The study was supported by the Basic Research Founding of the Physics Department and the Biology Department of the Naples University Federico II. The authors thank Dr. Claudia Angelini (Institute of Applied Calculus, Consiglio Nazionale delle Ricerche [CNR], Italy) for the statistical support. The authors thank Martina Scanu and Silvia Frassinet for their technical help with collecting the data, and the departmental technicians F. Cassese, G. Passeggio, and R. Rocco for their skillful assistance in the design and realization of the experimental setup. We thank Laura Gentile for helping conducting the experiment during the video shooting. We thank Diana Rose Udel from the University of Miami for shooting the interview statements of Alessandro Cresci.

The following protocol has been approved by the Institutional Animal Care and Use Committee of the University of Naples Federico II, Naples, Italy (2015).
1. Animal Maintenance
<ol>
	<li>Use tanks of at least 200 L to host a shoal of at least 50 individuals of both sexes in each tank. 
	NOTE: The density of the fish in the tank has to be one animal per 2 L or lower. Under these conditions, zebrafish will display normal shoaling behavior.</li>
	<li>Set the maintenance conditions as follow: temperature at 27&#8211;28 &#176;C; conductivity at &#60;500 &#956;S; pH 6.5&#8211;7.5; NO3 at &#60;0.25 mg/L; and a light:dark photoperiod at 10 h:14 h. 
	NOTE: Identical holding conditions must be used for both the mixed population and the separated proactive and reactive populations.</li>
</ol>
2. Personality Selection in Zebrafish
<ol>
	<li>Prepare and place the personality selection tank in a quiet room (Figure 3) with the same water as used in the maintenance tanks.</li>
	<li>Place a video camera above or at the side of the tank. Connect the camera to a computer with a monitor located in an area where there is no visual contact with the tank.</li>
	<li>Select nine fish at random from the maintenance tank and transfer them to the dark side of the personality selection tank, using a knotless net. 
	NOTE: Try to limit the interactions with the tanks and fish to the least amount of time possible. Avoid noise and fast movements. If necessary, transfer the animals in a small volume transporting tank (about 2 L) with water from the holding tank. To avoid air exposure of animals, use a 250 ml beaker and gently induce the animal to enter the beaker. Try to minimize the capture time, avoid collecting multiple fish as it might cause physical damage to the animals and do not hold fish for more than a few seconds in the net as these factors can increase stress. Fish must be fed ad libitum prior to the transfer to the experimental tank. This limits the possibility that different tendencies of food-seeking behavior would affect the behavior of the individuals during the following experiment22. Conduct replicate experiments at the same time of the day. This minimizes variability in the behavior of the experimental groups caused by possible circadian rhythms23.</li>
	<li>After 1 h of acclimatization, open the sliding door. 
	NOTE: Individuals who exit from the hole, exploring the bright side of the tank within 10 min, are considered proactive21.</li>
	<li>After 10 min, gently remove the proactive individuals from the tank and transfer them to the proactive maintenance tank.</li>
	<li>After 15 min, collect the fish that remain in the dark box, which are considered reactive21, and transfer them to the reactive maintenance tank. 
	NOTE: Discard fish that move to the bright side of the tank after 10 min21. Perform the personality test with nine fish at a time until the desired number of proactive and reactive fish necessary for the tests described in section 5 are collected. Consistency of the proactive and reactive personality can be checked regularly using the same approach.</li>
</ol>
3. Set up of the Magnetic Field with the One-dimensional Magnetic Field Manipulation27
<ol>
	<li>Switch on the Power unit (Figure 2A).</li>
	<li>Place the coiled tunnel in the location where the rheotactic protocol will be performed (section 5) but keep it disconnected from the swimming apparatus (Figure 2A). Place a magnetic probe connected with a Gauss/Teslameter inside the tunnel and verify which voltage is necessary to obtain the chosen magnetic field value along the major axis of the tunnel. 
	NOTE: Because of the magnetic properties of a solenoid, the field is reasonably uniform inside the tunnel; this can be checked by slowly moving the probe both horizontally and vertically.</li>
	<li>Disconnect the probe and connect the flow tunnel to the swimming apparatus.</li>
	<li>Start with the rheotactic protocol (section 5).</li>
</ol>
4. Set Up of the Magnetic Field with the Three-dimensional Magnetic Field Manipulation27
<ol>
	<li>Switch on the CPU, DAC, and coil drivers (Figure 2B).</li>
	<li>Set the chosen magnetic field on each one of the three axes (x, y, and z).</li>
