<p>It appears that they tested all of the participants (control &amp; stress) at the same time:</p>

<blockquote>
  <ul>
  <li><p>Memory was assessed 24 h after learning. According to the model
  by Joels and colleagues (2006), it can be predicted that learning under
  stress enhances memory, in particular for stress context-related
  information</p></li>
  <li><p>Twenty-four hours after learning, participants returned to the
  laboratory and completed a free recall test</p></li>
  <li><p>Immediately after the free recall test, participants were given a
  recognition test.</p></li>
  <li><p>All testing took place in the morning between 8 am and 1 pm to
  control for the diurnal variation of the stress hormone cortisol. On
  day 1, participants heard a list of eight neutral words that were related
  to the stressor as well as eight negative, eight positive and eight
  neutral, stressor-unrelated words while they were exposed to stress
  or a control condition (for details see below). On the following day,
  participants returned to the laboratory and completed a free recall
  and a recognition test for the words they heard the day before.</p></li>
  </ul>
</blockquote>

<p>I can't find anywhere within the text that says "To control for the effect of time on memory, we had another control group that was not stressed and did not reactivate experiences from their past."</p>

<p>They found that: </p>

<blockquote>
  <p>Learning under stress reduced both free recall and recognition
  performance 24 h after learning.</p>
</blockquote>

<p>All taken from your reference:</p>

<ul>
<li>Schwabe, L., &amp; Wolf, O. T. (2010). <a href="https://www.psy.uni-hamburg.de/arbeitsbereiche/kognitionspsychologie/publications/schwabe2010b-nlm.pdf" rel="nofollow">Learning under stress impairs memory formation. Neurobiology of learning and memory</a>, 93(2), 183-188. </li>
</ul>

CC BY-SA 3.0
2015-05-14T22:50:59.563Z
2015-05-14T22:50:59.563Z
queenslug
<p>Schwabe and Wolf (2010) </p>

<blockquote>
  <p>Rodent studies suggest that memory reconsolidating is impaired by stress. Here we examined in healthy humans the effect of stress on the reconsolidation of autobiographical memories. Participants recalled positive, negative and neutral episodes from their recent past and afterward exposed to a stressor (socially evaluated cold pressor test) or a non-arousing control condition. Additional groups of participants were exposed to the stressor without prior memory reactivation or were neither stressed nor asked to recall episodes from their past. Stress after memory reactivation impaired the memory for the neutral episodes 1 week later....</p>
</blockquote>

<p>How is the group that is not stressed and not reactivated (control) act as a control for time?  Or rather what does "control for time" mean?</p>

<p>The researchers wrote "To control for the effect of time on memory, we had another control group that was not stressed and did not reactivate experiences from their past." </p>

<p>I understand that the group makes a good baseline for comparing other results to, but where does time come into it? </p>

<p><strong>References</strong>:</p>

<ul>
<li>Schwabe, L., &amp; Wolf, O. T. (2010). Learning under stress impairs memory formation. Neurobiology of learning and memory, 93(2), 183-188. <a href="https://www.psy.uni-hamburg.de/arbeitsbereiche/kognitionspsychologie/publications/schwabe2010b-nlm.pdf" rel="nofollow">https://www.psy.uni-hamburg.de/arbeitsbereiche/kognitionspsychologie/publications/schwabe2010b-nlm.pdf</a></li>
</ul>

CC BY-SA 3.0
2015-05-13T06:14:37.183Z
@Zelda I have given the question an edit. This is a starting point for an acceptable question. You should further edit the question to make it a stand-alone question. I.e., (a) give a basic summary of the study as relevant to your question and (b) clearly define your question about the study.
Jeromy Anglim
CC BY-SA 3.0
2015-05-13T07:57:31.567Z
@faustus It was an experiment we looked at in class earlier in semester :) (which is how I came across it) but it is in fact just as stated. For my own personal development I'm looking to examine more psych experiments on stack exchange, do you have any advice for how to stop them from seeming to be homework questions?? because I want to compare my initial ideas for improving experiments to what other people suggest, so that i can develop my critical thinking.
Zelda Quandt 
CC BY-SA 3.0
2015-05-13T08:24:00.400Z
@ZeldaQuandt Homework questions are often extremely specific. Good questions are general and apply to many cases (e.g., http://cogsci.stackexchange.com/q/9414/2868 for a very short example). SE questions hang around for years and should remain useful to others after the author has moved on. There's also http://meta.cogsci.stackexchange.com/q/434/2868
Christian Hummeluhr
CC BY-SA 3.0
2015-05-13T11:27:02.863Z
@ZeldaQuandt people will tend to want to help you even if it is homework if you don't come across as being lazy. posting a link without full paper is not meeting people half way. why don't you do this: explain to me the major components of the experiment in short point. then explain what you think the relationship is between memory recall and: stress, rehearsal, and the passage of time.
faustus
CC BY-SA 3.0
2015-05-13T22:15:45.690Z
@faustus : The first test in humans to see if stress after reconsolidation impairs recall at a future time. Relationship between memory recall and stress is being tested to see if there is a difference to consolidation and stress (where memory is actually enhanced) (they're expecting memory to be impaired if we go off rodent models). Passage of time - required for long term memory making. I don't see how the group that has not been tested on the first day (not even present on first day), is a control for time (author's words), when they're only being tested on day 2 (a week after day 1)
Zelda Quandt 
CC BY-SA 3.0
2015-05-14T11:42:50.867Z
@ZeldaQuandt the passage of time improves memory? i always thought that it leads to forgetting. in fact, to know how much forgetting was due to the stress condition, and how much was simply due to forgetting, i would be compelled to have another control group. also: which paper are you assessing. the original paper, or this new one, which is completely different? if it isn't the original study looking at autobiographical memories, you should close this question.
faustus
<memory><cognitive-neuroscience><experimental-psychology><long-term-memory>
How does the group that is not stressed and not reactivated act as a control for time in Schwabe & Wolf 2010?
Zelda Quandt 
# How does the group that is not stressed and not reactivated act as a control for time in Schwabe & Wolf 2010?

