rewards and punishments can be integrated alongside physical ones.
The behavioral data measures can include the following,
- Average time to finish the task
- Frequency of arm choice (for each arm)
- Latency to initiate the task
- Latency to respond to the stimulus
- Latency to select an arm
- Navigational strategy used
- Number of reference memory errors (entering an unrewarded arm)
- Number of rewards
- Number of working memory errors (re-entering an arm)
- Percentage of correct choices
- Percentage of incorrect choices
- Time spent in the choice arms
- Time spent in the start alley
- Time to complete the task
- Total distance
Based on the requirements of the investigation fMRI data may also be recorded. Other measures (relevant to the investigation) may include assessment of stress, anxiety and heart rate levels, among others. Ancillary questionnaires may also be used to further refine the data and the understanding of the task performance.
Strengths and Limitations
The Virtual Radial Arm Maze tests participants’ place learning abilities by evaluating their skill in discriminating, remembering, and processing spatial information as they navigate the maze. Unlike the Morris Water Maze, the Radial Arm Maze features fixed pathways for traversal and does not rely on aversive stimuli, such as those found in virtual elevated T-Mazes. This maze can be customized to restrict certain strategies and incorporate inter-trial delays to better assess memory capabilities. The lack of significant stressors and the opportunity for participants to become familiar with the maze prior to testing help ensure accurate measurements of both working and reference memory.
However, variability in the virtual Radial Arm Maze design across different studies may affect result consistency. Factors such as participants’ comfort with the technology and virtual environment, as well as their mental and emotional states, can influence performance. Additionally, demographic factors like age and gender may impact outcomes. Compared to other behavioral tasks, the Radial Arm Maze might require more time to complete.
References
Bauer JA, Claus Henn B, Austin C, Zoni S, Fedrighi C, Cagna G, Placidi D, White RF, Yang Q, Coull BA, Smith D, Lucchini RG, Wright RO, Arora M (2017). Manganese in teeth and neurobehavior: Sex-specific windows of susceptibility. Environ Int. 108:299-308. doi: 10.1016/j.envint.2017.08.013.
Cyr M, Wang Z, Tau GZ, Zhao G, Friedl E, Stefan M, Terranova K, Marsh R (2016). Reward-Based Spatial Learning in Teens With Bulimia Nervosa. J Am Acad Child Adolesc Psychiatry. 55(11):962-971.e3. doi: 10.1016/j.jaac.2016.07.778.
Demanuele C, Bähner F, Plichta MM, Kirsch P, Tost H, Meyer-Lindenberg A, Durstewitz D (2015). A statistical approach for segregating cognitive task stages from multivariate fMRI BOLD time series. Front Hum Neurosci. 9:537. doi: 10.3389/fnhum.2015.00537.
Iglói K, Doeller CF, Paradis AL, Benchenane K, Berthoz A, Burgess N, Rondi-Reig L (2015). Interaction Between Hippocampus and Cerebellum Crus I in Sequence-Based but not Place-Based Navigation. Cereb Cortex. 25(11):4146-54. doi: 10.1093/cercor/bhu132.
Levy LJ, Astur RS, Frick KM (2005). Men and women differ in object memory but not performance of a virtual radial maze. Behav Neurosci.119(4):853-62.
Migo EM, O’Daly O, Mitterschiffthaler M, Antonova E, Dawson GR, Dourish CT, Craig KJ, Simmons A, Wilcock GK, McCulloch E, Jackson SH, Kopelman MD, Williams SC, Morris RG (2016). Investigating virtual reality navigation in amnestic mild cognitive impairment using fMRI. Neuropsychol Dev Cogn B Aging Neuropsychol Cogn. 23(2):196-217. doi: 10.1080/13825585.2015.1073218.
Olton, D.S., Samuelson, R.J. (1976) Remembrance of places passed: Spatial memory in rats. J. Exper. Psych. Animal Behav. Processes 2, 97-116
Raiesdana S (2018). Modeling the interaction of navigational systems in a reward-based virtual navigation task. J Integr Neurosci.;17(1):45-67. doi: 10.3233/JIN-170036.