AggressionNCT04879719
The Influence of Ego-depletion on Implicit Aggression and Cognitive Performance
A study testing Ego-depletion in people with Aggression, run by Universitätsklinikum Hamburg-Eppendorf at 1 site in Germany.
Trial summary
The aim of the planned online study is twofold. First, it opts to deliver further evidence for the existence of the construct ego-depletion. Second, it tries to further validate the German version of the word-stem completion task as a measure of implicit aggression. Read more about this study
- Who is it for?
- Ages 18 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Aggression
- What is being tested?
- Ego-depletion
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteGermany
- Study dates
- 17 Feb 2021to 17 May 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- being mentally healthy
- German as native language
- being between 18-55 years in age
Who cannot join
- working in a medical profession
Trial locations and contacts
1 site in 1 country.
Germany1 site, 1 recruiting
- Recruiting
University Clinic Hamburg-Eppendorf
Hamburg, 20246
Dimitrij Kugler, M.Sc., 0049 40 7410 24113, d.kugler@uke.de
About this study
The aim of the planned online study is twofold. First, it opts to deliver further evidence for the existence of the construct ego-depletion. Second, it tries to further validate the German version of the word-stem completion task as a measure of implicit aggression. The psychological assessment of aggression is not a trivial aspect, however. In general, explicit measures of aggression have a higher face validity than their implicit counterparts. However, even implicit measures, such as the implicit association test for aggression, have a certain amount of face validity, since participants might be able to infer that the task is related to aggression. Another implicit aggression measure is the word-stem completion task, which asks participants to complement word-stems in order to build words. Lately, we have developed a German version of this task and found some promising first results, i.e., a factor analysis indicated that the word-stem completion task explained unique variance in aggression. The present study aims to further validate the German version of the word-stem completion task by experimentally manipulating aggression through an ego-depletion paradigm, in which cognitive resources are depleted. It is expected that participants in the ego-depletion condition build more aggressive solutions on the word-stem completion task than participants in the control group.
Read the detailed description
Almost every one of us knows the experience of falling short of one's own resolutions, despite having the intention to behave differently. In dual-process models human behavior is proposed to be a result of reciprocal activity of an impulsive and a reflective system with the impulsive system being fast, associative, and mostly unconscious, while the activity of the reflective system is slow, rule-based and relies on cognitive resources. Hence, people are more prone to rely on the associative system if cognitive resources are diminished or temporarily unavailable. Such a state of low mental resources has been linked to various detrimental effects such as impulse buying, stereotyping, unhealthy food choices, aggression, as well as impaired cognitive performance in general and is referred to as ego-depletion. According to ego-depletion theory self-control functions like a muscle and activities that heavily rely on the exertion of self-control successively exhaust this limited resource. Lately, some critical concerns questioning the magnitude of ego-depletion effects or its existence altogether have been raised. Most recent meta-analytical findings resolved most of the uncertainty, however, and stressed the importance of the paradigm used to deplete cognitive resources with emotion suppression videos being best suited to induce a state of ego-depletion.
Therefore, an emotional video, showing sequences of a surgery will be used in the present research in order to manipulate the amount of cognitive resources available. While participants in the experimental group are asked to suppress any emotions while watching the video, the control group is requested to simply watch the video attentively.
The word-stem completion task is an implicit aggression measure that asks participants to complement word-stems with the assumption being that the more aggressive solutions a person generates the more aggressive that person is.
The experiment will use a sequential-task paradigm with half of the 60 participants being randomly assigned to the ego-depletion condition. After watching the emotional video, participants in both groups will be requested to complete the word-stem completion task, an aggression implicit association test, as well as a multi-source interference task. Furthermore, trait aggression and the amount of subjective emotion, experienced while watching the video, will be assessed as potential moderators.
It is expected that participants in the ego-depletion group will score higher on implicit aggression measures (word-stem completion task and implicit association task) and perform worse on the multi-source interference task, which measures cognitive performance.
Participants will be told that the experiment seeks to understand the relationship between emotional videos and cognition and creativity. At the end of the study, participants will be debriefed about the actual goal of the study and will receive monetary compensation for their participation.
- Conditions
- Aggression
- Being tested
- Ego-depletion, Control
- Keywords
- ego-depletion, implicit aggression, word-stem completion task, implicit association task
- Medical subject headings
- Aggression
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ego-depletionBehavioural
The surgery video lasts for 9 minutes and participants are asked to suppress their emotions. After the intervention several implicit aggression tests, as well as a task, measuring cognitive performance in general are assessed.
