Described results are obtained from the project supported by the National Science Centre in Poland under grant no. 2014/13/B/HS6/03155.

<ol>
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The authors have nothing to disclose.

In the study presented here, we have investigated whether older adults could benefit from working memory training and if it is connected to the initial level of their basic cognition. We used an n-back task as an experimental intervention and working memory capacity (measured with the OSPAN task) was the method to probe participants&#39; initial level of intellectual functioning. We had two critical steps in the protocol. The first and most important was the assessment of the initial WM level. The second was the careful matching of the two training regimens in every possible way but the &#34;cognitive content&#34; (i.e., working memory versus semantic memory). By introducing the assessment of the participants&#39; cognitive level at the beginning of the study, we were able to show how important it is to have a good estimate of it at the start of the intervention. It was the most important predictor of the cognitive training&#39;s effectiveness. We suspect that in most intervention studies, researchers assess, in one way or another, the initial cognitive level of participants. To obtain such information it is possible to use the results from the first measurement of a trained cognitive task as a predictor of the cognitive training effectiveness. As expected, the N level of n-back task fluctuated substantially through training sessions. What was even more interesting, individuals with higher maximal N achieved in the first training session improved faster than the rest of the group in the following sessions. That implies that the variability in performance between participants, noticed at the beginning of the study, only increased with time and training. To explore this effect deeper we conducted further analysis. The results showed the preliminary score in OSPAN task (WMC) to be a strong predictor of the improvement gained during the training course (in the dual n-back task). Participants characterized by higher initial WMC performed better in the training from the very first day and had stepper learning curve in comparison to seniors with WMC below the average of the sample. We are not the first to report such effect. Foster et al. (2017) described similar results29. They proved the existence of the correlation between the initial WM level and the performance of memory span training. This result is consistent not only with the ones here, but also with research on the so-called Matthew effect in WM training interventions, in which participants with initially higher skills profit more from training and score better in both: trained and untrained, tasks21,36,37,38,39. All this strengthens the conclusion that someone&#39;s ability to gain from WM training depends heavily on the initial intellectual level.
Regarding the regimens similarity, we applied the Mill&#39;s method of one difference40: when someone observes one situation that leads to a given effect, and another that does not result in the same way, and the only difference between these situations is a presence of a specific factor only in the first situation (here, the difference in the cognitive layer), there is the solid foundation to assume that it is the factor in question that caused the observed effect. We tried to match the training regimens in terms of motivation, superficial similarities (same amount of training sessions, similar feedback, etc.). It is worth noting that the first idea was to use the same task (n-back) but in its easiest form, where the N level is fixed to 1. It quickly becomes obvious that it was a wrong path as the participants (in pilot studies) not only reported weariness but also were dropping off the control condition at a much higher rate than from the experimental (with adaptive level of difficulty). This resulted in a different approach. After several pretests we decided for a &#34;different function&#34; approach (WM versus semantic memory) instead of having the same function in both conditions just with different intensity (fixed level of WM versus adaptive level of WM). One potential problem with such approach is that we can create a control condition, which is more attractive than the experimental condition. And, if motivation to engage is a crucial factor in cognitive trainings, we can have null results because of that decision.
It is worth noticing that there is a substantial change in a way we look now at results from cognitive intervention studies. For example, Reddick et al. suggest that positive effects observed in WM training groups when compared to control groups are due to decrease present in control group and not improvement of performance in experimental groups41. When we think about elderly population, even such output - maintaining of the initial cognitive level - could be a desirable outcome. But, surprisingly, in the study we did not observe a post-training reduction of performance in the control group, except for the go/no-go task. It might be, again, interpreted as evidence that even a simple memory quiz, if it is attractive and encourages participants to engage in some cognitive activity, could produce beneficial effects. What is also important, all of the participants (regardless of group assignment) volunteered for the study and some correlational studies have shown that voluntary work might be a protective factor against cognitive aging42,43. One of limitations of the study is that we do not have the representative population of older people. Instead, the elderly taking part in the study were probably more motivated and more proactive than seniors who, for example, do not leave their homes. However, the level of education and economic status (indirectly controlled - as an occupational activity that generate income) were measured in the study and the analysis showed that these were not factors affecting training progress. It can be also argued that improvement observed in both interventions is the result of mere test-retest effects. Due to the fact that there was no passive control group included in the study, this matter cannot be settled down in this study. It is therefore advisable to include another group in the subsequent tests - passive control. The most important message from the study is that the findings suggest that post-training gains are within reach of older adults, especially those characterized by a good overall cognitive functioning. What we wanted to delineate in this article was the way we were introducing and maintaining the participants in a training regimen. The most important thing in this study was to keep all features of the intervention exactly the same between the two groups apart from one thing - the cognitive function involved undergoing practice. As we did not observe substantial differences between the effectiveness of the training protocols, but the improvement was visible in both groups, it seems valid to conclude that any cognitive engagement can be beneficial for elderly people. As the main result refers to the initial level of cognitive functioning, we strongly recommend including initial measures of the trained function and verifying it as a possible predictor (or at least co-factor) of training effectiveness.