	<li>Place the tunnel in the center of the Helmholtz pairs set.</li>
	<li>Start with the rheotactic protocol (section 5).</li>
</ol>
5. Test of the Zebrafish Rheotaxis in the Flow Chamber
<ol>
	<li>Transfer one to five fish to the flow tunnel using a 2 L tank with the sides and the bottom obscured.</li>
	<li>Turn on the pump and set the flow rate in the tunnel to 1.7 cm/s. 
	NOTE: This slow-moving water will keep the water in the tunnel oxygenated and it will facilitate animal recovery.</li>
	<li>Let the animals acclimate to the swimming tunnel for 1 h.</li>
	<li>Start the video recording of the behavior of the fish in the tunnel. 
	NOTE: We used a camera (e.g., Yi 4K Action) with remote control (e.g., Bluetooth) and saved the video as .mpg (30 frames/s).</li>
	<li>Start the stepwise increase of the flow rate according to the chosen experimental protocol (1.3 cm/s in this study; Figure 4). 
	NOTE: For this protocol, we used low flow rates which, for zebrafish, range from 0 to 2.8 BL (body lengths)/s. These flow speeds are in the lower range of flow rates that induce continuous oriented swimming in zebrafish (3%&#8211;15% of critical swimming speed [Ucrit])24. The use of low flow rates (following Brett&#8217;s protocol25) is linked to the speci&#64257;c behavioral characteristics of this species in the presence of water currents. Zebrafish tend to swim along the major axis of the chamber, turning frequently, even in the presence of water &#64258;ow, and tend to swim both upstream and downstream24,26. This behavior is affected by the water &#64258;ow rate, disappearing at relatively high speeds (&#62;8 BL/s)26, when the animals continuously swim facing upstream (full positive rheotactic response). Vertical and transversal displacements are very rare.</li>
	<li>Perform morphometry of the animals (sex and total length [TL], fork length [FL], or BL) on pictures of fish in a morphometric chamber&#8203;.
	<ol>
		<li>Select the appropriate picture.</li>
		<li>Open the picture in ImageJ.</li>
		<li>Take note of the sex of the animal (male zebrafish are slender and tend to be yellowish, while females are more rounded and tend to have blue and white colorings).</li>
		<li>Click Analyze &#62; Set Scale and set the scale of the image in centimeters, using the whole horizontal length of the tunnel as reference.</li>
		<li>Click Analyze &#62; Measure and record the linear length of the animal.</li>
		<li>Calculate its body weight (BW). 
		NOTE: BW is calculated from sex-FL-BW relationships previously built in the lab or from metadata. The whole procedure avoids manipulation stress on the animals.</li>
	</ol>
	</li>
</ol>
6. Video Tracking
<ol>
	<li>Open the video file with Tracker 4.84 Video Analysis and Modeling Tool. 
	NOTE: If necessary, correct any video distortion using perspective and radial distortion &#64257;lters.</li>
	<li>Click on Coordinate system in the upper menu and set the length units to centimeters and the time units to seconds.</li>
	<li>Click on File &#62; Import &#62; Video and open one of the videos in Tracker 4.84.</li>
	<li>Click on &#8220;Coordinate axes&#8221; and set the reference system to track the position of the fish over time, with the x axis along the tunnel. Set the origin at the low corner of the downstream ending wall (at the water outlet).</li>
	<li>Click on Track &#62; New &#62; Point of mass and start tracking one fish at a time. Track the last 5 min of each step that the fish spent at each flow rate.</li>
	<li>Advance the video manually at five-frame intervals (0.5 s) and mark the time and position of the animal at each upstream-downstream turn (UDt; red dots in Figure 5) and at each downstream-upstream turn (DUt; blue dots in Figure 5). 
	NOTE: Use the &#64257;sh eye position as a reference for the &#64257;sh&#8217;s position. Track the animal&#8217;s position using a Point mass. Exclude from the tracking any period of non-oriented swimming (i.e., maneuvering time).</li>
	<li>At the end of each tracking session, select the x-values and time values from the table at the bottom-right corner of the software window. Right-click on the data and click Copy data &#62; Full precision.</li>
	<li>Save the time values and x-values of all turning positions on a template spreadsheet file to calculate the total upstream time (sum of all the intervals between UDts and DUts) and the total downstream time (sum of the intervals between DUts and UDt), as well as the values of the rheotactic index in percentages (RI%) for each flow step (see Figure 5). 
	NOTE: The rheotactic behavior is quantified by the proportion of the total oriented time that the fish spend facing upstream (swimming or rarely freezing [i.e., they stay still at the bottom of the tunnel]27). This proportion is defined as the RI% (Figure 5). 
	<img alt="Equation" src="/files/ftp_upload/59229/59229eq1.jpg" /></li>
</ol>