ControlBehavioural
The surgery video lasts for 9 minutes and participants in the control group are asked to watch the surgery video without the need to suppress their emotions. Several implicit aggression tests, as well as a task, measuring cognitive performance in general are assessed after the 9 minute video sequence.
| Study group | Role | What they receive |
|---|---|---|
| Ego-depletion group | Experimental | Participants in this condition are asked to suppress their emotion while watching an emotional video of a surgery. Suppressing the natural emotional reaction to such a video demands cognitive resources and thus can induce a state of ego-depletion. Receives: Behavioral: Ego-depletion |
| Control group | Active comparator | Participants in the control group are asked to watch the same emotional video. However, they are required to simply watch the video without suppressing any emotions. Receives: Behavioral: Control |
What is being measured
The primary outcome is the main question the study is designed to answer.
Word-stem completion task
In the word-stem completion task participants are presented with up to 100 word-stems in random order. The participants' task is to build as many words as possible within sic minutes by complementing the word-stems. Solution words can be either aggressive, partially aggressive or non-aggressive. Sum scores for all aggressive and partially aggressive solutions are built as a first index of implicit aggression. First results from the German version of the word-stem completion task, however, indicate that a score taking into account the number of total solutions, as well as the word frequencies in the German language is better suited to measure implicit aggression than the conventional sum score method. Therefore, the new weighted score will be used as main outcome variable.
Measured: All measures will be taken on a single occasion in a sequential-task paradigm, which is standard in ego-depletion research. Completion of all tasks takes 6 minutes
Implicit Association Test (IAT) for aggression
The IAT is a speeded classification task, which seeks to measure the inner strength of associations between certain concepts. During the IAT words are presented at the center of the screen and participants are asked to categorize stimuli either to the left or to the right based on the instructions of the respective block. IAT scores are obtained by comparing reaction times between blocks in which participants have to press the same button in response to aggressive as well as self-referential words with reaction times from blocks in which peaceful and self-referential words require the same response. If participants respond faster on trials in which aggressive and self-referential words require the same response this is thought to reflect higher levels of implicit aggression.
Measured: All measures will be taken on a single occasion in a sequential-task paradigm, which is standard in ego-depletion research. Completion of this task takes about 5 minutes.
Multi-source interference task (MSIT)
The MSIT is thought to measure cognitive control and cognitive performance in general. On each trial three items are presented next to each other at the center of the screen, with two of them being identical and one deviating from the others. Participants are asked to identify the number that differs from the other two presented items (mostly numbers) and to press the corresponding key on the keyboard. The position and the actual number can either be the same, e.g. the number 2 presented in between two other numbers or letters (so-called flankers), in which we speak of congruency or number and position can be incongruent, for instance the number 2 presented left to
Measured: All measures will be taken on a single occasion in a sequential-task paradigm, which is standard in ego-depletion research. Completion of this task takes about 5 minutes.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 May 2021
- Study start17 Feb 2021
- Primary completion17 May 2021 (estimated)
- Study completion17 May 2021 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for AggressionStudies of the same condition, open and under way.
- More trials run by Universitätsklinikum Hamburg-EppendorfThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants are randomly assigned to either a ego-depletion- or a control group.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitätsklinikum Hamburg-Eppendorf
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Simone Kühn, Prof. Dr., Principal investigator, Universitätsklinikum Hamburg-Eppendorf
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04879719
- Sponsor's protocol ID
- Ego-depletion study
- Status last verified
- May 2021
- First submitted
- 3 May 2021
- Last updated
- 10 May 2021
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Baumeister RF, Bratslavsky E, Muraven M, Tice DM. Ego depletion: is the active self a limited resource? J Pers Soc Psychol. 1998 May;74(5):1252-65. doi: 10.1037//0022-3514.74.5.1252.
PubMed 9599441Dang J. An updated meta-analysis of the ego depletion effect. Psychol Res. 2018 Jul;82(4):645-651. doi: 10.1007/s00426-017-0862-x. Epub 2017 Apr 8.
PubMed 28391367Hagger MS, Wood C, Stiff C, Chatzisarantis NL. Ego depletion and the strength model of self-control: a meta-analysis. Psychol Bull. 2010 Jul;136(4):495-525. doi: 10.1037/a0019486.