In many cognitive trainings studies, the dual n-back task is used as a method of working memory (WM) training. WM is a common target of cognitive interventions because of its importance for other, higher level intellectual functions1. However, the effectiveness of such training and its potential for creating a more general improvement in cognition, has been highly debated (for meta-analysis, see2,3,4,5,6,7,14 and for reviews, see4,8,9,10,11,12,13). While some researchers claim that &#39;&#39;&#8230; there was no convincing evidence of the generalization of working memory training to other skills&#39;&#39;4, others present meta-analytical data, which show highly significant effects of WM training2,3,5,6,11. The separate problem is the effectiveness of WM in the elderly population. Several WM training studies reported greater benefits in younger adults compared to older adults15,16,17,18,19,20, whereas others show that similar effects can be observed in both age groups21,22,23,24,25.
Various elements are believed to forecast the benefits of memory training26. Some of those factors appears to be potential moderators of WM training effectiveness21. Mental capacity, being described as the baseline cognitive capacity or general cognitive resource, seems to be one of the strongest choices for this position. In order to assess the role of the initial intellectual level, we put a special emphasis (the method described here) on the measurement of the cognitive capacity before applying a training regimen. It was dictated by the data showing that participants, who are characterized by higher cognitive capacity at the beginning of the training, achieved substantially better training outcomes compared to those with lower levels of initial cognitive functionning27. A similar phenomenon is observed in educational research, where it is referred to as the Matthew effect28, an observation that people with initially better skill improve even more when compared to those with preliminary lower level of ability in question.
It is thought-provoking, though, that not so many reports have been published on this topic21,29. Moreover, even substantial individual differences, especially when it comes to the elderly population, are often left unattended during data analysis and interpretation30. In the present study, we examine the impact of the initial level of working memory capacity on WM training success in the group of healthy older adults. In order to maintain every element of the training regimens as similar as possible between experimental and control groups, we employed an active control group design. Therefore, the training content (WM versus semantic memory) remained the one crucial factor determining the expected difference in the training results. Both groups performed computerized, home-based trainings. Members of the experimental group were assigned to an adaptive dual n-back training program and an active control group trained with a task based on a semantic memory quiz. New in the approach here is the emphasis on the initial evaluation of the participants&#39; cognitive level by assessing their working memory capacity (WMC). Additionally, the method of assessing the initial WMC level we present in this article has proven to be an effective tool in distinguishing between people who will and will not be successful during subsequent working memory training. We have previously described and published results from this study44. Therefore, in this article we are focusing on a detailed description of the protocol we used.

