This research was supported by a grant (AZ: 76202-29-3/11) from the Ministry for Science and Culture of Lower Saxony (Germany) to Andreas Mojzisch and Jan H&#228;usser.

Two studies11,12 that applied the described procedures have been approved by the ethics committee of the University of Hildesheim and were in line with the declaration of Helsinki.
1. Set-up
<img alt="Figure 1" src="/files/ftp_upload/53101/53101fig1.jpg" />
Figure 1.&#160;Sketch of the set-up in the two experimental rooms. P = real participant, C1/C2 = confederates, mic = microphone, cam = camera <a href="https://www.jove.com/files/ftp_upload/53101/53101fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<ol>
	<li>Use two separate rooms. One for the manipulation of the social/personal identity, the preparation phase of the TSST and the recovery phase after the TSST (Room 1), and one for the speech and mental arithmetic task of the TSST (Room 2). The set-up of both rooms is illustrated in Figure 1.
	<ol>
		<li>Place three chairs and one big table as depicted in Figure 1 in Room 1A (social identity manipulation, preparation phase of the TSST, and recovery phase). Place a box for Task 1 (see below) on the table and provide three pens and some sheets of paper for Task 1 and Task 2.
		<ol>
			<li>Provide nine T-shirts in three different colors&#8212;three T-shirts in each color (e.g., blue, green, and yellow). Provide three stick-on labels for the name tags.</li>
			<li>For the bogus lot drawing procedure, write &#8220;committee&#8221; on two small pieces of paper and fold them neatly. Write &#8220;applicant&#8221; on a third piece of paper and crumple it. Put the crumbled ball of paper and the two folded pieces of paper in a pouch.</li>
		</ol>
		</li>
		<li>Place three chairs and three small tables as depicted in Figure 1 in Room 1B (personal identity manipulation, preparation phase of the TSST, recovery phase). Place a box for Task 1 on each table. Provide the same additional materials as in the social identity condition.</li>
		<li>Place a table and two chairs for the committee members (the participant is standing) as depicted in Figure 1 in Room 2 (speech and mental arithmetic task of the TSST).
		<ol>
			<li>Provide the following items for the committee on the table in Room 2: Two pens and two sheets of papers for taking notes, two stopwatches, and two sheets with the solutions to the mental arithmetic task.</li>
			<li>Install two video cameras (Cam 1 and Cam 2), one pointing towards the position of the participant, which is defined by the microphone (Cam 1), and one pointing at the committee (Cam 2). Attach the cable of the microphone to Cam 1 or to a laptop.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>To assure a standardized behavior of the TSST-committee, use two trained confederates (one male and one female) who are of similar age as the studied population. Moreover, confederates need to be unfamiliar with the participants before the study since this may affect the level of identification. 
	Note: If using more than two confederates, then it is important that the different confederates are of similar age, appearance, and attractiveness and that the assignment of confederates is balanced across the different conditions in order to assure that a particular set of confederates is not confounded with a specific experimental condition.</li>
	<li>Assess different indicators of the psycho-physiological stress response (e.g., cortisol, self-reported stress, heart rate) to test the stress reaction evoked by the TSST.
	<ol>
		<li>Measure these stress indicators repeatedly before, during, and after the TSST in order to control for baseline differences, to examine the anticipatory stress response, the peak response level, and the recovery rate7. 
		Note: For cortisol, four (minimum three15) measurement points are sufficient to cover these requirements (for an example of integration in the experimental procedure, see Frisch et al.12). However, more measurement points increase the resolution of the stress response and the number of necessary measurements also depends on the temporal dynamics of the selected stress indicator7 (e.g., heart rate can be measured continuously during the TSST).</li>
	</ol>
	</li>
	<li>When measuring cortisol or any other physiological indicator of stress, apply the standard inclusion criteria17 for participants. Do not use participants for cortisol analyses who are pregnant, use hormonal contraception or other prescribed medication, smoke or suffer from psychiatric, endocrine, cardiovascular, or other chronic diseases. Moreover, have eligible participants refrain from consuming alcohol the day before the study, and eating meals, drinking caffeine, or exercising 2 hr before the beginning of the study. Furthermore, since cortisol follows a diurnal rhythm18, schedule experimental sessions at the same daytime.</li>
</ol>

