Name: Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards (Video) | JoVE Journal
Uploaded: 2006-12-14T00:00:00.000+00:00
Duration: 12 min 30 s
Description: Learn operant conditioning methods to test motion sensitivity in lizards using random-dot kinematograms and video playback. This approach reveals visual perception capabilities in reptiles for neuroscience research.

ai_agent_IP

ai_agent

maintenance

instantTrialDurationMinutes

isBiopharma

enableNewMyJoveSectionDesign

educationFeatures

seoMetaApi

ai_copilot_institution_blacklist

ai_chat_institution_blacklist

freeAccessWindow

ssoRoleCapture

scheduledMaintenanceBanner

joveLabsFeatures

disable_autoplay_for_bots

extended_trial_duration

5 minutes

I would like to thank Christopher Evans and Darren Burke from the Centre for the Integrative Study of Animal Behaviour (CISAB).

Jacky Dragons
Jacky lizards (A. muricatus) were held in climate-controlled captive facilities.
Enclosures were constructed of fabricated glass terrariums measuring 60 cm3. Enclosures were also filled with Sydney sand substrate, native foliage, and natural wooden perches. Enclosures were placed on top of movable trolleys that allowed for subjects to be placed in the middle of all viewing monitors.
Lizards were placed under a 14L:10D light cycle during simulated summer conditions, and were provided with both heat lamps (125W) and adequate ultraviolet (UV) lighting (300W) during the first half hour of daylight. Lizards were also provided with water ad libitum, fed crickets (Achetus domesticus) dusted with vitamins during non-experimental sessions, and routinely wormed for parasites using diluted doses of Ivermectin.
Equipment Used for Playback
Three video playback rigs are used for stimulus presentation (see Figure 1). The central rig consists of an iMac (Apple Computer Inc.) containing dot stimuli. The two additional rigs consist of an iMac with Final Cut Pro HD for stimulus presentation that contained playback stimuli (i.e., invertebrates).
The digital signal is sent to an advanced digital video converter (Canopus&copy;gt ADVC110, Melbourne, Victoria Australia) for digital-to-analog conversion for video playback and displayed on a Sony Trintron (Sony Corporation, Shinagawa, Tokyo Japan) monitor (Series Nos. PVM-14M2A/PVM-14L2/PVM-14N5A). A Canon (Model No. MV650i) digital camcorder with 22X optical zoom (Cannon Inc., Japan) is mounted directly above the testing area and records responses to stimuli directly to a Sony (Sony Corporation, Shinagawa, Tokyo Japan) video cassette recorder (Serial No. SLV-EZ717AS). 
Recorded images are sent to a colour viewfinder (NEC, Serial No. 1892, Kanagawa, Japan). At 7.5 seconds from the start of the dots display, an electronically generated sound marker is sent to a Canopus&reg; ADVC110 and records onto VHS. Video playback is adjusted for PAL-DV standard (5:1 compression; horizontal resolution 575 lines; 25 frames s-1).
Random-dot Kinematograms (RDKs)
RDKs can be developed using VPixx V1.79 (VPixx V1.79, VPixx Technologies Inc. 2002). 
Design stimuli with a 30 x 20 degree field, fill with 200 dots, with each dot measuring 5&nbsp;x 5 pixels. 
Build dot stimuli with eight variations in speed combined with eight levels of coherence and two directions, generating 128 different stimuli. 
Speed parameters were designed in degrees per second (&deg;/s). Speed variations were 0.5, 2.5, 5, 10, 20, 40, 80, and 160&deg;/s. Coherence percentages were 0, 2.5, 5, 10, 20, 40, 80, and 100% in either a left or right directional motion. 
Export each sequence as a Motion JPEG-B file. However, you can design the RDKs which an array of features.
Each sequence is a total 15 s in duration. The sequence begins with 2.5 s of 0% coherence matched with the trial speed variable. This period initiates the current trial. This is followed by 5 s of the variation in speed and coherence combination. The sequence was completed by 7.5 s of 100% in the appropriate direction.
Import all Motion JPEG-B sequences and edit in Apple Final Cut Pro HD (Apple Computers Inc.). Add a sound marker at each interval. This marker is only audible to VHS, and is used as a cue when scoring behaviour when the changes in stimulus presentation occur. Exported each of the 128 sequences as Final Cut Pro movies.
Primary reinforcers - Mealworms
Place subjects on a randomised reinforcement schedule of five trials per block trial (16 trials) during the experiment. Primary reinforcers are mealworms (Tenebrio molitor).
Secondary reinforcers&nbsp;- Animated Invertebrates 
Secondary reinforcers are to be paired with the primary reinforcer. Created biologically meaningful reinforcers, such as three types of computer-animated invertebrates: 1) cricket, 2) mite, and 3) spider.
Create animations using Lightwave v8.3 (NewTek Inc., San Antonio, TX, USA) for 15 s in length, with the initial 7.5 s of still background, and followed by 7.5 s of the invertebrate on the appropriate screen.
Photograph a background of natural vegetation to import as a JPEG in eah clip. Export each sequence into individual JPEG image sequences (375 frames), and compress into a movie file using Final Cut Pro HD for video playback. Design 50 unique clips to prevent habituation to the conditioning paradigm.
General Procedure
Place subjects between the viewing monitors. 
Randomize presentation of RDK stimuli for each subject. 
Show stimuli in blocks of 16 trials over eight days. Each trial is 15 s with intertrial intervals varying from 30-60 s. Segment each trial interval into 2.5 s of 0% coherence reflective of testing speed, 5 s of testing speed and coherence, and followed by 7.5 s of 100% in appropriate direction matched with speed.
During this 5 s critical-period, subjects are required to respond. Record dependent measures as orientation towards a left or right monitor and latency to respond. 
Use only five random trials with a primary reinforcer and reinforce each trial with an animated invertebrate. At the completion of each block trial, remove subject enclosures from the testing area, and introduce another enclosure.