<table border="0" cellpadding="0" cellspacing="0" style="width:976px;" width="976">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">GEx</td>
			<td style="width:121px;">n/a</td>
			<td style="width:289px;">authorial online platform: 
			used for N-back training, Quiz</td>
			<td style="width:349px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">IBM SPSS Statistics 26.0</td>
			<td style="width:121px;">IBM Corporation</td>
			<td style="width:289px;">SPSS software was used to compute statistical analysis.</td>
			<td style="width:349px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Inquisit version 4.0.8.0</td>
			<td style="width:121px;">Millisecond Software</td>
			<td style="width:289px;">software: tool for designing and administering experiments 
			used for: The Sternberg Task, The Linear Syllogism Task and presenting the instructions for baseline EEG recording</td>
			<td style="width:349px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">MATLAB R2018b</td>
			<td style="width:121px;">The MathWorks, Inc</td>
			<td style="width:289px;">MATLAB software was used to compute statistics and to export databases and&#160; visualisation of the results</td>
			<td style="width:349px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PsychoPy version 2 v.1.83.04</td>
			<td style="width:121px;">Jonathan Peirce; supported by University of Nottingham</td>
			<td style="width:289px;">open-source software 
			used for: Go/no Go Task, The Switching Task, Running Memory Span Taskckage based on Python</td>
			<td style="width:349px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sublime Text (version 2.0.2)</td>
			<td style="width:121px;">n/a</td>
			<td style="width:289px;">open-source software: HTML editor 
			used for: online OSPAN Task</td>
			<td style="width:349px;"></td>
		</tr>
	</tbody>
</table>

working memory training for older participants: a control group training regimen and initial intellectual functioning assessment

The efficacy of cognitive training interventions is recently highly debated. There is no consensus on what kind of training regimen is the most effective. Also, individual characteristics as predictors of training outcome are still being investigated. In this article, we show the attempt to address this issue by examining not only the impact of working memory (WM) training on cognitive effectiveness in older adults but also the influence of the initial WM capacity (WMC) on the training&#39;s outcome. We describe in detail how to perform 5 weeks of an adaptive dual n-back training with an active control group (memory quiz). We are focusing here on technical aspects of the training as well as on the initial assessment of participants&#39; WMC. The evaluation of pre and post training performance of other cognitive dimensions was based on the results of tests of memory updating, inhibition, attention shifting, short-term memory (STM) and reasoning. We have found that the initial level of WMC predicts the efficiency of the n-back training intervention. We have also noticed the post training improvement in almost all aspects of cognitive functioning we measured, but those effects were mostly intervention independent.

