The author extends thanks to members of the Whitman College Comparative Psychology Lab for their help in data collection, including Mark Arand, Michael Barker, Eva Davis, Kuba Jeffers, Brett Lambert, Tara Mah, Theo Pratt, Tvan Trinh, Lyla Wadia, and Patricia Xi.

The procedure described here is in accordance with the Office of Laboratory Animal Welfare and with US Public Health Service Policy on Humane Care and Use of Laboratory Animals, and was approved by Whitman College&#39;s Institutional Animal Care and Use Committee.
1. Reduce Pigeons&#39; Weights
NOTE: Pigeons&#39; weights are reduced to 80 - 85% of their free-feeding weight33 to ensure that the birds are healthy and adequately motivated to work for food.
<ol>
	<li>House na&#239;ve&#160;birds in individual cages with unlimited access to water, grit, and food.</li>
	<li>Weigh each pigeon at approximately the same time each day for 2 to 4 weeks, or until each bird&#39;s free-feeding weight has stabilized.</li>
	<li>Calculate a target weight for each pigeon equal to 85% of its stable free-feeding weight.</li>
	<li>Restrict food to gradually reduce each pigeon&#39;s weight until the target weight is reached34. Pigeons should still have unrestricted access to water and grit. 
	NOTE: Published experiments using this protocol29,30,31,32 have yielded significant results using between 4 and 6 pigeons per condition. Similar numbers should be adequate for a direct replication or subtle variation. Variations that reduce the magnitude of the change blindness effect could require a larger sample.</li>
</ol>
2. Train Pigeons to Peck Stimuli Displayed on the Response Keys in the Operant Chamber and to Eat Grain from the Food Hopper
NOTE: Training and experimental sessions require precise computer control, with temporal resolution of less than 1 ms. Use a flexible programming language (see Table of Materials) to control operant chambers via an I/O relay.
<ol>
	<li>At the beginning of each day&#39;s session, weigh pigeons and place them into operant chambers (see Table of Materials).&#160;Na&#239;ve pigeons may need time to acclimate to handling, weighing, and transport to and from the operant chamber.&#160; Until then, take extra care to handle birds gently and monitor them for signs of stress.</li>
	<li>Run 100 trials per daily session. For each trial:
	<ol>
		<li>Randomly select a visual stimulus element (such as a color or line) and one of the three keys (see Table of Materials) in the operant chamber. Illuminate the selected stimulus element on the relevant key using a compatible stimulus projector (see Table of Materials). 
		NOTE: The onset and offset times of the incandescent bulbs that are standard in many operant chambers are too slow to be appropriate for this method. Replace any incandescent bulbs in the operant chamber with a faster LED equivalent, and then confirm that the displays appear as intended and that the onset of stimuli is crisp (less than 1 ms from onset to peak brightness).</li>
		<li>Wait until a pigeon pecks the key on which the stimulus is displayed. Do not acknowledge pecks to any other keys. 
		NOTE: Experienced pigeons may immediately know to peck illuminated response keys. Na&#239;ve or less experienced birds&#39; pecking can be shaped using handshaping or autoshaping35 procedures as they would be for other laboratory tasks.</li>
		<li>Following a single peck to the proper response key, clear the stimulus display and provide access to grain from the food hopper for 2 - 3 seconds.</li>
	</ol>
	</li>
	<li>At the end of each session, remove pigeons from operant chambers and weigh them before returning them to their home cages. Adjust food access time between sessions to maintain birds&#39; individual running weights at 80 - 85% of their free-feeding weights.</li>
	<li>Continue pre-training sessions until pigeons respond quickly and consistently to all of the individual stimulus elements to be included in the experiment, on all three response keys.</li>
</ol>
3. Train Pigeons to Search for and Peck Changes Presented on Response Keys
<ol>
	<li>At the beginning of each day&#39;s session, weigh pigeons and place them into operant chambers.</li>