2. Manipulation of Social/Personal Identity
<ol>
	<li>Welcome participants (i.e., one real participant and two confederates) to Room 1.</li>
	<li>Place participants as depicted in Figure 1. In the social identity condition, seat the real participant and the confederates around one table. In the personal identity condition, seat the real participant and the confederates at individual tables.</li>
	<li>Tell participants a cover story about the study (e.g., that in this study new tasks for assessment centers are tested) and obtain their informed consent for participation. Importantly, ask participants not to interact with each other during the session.</li>
	<li>To induce a social identity, use the following means:
	<ol>
		<li>Always address participants as a group (e.g., &#8220;You all will do &#8230;&#8221;).</li>
		<li>Ask participants to introduce themselves (name, age, and subject of study). Have the real participant begin. Have the two confederates pretend to have a first name that has the same initial letter as the name of the real participant (e.g., John, Julia, Jim). Moreover, have the confederates declare to be at about the same age as the real participant and to be students.
		<ol>
			<li>Form a group name out of the three first name initials (e.g., JJJ) and let each participant write it on a stick-on label. Tell participants that for reasons of anonymity they will not be addressed by their own names but by this group name throughout the experimental session.</li>
		</ol>
		</li>
		<li>Ask participants to choose one out of three differently colored T-shirts. Tell them that wearing standardized clothes will help them to fully focus on the experiment. The real participant chooses first and the confederates each take a T-shirt of the same color. Ask participants (i.e., the real participants and the two confederates) to wear this T-shirt until the end of the experimental session. Have participants place the label with the group name on their T-shirts.</li>
		<li>Instruct participants to think about ways to improve the quality of life in their city (Task 1). Have participants write each idea on a single sheet of paper and put it into the box on the table. Tell participants that the group performance will be evaluated. Let participants perform this task for 3 min.</li>
		<li>Instruct participants to write down as many similarities (e.g., goals, wishes, and habits) as possible that they think they share with their fellow group members (Task 2). Let participants perform this task for 3 min.</li>
		<li>Take a group picture (optional).</li>
	</ol>
	</li>
	<li>To induce a personal identity (alternatively to 2.4) use the following means:
	<ol>
		<li>Always address participants personally (e.g., &#8220;Each of you will do &#8230;&#8221;).</li>
		<li>Ask participants to introduce themselves (name, age, and subject of study). Have the real participant always begin. Have the two confederates pretend to have a first name with a different initial letter as the real participant (e.g., John, Kate, Peter). Have one confederate declare to be younger and the other to be older than the real participant. Have one confederate declare to be a student and the other to be an employee of the university.
		<ol>
			<li>Have participants write down their respective first name initial on a stick-on label. Tell participants that for reasons of anonymity they will not be addressed by their own names but by their initials throughout the experimental session.</li>
		</ol>
		</li>
		<li>Ask participants to choose one out of three differently colored T-shirts. Tell them that wearing standardized clothes will help them to fully focus on the experiment. The real participant chooses first. Each confederate chooses a different T-shirt color than the real participant and the other confederate. Participants have to wear this T-shirt until the end of the experimental session. Have participants place the label with the personal initial on their T-shirts.</li>
		<li>Instruct participantsto think about ways to improve the quality of life in their city (Task 1). Ask participants to write each idea on a single sheet of paper and to put it into their individual box on the table. Tell participants that their individual performance will be evaluated. Let participants perform this task for 3 min.</li>
		<li>Instruct participants to write down as many differences (e.g., goals, wishes, and habits) as possible that they think may distinguish themselves from the other two participants (Task 2). Let participants perform this task for 3 min.</li>
		<li>Take a picture of each participant (optional).</li>
	</ol>
	</li>
	<li>Use the group identification measure of Frisch et al.12 (adapted from Doosje et al.19, see Table 1 for the items) to verify the success of the identity manipulation (i.e., participants in the social identity condition should report higher levels of group identification than participants in the personal identity condition).</li>
</ol>
3. Trier Social Stress Test (Including Manipulation of Ccommittee Behavior)
Note: Step 3.2 and 3.3 (faked drawing of lots procedure) are not mandatory. In case of no prior manipulation of the relationship between the committee members and the participant (i.e., the applicant), start with 3.1 and continue then directly with the TSST (3.4).
<ol>
	<li>Explain the TSST briefly to participants as a task that is frequently used in assessment centers and requires one participant to take the role of an applicant in a job interview and two participants to act as a selection committee. Tell the participants that the selection committee will be evaluating the applicant and that a video of him/her will be recorded which will be used for a later analysis of his/her nonverbal behavior and a voice frequency analysis7.</li>
	<li>Tell participants that the roles in this task will be assigned by lot. Let each participant draw a piece of paper out of the pouch on which his/her role will be indicated (either &#8220;applicant&#8221; or &#8220;committee&#8221;). Have the confederates always draw first and let them take the neatly folded lots on which &#8220;committee&#8221; is written (see above). Have the real participant draw last, so that he/she is always designated to be the applicant.</li>
	<li>Hand out the sheet with the TSST-instruction to the committee members (i.e., confederates) and tell them that they now have some time to prepare their roles. Note that these &#39;instructions&#39; are part of the cover story, so the real participant believes that the two confederates are real participants. 
	Note: Since the confederates are already familiar with the TSST procedure, it is not important what these instructions actually entail (e.g., as a reminder for the confederates they may entail the exact wording of the verbal instructions of the committee).</li>
	<li>Guide the two committee members to Room 2. Inform them now how they should behave in the upcoming TSST. Note that the confederates are not informed about the experimental condition earlier in order to avoid that the confederates&#8217; behavior during the identity manipulation is influenced in any way by whether the real participant is assigned to the supportive or unsupportive condition.</li>