<ol><li>Burghardt, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Learning+processes+in+reptiles%5BTitle%5D)+AND+%22Biology+of+the+reptilia%22%5BJournal%5D)">Learning processes in reptiles.</a> Biology of the reptilia. Gans, C., Tinkle, D. W. 7, Academic Press. New York. 555-681 (1977).</li>
<li>VPixx, Instruction Manual. VPixx Techniologies Inc. , 96(2002).</li>
</ol>

Funding was supported by the CISAB and Department of Psychology Postgraduate Award of Macquarie University, and the Australian Research Council. 
Research was conducted within the ethical guidelines of the Macquarie University Animal Ethics Committee (2003/014) and the New South Wales National Parks and Wildlife Services (S11024) of Australia.

Testing the sensory capacity in lizard species has been difficult, and has largely been both a tedious and arduous process. These difficulties stem from finding the correct reinforcer or establishing a functional protocol. Here, I established a successful protocol in which to test motion perception in lizards. This procedure may also be applicable in testing other visual characteristics as well as other sensory mechanisms. In addition, this procedure may be applicable to other species. The usefulness of this protocol no...

<table><tbody><tr><td>iMac</td><td>Computer</td><td>Apple</td><td></td><td>Three systems</td></tr><tr><td>Canopus&amp;#174;</td><td>Digital-to-analog converter</td><td>Canopus&amp;#174;</td><td>ADVC110</td><td></td></tr><tr><td>Sony Trintron</td><td>Colour viewfinder</td><td>Sony Corporation</td><td>PVM-14M2A, PVM-14L2, PVM-14N5A</td><td>Three monitors</td></tr><tr><td>Canon</td><td>Digital camcorder</td><td>Canon, inc.</td><td>MV650i</td><td>Records behavior</td></tr><tr><td>NEC</td><td>Colour viewfinder</td><td>NEC Corporation</td><td>1892</td><td>View responses</td></tr><tr><td>Sony VCR</td><td>VHS recorder</td><td>Sony Corporation</td><td>SLV-EZ717AS</td><td>Record behavior to VHS</td></tr><tr><td>VHS tape</td><td></td><td></td><td>Generic VHS</td><td>Recording media</td></tr><tr><td>VPixx</td><td>Software program</td><td>VPixx Technologies, Inc.</td><td>v1.79</td><td>To create RDKs</td></tr><tr><td>Final Cut Pro</td><td>Software program</td><td>Apple</td><td>HD</td><td>To create playback sequences</td></tr><tr><td>Lightwave&amp;#174; 3D</td><td>Software program</td><td>NewTek Inc.</td><td>v8.3</td><td>To create secondary reinforcers</td></tr><tr><td>Mealworm</td><td>Tenebrio molitor</td><td>Pisces Enterprises LTD</td><td></td><td>Primary reinforcer</td></tr><tr><td>Cricket</td><td>Achetus domesticus</td><td>Pisces Enterprises LTD</td><td></td><td>Food for husbandry</td></tr><tr><td>Terrariums</td><td>Glass</td><td>Crystal Palace Aquariums</td><td></td><td>Enclosure material for lizards (60 cm x 60 cm x 60 cm)</td></tr><tr><td>Globes</td><td>Spotone</td><td>Philips</td><td></td><td>125 W, Heat lamps for lizards</td></tr><tr><td>Ultraviolet globes</td><td>Ultra-Vitalux</td><td>Osram</td><td></td><td>300 W, UV lamps for lizards</td></tr><tr><td>Herptivite</td><td></td><td>Rep-Cal Research Labs</td><td></td><td>Vitamins: beta carotene, calcium, and vitamin D3</td></tr></tbody></table>

testing visual sensitivity to the speed and direction of motion in lizards

Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of the visual system provide more empirical evidence for functional applications. Investigation into the sensory system provides information about the sensory capacity, learning and memory ability, and establishes known baseline behaviour in which to gauge deviations (Burghardt, 1977). However, unlike mammalian or avian systems, testing for learning and memory in a reptile species is difficult. Furthermore, using an operant paradigm as a psychophysical measure of sensory ability is likewise as difficult. Historically, reptilian species have responded poorly to conditioning trials because of issues related to motivation, physiology, metabolism, and basic biological characteristics. Here, I demonstrate an operant paradigm used a novel model lizard species, the Jacky dragon (Amphibolurus muricatus) and describe how to test peripheral sensitivity to salient speed and motion characteristics. This method uses an innovative approach to assessing learning and sensory capacity in lizards. I employ the use of random-dot kinematograms (RDKs) to measure sensitivity to speed, and manipulate the level of signal strength by changing the proportion of dots moving in a coherent direction. RDKs do not represent a biologically meaningful stimulus, engages the visual system, and is a classic psychophysical tool used to measure sensitivity in humans and other animals. Here, RDKs are displayed to lizards using three video playback systems. Lizards are to select the direction (left or right) in which they perceive dots to be moving. Selection of the appropriate direction is reinforced by biologically important prey stimuli, simulated by computer-animated invertebrates.

Testing visual sensitivity in lizards using an operant conditioning paradigm that employs video playback of random-dot kinematograms and computer-generated invertebrates.

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of ...