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G., Struthers, G., Watts, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracking+Atlantic+salmon+smolts,+Salmo+salar+L.,+through+Loch+Voil,+Scotland.">Tracking Atlantic salmon smolts, Salmo salar L., through Loch Voil, Scotland.</a> Journal of Fish Biology. 19 (5), 519-537 (1981).</li><li>Bottesch, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+magnetic+compass+that+might+help+coral+reef+fish+larvae+return+to+their+natal+reef.">A magnetic compass that might help coral reef fish larvae return to their natal reef.</a> Current Biology. 26 (24), R1266-R1267 (2016).</li><li>Boles, L. C., Lohmann, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=True+navigation+and+magnetic+maps+in+spiny+lobsters.">True navigation and magnetic maps in spiny lobsters.</a> Nature. 421 (6918), 60-63 (2003).</li><li>Dingemanse, N. J., Kazem, A. J. N., R&#233;ale, D., Wright, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioural+reaction+norms:+animal+personality+meets+individual+plasticity.">Behavioural reaction norms: animal personality meets individual plasticity.</a> Trends in Ecology and Evolution. 25 (2), 81-89 (2010).</li></ol>

The authors have nothing to disclose.

The protocol described in this study allows scientists to quantify complex orientation responses of aquatic species resulting from the integration between two external cues (water current and geomagnetic field) and one internal factor of the animal, such as personality. The overall concept is to create an experimental design that allows scientists to separate individuals of different personality and investigate their orientation behavior while controlling separately or simultaneously the external environmental cues.
...