	<li>Go back to the real participant in Room 1.</li>
	<li>Tell the real participant that he/she now has 3 min to prepare his/her speech. Tell him/her: &#8220;Imagine you have applied for your dream job and you are invited to a job interview. Please prepare a 5 min talk in which you aim to convince the selection committee that you are the most qualified candidate for this job. The committee would like to hear what qualifies you for the job. Please imagine that the committee members have already read your curriculum vitae and that therefore, you should not tell them anything about your professional skills and work experiences; rather you should focus on your personality. You may take notes during the preparation of the talk, but you are not allowed to use these notes during the job interview.&#8221;</li>
	<li>Guide the participant to Room 2, turn on the video cameras, leave the room, and wait outside.</li>
	<li>For the speech task (5 min), have the committee members ask the participant to start with his/her speech. Note that the verbal instructions of the TSST-committee for the speech task of the TSST have been published elsewhere (see Birkett20 and Kudielka et al.7).</li>
	<li>For the mental arithmetic task (5 min), have the committee members introduce the mental arithmetic task to participants (i.e., counting backwards from 2,043 in steps of 17). When the time is up, have the committee members thank the participant and tell him/her to leave the room. Note that the verbal instructions of the TSST-committee for the mental arithmetic task of the TSST have been published elsewhere (see Birkett20 and Kudielka et al.7).</li>
	<li>During the speech and the mental arithmetic task of the TSST, have the committee act either supportively or unsupportively. This supportive/unsupportive behavior starts about 20 sec after the commencement of the speech task to make this behavior look reactive and natural (see Figure 2).
	<ol>
		<li>In the supportive committee condition, have the committee members show non-verbal affirmative signals throughout the TSST, for example, an open body posture (i.e., arms are open and not crossed, legs are parallel and not crossed), tilting the head, leaning forward, and smiling.
		<ol>
			<li>Have the committee members provide the participant with positive feedback by increasingly nodding and smiling as the task progresses. Have them exchange glances with each other indicating approval of the participant and his/her performance. Ensure that the committee members show these behaviors as a reaction to what the participant says or does (e.g., if the participant gives a correct number or if he/she says something positive about him-/herself in the speech task, the committee members will smile and nod).</li>
		</ol>
		</li>
		<li>In the unsupportive committee condition (alternatively to 3.10.1), have the committee members show non-verbal negative signals throughout the TSST, for example, a closed body posture (i.e., crossed arms and legs, leaning backwards), and frowning.
		<ol>
			<li>Have them provide the participant with negative feedback (independent of the real quality of his/her performance) by sighing, rolling eyes, shaking the head, staring at the participant in disbelief, looking skeptically at their notes, and exchanging glances with each other indicating mutual resentment. Ensure that the committee members show these behaviors as a reaction to what the participant says or does (e.g., if the participant gives a wrong number or if he/she says something positive about him-/herself in the speech task the committee members will look at him/her skeptically, in disbelief, and shake the head).</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
<img alt="Figure 2" src="/files/ftp_upload/53101/53101fig2.jpg" /> 
Figure 2.&#160;Picture of supportive and unsupportive committee. Example of the body posture and the facial expressions of the committee members during the TSST. A = supportive behavior, B = unsupportive behavior.
4. Resting Period
<ol>
	<li>Wait outside Room 2 for the participant to open the door and guide the participant and confederates back to Room 1.</li>
	<li>Hand out the manipulation check of committee behavior to the real participant. This questionnaire asks the participant how he/she perceived the committee members&#8217; behavior during the TSST (see Table 2 for the items). Note that in order to keep up the role of the confederates as real participants, hand out a similar questionnaire to the confederates asking them how they evaluate their own behavior during the TSST. 
	Note: This questionnaire is necessary in order to see if the manipulation of committee behavior was successful (i.e., participants that faced an unsupportive committee should report that the committee was unsupportive whereas participants that faced a supportive committee should report that the committee was supportive).</li>
	<li>Let participants rest and, if needed, take further samples of stress indicators under study.</li>
	<li>Let participants fill in a suspicion check in which they are asked to describe what they think the aim of the study was.
	<ol>
		<li>Exclude those participants who (a) suspected that the confederates were no real participants, (b) suspected the identity manipulation to aim at inducing a feeling of &#8220;we&#8221;-ness, (c) suspected the committee behavior to be scripted, or (d) guessed the aim of the study.</li>
	</ol>
	</li>
	<li>Thank, pay, and fully debrief participants. Include three important steps in the debriefing of participants (see also Kudielka et al.7):
	<ol>
		<li>Clarify that confederates were used and explain to the participant that this was necessary to assure a standardized committee behavior. Assure the participant that the behavioral reactions of the two confederates in the TSST (especially in the unsupportive condition) were scripted and absolutely unconnected to his/her person or his/her performance during the TSST. It is advisable that the two confederates take an active part in this phase of the debriefing.</li>
		<li>Explain the TSST to the participant and tell him/her that it is designed to induce high levels of stress and that almost every participant reports high levels of stress and fails to perform well in the speech and mental arithmetic task. Tell the participant that the recorded video will not be analyzed but will be deleted instead.</li>
