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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Psychol. 128 (2), 181-187 (2014).</li><li>Poling, A., Nickel, M., Alling, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Free+birds+aren't+fat:+Weight+gain+in+captured+wild+pigeons+maintained+under+laboratory+conditions.">Free birds aren't fat: Weight gain in captured wild pigeons maintained under laboratory conditions.</a> J. Exp. Anal. Behav. 53 (3), 423-424 (1990).</li><li>National Institute of Mental Health. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods and welfare considerations in behavioral research with animals: Report of a National Institutes of Health workshop (NIH Publication No. 02-5083). , (2002).</li><li>Brown, P. L., Jenkins, H. 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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...

Watch this Scientific Journal Video about A Method for Investigating Change Blindness in Pigeons Columba Livia at JoVE.com

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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Research

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Behavior

6.3K 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

Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects.

We discuss a novel method forviewpoint-rotation of visual stimuli, and demonstrate using a mirror stereoscopethe three-dimensional percept of rotation-in-depth. The technique can be used to investigate the role of stereoscopic cues in encoding viewpoint-rotated figures.

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this ...

A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

The ability to adjust behavior to sudden changes in the environment develops gradually in childhood and adolescence. For example, in the Dimensional Change Card Sort task, participants switch from sorting cards one way, such as shape, to sorting them a different way, such as color. Adjusting behavior in this way exacts a small performance cost, or switch cost, such that responses are typically slower and more error-prone on switch trials in which the sorting rule changes as compared to repeat trials in which the sorting rule remains the same. The ability to flexibly adjust behavior is often said to develop gradually, in part because behavioral costs such as switch costs typically decrease with increasing age. Why aspects of higher-order cognition, such as behavioral flexibility, develop so gradually remains an open question. One hypothesis is that these changes occur in association with functional changes in broad-scale cognitive control networks. On this view, complex mental operations, such as switching, involve rapid interactions between several distributed brain regions, including those that update and maintain task rules, re-orient attention, and select behaviors. With development, functional connections between these regions strengthen, leading to faster and more efficient switching operations. The current video describes a method of testing this hypothesis through the collection and multivariate analysis of fMRI data from participants of different ages.

This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data.

The ability to adjust behavior to sudden changes in the environment develops gradually in childhood and adolescence. For example, in the Dimensional ...

Transcranial Magnetic Stimulation for Investigating Causal Brain-behavioral Relationships and their Time Course

Transcranial magnetic stimulation (TMS) is a safe, non-invasive brain stimulation technique that uses a strong electromagnet in order to temporarily disrupt information processing in a brain region, generating a short-lived &#8220;virtual lesion.&#8221; Stimulation that interferes with task performance indicates that the affected brain region is necessary to perform the task normally. In other words, unlike neuroimaging methods such as functional magnetic resonance imaging (fMRI) that indicate correlations between brain and behavior, TMS can be used to demonstrate causal brain-behavior relations. Furthermore, by varying the duration and onset of the virtual lesion, TMS can also reveal the time course of normal processing. As a result, TMS has become an important tool in cognitive neuroscience. Advantages of the technique over lesion-deficit studies include better spatial-temporal precision of the disruption effect, the ability to use participants as their own control subjects, and the accessibility of participants. Limitations include concurrent auditory and somatosensory stimulation that may influence task performance, limited access to structures more than a few centimeters from the surface of the scalp, and the relatively large space of free parameters that need to be optimized in order for the experiment to work. Experimental designs that give careful consideration to appropriate control conditions help to address these concerns. This article illustrates these issues with TMS results that investigate the spatial and temporal contributions of the left supramarginal gyrus (SMG) to reading.

Transcranial magnetic stimulation (TMS) is a technique for non-invasively disrupting neural information processing and measuring its effect on behavior. When TMS interferes with a task, it indicates that the stimulated brain region is necessary for normal task performance, allowing one to systematically relate brain regions to cognitive functions.

Transcranial magnetic stimulation (TMS) is a safe, non-invasive brain stimulation technique that uses a strong electromagnet in order to temporarily ...

