The authors thank Perrine Labeaume and Fanny Vieu for their help.

The Institutional Review Board of the University approved this research.
NOTE: An example of mixed methods using the enactive phenomenological protocol.
1. Exclusion Criteria
<ol>
	<li>Use a questionnaire before the experiment in order to exclude some participants, as necessary, on the following criteria: smoking (over five cigarettes per day), drinking (over two glasses of alcohol per day), taking medication, using drugs, having an endocrine problem, experiencing chronic stress (e.g., as determined by the French version of the Perceived Stress Scale [PSS])33, and experiencing psychological distress (e.g., as determined by the French version of the General Health Questionnaire [GHQ-12])34.</li>
</ol>
2. Preliminary Instructions
NOTE: The following preliminary instructions need to be given 1 day before the experimentation.
<ol>
	<li>Tell the participants not to take any medication, perform physical exercises, or consume alcohol the day before the test.</li>
	<li>Tell the participants to wake up at least 3 h before the test.</li>
	<li>Tell the participants to not drink or eat anything, smoke, or brush their teeth 1 h before the test.</li>
</ol>
3. Pretest Measurements
NOTE: The protocol presented in this section was used in the earlier publication mentioned in the introduction13. Prestress measurements can be done after an inactive wait of 45 min10; also, the first point of measure can be done 20 min before the TSST35.
<ol>
	<li>First saliva collection 
	NOTE: Salivary cortisol is commonly used as a physiological marker of stress with the TSST9,36.
	<ol>
		<li>Use the passive drool method: ask the participant to tilt their head forward to allow saliva to pool in their mouth, and instruct them to guide it into a small polypropylene tube.</li>
		<li>Freeze the tube immediately at -20 &#176;C.</li>
	</ol>
	</li>
	<li>First questionnaire collection
	<ol>
		<li>Measure the participant&#39;s anxiety. Ask them to fill out the State-Trait Anxiety Inventory (STAI)37 questionnaire. 
		NOTE: STAI is an example of a questionnaire that can be used to measure anxiety. It is a Likert scale with a range of four options (1 = not at all, 4 = very much so); using this range, participants were asked to respond to 12 items (e.g., &#34;I feel tense&#34;). A composite variable was constructed with the scores of all items.</li>
		<li>Measure the participant&#39;s emotional state. Ask them to fill out the Self-Assessment Manikin (SAM)38 questionnaire. 
		NOTE: SAM is a Likert scale that uses a nonverbal pictorial technique with nine figures to evaluate pleasure, arousal, and dominance. Participants have to circle a figure for each item.</li>
		<li>Then, bring the participant into the TSST room.</li>
	</ol>
	</li>
</ol>
4. Performance of the TSST or the TSST-G
NOTE: Different aspects of the TSST have already been described in other JoVE articles10,12,39.
<ol>
	<li>Protocol context
	<ol>
		<li>Position the participant in the protocol room on a red cross drawn on the floor.</li>
		<li>Question the participants one by one for the TSST.</li>
		<li>Use a group of participants (e.g., six participants separated by little walls to limit social and visual interaction13) for the TSST-G.</li>
		<li>Ensure that the experimenters (two or three) are neutral and look like scientists with white lab coats.</li>
		<li>Explain that the committee members are specialists in nonverbal behavior analysis and all actions are filmed for future analysis.</li>
	</ol>
	</li>
	<li>Mock job interview
	<ol>
		<li>Ask the participant to imagine a job of their choice.</li>
		<li>Give the participant 3 min of preparation time (10 min for the TSST-G).</li>
		<li>Specify that preparation notes cannot be used during the interview.</li>
		<li>Give the participant 5 min of presentation time (2 min for the TSST-G, performed in random order) in front of the committee to explain why they are the best candidate for this job.</li>