	<li>At the beginning of each of 100 trials in a daily session, determine the details of the upcoming stimulus display. Details for each trial can be randomly selected by the experimental control software. A sample program to run a daily experimental session is included as a supplemental file (change.cpp); elements present there could also be used to perform the simpler actions in step 2.
	<ol>
		<li>Randomly choose an Inter-Stimulus Interval (ISI) of either 250 ms or 0 ms (with p = 0.5 for each).</li>
		<li>Randomly determine the number of change repetitions to present, either 1, 2, 4, 8, or 16 (with p = 0.2 for each).</li>
		<li>Define an original stimulus display consisting of one or more elements (the colors or lines presented during pretraining) on each response key.</li>
		<li>Change the original stimulus display to define a modified display by adding, deleting, or changing one element on one key. See Figure 1 for examples of original and modified stimulus displays.</li>
		<li>Ensure that pigeons will not see all possible stimulus displays during training. If necessary, designate a subset of displays for transfer (step 4) and refrain from presenting them during training.</li>
	</ol>
	</li>
	<li>Present a 5 s Inter-Trial Interval (ITI), with the houselight on and all response keys dark to separate each trial from the immediately preceding trial.</li>
	<li>Present a stimulus display using the values determined for the current trial in step 3.2.
	<ol>
		<li>Illuminate the stimulus elements that compose the original display for 250 ms.</li>
		<li>Clear the stimulus display and wait for an ISI of either 0 or 250 ms.</li>
		<li>Illuminate the stimulus elements that compose the modified display for 250 ms.</li>
		<li>Clear the stimulus display and wait for an ISI of either 0 or 250 ms.</li>
		<li>Repeat steps 3.4.1 to 3.4.4 until completion of the number of repetitions previously determined for the current trial. Present all repetitions in their entirety and ignore any keypecks during stimulus presentation.</li>
	</ol>
	</li>
	<li>Illuminate all three response keys with white light and wait until a pigeon pecks one of the three response keys. Consider the first peck on any response key after stimulus presentation is complete to be the response for that trial. See Figure 2 for a schematic description of trials with or without an ISI.</li>
	<li>Clear all keys and conclude the trial with either reinforcement or an error signal:
	<ol>
		<li>If a bird&#39;s response was on the key that displayed a change, provide access to grain from the food hopper for 2 - 3 s.</li>
		<li>If a bird&#39;s response was not on the key that changed, switch the houselight between on and off every 0.5 s for 10 seconds to indicate an incorrect response.</li>
	</ol>
	</li>
	<li>At the end of each session, remove pigeons from operant chambers and weigh them before returning them to their home cages. Adjust food access time between sessions to maintain birds&#39; individual running weights at 80 - 85% of their free-feeding weights.</li>
	<li>Continue daily training sessions until the accuracy of pigeons&#39; responses is stable, and reliably better than chance accuracy of 33%. A sample file is provided (change.xlsx) that analyzes raw data to show the effects of ISI presence and number of repetitions.</li>
</ol>
4. Present Novel Transfer Trials Within Daily Sessions
<ol>
	<li>Follow the procedure exactly as outlined in step 3, but without any potential displays excluded (see step 3.2.5). 
	NOTE: With large numbers of potential stimulus displays, it is not necessary to exclude potential displays during training and introduce them later. In those cases, simply continue training as normal, as never-before-seen displays will occur naturally.</li>
	<li>Analyze accuracy on novel, never-before-seen stimulus displays, excluding any displays pigeons have previously encountered. Better than chance accuracy will confirm that pigeons have learned a general change detection rule and are not relying on memorization of familiar stimulus displays.</li>
</ol>