A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate drug-seeking behavior and prompt relapse in abstinent drug users. We have developed a procedure to study the behavioral and neural processes that mediate the impact of context on alcohol-seeking behavior in rats. Following acclimation to the taste and pharmacological effects of 15% ethanol in the home cage, male Long-Evans rats receive Pavlovian discrimination training (PDT) in conditioning chambers. In each daily (Mon-Fri) PDT session, 16 trials each of two different 10 sec auditory conditioned stimuli occur. During one stimulus, the CS+, 0.2 ml of 15% ethanol is delivered into a fluid port for oral consumption. The second stimulus, the CS-, is not paired with ethanol. Across sessions, entries into the fluid port during the CS+ increase, whereas entries during the CS- stabilize at a lower level, indicating that a predictive association between the CS+ and ethanol is acquired. During PDT each chamber is equipped with a specific configuration of visual, olfactory and tactile contextual stimuli. Following PDT, extinction training is conducted in the same chamber that is now equipped with a different configuration of contextual stimuli. The CS+ and CS- are presented as before, but ethanol is withheld, which causes a gradual decline in port entries during the CS+. At test, rats are placed back into the PDT context and presented with the CS+ and CS- as before, but without ethanol. This manipulation triggers a robust and selective increase in the number of port entries made during the alcohol predictive CS+, with no change in responding during the CS-. This effect, referred to as context-induced renewal, illustrates the powerful capacity of contexts associated with alcohol consumption to stimulate alcohol-seeking behavior in response to Pavlovian alcohol cues.

A procedure to study the capacity of an alcohol associated environmental context to trigger the renewal of alcohol-seeking behavior in rats is described.

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate ...

A Pressure Injection System for Investigating the Neuropharmacology of Information Processing in Awake Behaving Macaque Monkey Cortex

The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation of sensory information processing by attention. However, little is known about which neurotransmitter systems are involved in such modulations. A practical way to address this question is to combine single-cell recording with local and temporary neuropharmacological manipulation in a suitable animal model. Here we demonstrate a technique combining acute single-cell recordings with the injection of neuropharmacological agents in the direct vicinity of the recording electrode. The video shows the preparation of the pressure injection/recording system, including preparation of the substance to be injected. We show a rhesus monkey performing a visual attention task and the procedure of single-unit recording with block-wise pharmacological manipulations.

Here, we show the pressure injection of neuropharmacological substances during single-cell recording in an awake, behaving macaque monkey. This procedure allows pharmacological manipulation in the direct vicinity of a cortical recording site.

The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation ...

Psychophysical Tracking Method to Measure Taste Preferences in Children and Adults

The Monell two-series, forced-choice, paired-comparison tracking method provides a reliable measure of sweet taste preferences from childhood to adulthood. The method, which is identical for children, adolescents, and adults, is of short duration (&#60; 15 min), does not rely on sustained attention or place demands on memory (which would yield spurious age differences), and minimizes the impact of language development, making this method amenable to the cognitive limitations of pediatric populations. In this whole-mouth tasting method, subjects are asked to taste (without swallowing) pairs of solutions of different sucrose concentrations and to point to the solution they prefer. Each subsequent pair contains the participant&#39;s preceding preferred concentration and an adjacent stimulus concentration. The procedure continues until the subject chooses either a given concentration of sucrose when paired with both a higher and a lower concentration, or the highest or lowest concentration two consecutive times. Subjects are prevented from reaching response criteria on the basis of first or second position bias by the two-series design of the method, which counterbalances the order of solution presentation within each pair between the series (the weaker concentration is presented first in Series 1, second in Series 2). The geometric mean of the two sucrose concentrations chosen in Series 1 and 2 is an estimate of the participant&#39;s most preferred level of sucrose. Sucrose preference as determined with this laboratory-based measure has been shown to be associated with preference for sugars in foods and beverages and with taste receptor genotype, family history of alcoholism, and race/ethnicity, as well as depressive symptomatology among pediatric populations. The method has real-world relevance and has been applied to determine most preferred level of other tastes (e.g., salt), making it a valuable psychophysical tool.

Sweet taste has powerful hedonic appeal among people of all ages, particularly children. Described herein is a reliable and valid method that can be used to determine the level of sweetness most preferred, making it a valuable psychophysical tool for scientists.

The Monell two-series, forced-choice, paired-comparison tracking method provides a reliable measure of sweet taste preferences from childhood to ...

Investigating Motor Skill Learning Processes with a Robotic Manipulandum

Skilled reaching tasks are commonly used in studies of motor skill learning and motor function under healthy and pathological conditions, but can be time-intensive and ambiguous to quantify beyond simple success rates. Here, we describe the training procedure for reach-and-pull tasks with ETH Pattus, a robotic platform for automated forelimb reaching training that records pulling and hand rotation movements in rats. Kinematic quantification of the performed pulling attempts reveals the presence of distinct temporal profiles of movement parameters such as pulling velocity, spatial variability of the pulling trajectory, deviation from midline, as well as pulling success. We show how minor adjustments in the training paradigm result in alterations in these parameters, revealing their relation to task difficulty, general motor function or skilled task execution. Combined with electrophysiological, pharmacological and optogenetic techniques, this paradigm can be used to explore the mechanisms underlying motor learning and memory formation, as well as loss and recovery of function (e.g. after stroke).