		<li>Tell the participant to continue when they stop talking by saying &#34;You still have time remaining.&#34;</li>
		<li>Remain silent for 20 s when that participant stops talking for the second time.</li>
		<li>Ask standardized questions if the participant does not resume speaking (e.g., &#34;Please list your weaknesses.&#34;).</li>
	</ol>
	</li>
	<li>Mental arithmetic task
	<ol>
		<li>Ask the participant to count aloud backward from 2023 in steps of 17. For the TSST-G, the numbers are different for each participant.</li>
		<li>Explain the participant they must calculate as quickly and correctly as possible.</li>
		<li>Point out each mistake and tell the participant to start all over again.</li>
		<li>Make sure the task lasts 5 min (80 s for the TSST-G, performed in random order).</li>
	</ol>
	</li>
</ol>
5. Posttest Measurements
NOTE: Then, collect a second saliva sample and let the participant complete questionnaires in another room (same process as the first collections, described in section 3 of this protocol).
<ol>
	<li>Second saliva collection 
	NOTE: The measurement of cortisol levels is repeated (6 to 9 times) to analyze the cortisol response.
	<ol>
		<li>Following the passive drool method, collect saliva from the participant into a small polypropylene tube, as described previously (step 3.1.1).</li>
		<li>Freeze the tube immediately at -20 &#176;C.</li>
	</ol>
	</li>
	<li>Second questionnaire collection
	<ol>
		<li>Measure the anxiety. Ask the participant to fill out the STAI37 questionnaire. 
		NOTE: STAI is a Likert scale with a range of four items (1 = not at all, 4 = very much so); using this range, participants responded to 12 items (e.g., &#34;I feel tense&#34;). A composite variable was constructed with the scores of all items.</li>
		<li>Measure emotional states. Ask the participant to fill out the SAM38 questionnaire. 
		NOTE: SAM is a Likert scale that uses a nonverbal pictorial technique with nine figures to evaluate pleasure, arousal, and dominance. Participants have to circle a figure for each item.</li>
	</ol>
	</li>
</ol>
6. Qualitative Investigations
<ol>
	<li>Use a wide-angle camera to record the participant&#39;s behavior and their interaction during the TSST or the TSST-G.</li>
	<li>Conduct enactive interviews to access the participant&#39;s experience.
	<ol>
		<li>Perform the interview as soon as possible after the performance of the TSST or the TSST-G to ensure the participant still remembers (preferably within 48 h).</li>
		<li>Explain that the participant must relive the past activities, helped by their own audio-visual record of the TSST or the TSST-G. Avoid stating the precise aim of the experiment to the participant.</li>
		<li>Select an experienced rater who is used to conducting enactive interviews.</li>
		<li>Confront the participant with their own recording to help them relive the experience as close as possible.</li>
		<li>Ask directive questions to help the re-emergence of the past experience. For instance, point at an image from the video and ask: &#34;What are you doing here?&#34;</li>
		<li>Help the participant to remember with questions focused on the video to allow them to describe, comment on, and show their lived experience step by step: &#34;What is happening here on the video?&#34;</li>
		<li>Investigate the experience&#39;s components as intentions and perceptions by asking: &#34;What were your intentions here?&#34;, &#34;What did you perceive at this precise moment?&#34;</li>
		<li>Stop the participant if they use global discourse, a posteriori analysis, or generalization, or when they digress from the precise moment that is being discussed, as suggested for phenomenological research40.</li>
		<li>Ask follow-up questions based on the participant&#39;s response. For example, when the participant says: &#34;I am out&#34;, ask &#34;What does &#39;I am out&#39; mean?&#34; and, then, continue to investigate what happens from the participant&#39;s point of view.</li>