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The author has nothing to disclose.

The method presented here is inspired by the so-called &#34;flicker paradigm&#34; commonly used by cognitive psychologists to study change blindness in humans9. In this human research, change blindness is operationally defined as the impairment in change detection produced by the presence of an ISI that interrupts transitions between stimulus displays. The same is true for the pigeon implementation described here. Furthermore, humans tend to approach the flicker task using a serial search strategy...

Cognitive psychology has repeatedly demonstrated striking and often surprising imperfections in our own cognitive processes. Some of the more notable examples include but are not limited to false memories1, suboptimal decision heuristics2, and faulty statistical reasoning3. A more recent addition to this list is the phenomenon of change blindness. Change blindness is a consistent failure of attention, in which one fails to notice even prominent changes to one&#39;s environment. In one demonstration4, experimenters had a confederate approach individuals to request directions. During their conversation, workers carrying a door passed between the two, briefly interrupting visual contact and providing an opportunity to swap out the confederate for a different person. After this surreptitious exchange, most individuals failed to notice that their conversation partner was no longer the same person. This failure is surprising because moment-to-moment changes would seem to be signals of potentially important events that ought to draw our attention.
In order to better understand how and why change blindness occurs, researchers have brought it into the lab and developed several ingenious procedures5,6,7,8 for studying it under more controlled conditions. One particularly successful approach has been dubbed &#34;the flicker task&#34;9. In this procedure, the experimenters edited photographs by removing a feature, and then presented the images to participants, rapidly alternating between the original and modified versions. Participants quickly spotted the differences. However, if a brief blank field was inserted between consecutive images (producing a flickering display for which the procedure is named) change detection was much more difficult, resulting in worse accuracy and slower response times. This procedure is appealing because it provides a precise measure of change blindness, and it is easy to manipulate specific aspects of the display such as the size, salience, or timing of a change.
The flicker paradigm has proven to be a powerful tool for learning about perception and attention in humans10. The effect is surprisingly powerful and persistent. Change blindness can occur for changes to the only object in a simple animation11, and when looking directly at a change location12. Even experience with change blindness and awareness of the phenomenon does not eliminate it13. Furthermore, change blindness is quite diverse, and can be induced by a number of different events, such as eye saccades5, mudsplashes14, motion picture cuts7, or visual occlusion4. A parallel phenomenon occurs in auditory15 and tactile16 modalities, indicating that it may not be exclusive to visual stimuli and may be a more general phenomenon of attention.
Humans of course, are not the only animal that makes use of attention. Pigeons, for example, show many of the same attentional abilities that humans do. They can select specific features for preferential processing (as when they use a search image to find specific food targets)17,18. They can direct attention toward specific regions or spatial locations19. They can shift their attention between hierarchical levels of organization20,21. They can also divide attention between different aspects of a stimulus display22,23. It seems then, that pigeons possess many of the same abilities that make attention useful for humans. If change blindness has to do with some of the inherent limitations of attention, we might expect to see a parallel change blindness effect in pigeons (and perhaps other animals). Furthermore, there have recently been multiple successful studies of change detection conducted using pigeons, implementing widely varying methods24,25,26,27,28.
Recent research29,30,31,32 has adapted the flicker paradigm to investigate change blindness in pigeons, and has produced results that parallel human change blindness. The current report describes a simple method for implementing this procedure in an operant chamber. As with human versions of the task, it is easy to isolate and manipulate specific aspects of stimulus presentation in order to investigate their influence over change detection and change blindness. Thus, the procedure should constitute a valuable tool for research on the limitations of avian attention, and the extent to which they are similar to the limitations of human attention.

<table><tbody><tr><td>Small Environment Cublicle</td><td>BRS/LVE</td><td>SEC-002</td><td></td></tr><tr><td>Pigeon Intelligence Panel</td><td>BRS/LVE</td><td>PIP-016</td><td></td></tr><tr><td>Grain Feeder</td><td>BRS/LVE</td><td>GFM-001</td><td></td></tr><tr><td>Pigeon Pecking Key</td><td>BRS/LVE</td><td>PPK-001</td><td></td></tr><tr><td>Stimulus projector</td><td>BRS/LVE</td><td>IC-901</td><td></td></tr><tr><td>LED Lamp</td><td>Martek Industries, Cherry Hill NJ</td><td>1820</td><td></td></tr><tr><td>I/O module</td><td>Acces IO</td><td>USB-IDIO-8</td><td></td></tr><tr><td>Personal Computer</td><td>Dell</td><td>Optiplex 3040</td><td></td></tr><tr><td>Visual C++</td><td>Microsoft</td><td></td><td></td></tr><tr><td>White Carneau pigeons</td><td>Double-T Farm</td><td></td><td></td></tr></tbody></table>

a method for investigating change blindness in pigeons (columba livia)