In the present study, we describe a lab-based behavioral protocol which has the scope of investigating the role of fish personality on the orientation response of shoaling fish to external orientation cues, such as water currents and magnetic fields.
The orienting decisions of animals result from weighing various sensory information. The decision process is influenced by the ability of the animal to navigate (e.g., the capacity to select and keep a direction), its internal state (e.g., feeding or reproductive needs), its ability to move (e.g., locomotion biomechanics), and several additional external factors (e.g., time of day, interaction with conspecifics)1.
The role of the internal state or animal personality in the orientation behavior is often poorly understood or not explored2. Additional challenges arise in the study of the orientation of social aquatic species, which often perform coordinated and polarized group movement behavior3.
Water currents play a key role in the orientation process of fish. Fish orient to water currents through an unconditioned response called rheotaxis4, which can be positive (i.e., upstream oriented) or negative (i.e. downstream oriented) and is used for several activities, ranging from foraging to the minimization of energetic expenditure5,6. Moreover, a growing body of literature reports that many fish species use the geomagnetic field for orientation and navigation7,8,9.
The study of rheotaxis and swimming performance in the fish is usually conducted in flow chambers (flume), where fish are exposed to the stepwise increase of the flow speed, from low to high speeds, often until exhaustion (called critical speed)10,11. On the other hand, previous studies investigated the role of the magnetic field in the orientation through the observation of the swimming behavior of the animals in arenas with still water12,13. Here, we describe a laboratory technique that allows researchers to study the behavior of fish while manipulating both the water currents and the magnetic field. This method was utilized for the first time on shoaling zebrafish (Danio rerio) in our previous study, leading to the conclusion that the manipulation of the surrounding magnetic field determines the rheotactic threshold (i.e., the minimal water speed at which shoaling fish orient upstream)14. This method is based on the use of a flume chamber with slow flows combined with a setup designed to control the magnetic field in the flume, within the range of the earth&#8217;s magnetic field intensity.
The swimming tunnel utilized to observe the behavior of zebrafish is outlined in Figure 1. The tunnel (made of a nonre&#64258;ecting acrylic cylinder with a 7 cm diameter and 15 cm in length) is connected to a setup for the control of the flow rate14. With this setup, the range of flow rates in the tunnel varies between 0 and 9 cm/s.
To manipulate the magnetic field in the swimming tunnel, we use two methodological approaches: the first is one-dimensional and the second is three-dimensional. For any application, these methods manipulate the geomagnetic field to obtain specific magnetic conditions in a defined volume of water&#8212;thus, all the values of magnetic field intensity reported in this study include the geomagnetic field.
Concerning the one-dimensional approach15, the magnetic field is manipulated along the water flow direction (defined as the x-axis) using a solenoid wrapped around the swimming tunnel. This is connected to a power unit, and it generates uniform static magnetic fields (Figure 2A). Similarly, in the case of the three-dimensional approach, the geomagnetic field in the volume containing the swimming tunnel is modified using coils of electric wires. However, to control the magnetic field in three dimensions, the coils have the design of three orthogonal Helmholtz pairs (Figure 2B). Each Helmholtz pair is composed of two circular coils oriented along the three orthogonal space directions (x, y, and z) and equipped with a three-axial magnetometer working in closed-loop conditions. The magnetometer works with field intensities comparable with the earth&#8217;s natural field, and it is located close to the geometrical center of the coils set (where the swimming tunnel is located).
We implement the techniques described above to test the hypothesis that the personality traits of the fish composing a shoal influence the way they respond to magnetic fields16. We test the hypothesis that individuals with proactive and reactive personality17,18 respond differently when exposed to water flows and magnetic fields. To test this, we first sort zebrafish using an established methodology to assign and group individuals that are proactive or reactive17,19,20,21. Then, we evaluate the rheotactic behavior of zebrafish swimming in shoals composed of only reactive individuals or composed of only proactive individuals in the magnetic flume tank, which we present as sample data.
The sorting method is based on the different tendency of the proactive and reactive individuals to explore novel environments21. Specifically, we use a tank divided into a bright and a dark side17,19,20,21 (Figure 3). Animals are acclimated to the dark side. When access to the bright side is open, proactive individuals tend to quickly exit the dark half of the tank to explore the new environment, while the reactive fish do not leave the dark tank.

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			<td style="width:389px;">Thermo-cryostat&#160;</td>
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assessing the influence of personality on sensitivity to magnetic fields in zebrafish

To orient themselves in their environment, animals integrate a wide array of external cues, which interact with several internal factors, such as personality. Here, we describe a behavioral protocol designed for the study of the influence of zebrafish personality on their orientation response to multiple external environmental cues, specifically water currents and magnetic fields. This protocol aims to understand whether proactive or reactive zebrafish display different rheotactic thresholds (i.e., the flow speed at which the fish start swimming upstream) when the surrounding magnetic field changes its direction. To identify zebrafish with the same personality, fish are introduced in the dark half of a tank connected with a narrow opening to a bright half. Only proactive fish explore the novel, bright environment. Reactive fish do not exit the dark half of the tank. A swimming tunnel with low flow rates is used to determine the rheotactic threshold. We describe two setups to control the magnetic field in the tunnel, in the range of the earth&#8217;s magnetic field intensity: one that controls the magnetic field along the flow direction (one dimension) and one that allows a three-axial control of the magnetic field. Fish are filmed while experiencing a stepwise increase of the flow speed in the tunnel under different magnetic fields. Data on the orientation behavior are collected through a video-tracking procedure and applied to a logistic model to allow the determination of the rheotactic threshold. We report representative results collected from shoaling zebrafish. Specifically, these demonstrate that only reactive, prudent fish show variations of the rheotactic threshold when the magnetic field varies in its direction, while proactive fish do not respond to magnetic field changes. This methodology can be applied to the study of magnetic sensitivity and rheotactic behavior of many aquatic species, both displaying solitary or shoaling swimming strategies.