		<li>Respect the time sequence of the video and avoid changing the time-flow to access the dynamics of the experience step by step.</li>
		<li>Allow the participant to pause the video when they want to describe their own experience.</li>
	</ol>
	</li>
</ol>
7. Data Analysis
<ol>
	<li>Perform a saliva analysis.
	<ol>
		<li>Determine the participant&#39;s cortisol level by the enzyme-linked immunosorbent assay (ELISA) technique using assay kits (see Table of Materials).</li>
		<li>Measure the concentration related to the absorbance at 450 nm with a 96-well microplate spectrophotometer (see Table of Materials).</li>
		<li>Calculate the intra-assay precision with the average value of individual variability for all of the duplicates within each microplate.</li>
		<li>Obtain concentrations of unknown samples (nmol/L) with a four-parameter nonlinear regression curve fit, following the ELISA kit protocol recommendations, based on cortisol standards (82.77, 27.59, 9.19, 3.06, 1.02, 0.33 nmol/L).</li>
	</ol>
	</li>
	<li>Perform a statistical analysis using repeated measures ANOVAs with a level of significance at p &#60; 0.05.</li>
	<li>Calculate the effect sizes with a partial eta squared. 
	&#8203;NOTE: Eta squared is a statistical measure of effect size for use in ANOVA.</li>
	<li>Perform a phenomenological analysis.
	<ol>
		<li>Transcribe all the enactive interviews with the maximum of detail, such as verbal clutter, demonstration, hesitation, etc.</li>
		<li>Construct a two-part table that outlines the time flow, transcription, and a report of the behaviors and discussion helped by the recordings (Table 1).</li>
		<li>Identify components of the experience, beginning with the elementary units of meaning corresponding to the smallest units of activity meaningful to a participant.</li>
		<li>Identify perception, analyzing the meaningful sensation, sentiment, and informational aspects (visual, acoustic, or kinesthetic) in the situation.</li>
		<li>Identify intention, analyzing the participant&#39;s concern in the situation.</li>
		<li>Categorize sequences by grouping units of meaning related to the same story.</li>
		<li>For each participant, identify their typical experience descriptively, statistically, generatively, and significantly21 (e.g., typical action, typical intention, and typical perception).</li>
		<li>Identify the typical experiences of all the participants, finding similarities between each typical experience.</li>
		<li>Construct tables of typical experience for all the participants, using the following values: timeline, typical sequences, typical perceptions, typical actions, and typical intentions.</li>
		<li>Normalize the formulation of each category using a group of words to express the typical sequence, an &#34;ing&#34; for the typical action, and an infinitive verb for the typical intention.</li>
		<li>Compare the TSST and the TSST-G using the two tables of typical lived experience.</li>
		<li>Present the common aspects of experience during both protocols.</li>
		<li>Present the singular aspects of experience during each protocol.</li>
	</ol>
	</li>
	<li>Perform a case study analysis to understand the local processes, for example, the four lowest and highest cortisol responders.
	<ol>
		<li>Identify the components of the experience (see the preceding protocol).</li>
		<li>Rebuild the meaningful experience for each participant following the TSST or the TSST-G steps.</li>
	</ol>
	</li>
	<li>Compare the mixed methods.
	<ol>
		<li>Compare the quantitative and qualitative results conducting analyses and interpretation separately (cortisol, state anxiety, emotional states, experience data).</li>
		<li>Verify whether the quantitative analysis&#39; results of the stress dynamics are similar to those of the qualitative analysis.</li>
		<li>Analyze whether what happened in the participants&#39; experiences can help in understanding quantitative stress variation.</li>
	</ol>
	</li>
</ol>