		<li>Explain the design of the study and the research question to the participant. Furthermore, ask participants not to share the details of this study with other people in order to prevent contamination of the pool of participants.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Jowett, B., Davis, H. W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Aristotle's Politics. , (1920).</li><li>Baumeister, R. F., Leary, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+need+to+belong:+desire+for+interpersonal+attachments+as+a+fundamental+human+motivation.">The need to belong: desire for interpersonal attachments as a fundamental human motivation.</a> Psychol. Bull. 117 (3), 497-529 (1995).</li><li>Thorsteinsson, E. B., James, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+meta-analysis+of+the+effects+of+experimental+manipulations+of+social+support+during+laboratory+stress.">A meta-analysis of the effects of experimental manipulations of social support during laboratory stress.</a> Psychol. Health. 14 (5), 869-886 (1999).</li><li>Uchino, B. N., Cacioppo, J. T., Kiecolt-Glaser, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relationship+between+social+support+and+physiological+processes:+a+review+with+emphasis+on+underlying+mechanisms+and+implications+for+health.">The relationship between social support and physiological processes: a review with emphasis on underlying mechanisms and implications for health.</a> Psychol. Bull. 119 (3), 488-531 (1996).</li><li>Frisch, J. U., H&#228;usser, J. A., Mojzisch, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Trier+Social+Stress+Test+as+a+paradigm+to+study+how+people+respond+to+threat+in+social+interactions.">The Trier Social Stress Test as a paradigm to study how people respond to threat in social interactions.</a> Front. Psychol. 6 (14), (2015).</li><li>Kirschbaum, C., Pirke, K., Hellhammer, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+'Trier+Social+Stress+Test'&#8212;a+tool+for+investigating+psychobiological+stress+response+in+a+laboratory+setting.">The 'Trier Social Stress Test'&#8212;a tool for investigating psychobiological stress response in a laboratory setting.</a> Neuropsychobiology. 28 (1-2), 76-81 (1993).</li><li>Kudielka, B. M., Hellhammer, D. H., Kirschbaum, C., Harmon-Jones, E., Winkielman, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ten+years+of+research+with+the+Trier+Social+Stress+Test&#8212;revisited.">Ten years of research with the Trier Social Stress Test&#8212;revisited.</a> Social neuroscience: integrating biological and psychological explanations. , (2007).</li><li>von Dawans, B., Kirschbaum, C., Heinrichs, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Trier+Social+Stress+Test+for+Groups+(TSST-G):+a+new+research+tool+for+controlled+simultaneous+social+stress+exposure+in+a+group+format.">The Trier Social Stress Test for Groups (TSST-G): a new research tool for controlled simultaneous social stress exposure in a group format.</a> Psychoneuroendocrino. 36 (4), 514-522 (2011).</li><li>Tajfel, H., Turner, J. C., Austin, W. G., Worchel, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+integrative+theory+of+intergroup+conflict.">An integrative theory of intergroup conflict.</a> The social psychology of intergroup relations. , (1979).</li><li>Gockel, C., Kerr, N. L., Seok, D. -. H., Harris, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Indispensability+and+group+identification+as+sources+of+task+motivation.">Indispensability and group identification as sources of task motivation.</a> J. Exp. Soc. Psychol. 44 (5), 1316-1321 (2008).</li><li>H&#228;usser, J. A., Kattenstroth, M., van Dick, R., Mojzisch, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=“We”+are+not+stressed:+social+identity+in+groups+buffers+neuroendocrine+stress+reactions.">“We” are not stressed: social identity in groups buffers neuroendocrine stress reactions.</a> J. Exp. Soc. Psychol. 48 (4), 973-977 (2012).</li><li>Frisch, J. U., H&#228;usser, J. A., van Dick, R., Mojzisch, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Making+support+work:+the+interplay+between+social+support+and+social+identity.">Making support work: the interplay between social support and social identity.</a> J. Exp. Soc. Psychol. 55, 154-161 (2014).</li><li>Nuttin, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Narcissism+beyond+Gestalt+and+awareness:+the+name+letter+effect.">Narcissism beyond Gestalt and awareness: the name letter effect.</a> Eur. J. Soc. Psychol. 15 (3), 353-361 (1985).</li><li>Jones, J. T., Pelham, B. W., Carvallo, M., Mirenberg, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+do+I+love+thee?+Let+me+count+the+Js:+implicit+egotism+and+interpersonal+attraction.">How do I love thee? Let me count the Js: implicit egotism and interpersonal attraction.</a> J. Pers. Soc. Psychol. 87 (5), 665-683 (2004).</li><li>Taylor, S. E., Seeman, T. E., Eisenberger, N. I., Kozanian, T. A., Moore, A. N., Moons, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+a+supportive+or+an+unsupportive+audience+on+biological+and+psychological+responses+to+stress.">Effects of a supportive or an unsupportive audience on biological and psychological responses to stress.</a> J. Pers. Soc. Psychol. 98 (1), 47-56 (2010).</li><li>Haslam, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Psychology in organizations: the social identity approach. , (2004).</li><li>Kudielka, B. M., Hellhammer, D. H., W&#252;st, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Why+do+we+respond+so+differently?+Reviewing+determinants+of+human+salivary+cortisol+responses+to+challenge.">Why do we respond so differently? Reviewing determinants of human salivary cortisol responses to challenge.</a> Psychoneuroendocrino. 34 (1), 2-18 (2009).</li><li>Kudielka, B. M., Gierens, A., Hellhammer, D. H., W&#252;st, S., Schlotz, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salivary+cortisol+in+ambulatory+assessment&#8212;some+dos,+some+don&#8217;ts,+and+some+open+questions.">Salivary cortisol in ambulatory assessment&#8212;some dos, some don&#8217;ts, and some open questions.</a> Psychosom. Med. 74 (4), 418-431 (2012).</li><li>Doosje, B., Ellemers, N., Spears, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perceived+intragroup+variability+as+a+function+of+group+status+and+identification.">Perceived intragroup variability as a function of group status and identification.</a> J. Exp. Soc. Psychol. 31 (5), 410-436 (1995).</li><li>Birkett, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Trier+Social+Stress+Test+protocol+for+inducing+psychological+stress.">The Trier Social Stress Test protocol for inducing psychological stress.</a> J. Vis. Exp. (56), e3238 (2011).</li><li>Schwabe, L., Haddad, L., Schachinger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HPA+axis+activation+by+a+socially+evaluated+cold-pressor+test.">HPA axis activation by a socially evaluated cold-pressor test.</a> Psychoneuroendocrino. 33 (6), 890-895 (2008).</li><li>Berg, J., Dickhaut, J., McCabe, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trust,+reciprocity,+and+social+history.">Trust, reciprocity, and social history.</a> Game Econ. Behav. 10 (1), 122-142 (1995).</li><li>Pruitt, D. G., Lewis, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+integrative+solutions+in+bilateral+negotiation.">Development of integrative solutions in bilateral negotiation.</a> J. Pers. Soc. Psychol. 31 (4), 621-633 (1975).</li><li>Stasser, G., Titus, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pooling+of+unshared+information+in+group+decision+making:+biased+information+sampling+during+discussion.">Pooling of unshared information in group decision making: biased information sampling during discussion.</a> J. Per. Soc. Psychol. 48 (6), 1467-1478 (1985).</li><li>Mojzisch, A., Schulz-Hardt, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Knowing+others'+preferences+degrades+the+quality+of+group+decisions.">Knowing others' preferences degrades the quality of group decisions.</a> J. Pers. Soc. Psychol. 98 (5), 794-808 (2010).</li></ol>