Change blindness is a phenomenon of visual attention, whereby changes to a visual display go unnoticed under certain specific circumstances. While many laboratory procedures have been developed that produce change blindness in humans, the flicker paradigm has emerged as a particularly effective method. In the flicker paradigm, two visual displays are presented in alternation with one another. If successive displays are separated by a short inter-stimulus interval (ISI), change detection is impaired. The simplicity of the procedure and the clear, performance-based operational definition of change blindness make the flicker paradigm well-suited to comparative research using nonhuman animals. Indeed, a variant has been developed that can be implemented in operant chambers to study change blindness in pigeons. Results indicate that pigeons, like humans, are worse at detecting the location of a change if two consecutive displays are separated in time by a blank ISI. Furthermore, pigeons&#39; change detection is consistent with an active, location-by-location search process that requires selective attention. The flicker task thus has the potential to contribute to investigations of the dynamics of pigeons&#39; selective spatial attention in comparison to humans. It also illustrates that the phenomenon of change blindness is not exclusive to humans&#39; visual perception, but may instead be a general consequence of selective attention. Finally, while the useful aspects of attention are widely appreciated and understood, it is also important to acknowledge that they may be accompanied by specific imperfections such as change blindness, and that these imperfections have consequences across a wide range of contexts.

The primary result of interest is the difference in accuracy between trials with and without an ISI. In particular, the operational definition of change blindness in the flicker paradigm is significantly reduced change-detection accuracy on trials with an ISI relative to trials without an ISI. This effect can be seen in Figure 3, which shows previously published data29. In that experiment, pigeons detected changes to stimuli consisting...

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A Method for Investigating Change Blindness in Pigeons Columba Livia

Change blindness is a phenomenon of visual attention, whereby changes to a visual display go unnoticed under certain specific circumstances. This protocol describes a variation on the flicker paradigm for investigating change blindness that is appropriate and effective for research with pigeons.

A Method for Investigating Change Blindness in Pigeons (Columba Livia)

Change blindness is a phenomenon of visual attention, whereby changes to a visual display go unnoticed under certain specific circumstances. While many ...

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6.4K Views.  Whitman College. Change blindness is a phenomenon of visual attention, whereby changes to a visual display go unnoticed under certain specific circumstances. This protocol describes a variation on the flicker paradigm for investigating change blindness that is appropriate and effective for research with pigeons.

Video: A Method for Investigating Change Blindness in Pigeons Columba Livia

Automated, Quantitative Cognitive/Behavioral Screening of Mice: For Genetics, Pharmacology, Animal Cognition and Undergraduate Instruction

We describe a high-throughput, high-volume, fully automated, live-in 24/7 behavioral testing system for assessing the effects of genetic and pharmacological manipulations on basic mechanisms of cognition and learning in mice. A standard polypropylene mouse housing tub is connected through an acrylic tube to a standard commercial mouse test box. The test box has 3 hoppers, 2 of which are connected to pellet feeders. All are internally illuminable with an LED and monitored for head entries by infrared (IR) beams. Mice live in the environment, which eliminates handling during screening. They obtain their food during two or more daily feeding periods by performing in operant (instrumental) and Pavlovian (classical) protocols, for which we have written protocol-control software and quasi-real-time data analysis and graphing software. The data analysis and graphing routines are written in a MATLAB-based language created to simplify greatly the analysis of large time-stamped behavioral and physiological event records and to preserve a full data trail from raw data through all intermediate analyses to the published graphs and statistics within a single data structure. The data-analysis code harvests the data several times a day and subjects it to statistical and graphical analyses, which are automatically stored in the &#34;cloud&#34; and on in-lab computers. Thus, the progress of individual mice is visualized and quantified daily. The data-analysis code talks to the protocol-control code, permitting the automated advance from protocol to protocol of individual subjects. The behavioral protocols implemented are matching, autoshaping, timed hopper-switching, risk assessment in timed hopper-switching, impulsivity measurement, and the circadian anticipation of food availability. Open-source protocol-control and data-analysis code makes the addition of new protocols simple. Eight test environments fit in a 48 in x 24 in x 78 in&#160;cabinet; two such cabinets (16 environments) may be controlled by one computer.