The authors have nothing to disclose.

In this article, we present an original mixed methods approach combining an experimental protocol with the enactive phenomenological approach. This kind of mixed methods is helpful to access experience, to understand participants&#39; points of view, and to analyze in depth the dynamics of cognitive processes like intentions, perceptions, enacted knowledge, and emotions.
Mixed methods can be used in different ways. Green et al.6 present five functions: triangul...

Mixed methods give various advantages when trying to understand a phenomenon1,2,3,4,5. Greene et al.6 define them as protocols that include a quantitative method to analyze numbers and a qualitative method to analyze words. This approach aims to move beyond paradigm wars or conflicts between qualitative and quantitative research. The goal is to increase the strengths of studies and diminish the weaknesses of single studies3; thus, it functions as a third research paradigm. Combining different kinds of analyses on the same object makes it possible to have different points of view. This paper presents a particular form of mixed methods, combining an experimental protocol with experiential data using the single TSST7and the TSST-G8. The TSST is the most used protocol to experimentally perform psychosocial stress investigations9,10. These tests are based on uncontrollability and social-evaluative threat, linked with physiological and psychological consequences. Different empirical, theoretical, or meta-analysis studies11 have shown that the TSST and the TSST-G elicit psychological effects and activate the HPA axis, leading, for example, to negative emotional states, self-reported anxiety, and cortisol rise. Many experimental studies investigated these markers of stress, their relations, and their influences12. However, only one qualitative approach has been conducted13 to understand the participants&#39; lived experiences during these tests.
The present protocol develops the original mixed methods approach mainly used in an earlier publication13. The originality of this mixed methods research lies in the qualitative approach based on an enactive phenomenological framework13,14,15,16 to examine accurately participants&#39; experiences when confronted with the TSST and the TSST-G. Qualitative investigations can be heuristic because they make it possible to characterize and analyze what is happening psychologically for participants in a particular situation17. Last, the enactive phenomenological approach allows researchers to understand the participants&#39; points of view and, thus, to analyze stress and emotion18,19,20. Following this approach, participants can describe, comment on, and show their lived experience step-by-step. This enactive phenomenological framework has two main assumptions16,21. First, action and situation are coupled22,23 (i.e., the dynamics of the action emerge within a specific context). This assumption provides access to the dynamics of the participant&#39;s experience confronted with the TSST and the TSST-G and to identify particular components of the context for the actor. Secondly, every action carries significations for the actor23,24. This approach provides access to the actor&#39;s signification construction of the experience during the action, thanks to a rigorous method originating from phenomenological interviews and named enactive interviews16,25. The actor&#39;s experience can be characterized in its emotional, perceptional, and situational dimensions26. Different kinds of mixed methods are based on this enactive phenomenological approach, which has already produced heuristic results in different areas, namely sport14,15,18,27, doping28, work29, and education30,31,32.
The mixed methods presented here aim to give confirmation and comprehension to findings in the TSST literature: confirmation through a comparison of the effect of the TSST and the TSST-G on physiological indicators (like cortisol), on self-reported indicators (like anxiety and emotional states), and on experiential indicators (like participants&#39; voices) and comprehension through the qualitative method accessing participants&#39; dynamics of action as they emerge in these stressful protocols. This is an original way to access in-depth the dynamics of psychosocial stress and to understand the participants&#39; voices about the stressful moment of the TSST and the TSST-G. This protocol is, thus, an example of mixed methodology, showing the added value of using the enactive phenomenological approach to analyze the experimental protocol more deeply.

<table border="0" cellpadding="0" cellspacing="0" style="width:1003px;" width="1001">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:281px;">Enzyme-linked immunosorbent assay (ELISA)</td>
			<td style="width:167px;">Salimetrics, UK</td>
			<td style="width:128px;">Kit-- N&#176; No. 1-3002</td>
			<td style="width:427px;">Expanded Range High Sensitivity Salivary Cortisol Enzyme Immunoassay</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:281px;">Spectrophotometer</td>
			<td>Thermo Fisher, Germany</td>
			<td style="width:128px;"></td>
			<td>Multiska FC Microplate Photometer</td>
		</tr>
	</tbody>
</table>

enactive phenomenological approach to the trier social stress test: a mixed methods point of view

The single Trier Social Stress Test (TSST) and the TSST for groups (TSST-G) are the most used protocols to experimentally induce psychosocial stress. These tests are based on uncontrollability and social-evaluative threat, inducing psychological and physiological consequences (e.g., anxiety, emotional states, salivary cortisol increases). Many quantitative experimental studies have investigated these stress inducers and these consequences. But, as far as we know, this study is the first to provide a qualitative analysis to access the participants' voices so as to understand the dynamics of their experience throughout the TSST and the TSST-G. This paper outlines a mixed methods approach to the TSST. This approach can help to maximize the information that can be gained from the TSST, which researchers often use without looking more closely at what is qualitatively happening psychologically for participants during the stressor itself. In this way, this protocol is an example of mixed methods, showing the added value of using the enactive phenomenological approach to analyze experimental protocols more deeply. This kind of mixed methods is helpful to access the experience, to understand the actor's point of view, and to analyze in-depth the dynamics of cognitive processes like intentions, perceptions, enacted knowledge, and emotion. The discussion section shows the different uses of a mixed methods protocol, exploiting the enactive phenomenological approach to analyze a protocol or to give a cross vision of the same research subject. This section deals with different existing applications, pointing out some critical steps in this mixed methods approach.