The authors have nothing to disclose.

This protocol describes two effective manipulations of (a) the relationship between different protagonists in the TSST (i.e., between participants in the TSST-G11 or between the TSST-committee and the participant12) and (b)&#160;the behavior of the TSST-committee12.
The proposed manipulation of social identity has several strengths. First, it can be easily implemented before commencing the TSST. Hence, it does not alter the standard TSST protocol, whic...

As social animals1, humans strive for belongingness2. Hence, for humans the behavior of significant others as well as their relationships with them are of great importance, especially in unfamiliar and challenging situations. For example, in stressful situations supportive behavior of other people as well as positive social relationships can act as powerful resources to cope with stress3,4. These social resources, however, interact in a complex way and are sometimes not effective stress buffers5 per se . In order to study the conditions under which supportive behavior and social relationships have an effect on stress reactions, two different manipulations are introduced that can be implemented in the Trier Social Stress Test (TSST)6,7 or the group version of the TSST (TSST-G)8. Both are standard protocols to induce high levels of psychological and physiological stress in the laboratory7. The TSST(-G) is framed as a simulated job interview, in which participants are supposed to convince two interviewers (i.e., the selection committee) that they are the most suitable candidate for a job position. Additionally, participants have to perform a mental arithmetic task in front of the selection committee. In order to increase the social-evaluative threat, participants are told that a video of them will be recorded for an analysis of their nonverbal behavior and a voice frequency analysis6,7.
Manipulation of social versus personal identity
To manipulate social relationships within the TSST(-G), different techniques to induce a shared social identity9&#8212;a feeling of &#8220;we&#8221;-ness&#8212;between protagonists in the TSST/TSST-G are proposed (compare Gockel et al.10, H&#228;usser et al.11). Specifically, the manipulation of a&#160;social identity &#160;consists of the following steps11,12: (1) Participants are placed at the same table. (2) Throughout the experimental procedure participants are addressed as a group. (3) The initial letter of participants&#8217; names is manipulated to be identical because people prefer letters constituting their own name13. This name letter effect can be linked to increased interpersonal attraction14. (4) Participants&#8217; age and occupation are manipulated to be similar. (5) Participants are given T-shirts of the same color. (6) Participants work alone on a task in which they have to generate and write down ideas to improve the quality of life in their city (Task 1). Their ideas are put into a collective box and they are told that the group performance will be analyzed. (7) Participants are asked to think of similarities (e.g., goals, wishes, and habits) between themselves and their fellow group members (Task 2). (8) A group picture is taken.
In order to induce a personal identity, the following means are taken: (1) Participants are seated at three individual tables. (2) Throughout the experimental procedure participants are addressed as individuals. (3) The initial letter of participants&#8217; names is manipulated to be different. (4) Participants&#8217; age and occupation are manipulated to be different. (5) Participants are given T-shirts of different colors. (6) Participants also work on Task 1. However, their ideas for improving the quality of life are put into individual boxes and it is emphasized that their individual performance will be analyzed. (7) Participants should think of things (e.g., goals, wishes, and habits) that distinguish themselves from their fellow group members. (8) An individual picture of each participant is taken. Importantly, in both conditions participants are not allowed to interact with each other in any form. Furthermore, please note that the realization of steps 3 and 4 requires the use of confederates and may therefore not be applicable in every study design.
Manipulation of supportive versus unsupportive behavior
To study the effects of (un)supportive behavior, an experimental manipulation of non-verbal behavior of the TSST-selection committee members (compare Taylor et al.15) is introduced. Importantly, only the non-verbal behavior of the committee is altered: In stark contrast to the standard version of the TSST6, in which the committee members are trained to communicate with the participant in an unresponsive neutral manner (i.e., the committee members provide no facial feedback at all), the committee members now behave either supportively or unsupportively. However, the standardized verbal statements of the committee members and the procedure of the TSST are unchanged.
These two experimental manipulations can be applied independently of each other but can also be combined. In sum, the identity manipulation has been tested in our laboratory on 186 male and female healthy students and the manipulation of committee behavior on 90 male and female healthy students. In the present article, we describe the combination of both manipulations as conducted by Frisch et al.12. Building on the social identity approach16, Frisch et al. 12 hypothesized that social support in a stressful situation will only be effective in buffering stress responses, if the provider and the recipient of support share a social identity. This hypothesis was tested using a 2 (social versus personal identity) &#215; 2 (unsupportive versus supportive committee behavior) between-subjects design. In the first part of this experiment, a shared social identity (versus personal identity) was induced between three participants. In fact, there was only one real participant and the other two persons were confederates who pretended to be real participants throughout the study. The two confederates were used in order to assure a standardized committee behavior in the upcoming TSST. In this second part of the experiment, the TSST was introduced to the participants and they were told that one of them would have to serve as job applicant and the other two would constitute the committee. The two confederates were designated as members of the TSST-committee by using a bogus drawing of lots procedure. During the TSST, the non-verbal behavior of those two committee members was manipulated and they acted either supportively or unsupportively. The following protocol describes the procedure of this experiment12 and the manipulations in more detail.