As sample data we present results obtained controlling the magnetic field along the water flow direction on proactive and reactive shoaling zebrafish16 using the setup shown in Figure 2A (see section 3 of the protocol). These results show how the described protocol can highlight differences in responses to the magnetic field in fish with different personalities. The overall concept of these trials relies on the finding that the directi...

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Assessing the Influence of Personality on Sensitivity to Magnetic Fields in Zebrafish

We describe a behavioral protocol designed to assess how zebrafish&#8217;s personalities influence their response to water currents and weak magnetic fields. Fishes with the same personalities are separated based on their explorative behavior. Then, their rheotactic orientation behavior in a swimming tunnel with a low flow rate and under different magnetic conditions is observed.

To orient themselves in their environment, animals integrate a wide array of external cues, which interact with several internal factors, such as ...

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6.6K Views.  University of Miami. We describe a behavioral protocol designed to assess how zebrafish’s personalities influence their response to water currents and weak magnetic fields. Fishes with the same personalities are separated based on their explorative behavior. Then, their rheotactic orientation behavior in a swimming tunnel with a low flow rate and under different magnetic conditions is observed.

Video: Assessing the Influence of Personality on Sensitivity to Magnetic Fields in Zebrafish

A Procedure to Study the Effect of Prolonged Food Restriction on Heroin Seeking in Abstinent Rats

In human drug addicts, exposure to drug-associated cues or environments that were previously associated with drug taking can trigger relapse during abstinence. Moreover, various environmental challenges can exacerbate this effect, as well as increase ongoing drug intake.
The procedure we describe here highlights the impact of a common environmental challenge, food restriction, on drug craving that is expressed as an augmentation of drug seeking in abstinent rats.
Rats are implanted with chronic intravenous i.v. catheters, and then trained to press a lever for i.v. heroin over a period of 10-12 days. Following the heroin self-administration phase the rats are removed from the operant conditioning chambers and housed in the animal care facility for a period of at least 14 days. While one group is maintained under unrestricted access to food (sated group), a second group (FDR group) is exposed to a mild food restriction regimen that results in their body weights maintained at 90% of their nonrestricted body weight. On day 14 of food restriction the rats are transferred back to the drug-training environment, and a drug-seeking test is run under extinction conditions (i.e.&#160;lever presses do not result in heroin delivery).
The procedure presented here results in a highly robust augmentation of heroin seeking on test day in the food restricted rats. In addition, compared to the acute food deprivation manipulations we have used before, the current procedure is a more clinically relevant model for the impact of caloric restriction on drug seeking. Moreover, it might be closer to the human condition as the rats are not required to go through an extinction-training phase before the drug-seeking test, which is an integral component of the popular reinstatement procedure.

A procedure that allows a demonstration of robust augmentation of drug seeking in food-restricted rats is described. Following heroin self-administration training, rats go through an abstinence period, in a drug-free environment, during which they are mildly food restricted. Drug seeking is then tested in the drug-associated environment.

In human drug addicts, exposure to drug-associated cues or environments that were previously associated with drug taking can trigger relapse during ...

Assessing Functional Performance in the Mdx Mouse Model

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential pharmaceutical compounds and gene therapy approaches have progressed into clinical trials. With improvement in muscle function being the most important end point in these trials, a lot of emphasis has been placed on setting up reliable, reproducible, and easy to perform functional tests to pre clinically assess muscle function, strength, condition, and coordination in the mdx mouse model for DMD. Both invasive and noninvasive tests are available. Tests that do not exacerbate the disease can be used to determine the natural history of the disease and the effects of therapeutic interventions (e.g. forelimb grip strength test, two different hanging tests using either a wire or a grid and rotarod running). Alternatively, forced treadmill running can be used to enhance disease progression and/or assess protective effects of therapeutic interventions on disease pathology. We here describe how to perform these most commonly used functional tests in a reliable and reproducible manner. Using these protocols based on standard operating procedures enables comparison of data between different laboratories.