(Asked by: username_0 on 2015-05-13)

Schwabe and Wolf (2010)

> Rodent studies suggest that memory reconsolidating is impaired by stress. Here we examined in healthy humans the effect of stress on the reconsolidation of autobiographical memories. Participants recalled positive, negative and neutral episodes from their recent past and afterward exposed to a stressor (socially evaluated cold pressor test) or a non-arousing control condition. Additional groups of participants were exposed to the stressor without prior memory reactivation or were neither stressed nor asked to recall episodes from their past. Stress after memory reactivation impaired the memory for the neutral episodes 1 week later....

How is the group that is not stressed and not reactivated (control) act as a control for time? Or rather what does "control for time" mean?

The researchers wrote "To control for the effect of time on memory, we had another control group that was not stressed and did not reactivate experiences from their past."

I understand that the group makes a good baseline for comparing other results to, but where does time come into it?

**References**:

* Schwabe, L., & Wolf, O. T. (2010). Learning under stress impairs memory formation. Neurobiology of learning and memory, 93(2), 183-188. <https://www.psy.uni-hamburg.de/arbeitsbereiche/kognitionspsychologie/publications/schwabe2010b-nlm.pdf>

**Tags:** memory, cognitive-neuroscience, experimental-psychology, long-term-memory

> **Comments:**
> **username_1**: @Zelda I have given the question an edit. This is a starting point for an acceptable question. You should further edit the question to make it a stand-alone question. I.e., (a) give a basic summary of the study as relevant to your question and (b) clearly define your question about the study.  
> **username_0**: @username_3 It was an experiment we looked at in class earlier in semester :) (which is how I came across it) but it is in fact just as stated. For my own personal development I'm looking to examine more psych experiments on stack exchange, do you have any advice for how to stop them from seeming to be homework questions?? because I want to compare my initial ideas for improving experiments to what other people suggest, so that i can develop my critical thinking.  
> **username_2**: @ZeldaQuandt Homework questions are often extremely specific. Good questions are general and apply to many cases (e.g., http://cogsci.stackexchange.com/q/9414/2868 for a very short example). SE questions hang around for years and should remain useful to others after the author has moved on. There's also http://meta.cogsci.stackexchange.com/q/434/2868  
> **username_3**: @ZeldaQuandt people will tend to want to help you even if it is homework if you don't come across as being lazy. posting a link without full paper is not meeting people half way. why don't you do this: explain to me the major components of the experiment in short point. then explain what you think the relationship is between memory recall and: stress, rehearsal, and the passage of time.  
> **username_0**: @username_3 : The first test in humans to see if stress after reconsolidation impairs recall at a future time. Relationship between memory recall and stress is being tested to see if there is a difference to consolidation and stress (where memory is actually enhanced) (they're expecting memory to be impaired if we go off rodent models). Passage of time - required for long term memory making. I don't see how the group that has not been tested on the first day (not even present on first day), is a control for time (author's words), when they're only being tested on day 2 (a week after day 1)  
> **username_3**: @ZeldaQuandt the passage of time improves memory? i always thought that it leads to forgetting. in fact, to know how much forgetting was due to the stress condition, and how much was simply due to forgetting, i would be compelled to have another control group. also: which paper are you assessing. the original paper, or this new one, which is completely different? if it isn't the original study looking at autobiographical memories, you should close this question.  

---

## 1 answers

### Answer by username_4 on 2015-05-14. Score: 3

It appears that they tested all of the participants (control & stress) at the same time:

> * Memory was assessed 24 h after learning. According to the model
>   by Joels and colleagues (2006), it can be predicted that learning under
>   stress enhances memory, in particular for stress context-related
>   information
> * Twenty-four hours after learning, participants returned to the
>   laboratory and completed a free recall test
> * Immediately after the free recall test, participants were given a
>   recognition test.
> * All testing took place in the morning between 8 am and 1 pm to
>   control for the diurnal variation of the stress hormone cortisol. On
>   day 1, participants heard a list of eight neutral words that were related
>   to the stressor as well as eight negative, eight positive and eight
>   neutral, stressor-unrelated words while they were exposed to stress
>   or a control condition (for details see below). On the following day,
>   participants returned to the laboratory and completed a free recall
>   and a recognition test for the words they heard the day before.

I can't find anywhere within the text that says "To control for the effect of time on memory, we had another control group that was not stressed and did not reactivate experiences from their past."

They found that:

> Learning under stress reduced both free recall and recognition
> performance 24 h after learning.

All taken from your reference:

* Schwabe, L., & Wolf, O. T. (2010). [Learning under stress impairs memory formation. Neurobiology of learning and memory](https://www.psy.uni-hamburg.de/arbeitsbereiche/kognitionspsychologie/publications/schwabe2010b-nlm.pdf), 93(2), 183-188.


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