Fully automated system for measuring physiologically meaningful properties of the mechanisms mediating spatial localization, temporal localization, duration, rate&#160;and probability estimation, risk assessment, impulsivity, and the accuracy and precision of memory, in order to assess the effects of genetic and pharmacological manipulations on foundational mechanisms of cognition in mice.

We describe a high-throughput, high-volume, fully automated, live-in 24/7 behavioral testing system for assessing the effects of genetic and ...

The Attentional Set Shifting Task: A Measure of Cognitive Flexibility in Mice

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many neuropsychiatric and neurodevelopmental disorders, including depression, post-traumatic stress disorder, schizophrenia and autism spectrum disorder. Deficits in cognitive function also represent the most difficult symptom domain&#160;to successfully treat, as serotonin reuptake inhibitors and tricyclic antidepressants have only modest effects. Functional neuroimaging studies and postmortem analysis of human brain tissue implicate the PFC as being a primary region of dysregulation in patients with these disorders. However, preclinical behavioral assays used to assess these deficits in mouse models which can be readily manipulated genetically and could provide the basis for studies of new treatment avenues have been underutilized. Here we describe the adaptation of a behavioral assay, the attentional set shifting task (AST), to be performed in mice to assess prefrontal cortex mediated cognitive deficits. The neural circuits underlying behavior during the AST are highly conserved across humans, nonhuman primates and rodents, providing excellent face, construct and predictive validity.

The goal of this protocol is to perform a behavioral assay such as the attentional set shifting task (AST) to assess prefrontal cortex-mediated cognitive flexibility in mice.

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many ...

A Dual Task Procedure Combined with Rapid Serial Visual Presentation to Test Attentional Blink for Nontargets

When viewers search for targets in a rapid serial visual presentation (RSVP) stream, if two targets are presented within about 500 msec of each other, the first target may be easy to spot but the second is likely to be missed. This phenomenon of attentional blink (AB) has been widely studied to probe the temporal capacity of attention for detecting visual targets. However, with the typical procedure of AB experiments, it is not possible to examine how the processing of non-target items in RSVP may be affected by attention. This paper describes a novel dual task procedure combined with RSVP to test effects of AB for nontargets at varied stimulus onset asynchronies (SOAs). In an exemplar experiment, a target category was first displayed, followed by a sequence of 8 nouns. If one of the nouns belonged to the target category, participants would respond &#8216;yes&#8217; at the end of the sequence, otherwise participants would respond &#8216;no&#8217;. Two 2-alternative forced choice memory tasks followed the response to determine if participants remembered the words immediately before or after the target, as well as a random word from another part of the sequence. In a second exemplar experiment, the same design was used, except that 1) the memory task was counterbalanced into two groups with SOAs of either 120 or 240 msec and 2) three memory tasks followed the sequence and tested remembrance for nontarget nouns in the sequence that could be anywhere from 3 items prior the target noun position to 3 items following the target noun position. Representative results from a previously published study demonstrate that our procedure can be used to examine divergent effects of attention that not only enhance targets but also suppress nontargets. Here we show results from a representative participant that replicated the previous finding.&#160;

This paper describes a novel dual task procedure combined with Rapid Serial Visual Presentation to look at attentional blink at varied stimulus onset asynchronies. This experimental procedure differed from others in that it tested attentional blink for nontargets.

When viewers search for targets in a rapid serial visual presentation (RSVP) stream, if two targets are presented within about 500 msec of each other, the ...