The results shown here come from a review of literature (for the cortisol)8 and two studies on stress done in our lab (for the state anxiety, the affective reaction, and the qualitative approach)13,41. The results presented here are representative of what can be found, using the protocol, about (1) salivary cortisol levels, (2) state anxiety, (3) pleasure, arousal, and dominance, and (4) meaningful experien...

Watch this Scientific Journal Video about Enactive Phenomenological Approach to the Trier Social Stress Test: A Mixed Methods Point of View at JoVE.com

Enactive Phenomenological Approach to the Trier Social Stress Test: A Mixed Methods Point of View

Here, we present an original mixed method combining a quantitative and a qualitative approach to examine accurately participants&#39; experiences during the Trier Social Stress Test and the Trier Social Stress Test for groups.

The single Trier Social Stress Test (TSST) and the TSST for groups (TSST-G) are the most used protocols to experimentally induce psychosocial stress. ...

enactive-phenomenological-approach-to-trier-social-stress-test-mixed

Research

JoVE Journal

Behavior

6.6K Views.  Institut des Sciences du Mouvement (ISM). Here, we present an original mixed method combining a quantitative and a qualitative approach to examine accurately participants' experiences during the Trier Social Stress Test and the Trier Social Stress Test for groups.

Video: Enactive Phenomenological Approach to the Trier Social Stress Test: A Mixed Methods Point of View

The Resident-intruder Paradigm: A Standardized Test for Aggression, Violence and Social Stress

This video publication explains in detail the experimental protocol of the resident-intruder paradigm in rats. This test is a standardized method to measure offensive aggression and defensive behavior in a semi natural setting. The most important behavioral elements performed by the resident and the intruder are demonstrated in the video and illustrated using artistic drawings. The use of the resident intruder paradigm for acute and chronic social stress experiments is explained as well. Finally, some brief tests and criteria are presented to distinguish aggression from its more violent and pathological forms.

This video shows the resident-intruder paradigm in rats. This test is a standardized method to measure offensive aggression, defensive behavior and violence in a semi-natural setting. The use of the paradigm for social stress experiments is explained as well.

This video publication explains in detail the experimental protocol of the resident-intruder paradigm in rats. This test is a standardized method to ...

Using Chronic Social Stress to Model Postpartum Depression in Lactating Rodents

Exposure to chronic stress is a reliable predictor of depressive disorders, and social stress is a common ethologically relevant stressor in both animals and humans. However, many animal models of depression were developed in males and are not applicable or effective in studies of postpartum females. Recent studies have reported significant effects of chronic social stress during lactation, an ethologically relevant and effective stressor, on maternal behavior, growth, and behavioral neuroendocrinology. This manuscript will describe this chronic social stress paradigm using repeated exposure of a lactating dam to a novel male intruder, and the assessment of the behavioral, physiological, and neuroendocrine effects of this model. Chronic social stress (CSS) is a valuable model for studying the effects of stress on the behavior and physiology of the dam as well as her offspring and future generations. The exposure of pups to CSS can also be used as an early life stress that has long term effects on behavior, physiology, and neuroendocrinology.

This article describes the use of chronic resident intruder social stress as an ethologically relevant paradigm to model postpartum depression and anxiety in lactating rodents.

Exposure to chronic stress is a reliable predictor of depressive disorders, and social stress is a common ethologically relevant stressor in both animals ...