Assessing Functional Performance in the Mdx Mouse Model

The primary outcome measure in clinical trials for neuromuscular disorders is generally improved muscle function. Therefore, assessing the effect of potential therapeutic compounds on muscle performance pre clinically in mouse models is of great importance. We here describe several functional tests to address this.

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential ...

Methods to Explore the Influence of Top-down Visual Processes on Motor Behavior

Kinesthetic awareness is important to successfully navigate the environment. When we interact with our daily surroundings, some aspects of movement are deliberately planned, while others spontaneously occur below conscious awareness. The deliberate component of this dichotomy has been studied extensively in several contexts, while the spontaneous component remains largely under-explored. Moreover, how perceptual processes modulate these movement classes is still unclear. In particular, a currently debated issue is whether the visuomotor system is governed by the spatial percept produced by a visual illusion or whether it is not affected by the illusion and is governed instead by the veridical percept. Bistable percepts such as 3D depth inversion illusions (DIIs) provide an excellent context to study such interactions and balance, particularly when used in combination with reach-to-grasp movements. In this study, a methodology is developed that uses a DII to clarify the role of top-down processes on motor action, particularly exploring how reaches toward a target on a DII are affected in both deliberate and spontaneous movement domains.

It is unclear how top-down signals from the ventral visual stream affect movement. We developed a paradigm to test motor behavior towards a target on a 3D depth inversion illusion. Significant differences are reported in both deliberate, goal-directed movements and automatic actions under illusory and veridical viewing conditions.

Kinesthetic awareness is important to successfully navigate the environment. When we interact with our daily surroundings, some aspects of movement are ...

Uncovering Beat Deafness: Detecting Rhythm Disorders with Synchronized Finger Tapping and Perceptual Timing Tasks

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here with the goal of uncovering rhythm disorders, such as beat deafness. Beat deafness is characterized by poor performance in perceiving durations in auditory rhythmic patterns or poor synchronization of movement with auditory rhythms (e.g., with musical beats). These tasks include the synchronization of finger tapping to the beat of simple and complex auditory stimuli and the detection of rhythmic irregularities (anisochrony detection task) embedded in the same stimuli. These tests, which are easy to administer, include an assessment of both perceptual and sensorimotor timing abilities under different conditions (e.g., beat rates and types of auditory material) and are based on the same auditory stimuli, ranging from a simple metronome to a complex musical excerpt. The analysis of synchronized tapping data is performed with circular statistics, which provide reliable measures of synchronization accuracy (e.g., the difference between the timing of the taps and the timing of the pacing stimuli) and consistency. Circular statistics on tapping data are particularly well-suited for detecting individual differences in the general population. Synchronized tapping and anisochrony detection are sensitive measures for identifying profiles of rhythm disorders and have been used with success to uncover cases of poor synchronization with spared perceptual timing. This systematic assessment of perceptual and sensorimotor timing can be extended to populations of patients with brain damage, neurodegenerative diseases (e.g., Parkinson&#8217;s disease), and developmental disorders (e.g., Attention Deficit Hyperactivity Disorder).

Behavioral tasks that allow for the assessment of perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) are presented. Synchronization of finger tapping to the beat of an auditory stimuli and detecting rhythmic irregularities provides a means of uncovering rhythm disorders.

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here ...