A paradigm is presented for training and analysis of an automated skilled reaching task in rats. Analysis of pulling attempts reveals distinct subprocesses of motor learning.

Skilled reaching tasks are commonly used in studies of motor skill learning and motor function under healthy and pathological conditions, but can be ...

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors remains poorly understood. In Drosophila melanogaster, environmental cues, such as food availability, affect mating activity offering a tractable system to investigate the mechanisms modulating sexual behavior. In D. melanogaster, environmental cues are often sensed via the chemosensory gustatory and olfactory systems. Here, we present a method to test the effect of environmental chemical cues on mating behavior. The assay consists of a small mating arena containing food medium and a mating couple. The mating frequency for each couple is continuously monitored for 24 h. Here we present the applicability of this assay to test environmental compounds from an external source through a pressurized air system as well as manipulation of the environmental components directly in the mating arena. The use of a pressurized air system is especially useful to test the effect of very volatile compounds, while manipulating components directly in the mating arena can be of value to ascertain a compound's presence. This assay can be adapted to answer questions about the influence of genetic and environmental cues on mating behavior and fecundity as well as other male and female reproductive behaviors.

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

We demonstrate an assay to analyze the environmental and genetic cues that influence mating behavior in the fruit fly Drosophila melanogaster.

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors ...

A Behavioral Assay for Investigating the Role of Spatial Memory During Instinctive Defense in Mice

Evolution has selected a repertoire of defensive behaviors that are essential for survival across all animal species. These behaviors are often stereotyped actions elicited in response to innately aversive sensory stimuli, but their success requires enough flexibility for adapting to different spatial environments, which can change rapidly. Here, we describe a behavioral assay to evaluate the influence of learned spatial knowledge on defensive behaviors in mice. We have adapted the widely used Barnes maze spatial memory assay to investigate how mice navigate to a shelter during escape responses to innately aversive sensory stimuli in a novel environment, and how they adapt to acute changes in the environment. This new assay is an ethological paradigm that does not require training and exploits the natural exploration patterns and navigation strategies in mice. We propose that the set of protocols described here are a powerful means of studying goal-directed behaviors and stimulus-triggered navigation, which should be of interest to both the fields of instinctive behaviors and spatial memory.

This protocol describes a behavioral assay, based on the Barnes maze test, to study how instinctive defensive actions are modified by the knowledge of spatial environment.

Evolution has selected a repertoire of defensive behaviors that are essential for survival across all animal species. These behaviors are often ...

A New Method for Inducing a Depression-Like Behavior in Rats

Contagious depression is a phenomenon that is yet to be fully recognized and this stems from insufficient material on the subject. At the moment, there is no existing format for studying the mechanism of action, prevention, containment, and treatment of contagious depression. The purpose of this study, therefore, was to establish the first animal model of contagious depression.
Healthy rats can contract depressive behaviors if exposed to depressed rats. Depression is induced in rats by subjecting them to several manipulations of chronic unpredictable stress (CUS) over 5 weeks, as described in the protocol. A successful sucrose preference test confirmed the development of depression in the rats. The CUS-exposed rats were then caged with na&#239;ve rats from the contagion group (1 na&#239;ve rat/2 depressed rats in a cage) for an additional 5 weeks. 30 social groups were created from the combination of CUS-exposed rats and na&#239;ve rats.
This proposed depression-contagion protocol in animals consists mainly of cohabiting CUS-exposed and healthy rats for 5 weeks. To ensure that this method works, a series of tests are carried out - first, the sucrose preference test upon inducing depression to rats, then, the sucrose preference test, alongside the open field and forced-swim tests at the end of the cohabitation period. Throughout the experiment, rats are given tags and are always returned to their cages after each test.
A few limitations to this method are the weak differences recorded between the experimental and control groups in the sucrose preference test and the irreversible traumatic outcome of the forced swim test. These may be worth considering for suitability before any future application of the protocol. Nonetheless, following the experiment, na&#239;ve rats developed contagion depression after 5 weeks of sharing the same cage with the CUS-exposed rats.

This protocol describes a new model by which healthy rats could contract depression over a given time periodthrough contagion by exposure to chronic unpredictable stressed (CUS) rats.

Contagious depression is a phenomenon that is yet to be fully recognized and this stems from insufficient material on the subject. At the moment, there is ...