Irrelevant Stimuli and Action Control: Analyzing the Influence of Ignored Stimuli via the Distractor-Response Binding Paradigm

Selection tasks in which simple stimuli (e.g. letters) are presented and a target stimulus has to be selected against one or more distractor stimuli are frequently used in the research on human action control. One important question in these settings is how distractor stimuli, competing with the target stimulus for a response, influence actions. The distractor-response binding paradigm can be used to investigate this influence. It is particular useful to separately analyze response retrieval and distractor inhibition effects. Computer-based experiments are used to collect the data (reaction times and error rates). In a number of sequentially presented pairs of stimulus arrays (prime-probe design), participants respond to targets while ignoring distractor stimuli. Importantly, the factors response relation in the arrays of each pair (repetition vs. change) and distractor relation (repetition vs. change) are varied orthogonally. The repetition of the same distractor then has a different effect depending on response relation (repetition vs. change) between arrays. This result pattern can be explained by response retrieval due to distractor repetition. In addition, distractor inhibition effects are indicated by a general advantage due to distractor repetition. The described paradigm has proven useful to determine relevant parameters for response retrieval effects on human action.

The distractor-response binding paradigm is described. It can be used to shed light on the influence irrelevant stimuli, competing with targets for a response, can have on human action. Both response retrieval effects and distractor inhibition effects can be analyzed within the paradigm.

Selection tasks in which simple stimuli (e.g. letters) are presented and a target stimulus has to be selected against one or more distractor stimuli are ...

Mindfulness in Motion (MIM): An Onsite Mindfulness Based Intervention (MBI) for Chronically High Stress Work Environments to Increase Resiliency and Work Engagement

A pragmatic mindfulness intervention to benefit personnel working in chronically high-stress environments, delivered onsite during the workday, is timely and valuable to employee and employer alike. Mindfulness in Motion (MIM) is a Mindfulness Based Intervention (MBI) offered as a modified, less time intensive method (compared to Mindfulness-Based Stress Reduction), delivered onsite, during work, and intends to enable busy working adults to experience the benefits of mindfulness. It teaches mindful awareness principles, rehearses mindfulness as a group, emphasizes the use of gentle yoga stretches, and utilizes relaxing music in the background of both the group sessions and individual mindfulness practice. MIM is delivered in a group format, for 1 hr/week/8 weeks. CDs and a DVD are provided to facilitate individual practice. The yoga movement is emphasized in the protocol to facilitate a quieting of the mind. The music is included for participants to associate the relaxed state experienced in the group session with their individual practice. To determine the intervention feasibility/efficacy we conducted a randomized wait-list control group in Intensive Care Units (ICUs). ICUs represent a high-stress work environment where personnel experience chronic exposure to catastrophic situations as they care for seriously injured/ill patients. Despite high levels of work-related stress, few interventions have been developed and delivered onsite for such environments. The intervention is delivered on site in the ICU, during work hours, with participants receiving time release to attend sessions. The intervention is well received with 97% retention rate. Work engagement and resiliency increase significantly in the intervention group, compared to the wait-list control group, while participant respiration rates decrease significantly pre-post in 6/8 of the weekly sessions. Participants value institutional support, relaxing music, and the instructor as pivotal to program success. This provides evidence that MIM is feasible, well accepted, and can be effectively implemented in a chronically high-stress work environment.

Mindfulness in Motion MIM: An Onsite Mindfulness Based Intervention MBI for Chronically High Stress Work Environments to Increase Resiliency and Work Engagement

The Mindfulness in Motion (MIM) protocol offers a pragmatic Mindfulness Based Intervention (MBI) on-site, for persons working in chronically high-stress work environments that significantly increases resiliency and work engagement. The protocol has proven feasible, beneficial, and is easily adaptable to other high-stress workplaces.

A pragmatic mindfulness intervention to benefit personnel working in chronically high-stress environments, delivered onsite during the workday, is timely ...