A Video Demonstration of Preserved Piloting by Scent Tracking but Impaired Dead Reckoning After Fimbria-Fornix Lesions in the Rat

Piloting and dead reckoning navigation strategies use very different cue constellations and computational processes (Darwin, 1873; Barlow, 1964; O&#x2019;Keefe and Nadel, 1978; Mittelstaedt and Mittelstaedt, 1980; Landeau et al., 1984; Etienne, 1987; Gallistel, 1990;
Maurer and S&#233;guinot, 1995). Piloting requires the use of the relationships between relatively stable external (visual, olfactory, auditory) cues, whereas dead reckoning requires the integration of cues generated by self-movement. Animals obtain self-movement information from vestibular receptors, and possibly muscle and joint receptors, and efference copy of commands that generate movement. An animal may also use the flows of visual, auditory, and olfactory stimuli caused by its movements. Using a piloting strategy an animal can use geometrical calculations to determine directions and distances to places in its environment, whereas using an dead reckoning strategy it can integrate cues generated by its previous movements to return to a just left location. Dead reckoning is colloquially called "sense of direction" and "sense of distance."

Although there is considerable evidence that the hippocampus is involved in piloting (O&#x2019;Keefe and Nadel, 1978; O&#x2019;Keefe and Speakman, 1987), there is also evidence from behavioral (Whishaw et al., 1997; Whishaw and Maaswinkel, 1998; Maaswinkel and Whishaw, 1999), modeling (Samsonovich and McNaughton, 1997), and electrophysiological (O&#x2019;Mare et al., 1994; Sharp et al., 1995; Taube and Burton, 1995; Blair and Sharp, 1996; McNaughton et al., 1996; Wiener, 1996; Golob and Taube, 1997) studies that the hippocampal formation is involved in dead reckoning. The relative contribution of the hippocampus to the two forms of navigation is still uncertain, however. Ordinarily, it is difficult to be certain that an animal is using a piloting versus a dead reckoning strategy because animals are very flexible in their use of strategies and cues (Etienne et al., 1996; Dudchenko et al., 1997; Martin et al., 1997; Maaswinkel and Whishaw, 1999). The objective of the present video demonstrations was to solve the problem of cue specification in order to examine the relative contribution of the hippocampus in the use of these strategies. The rats were trained in a new task in which they followed linear or polygon scented trails to obtain a large food pellet hidden on an open field. Because rats have a proclivity to carry the food back to the refuge, accuracy and the cues used to return to the home base were dependent variables (Whishaw and Tomie, 1997). To force an animal to use a a dead reckoning strategy to reach its refuge with the food, the rats were tested when blindfolded or under infrared light, a spectral wavelength in which they cannot see, and in some experiments the scent trail was additionally removed once an animal reached the food. To examine the relative contribution of the hippocampus, fimbria&#x2013;fornix (FF) lesions, which disrupt information flow in the hippocampal formation (Bland, 1986), impair memory (Gaffan and Gaffan, 1991), and produce spatial deficits (Whishaw and Jarrard, 1995), were used.

In a piloting scent tracking task, the ability of the rats to return to a refuge with food using visual an odor trail or using dead reckoning in infrared light, the integrated record of previous movements, demonstrates that the hippocampus is necessary for dead reckoning.

Piloting and dead reckoning navigation strategies use very different cue constellations and computational processes (Darwin, 1873; Barlow, 1964; ...

Biology

Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed single-neuron activity while animals are acquiring an operantly conditioned response, or when that response is extinguished. But even in these cases, observation periods usually encompass only a single stage of learning, i.e. acquisition or extinction, but not both (exceptions include protocols employing reversal learning; see Bingman&#160;et al.1 for an example). However, acquisition and extinction entail different learning mechanisms and are therefore expected to be accompanied by different types and/or loci of neural plasticity.
Accordingly, we developed a behavioral paradigm which institutes three stages of learning in a single behavioral session and which is well suited for the simultaneous recording of single neurons&#39; action potentials. Animals are trained on a single-interval forced choice task which requires mapping each of two possible choice responses to the presentation of different novel visual stimuli (acquisition). After having reached a predefined performance criterion, one of the two choice responses is no longer reinforced (extinction). Following a certain decrement in performance level, correct responses are reinforced again (reacquisition). By using a new set of stimuli in every session, animals can undergo the acquisition-extinction-reacquisition process repeatedly. Because all three stages of learning occur in a single behavioral session, the paradigm is ideal for the simultaneous observation of the spiking output of multiple single neurons. We use pigeons as model systems, but the task can easily be adapted to any other species capable of conditioned discrimination learning.