Assessing the Effects of Music Listening on Psychobiological Stress in Daily Life

Music listening is associated with stress-reducing effects. However, most of the results on music listening and stress were gathered in experimental settings. As music listening is a popular activity of daily life, it is of utmost importance to study the effects of music listening on psychobiological stress in an everyday, daily-life setting. Here, a study protocol is presented that allows the assessment of associations between music listening and psychobiological stress in daily life by noninvasively measuring salivary cortisol (as a marker of the Hypothalamic-Pituitary-Adrenal (HPA) axis) and salivary alpha-amylase (as a marker of the Autonomic Nervous System (ANS)). The protocol includes advice on the study design (e.g., sampling protocol), the materials and methods (e.g., the assessment of psychobiological stress in daily life, the assessment of music listening, and the manual), the selection of participants (e.g., the approval of the institutional review board and inclusion criteria), and the statistical analyses (e.g., the multilevel approach). The representative results provide evidence for a stress-reducing effect of music listening in daily life. Particularly, specific reasons for listening to music (especially relaxation), as well as the presence of others while doing so, increase this stress-reducing effect. At the same time, music listening in daily life differentially affects the HPA axis and ANS functioning, thus emphasizing the need for a multi-dimensional assessment of stress in daily life.

A study protocol is presented on how to assess associations between music listening and psychobiological stress (as measured by subjective stress levels, salivary cortisol, and salivary alpha-amylase) in daily life. Advice on study design, materials, methods, selection of participants, and statistical handling is provided. Representative results are presented and discussed.

Music listening is associated with stress-reducing effects. However, most of the results on music listening and stress were gathered in experimental ...

Use of a Psychophysiological Script-driven Imagery Experiment to Study Trauma-related Dissociation in Borderline Personality Disorder

This protocol offers a detailed description of a psychophysiological experiment using script-driven trauma-related imagery and standardized clinical instruments within a comparative design assessing physiological and psychopathological features of individuals with BPD. This method aims at studying the psychological and physiological effects of trauma-related dissociation. Since the psychodiagnostic classification of trauma-related disorders relies on the observation of evolutionarily determined responses to life-threat, an integrated assessment paradigm for the study of reactions to traumatic memories proposes a very appropriate methodological approach.
The employed script-driven imagery paradigm uses individual recall instructions to activate trauma-related memory networks and prompt associated emotional and physiological responses. These responses are measured by means of self-rating scales and physiological assessments. During the individual recall, participants are asked to vividly imagine traumatic and everyday experiences and other situations triggered by short personalized verbal scripts they authored beforehand together with the experimenters. A wide range of affective reactions and different physiological parameters can be measured. We used this paradigm to investigate dissociative states in BPD and to find physiological and affective correlates of dissociative states. Some of the participants were having severe traumatic antecedents.
To investigate different reaction patterns within the same diagnostic group, participants with different levels of traumatic histories, symptom severities, and co-morbidities should be included. By using short verbal scripts, the level of stress induced to participants is held as low as possible without affecting the validity of the object of investigation.

We present a protocol of personalized script-driven trauma-related imagery and clinical assessments within a comparison design for investigating peritraumatic dissociation (PD), psychophysiological reactions, i.e. heart rate (HR) and skin conductance (SC), and psychological features of often severely traumatized individuals with borderline personality disorder (BPD).

This protocol offers a detailed description of a psychophysiological experiment using script-driven trauma-related imagery and standardized clinical ...

Driving Under the Influence: How Music Listening Affects Driving Behaviors

Car driving is a daily activity for many individuals in modern societies. Drivers often listen to music while driving. The method presented here investigates how listening to music influences driving behaviors. A driving simulation was selected because it offers both a well-controlled environment and a good level of ecological validity. Driving behaviors were assessed through a car-following task. In practice, participants were instructed to follow a lead vehicle as they would do in real life. The lead vehicle speed changed over time requiring constant speed adjustments for the participants. The inter-vehicular time was used to assess driving behaviors. To complement the driving behaviors, the subjective mood and physiological level of arousal were also collected. As such, the results collected using this method offer insights on both the human internal state (i.e., subjective mood and physiological arousal) and driving behaviors in the car following task.

Here, we present a protocol to assess driving behaviors while following a vehicle in a simulated driving environment. The presented protocol is used to compare the impact of different auditory backgrounds on driving behaviors.

Car driving is a daily activity for many individuals in modern societies. Drivers often listen to music while driving. The method presented here ...