Methods to Test Visual Attention Online

Online data collection methods have particular appeal to behavioral scientists because they offer the promise of much larger and much more representative data samples than can typically be collected on college campuses. However, before such methods can be widely adopted, a number of technological challenges must be overcome &#8211; in particular in experiments where tight control over stimulus properties is necessary. Here we present methods for collecting performance data on two tests of visual attention. Both tests require control over the visual angle of the stimuli (which in turn requires knowledge of the viewing distance, monitor size, screen resolution, etc.) and the timing of the stimuli (as the tests involve either briefly flashed stimuli or stimuli that move at specific rates). Data collected on these tests from over 1,700 online participants were consistent with data collected in laboratory-based versions of the exact same tests. These results suggest that with proper care, timing/stimulus size dependent tasks can be deployed in web-based settings.

To replicate laboratory settings, online data collection methods for visual tasks require tight control over stimulus presentation. We outline methods for the use of a web application to collect performance data on two tests of visual attention.

Online data collection methods have particular appeal to behavioral scientists because they offer the promise of much larger and much more representative ...

A Mouse Model of Subchronic and Mild Social Defeat Stress for Understanding Stress-induced Behavioral and Physiological Deficits

Stressful life events often increase the incidence of depression in humans. To study the mechanisms of depression, the development of animal models of depression is essential. Because there are several types of depression, various animal models are needed for a deeper understanding of the disorder. Previously, a mouse model of subchronic and mild social defeat stress (sCSDS) using a modified chronic social defeat stress (CSDS) paradigm was established. In the paradigm, to reduce physical injuries from aggressors, the duration of physical contact between the aggressor and a subordinate was reduced compared to in the original CSDS paradigm. sCSDS mice showed increased body weight gain, food intake, and water intake during the stress period, and their social behaviors were suppressed after the stress period. In terms of the face validity of the stress-induced overeating and overdrinking following the increased body weight gain, the sCSDS mice may show some features related to atypical depression in humans. Thus, a mouse model of sCSDS may be useful for studying the pathogenic mechanisms underlying depression. This protocol will help establish the sCSDS mouse model, especially for studying the mechanisms underlying stress-induced weight gain and polydipsia- and hyperphagia-like symptoms.

Here, methods for developing a mouse model of subchronic and mild social defeat stress are described and used to investigate the pathogenic features of depression including hyperphagia- and polydipsia-like symptoms following increased body weight.

Stressful life events often increase the incidence of depression in humans. To study the mechanisms of depression, the development of animal models of ...

The Social Dimension of Stress: Experimental Manipulations of Social Support and Social Identity in the Trier Social Stress Test

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress. In order to study the interplay between these variables, this protocol describes two effective experimental manipulations of social relationships and supportive behavior in the laboratory. In the present article, these two manipulations are implemented in the Trier Social Stress Test (TSST)&#8212;a standard stress induction paradigm in which participants are subjected to a simulated job interview. More precisely, we propose (a) a manipulation of the relationship between different protagonists in the TSST by making a shared social identity salient and (b) a manipulation of the behavior of the TSST-selection committee, which acts either supportively or unsupportively. These two experimental manipulations are designed in a modular fashion and can be applied independently of each other but can also be combined. Moreover, these two manipulations can also be integrated into other stress protocols and into other standardized social interactions such as trust games, negotiation tasks, or other group tasks.

Previous research on the social dimension of stress has focused on two important variables: social identity and social support. This protocol introduces an effective experimental manipulation of these two social variables and describes their implementation in a standard stress induction paradigm (Trier Social Stress Test).

In many situations humans are influenced by the behavior of other people and their relationships with them. For example, in stressful situations ...

A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants

Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental paradigms and analysis tools have been limited to constrained laboratory tasks and contexts due to technical limitations imposed by the available set of measuring and analysis techniques and the age of the subjects. These limitations severely limit the study of developmental neural dynamics and associated neural networks engaged in cognition, perception and action in infants performing &#8220;in action and in context&#8221;. This protocol presents a novel approach to study infants and young children as they freely organize their own behavior, and its consequences in a complex, partly unpredictable and highly dynamic environment. The proposed methodology integrates synchronized high-density active scalp electroencephalography (EEG), inertial measurement units (IMUs), video recording and behavioral analysis to capture brain activity and movement non-invasively in freely-behaving infants. This setup allows for the study of neural network dynamics in the developing brain, in action and context, as these networks are recruited during goal-oriented, exploration and social interaction tasks.