Learning new stimulus-response associations engages a wide range of neural processes which are ultimately reflected in changing spike output of individual neurons. Here we describe a behavioral protocol allowing for the continuous registration of single-neuron activity while animals acquire, extinguish, and reacquire a conditioned response within a single experimental session.

While the subject of learning has attracted immense interest from both behavioral and neural scientists, only relatively few investigators have observed ...

Neuroscience

A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

Measurement of the visual function in the tadpoles of the frog, Xenopus laevis, allows screening for blindness in live animals. The optokinetic response is a vision-based, reflexive behavior that has been observed in all vertebrates tested. Tadpole eyes are small so the tail flip response was used as alternative measure, which requires a trained technician to record the subtle response. We developed an alternative behavior assay based on the fact that tadpoles prefer to swim on the white side of a tank when placed in a tank with both black and white sides. The assay presented here is an inexpensive, simple alternative that creates a response that is easily measured. The setup consists of a tripod, webcam and nested testing tanks, readily available in most Xenopus laboratories. This article includes a movie showing the behavior of tadpoles, before and after severing the optic nerve. In order to test the function of one eye, we also include representative results of a tadpole in which each eye underwent retinal axotomy on consecutive days. Future studies could develop an automated version of this assay for testing the vision of many tadpoles at once.

A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

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.

Measurement of the visual function in the tadpoles of the frog, Xenopus laevis, allows screening for blindness in live animals. The optokinetic response ...

Eye Tracking During A Complex Aviation Task For Insights Into Information Processing

Eye tracking has been used extensively as a proxy to gain insight into the cognitive, perceptual, and sensorimotor processes that underlie skill performance. Previous work has shown that traditional and advanced gaze metrics reliably demonstrate robust differences in pilot expertise, cognitive load, fatigue, and even situation awareness (SA).
This study describes the methodology for using a wearable eye tracker and gaze mapping algorithm that captures naturalistic head and eye movements (i.e., gaze) in a high-fidelity flight motionless simulator. The method outlined in this paper describes the area of interest (AOI)-based gaze analyses, which provides more context related to where participants are looking, and dwell time duration, which indicates how efficiently they are processing the fixated information. The protocol illustrates the utility of a wearable eye tracker and computer vision algorithm to assess changes in gaze behavior in response to an unexpected in-flight emergency.
Representative results demonstrated that gaze was significantly impacted when the emergency event was introduced. Specifically, attention allocation, gaze dispersion, and gaze sequence complexity significantly decreased and became highly concentrated on looking outside the front window and at the airspeed gauge during the emergency scenario (all p values &#60; 0.05). The utility and limitations of employing a wearable eye tracker in a high-fidelity motionless flight simulation environment to understand the spatiotemporal characteristics of gaze behavior and its relation to information processing in the aviation domain are discussed.

Eye tracking is a non-invasive method to probe information processing. This article describes how eye tracking can be used to study gaze behavior during a flight simulation emergency task in low-time pilots (i.e., &lt;350 flight hours).

Eye tracking has been used extensively as a proxy to gain insight into the cognitive, perceptual, and sensorimotor processes that underlie skill ...