Exploring Infant Sensitivity to Visual Language using Eye Tracking and the Preferential Looking Paradigm

We discuss the use of the preferential looking paradigm in eye tracking studies in order to study how infants develop, understand, and attend to the world around them. Eye tracking is a safe and non-invasive way to collect gaze data from infants, and the preferential looking paradigm is simple to design and only requires the infant to be attending to the screen. By simultaneously showing two visual stimuli that differ in one dimension, we can assess whether infants show different looking behavior for either stimulus, thus demonstrating sensitivity to that difference. The challenges in such experimental approaches are that experiments must be kept brief (no more than 10 min) and be carefully controlled such that the two stimuli differ in only one way. The interpretation of null results must also be carefully considered. In this paper, we illustrate a successful example of an infant eye tracking study with a preferential looking paradigm to discover that 6-month-olds are sensitive to linguistic cues in a signed language despite having no prior exposure to signed language, suggesting that infants possess intrinsic or innate sensitivities to these cues.

Eye tracking studies using a preferential looking paradigm can be used to study infants&#39;&#160;emerging understanding of, and attention to, their external visual world.

We discuss the use of the preferential looking paradigm in eye tracking studies in order to study how infants develop, understand, and attend to the world ...

Assessing the Coherence of Parents' Short Narratives Regarding their Child Using the Five-Minute Speech Sample Procedure

Valid and efficient measures for assessing the quality of parent-child relationships are needed to facilitate research and evidence-based practice with parents. This paper focuses on such a method, namely Five-Minute Speech Sample-Coherence (FMSS-Coherence). In this method, a parent is asked to speak for five uninterrupted minutes about her/his child and their relationship. The resulted narrative is coded for coherence, namely the extent to which the parent provides&#160;in the narrative&#160;a clear, consistent, multidimensional and well-supported portrayal of the child. FMSS-Coherence is based on attachment research that shows that the coherence of parents&#8217; narratives is indicative of the quality of the parent-child relationship and child adjustment. It overcomes the limitations of attachment narrative measures which are typically labor intensive. FMSS-Coherence is less nuanced than extant attachment narrative measures. Yet, studies of families from different cultural backgrounds, across different child ages and in the context of typically developing children as well as children with special needs suggest that coherence can be reliably evaluated using the FMSS procedure. Furthermore, parents&#8217; FMSS-Coherence is associated with parenting quality and children&#8217;s socio-emotional adjustment. Thus, it holds promise for researchers and practitioners who seek a relatively time- and cost-effective method for assessing the coherence of parents&#8217; narratives regarding their child.

This paper introduces a method for assessing the coherence of parents' short narratives regarding their child and their relationship using the five-minute speech sample procedure.

Valid and efficient measures for assessing the quality of parent-child relationships are needed to facilitate research and evidence-based practice with ...

A Task for Assessing the Impact of a Partner on the Speed and Accuracy of Motor Performance in Rats

To our knowledge, no study has examined the effect of mere presence on accuracy of performance in animals. Therefore, we developed an experimental task to measure rats&#8217; motor performance (speed and accuracy) in a social condition. Rats were trained to run on a runway and pull down a lever at the end of the runway. In testing, rats performed the task solitarily (single) or in the presence of a confederate rat beyond the lever (pair or a social condition). As indices of the performance speed, we measured the time needed to start running, run through the runway, and pull down the lever. As the index of performance accuracy, we counted the number of trials in which rats could pull down the lever during their first attempt. One-way and two-way repeated-measure analyses of variance were used to analyze the data. This run-and-pull task enabled us to examine the effect of the presence of another conspecific on both speed and accuracy of motor performance in one experiment. The results showed that rats performed the task faster but less accurately in pair sessions than in single sessions. This protocol would be a valid animal model to examine the effect of mere presence on speed and accuracy of motor performance in rats.

A procedure to measure the speed and accuracy of rats&rsquo; motor performance in a social condition is described. The protocol enables us to investigate the effect of the mere presence of others on speed and accuracy of motor performance in one experiment.

To our knowledge, no study has examined the effect of mere presence on accuracy of performance in animals. Therefore, we developed an experimental task to ...