Hi, I'm Kevin Wu from the Center for the Integrative Study of Animal Behavior at Macquarie University here in Sydney, Australia. In this video-based article, I'm gonna be talking about testing motion sensitivity and lizards. And when I talk about testing motion sensitivity, I'm talking about using an operating conditioning paradigm.And when I'm talking about upper and conditioning, that's when you take a subject animal participant or human and teach them the characteristics about an object in which they hope to learn and respond to appropriately when the object is presented and hopes to get reinforced for that response. Now, offering conditioning generally allows us to understand two things. One, it allows us to understand a learning and memory sensor or capacity, and two, it allows us to understand the sensory capacity of that particular individual or species.Now testing motion sensitivity and learning and memory and lizards has been quite difficult in so much that there are particular parameters that have been difficult to uncover. One is that lizards are notoriously difficult in establishing a particular motivational system as well as finding the right reinforcement in which to keep them interested at the tasks at hand here we're going to use the Jackie Lizard as a model species in which to test both learning and memory and especially motion sensitivity. Jackie lizards are a native, a gammut species to Australia that are highly cryptic but active during the day, but can be characterized by highly stereotype visual displays that are used for social communication.And I see visual displays that make this particular species quite visual. So what we're going to demonstrate at this video is that not only can Jackie Dragons learn and it can remember certain things, but they have quite a high level of sensitivity. In addition, I hope to demonstrate that Jackie Liz can also be used for or as a model species for other Particular tasks.As Seen before, random grams are highly saline and engaging the visual system. They do not engage recognition, they do not resemble anything biologically meaningful and there are classic psychophysics technique in both human and animal perception. And when we talk about psychophysics, we're really talking about understanding the characteristics or properties about a sound or an object.Responses by an animal subject or participant allow us to understand which thresholds that these particular characteristics are either heard or seen, and this gives us an understanding into the sensory perception of these organisms. Here's an example of what VPX can do. In this example, we have an inner circle with dots coming towards the foreground, but in the background we have random dots.V PPIC X allows you to create a series of different illusions in which to test different characteristics of sensory perception. In addition to these characteristics, it allows us to control things such as coherence, which is the direction of movement and also the speed of these dots. Final Cut Pro is a video editing program available from Apple.There are three main parts of final Cut Pro. On the canvas is where you view your sequence as it's being built. The timeline is where you place each part of the sequence or each segment and can view it as it is, as it says on a timeline, and the bin allows for multiple storage of sequences or the sequences to be put in the timeline.All dot sequences are completed using Final Cut Pro. All sequences initially designed in VIX are imported into the bin. On the canvas view you can see an example of the dots being formulated.However, all dots are constructed using the timeline. So here you can see our example shows 2.5 seconds of 0%coherence initially followed by five seconds of the variable stimulus, and then finally 7.5 seconds of a hundred percent coherence. You'll now see examples of varying dot speed and dot coherence.Speed again is measured in degrees per second, and coherence is the percentage of dots moving in either the left or right direction. This Is an example