<table border="0" cellpadding="0" cellspacing="0" width="841">
	<tbody>
		<tr>
			<td>9 T-shirts in 3 colors (i.e., 3 in each color)</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Social/personal identity manipulation.</td>
		</tr>
		<tr>
			<td>3 stick-on labels</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Social/personal identity manipulation.</td>
		</tr>
		<tr>
			<td>3 boxes (e.g., made of cardboard)</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Social/personal identity manipulation (task 1).</td>
		</tr>
		<tr>
			<td>a little pouch&#160;</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Bogus lot drawing procedure (entails three lots: two neatly folded lots labeled with with &#8220;committee&#8221; and one crumpled-up lot labeled with &#8220;applicant&#8221;).</td>
		</tr>
		<tr>
			<td>2 stopwatches</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Place them on the table in Room 2 (for the TSST-committee).</td>
		</tr>
		<tr>
			<td>2 video cameras</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Place in Room 2 (one for allegedly filming the participant, one for filming the behavior of the committee).</td>
		</tr>
		<tr>
			<td>2 tripods</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Place in Room 2.</td>
		</tr>
		<tr>
			<td>1 microphone</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Place in Room 2 (for allegedly recording the speech and the answers of the participant).</td>
		</tr>
		<tr>
			<td>1 microphone stand</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Place in Room 2.</td>
		</tr>
		<tr>
			<td>several pens</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Furniture</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>3 chairs</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Room 1 A and B (social/ personal identity manipulation).</td>
		</tr>
		<tr>
			<td>1 big table</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Room 1A (social identity manipulation).</td>
		</tr>
		<tr>
			<td>3 small tables</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Room 1B (personal identity manipulation).</td>
		</tr>
		<tr>
			<td>1 big table</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Room 2 (TSST-committee).</td>
		</tr>
		<tr>
			<td>2 chairs</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Room 2 (TSST-committee).</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Questionnaires/ instructions</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>3 informed consents</td>
			<td></td>
			<td></td>
			<td>Use the&#160; informed consent of your institution (for all participants, i.e., the two confederates and the real participant).</td>
		</tr>
		<tr>
			<td>3 manipulation checks of identity salience</td>
			<td>Items of Frisch et al. (2014), H&#228;usser et al. (2012) or Doosje et al. (1995)</td>
			<td></td>
			<td>Hand out after the identity salience manipulation (for all participants, i.e., the two confederates and the real participant).&#160;</td>
		</tr>
		<tr>
			<td>2 &#34;instructions&#34; for the TSST-committee</td>
			<td></td>
			<td></td>
			<td>Hand out to the committee members (i.e., the confederates) at the end of the bogus lot drawing procedure. These &#34;instructions&#34; are part of the cover story so that the real participant believes that the two confederates are real participants as well and need to be informed about their roles in the TSST. However, since the confederates are of course already familiar with the TSST procedure, it is not important what these instructions actually entail (e.g., as a reminder for the confederates they may entail the exact wording of the verbal instructions of the committee).</td>
		</tr>
		<tr>
			<td>2 solutions to the mental arithmetic task</td>
			<td></td>
			<td></td>
			<td>Place them on the table in Room 2 (for the TSST-committee).</td>
		</tr>
		<tr>
			<td>1 (or 3) manipulation check(s) of committee behavior</td>
			<td>Items of Frisch et al. (2014)</td>
			<td></td>
			<td>Hand out after the TSST (for the real participant only). (However, in order to keep up the role of the confederates as real participants, a similar questionnaire can be handed out to the confederates asking them how they evaluate their own behavior during the TSST.)&#160;</td>
		</tr>
		<tr>
			<td>several sheets of blank paper</td>
			<td>any brand/manufacturer is suitable</td>
			<td></td>
			<td>Hand out for task 1, task 2, preparation time of TSST (for the real participant), notes during the TSST (for the TSST-committee).</td>
		</tr>
	</tbody>
</table>