Pupillometry to Assess Auditory Sensation in Guinea Pigs

Noise exposure is a leading cause of sensorineural hearing loss. Animal models of noise-induced hearing loss have generated mechanistic insight into the underlying anatomical and physiological pathologies of hearing loss. However, relating behavioral deficits observed in humans with hearing loss to behavioral deficits in animal models remains challenging. Here, pupillometry is proposed as a method that will enable the direct comparison of animal and human behavioral data. The method is based on a modified oddball paradigm - habituating the subject to the repeated presentation of a stimulus and intermittently presenting a deviant stimulus that varies in some parametric fashion from the repeated stimulus. The fundamental premise is that if the change between the repeated and deviant stimulus is detected by the subject, it will trigger a pupil dilation response that is larger than that elicited by the repeated stimulus. This approach is demonstrated using a vocalization categorization task in guinea pigs, an animal model widely used in auditory research, including in hearing loss studies. By presenting vocalizations from one vocalization category as standard stimuli and a second category as oddball stimuli embedded in noise at various signal-to-noise ratios, it is demonstrated that the magnitude of pupil dilation in response to the oddball category varies monotonically with the signal-to-noise ratio. Growth curve analyses can then be used to characterize the time course and statistical significance of these pupil dilation responses. In this protocol, detailed procedures for acclimating guinea pigs to the setup, conducting pupillometry, and evaluating/analyzing data are described. Although this technique is demonstrated in normal-hearing guinea pigs in this protocol, the method may be used to assess the sensory effects of various forms of hearing loss within each subject. These effects may then be correlated with concurrent electrophysiological measures and post-hoc anatomical observations.

Pupillometry, a simple and non-invasive technique, is proposed as a method to determine hearing-in-noise thresholds in normal hearing animals and animal models of various auditory pathologies.

Noise exposure is a leading cause of sensorineural hearing loss. Animal models of noise-induced hearing loss have generated mechanistic insight into the ...

Finding Your Blind Spot and Perceptual Filling-in

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
In the back of everyone's eye is a small piece of neural tissue called the retina. The retina has photosensitive cells that respond to stimulation by light. The responses of these cells are sent into the brain through the optic nerve, a bundle of neural fibers. In each retina there is a place somewhere in the periphery where the outputs from retinal cells collect and the bundled optic nerve exits to the brain. At that location, there is no photosensitivity-whatever light reflects from the world and lands in that position does not produce a signal in the brain. As a result, humans have a blind spot, a place in the visual field for which they don't process incoming stimuli. 
However, people are not aware that they have blind spots; there is not an empty hole in the visual images in front of the eyes. So what do people see in their blind spots? The brain actually fills-in missing input based on the surroundings. 
This video demonstrates how to find a person's blind spot, and how to investigate the mechanisms of perceptual filling-in.

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
In the back of everyone's eye is a small piece of neural tissue called the retina. ...

Education

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Psychology

Sensation and Perception

Motion-induced Blindness

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
One thing becomes very salient after basic exposure to the science of visual perception and sensation: what people see is a creation of the brain. As a result people may fail to see things, see things that are not there, or see things in a distorted way. 
To distinguish between physical reality and what people perceive, scientists use the term awareness to refer to what people perceive. To study awareness, vision scientists often rely on illusions-misperceptions that can reveal the ways that the brain constructs experience. In 2001, a group of researchers discovered a striking new illusion called motion-induced blindness that has become a powerful tool in the study of visual awareness.1
This video demonstrates typical stimuli and methods used to study awareness with motion-induced blindness.

Studying Visual Awareness and Motion-Induced Blindness

Source: Laboratory of Jonathan Flombaum&#8212;Johns Hopkins University
One thing becomes very salient after basic exposure to the science of visual ...

A Method for Investigating Change Blindness in Pigeons (Columba Livia)

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Chapters in this video

Automated, Quantitative Cognitive/Behavioral Screening of Mice: For Genetics, Pharmacology, Animal Cognition and Undergraduate Instruction

The Attentional Set Shifting Task: A Measure of Cognitive Flexibility in Mice

A Dual Task Procedure Combined with Rapid Serial Visual Presentation to Test Attentional Blink for Nontargets

A Video Demonstration of Preserved Piloting by Scent Tracking but Impaired Dead Reckoning After Fimbria-Fornix Lesions in the Rat

Recording Single Neurons' Action Potentials from Freely Moving Pigeons Across Three Stages of Learning

A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

Eye Tracking During A Complex Aviation Task For Insights Into Information Processing

Pupillometry to Assess Auditory Sensation in Guinea Pigs

Finding Your Blind Spot and Perceptual Filling-in

Motion-induced Blindness