of a completed dot sequence. All the dots here are moving at 10 degrees per second.Initially 2.5 seconds are shown with 0%coherence. In this example at the variable stage, 40%of the dots will be moving the left direction for the next five seconds. This will then be followed by 7.5 seconds of a hundred percent coherence going in the left direction.The total sequence is 15 seconds. Our setup consisted of three video playback rigs. On the central monitor is where the random dot kin monograms were displayed.On the adjacent monitors is where the secondary reinforces would be displayed once the subject is made a correct choice. The IMAX seen here on the right hand side stored all the video clips on the displays. The camera, which was situated above the testing arena was videotaped and recorded and seen on a viewfinder and VCR.All digital sequences were converted from analog using a cannabis box. Secondary Reinforces were created using LightWave layout version 8.3. LightWave is a 3D animation tool that allows us to build scenes in which these animations are created.There are two particular features of light wave layout. First is a camera and where the object can be seen, second is light and these light or lights will illuminate the area in which the object is seen. We selected three animated invertebrates to use as a secondary reinforces.These were cricket, mite and spider. These invertebrates were quite similar to what these subjects would see out in the wild. The movements of these invertebrates were also mimicked off of realistic movements, videotaped and recorded using a digital camcorder.This Is Our basic testing setup. The red circle identifies our subject.Initially. The subject will say 2.5 seconds of 0%coherence on the screen in front of him.After 2.5 seconds of 0%coherence, the subject will be shown five seconds in which dot speed and coherence will vary. It is within this five second critical period that the subjects supposed to select either the left or right monitor. Based on variations in these visual characteristics, the ability to select the correct monitor provides us with an understanding of their sensory capacity.In this example, subjects are expected to go to the left monitor as the dots are going at a hundred percent. During This period, the subject is then expected to use the information acquired from the moving dots and move to the left monitor. Within the five second critical period, our subject should select the appropriate monitor.In this case it should be the left monitor. Then at 7.5 seconds, if the subject has selected the appropriate monitor, it will be presented with a secondary reinforcer and in this case, our secondary reinforcer is a cyber invertebrate. In the next section, you'll then see the completion of what an actual trial looks like.Early attempts to Establish this a reliable procedure were highly unsuccessful and there are a few reasons for this. First, there were no primary reinforces. Secondly, instead of cyber invertebrates, lizard footage displaying social displays were used as a secondary enforcer.And thirdly, that the length of each trial was too long. Each of these particular factors prevented the subjects from actually acquiring contingency and in fact increased aversive displays between the subjects themselves. I believe that are these factors that were now eliminated and if not modified, that therefore prevented from subjects from acquiring the contingency.Now we have established a successful procedure and this has largely been a trial and error process, and although Liz is are notorious for being quite difficult in establishing particular opera procedures, this method has been successful and quite reliable. So not only can we study visual communication and visual sensitivity and Jackie lizards, but quite possibly we can apply this methodology to other lizards and other species in so much. We can also apply this methodology to other aspects of vision.We can also apply to other sensory modalities such as audition chemoreception and tactile perception.