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.

Two studies (H&#228;usser et al.11 and Frisch et al.12) showed the effectiveness of the identity manipulation on 186 healthy students (97 females, age range 18 to 35 years, mean (M) age = 22.40 years, standard deviation (SD) = 2.83 years). Moreover, Frisch et al.12 tested the effectiveness of the committee behavior manipulation on 90 healthy students (49 females, age range 18 to 29, M = 22.00 years, SD = 2.31 years).
<p cl...

Watch this Scientific Journal Video about The Social Dimension of Stress: Experimental Manipulations of Social Support and Social Identity in the Trier Social Stress Test at JoVE.com

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

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 ...

the-social-dimension-stress-experimental-manipulations-social-support

Research

Education

JoVE Journal

JoVE Core

Behavior

Social Psychology

Introduction to Psychology

Foundations of Social Psychology

Unit 1

An Introduction to Psychology

The Social Self

SCIENTISTS IN ACTION

13.6K Views.  University of Hildesheim. 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). 

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

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 ...

The Modified Hole Board - Measuring Behavior, Cognition and Social Interaction in Mice and Rats

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure multiple dimensions of unconditioned behavior in small laboratory mammals (e.g., mice, rats, tree shrews and small primates). This paradigm is a valuable alternative for the use of a behavioral test battery, since a broad behavioral spectrum of an animal&#8217;s behavioral profile can be investigated in one single test.
The apparatus consists of a box, representing the &#8216;protected&#8217; area, separated from a group compartment. A board, on which small cylinders are staggered in three lines, is placed in the center of the box, representing the &#8216;unprotected&#8217; area of the set-up. The cognitive abilities of the animals can be measured by baiting some cylinders on the board and measuring the working and reference memory. Other unconditioned behavior, such as activity-related-, anxiety-related- and social behavior, can be observed using this paradigm. Behavioral flexibility and the ability to habituate to a novel environment can additionally be observed by subjecting the animals to multiple trials in the mHB, revealing insight into the animals&#8217; adaptive capacities.
Due to testing order effects in a behavioral test battery, na&#239;ve animals should be used for each individual experiment. By testing multiple behavioral dimensions in a single paradigm and thereby circumventing this issue, the number of experimental animals used is reduced. Furthermore, by avoiding social isolation during testing and without the need to food deprive the animals, the mHB represents a behavioral test system, inducing if any, very low amount of stress.

This protocol describes the modified hole board, which is a behavioral test set-up that comprises the characteristics of an open field and a traditional hole board. This set-up enables the differential analysis of unconditioned behavior of small laboratory mammals as well as the analysis of cognitive abilities.

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure ...

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 ...

Quantifying Social Motivation in Mice Using Operant Conditioning

In this protocol, social motivation is measured in mice through a pair of operant conditioning paradigms. To conduct the experiments, two-chambered shuttle boxes were equipped with two operant levers (left and right) and a food receptacle in one chamber, which was then divided from the second chamber by an automated guillotine door covered by a wire grid. Different stimulus mice, rotated across testing days, served as a social stimulus behind the wire grid, and were only visible following the opening of the guillotine door. Test mice were trained to lever press in order to open the door and gain access to the stimulus partner for 15 sec. The number of lever presses required to obtain the social reward progressively increased on a fixed schedule of 3. Testing sessions ended after test mice stopped lever pressing for 5 consecutive minutes. The last reinforced ratio or breakpoint can be used as a quantitative measure of social motivation. For the second paradigm, test mice were trained to discriminate between left and right lever presses in order to obtain either a food reward or the social reward. Mice were rewarded for every 3 presses of each respective lever. The number of food and social rewards can be compared as a measurement of the value placed upon each reward. The ratio of each reward type can also be compared between mouse strains and the change in this ratio can be monitored within testing sessions to measure satiation with a given reward type. Both of these operant conditioning paradigms are highly useful for the quantification of social motivation in mouse models of autism and other disorders of social behavior.