PubMed 20565167Strack F, Deutsch R. Reflective and impulsive determinants of social behavior. Pers Soc Psychol Rev. 2004;8(3):220-47. doi: 10.1207/s15327957pspr0803_1.
PubMed 15454347
Study at a glance
From the registry record, last updated by the sponsor on 10 May 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Influence of Ego-depletion on Implicit Aggression and Cognitive Performance
- ClinicalTrials.gov ID
- NCT04879719
- Acronym / sponsor ID
- Ego-depletion study
- Conditions
- Aggression
- Keywords
- ego-depletion, implicit aggression, word-stem completion task, implicit association task
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Universitätsklinikum Hamburg-EppendorfUniversity, hospital or other
- Study start
- 17 Feb 2021 (actual)
- Primary completion
- 17 May 2021 (estimated)
- Study completion
- 17 May 2021 (estimated)
- First posted
- 10 May 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of the planned online study is twofold. First, it opts to deliver further evidence for the existence of the construct ego-depletion. Second, it tries to further validate the German version of the word-stem completion task as a measure of implicit aggression. The psychological assessment of aggression is not a trivial aspect, however. In general, explicit measures of aggression have a higher face validity than their implicit counterparts. However, even implicit measures, such as the implicit association test for aggression, have a certain amount of face validity, since participants might be able to infer that the task is related to aggression. Another implicit aggression measure is the word-stem completion task, which asks participants to complement word-stems in order to build words. Lately, we have developed a German version of this task and found some promising first results, i.e., a factor analysis indicated that the word-stem completion task explained unique variance in aggression. The present study aims to further validate the German version of the word-stem completion task by experimentally manipulating aggression through an ego-depletion paradigm, in which cognitive resources are depleted. It is expected that participants in the ego-depletion condition build more aggressive solutions on the word-stem completion task than participants in the control group.
Detailed description
Almost every one of us knows the experience of falling short of one's own resolutions, despite having the intention to behave differently. In dual-process models human behavior is proposed to be a result of reciprocal activity of an impulsive and a reflective system with the impulsive system being fast, associative, and mostly unconscious, while the activity of the reflective system is slow, rule-based and relies on cognitive resources. Hence, people are more prone to rely on the associative system if cognitive resources are diminished or temporarily unavailable. Such a state of low mental resources has been linked to various detrimental effects such as impulse buying, stereotyping, unhealthy food choices, aggression, as well as impaired cognitive performance in general and is referred to as ego-depletion. According to ego-depletion theory self-control functions like a muscle and activities that heavily rely on the exertion of self-control successively exhaust this limited resource. Lately, some critical concerns questioning the magnitude of ego-depletion effects or its existence altogether have been raised. Most recent meta-analytical findings resolved most of the uncertainty, however, and stressed the importance of the paradigm used to deplete cognitive resources with emotion suppression videos being best suited to induce a state of ego-depletion.
Therefore, an emotional video, showing sequences of a surgery will be used in the present research in order to manipulate the amount of cognitive resources available. While participants in the experimental group are asked to suppress any emotions while watching the video, the control group is requested to simply watch the video attentively.
The word-stem completion task is an implicit aggression measure that asks participants to complement word-stems with the assumption being that the more aggressive solutions a person generates the more aggressive that person is.
The experiment will use a sequential-task paradigm with half of the 60 participants being randomly assigned to the ego-depletion condition. After watching the emotional video, participants in both groups will be requested to complete the word-stem completion task, an aggression implicit association test, as well as a multi-source interference task. Furthermore, trait aggression and the amount of subjective emotion, experienced while watching the video, will be assessed as potential moderators.
It is expected that participants in the ego-depletion group will score higher on implicit aggression measures (word-stem completion task and implicit association task) and perform worse on the multi-source interference task, which measures cognitive performance.