testing-visual-sensitivity-to-speed-direction-motion

Research

JoVE Journal

Biology

Computer-generated stimuli using the Jacky dragon as a model.

Computer-Generated Animal Model Stimuli

We developed the Visual-Motor Response to quantitate the motor output of larval zebrafish in response to light increments and decrements.  We also examined zebrafish vision mutants, including the no optokinetic response (nrc) mutants, which were thought to be completely blind when tested by another vision assay, the optokinetic reflex.

A Behavioral Assay to Measure Responsiveness of Zebrafish to Changes in Light Intensities 

We describe a method to record motor activity, timed to the electrically recorded tarsal contact signal in a tethered insect, walking on a slippery surface. This is used to study the neural basis of adaptive behavior under reduced influence of mechanical interaction between legs through the substrate.

Studying the Neural Basis of Adaptive Locomotor Behavior in Insects

Xenopus laevis tadpoles prefer swimming on the white side of a black/white tank. This behavior is guided by their vision. Based on this behavior, we present a simple assay to test the visual function of tadpoles.

A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

This paper describes a modification of the Barnes maze, a standard rodent paradigm used to assess spatial memory and learning, for use in small squamate reptiles.

Assessing Spatial Learning and Memory in Small Squamate Reptiles

This protocol describes how to use an in vitro isolated turtle head preparation to measure the kinematics of their eye movements. After removal of the brain from the cranium, cranial nerves can be stimulated with currents to quantify rotations of the eye and changes in pupil sizes.

Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle

This experimental protocol combined eye tracking and the assessment of presaccadic visual sensitivity in a dual task paradigm, consisting of a free choice saccade task and a visual discrimination task, to investigate the deployment of visual spatial attention before both, accurate and averaging saccades.

Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity

To examine mouse vision, we conducted a looming test. Mice were placed in a large square arena with a monitor on its ceiling. The looming visual stimulus consistently evoked freezing or flight reactions in the mice.

Using Looming Visual Stimuli to Evaluate Mouse Vision

This protocol introduces a light-spot assay to investigate Drosophila larval phototactic behavior. In this assay, a light spot is generated as light stimulation, and the process of larval light avoidance is recorded by an infrared light-based imaging system.

Light Spot-Based Assay for Analysis of Drosophila Larval Phototaxis

A novel motion-based acuity test that allows the assessment of central and peripheral visual processing in low-vision and healthy individuals, along with goggles limiting peripheral vision compatible with MRI protocols, are described here. This method offers a comprehensive vision assessment for functional impairments and dysfunctions of the visual system.

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes

The protocol describes how to measure the optomotor response in 13-lined ground squirrels, a cone-dominant species with retinal features resembling the human macula. The platform design enhances handling and reduces anxiety, improving the animal's ability to stay on the raised platform, enabling non-invasive assessment of changes in visual function.

Non-aversive Animal Restraint Enabling Recording of Optomotor Reflex in Ground Squirrels

Learn operant conditioning methods to test motion sensitivity in lizards using random-dot kinematograms and video playback. This approach reveals visual perception capabilities in reptiles for neuroscience research.

Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards

Explore More Videos