This protocol presents a novel methodology for the neural decoding of intent from freely-behaving infants during unscripted social interaction with an actor. Neural activity is acquired using non-invasive high-density active scalp electroencephalography (EEG). Kinematic data is collected with inertial measurement units and supplemented with synchronized video recording.

Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental ...

A Novel Approach to Assess Motor Outcome of Deep Brain Stimulation Effects in the Hemiparkinsonian Rat: Staircase and Cylinder Test

Deep brain stimulation of the subthalamic nucleus is an effective treatment option for Parkinson&#39;s disease. In our lab we established a protocol to screen different neurostimulation patterns in hemiparkinsonian (unilateral lesioned) rats. It consists of creating a unilateral Parkinson&#39;s lesion by injecting 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle, implanting chronic stimulation electrodes into the subthalamic nucleus and evaluating motor outcomes at the end of 24 hr periods of cable-bound external neurostimulation. The stimulation was conducted with constant current stimulation. The amplitude was set 20% below the individual threshold for side effects. The motor outcome evaluation was done by the assessment of spontaneous paw use in the cylinder test according to Shallert and by the assessment of skilled reaching in the staircase test according to Montoya. This protocol describes in detail the training in the staircase box, the cylinder test, as well as the use of both in hemiparkinsonian rats. The use of both tests is necessary, because the staircase test seems to be more sensitive for fine motor skill impairment and exhibits greater sensitivity to change during neurostimulation. The combination of the unilateral Parkinson model and the two behavioral tests allows the assessment of different stimulation parameters in a standardized way.

Deep brain stimulation (DBS) is an effective treatment option for Parkinson's disease. We established a study design to screen novel stimulation paradigms in rats. The protocol describes the use of the staircase test and cylinder test for motor outcome assessment in DBS treated hemiparkinsonian rats.

Deep brain stimulation of the subthalamic nucleus is an effective treatment option for Parkinson&#39;s disease. In our lab we established a protocol to ...

A Visual Guide for Studying Behavioral Defenses to Pathogen Attacks in Leaf-Cutting Ants

The complex lifestyle, evolutionary history of advanced cooperation, and disease defenses of leaf-cutting ants are well studied. Although numerous studies have described the behaviors connected with disease defense, and the associated use of chemicals and antimicrobials, no common visual reference has been made. The main aim of this study was to record short clips of behaviors involved in disease defense, both prophylactically and directly targeted towards an antagonist of the colony following infection. To do so we used an infection experiment, with sub-colonies of the leaf-cutting ant species Acromyrmex echinatior, and the most significant known pathogenic threat to the ants&#39; fungal crop (Leucoagaricus gongylophorus), a specialized pathogenic fungus in the genus Escovopsis. We filmed and compared infected and uninfected colonies, at both early and more advanced stages of infection. We quantified key defensive behaviors across treatments and show that the behavioral response to pathogen attack likely varies between different castes of worker ants, and between early and late detection of a threat. Based on these recordings we have made a library of behavioral clips, accompanied by definitions of the main individual defensive behaviors. We anticipate that such a guide can provide a common frame of reference for other researchers working in this field, to recognize and study these behaviors, and also provide greater scope for comparing different studies to ultimately help better understand the role these behaviors play in disease defense.

We present a visual guide to disease defense behaviors in leaf-cutting ants, with individual clips and accompanying definitions, illustrated in an experimental infection scenario. Our main aim is to help other researchers recognize key defensive behaviors and to provide a common understanding for future research in this field.

The complex lifestyle, evolutionary history of advanced cooperation, and disease defenses of leaf-cutting ants are well studied. Although numerous studies ...