Participants will be told that the experiment seeks to understand the relationship between emotional videos and cognition and creativity. At the end of the study, participants will be debriefed about the actual goal of the study and will receive monetary compensation for their participation.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Participants are randomly assigned to either a ego-depletion- or a control group.
| Arm | Type | Receives |
|---|---|---|
| Ego-depletion group | Experimental | Behavioral: Ego-depletionParticipants in this condition are asked to suppress their emotion while watching an emotional video of a surgery. Suppressing the natural emotional reaction to such a video demands cognitive resources and thus can induce a state of ego-depletion. |
| Control group | Active comparator | Behavioral: ControlParticipants in the control group are asked to watch the same emotional video. However, they are required to simply watch the video without suppressing any emotions. |
Who may qualify
- Ages
- 18 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- being mentally healthy
- German as native language
- being between 18-55 years in age
Key exclusion criteria (1 listed)
- working in a medical profession
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ego-depletionThe surgery video lasts for 9 minutes and participants are asked to suppress their emotions. After the intervention several implicit aggression tests, as well as a task, measuring cognitive performance in general are assessed. | Behavioural | Ego-depletion group |
| ControlThe surgery video lasts for 9 minutes and participants in the control group are asked to watch the surgery video without the need to suppress their emotions. Several implicit aggression tests, as well as a task, measuring cognitive performance in general are assessed after the 9 minute video sequence. | Behavioural | Control group |
Primary outcome
Word-stem completion task
Time frame: All measures will be taken on a single occasion in a sequential-task paradigm, which is standard in ego-depletion research. Completion of all tasks takes 6 minutes
In the word-stem completion task participants are presented with up to 100 word-stems in random order. The participants' task is to build as many words as possible within sic minutes by complementing the word-stems. Solution words can be either aggressive, partially aggressive or non-aggressive. Sum scores for all aggressive and partially aggressive solutions are built as a first index of implicit aggression. First results from the German version of the word-stem completion task, however, indicate that a score taking into account the number of total solutions, as well as the word frequencies in the German language is better suited to measure implicit aggression than the conventional sum score method. Therefore, the new weighted score will be used as main outcome variable.
Implicit Association Test (IAT) for aggression
Time frame: All measures will be taken on a single occasion in a sequential-task paradigm, which is standard in ego-depletion research. Completion of this task takes about 5 minutes.
The IAT is a speeded classification task, which seeks to measure the inner strength of associations between certain concepts. During the IAT words are presented at the center of the screen and participants are asked to categorize stimuli either to the left or to the right based on the instructions of the respective block. IAT scores are obtained by comparing reaction times between blocks in which participants have to press the same button in response to aggressive as well as self-referential words with reaction times from blocks in which peaceful and self-referential words require the same response. If participants respond faster on trials in which aggressive and self-referential words require the same response this is thought to reflect higher levels of implicit aggression.
Multi-source interference task (MSIT)
Time frame: All measures will be taken on a single occasion in a sequential-task paradigm, which is standard in ego-depletion research. Completion of this task takes about 5 minutes.
The MSIT is thought to measure cognitive control and cognitive performance in general. On each trial three items are presented next to each other at the center of the screen, with two of them being identical and one deviating from the others. Participants are asked to identify the number that differs from the other two presented items (mostly numbers) and to press the corresponding key on the keyboard. The position and the actual number can either be the same, e.g. the number 2 presented in between two other numbers or letters (so-called flankers), in which we speak of congruency or number and position can be incongruent, for instance the number 2 presented left to
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 May 2021.
- Background: PubMed 9599441Baumeister RF, Bratslavsky E, Muraven M, Tice DM. Ego depletion: is the active self a limited resource? J Pers Soc Psychol. 1998 May;74(5):1252-65. doi: 10.1037//0022-3514.74.5.1252.
- Background: PubMed 28391367Dang J. An updated meta-analysis of the ego depletion effect. Psychol Res. 2018 Jul;82(4):645-651. doi: 10.1007/s00426-017-0862-x. Epub 2017 Apr 8.
- Background: PubMed 20565167Hagger MS, Wood C, Stiff C, Chatzisarantis NL. Ego depletion and the strength model of self-control: a meta-analysis. Psychol Bull. 2010 Jul;136(4):495-525. doi: 10.1037/a0019486.
- Background: PubMed 15454347Strack F, Deutsch R. Reflective and impulsive determinants of social behavior. Pers Soc Psychol Rev. 2004;8(3):220-47. doi: 10.1207/s15327957pspr0803_1.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Simone Kühn, Prof. Dr. principal investigator
Universitätsklinikum Hamburg-Eppendorf
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ego-depletion in people with Aggression, run by Universitätsklinikum Hamburg-Eppendorf at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 10 May 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Dimitrij Kugler, M.Sc. (040 741024113, d.kugler@uke.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Word-stem completion task (time frame: All measures will be taken on a single occasion in a sequential-task paradigm, which is standard in ego-depletion research. Completion of all tasks takes 6 minutes). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04879719, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 May 2021.