This article describes a new protocol for the quantitative measurement of social motivation in mice using operant conditioning for a social reward. The protocol is useful for the measurement of social motivation in mouse models of autism and other disorders of social behavior.

In this protocol, social motivation is measured in mice through a pair of operant conditioning paradigms. To conduct the experiments, two-chambered ...

Experimental Research Examining How People Can Cope with Uncertainty Through Soft Haptic Sensations

Human beings are constantly surrounded by uncertainty and change. The question arises how people cope with such uncertainty. To date, most research has focused on the cognitive strategies people adopt to deal with uncertainty. However, especially when uncertainty is due to unpredictable societal events (e.g., economical crises, political revolutions, terrorism threats) of which one is unable to judge the impact on one&#8217;s future live, cognitive strategies (like seeking additional information) is likely to fail to combat uncertainty. Instead, the current paper discusses a method demonstrating that people might deal with uncertainty experientially through soft haptic sensations. More specifically, because touching something soft creates a feeling of comfort and security, people prefer objects with softer as compared to harder properties when feeling uncertain. Seeking for softness is a highly efficient and effective tool to deal with uncertainty as our hands are available at all times. This protocol describes a set of methods demonstrating 1) how environmental (un)certainty can be situationally activated with an experiential priming procedure, 2) that the quality of the softness experience (what type of softness and how it is experienced) matters and 3) how uncertainty can be reduced using different methods.

To date research has focused on cognitive strategies people adopt to cope with uncertainty. This research examines instead an experiential way of dealing with uncertainty and introduces a set of experimental methods showing how the experience of haptic softness can serve as a tool to deal with uncertainty.

Human beings are constantly surrounded by uncertainty and change. The question arises how people cope with such uncertainty. To date, most research has ...

Examining Recall Memory in Infancy and Early Childhood Using the Elicited Imitation Paradigm

The ability to recall the past allows us to report on details of previous experiences, from the everyday to the significant. Because recall memory is commonly assessed using verbal report paradigms in adults, studying the development of this ability in preverbal infants and children proved challenging. Over the past 30 years, researchers have developed a non-verbal means of assessing recall memory known as the elicited or deferred imitation paradigm. In one variant of the procedure, participants are presented with novel three-dimensional stimuli for a brief baseline period before a researcher demonstrates a series of actions that culminate in an end- or goal-state. The participant is allowed to imitate the demonstrated actions immediately, after a delay, or both. Recall performance is then compared to baseline or to performance on novel control sequences presented at the same session; memory can be assessed for the individual target actions and the order in which they were completed. This procedure is an accepted analogue to the verbal report techniques used with adults, and it has served to establish a solid foundation of the nature of recall memory in infancy and early childhood. In addition, the elicited or deferred imitation procedure has been modified and adapted to answer questions relevant to other aspects of cognitive functioning. The broad utility and application of imitation paradigms is discussed, along with limitations of the approach and directions for future research.

The elicited imitation procedure was established to examine the development of recall memory in infancy and early childhood. This procedure has been widely used to establish a solid foundation of the nature of recall memory in infancy and early childhood.

The ability to recall the past allows us to report on details of previous experiences, from the everyday to the significant. Because recall memory is ...

A Within-subjects Experimental Protocol to Assess the Effects of Social Input on Infant EEG

Despite the importance of social interactions for infant brain development, little research has assessed functional neural activation while infants socially interact. Electroencephalography (EEG) power is an advantageous technique to assess infant functional neural activation. However, many studies record infant EEG only during one baseline condition. This protocol describes a paradigm that is designed to comprehensively assess infant EEG activity in both social and nonsocial contexts as well as tease apart how different types of social inputs differentially relate to infant EEG. The within-subjects paradigm includes four controlled conditions. In the nonsocial condition, infants view objects on computer screens. The joint attention condition involves an experimenter directing the infant's attention to pictures. The joint attention condition includes three types of social input: language, face-to-face interaction, and the presence of joint attention. Differences in infant EEG between the nonsocial and joint attention conditions could be due to any of these three types of input. Therefore, two additional conditions (one with language input while the experimenter is hidden behind a screen and one with face-to-face interaction) were included to assess the driving contextual factors in patterns of infant neural activation. Representative results demonstrate that infant EEG power varied by condition, both overall and differentially by brain region, supporting the functional nature of infant EEG power. This technique is advantageous in that it includes conditions that are clearly social or nonsocial and allows for examination of how specific types of social input relate to EEG power. This paradigm can be used to assess how individual differences in age, affect, socioeconomic status, and parent-infant interaction quality relate to the development of the social brain. Based on the demonstrated functional nature of infant EEG power, future studies should consider the role of EEG recording context and design conditions that are clearly social or nonsocial.

This novel protocol is designed to assess the neural bases of social interaction in infants. The paradigm is designed to tease apart how various social inputs such as language, joint attention, and face-to-face interaction relate to infant neural activation. Infant EEG power is recorded during both social and nonsocial conditions.

Despite the importance of social interactions for infant brain development, little research has assessed functional neural activation while infants ...

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 ...

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.

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. ...