Training-related effects
85 subjects participated in the study (29 were male) and they were on average 66.7 years old. Due to technical problems, data from one participant in the n-back training group was not recorded. Finally, the data from 43 participants in n-back training group and 42 in Quiz training group were analyzed. Multivariate analysis of variance (MANOVA) with repeated measures was used to analyze training specific effects for both training groups over time (pre-, post-training). The results of each cognitive test were dependent variables (Table 1), and training group and measurement points (pre- versus post-training) were independent variables. These results are presented in Table 2.
The results of the analysis indicated a statistically significant post-training improvement in the syllogisms task: (F(1,83)=31,22, p&#60;0.001, &#951;p2=0.27) and attention switching task: (F(1,83)= 5.79, p=0.02, &#951;p2=0.07). A significant training group effect was observed for memory SPAN task (F(1,83)=7.72, p=0.01, &#951;p2=0.09) and OSPAN task (F(1,83)=13.01, p=0.01, &#951;p2=0.14). None of the interaction effects (time x training group) has proven to be statistically significant. However, we found significant within group effects for some analysis. In the OSPAN task, the n-back training group improved their results in second session), while for the quiz group, both performances were similar. This effect needs to be interpreted in reference to the fact that the quiz and the n-back group differed in the first measurement. Thus, results of the n-back group where initial OSPAN performance was higher improved, while the control group did not. The performance in Sternberg&#39;s and a go/no-go task was not related to a training group assignment or the time of measurement.
Overall, the results show that participants&#39; cognitive performance was improved in the post-training execution of attention and higher cognitive functions (reasoning) engaging tests, regardless of the group affiliation.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td colspan="2"></td>
			<td colspan="4">N-back training</td>
			<td colspan="4">Quiz training</td>
		</tr>
		<tr>
			<td rowspan="2"></td>
			<td rowspan="2">session</td>
			<td rowspan="2">N</td>
			<td rowspan="2">Mean</td>
			<td>Std.</td>
			<td>Std.</td>
			<td rowspan="2">N</td>
			<td rowspan="2">Mean</td>
			<td>Std.</td>
			<td>Std.</td>
		</tr>
		<tr>
			<td>Err</td>
			<td>Dev.</td>
			<td>Err</td>
			<td>Dev.</td>
		</tr>
		<tr>
			<td>OSPAN</td>
			<td>1</td>
			<td>42</td>
			<td>15.31</td>
			<td>1.64</td>
			<td>10.62</td>
			<td>40</td>
			<td>9.07</td>
			<td>1.77</td>
			<td>11.22</td>
		</tr>
		<tr>
			<td>task</td>
			<td>2</td>
			<td>43</td>
			<td>20.74</td>
			<td>2.48</td>
			<td>16.3</td>
			<td>40</td>
			<td>10</td>
			<td>1.81</td>
			<td>11.45</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">Syllogisms task</td>
			<td>1</td>
			<td>43</td>
			<td>0.59</td>
			<td>0.03</td>
			<td>0.2</td>
			<td>42</td>
			<td>0.58</td>
			<td>0.03</td>
			<td>0.21</td>
		</tr>
		<tr>
			<td>2</td>
			<td>43</td>
			<td>0.67</td>
			<td>0.03</td>
			<td>0.21</td>
			<td>42</td>
			<td>0.69</td>
			<td>0.03</td>
			<td>0.19</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">Memory SPAN task</td>
			<td>1</td>
			<td>42</td>
			<td>0.37</td>
			<td>0.03</td>
			<td>0.16</td>
			<td>42</td>
			<td>0.2</td>
			<td>0.02</td>
			<td>0.16</td>
		</tr>
		<tr>
			<td>2</td>
			<td>41</td>
			<td>0.4</td>
			<td>0.03</td>
			<td>0.18</td>
			<td>42</td>
			<td>0.22</td>
			<td>0.03</td>
			<td>0.18</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">Go/no-go task</td>
			<td>1</td>
			<td>42</td>
			<td>0.14</td>
			<td>0.05</td>
			<td>0.33</td>
			<td>42</td>
			<td>0.16</td>
			<td>0.03</td>
			<td>0.01</td>
		</tr>
		<tr>
			<td>2</td>
			<td>42</td>
			<td>0.17</td>
			<td>0.03</td>
			<td>0.18</td>
			<td>42</td>
			<td>0.04</td>
			<td>0.05</td>
			<td>0.12</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">Sternberg&#8217;s task</td>
			<td>1</td>
			<td>43</td>
			<td>0.93</td>
			<td>0.02</td>
			<td>0.11</td>
			<td>42</td>
			<td>0.9</td>
			<td>0.02</td>
			<td>0.15</td>
		</tr>
		<tr>
			<td>2</td>
			<td>43</td>
			<td>0.94</td>
			<td>0.01</td>
			<td>0.05</td>
			<td>42</td>
			<td>0.93</td>
			<td>0.01</td>
			<td>0.07</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">Attention switching task</td>
			<td>1</td>
			<td>42</td>
			<td>0.49</td>
			<td>0.04</td>
			<td>0.28</td>
			<td>41</td>
			<td>0.52</td>
			<td>0.05</td>
			<td>0.3</td>
		</tr>
		<tr>
			<td>2</td>
			<td>42</td>
			<td>0.41</td>
			<td>0.04</td>
			<td>0.23</td>
			<td>42</td>
			<td>0.46</td>
			<td>0.04</td>
			<td>0.25</td>
		</tr>
	</tbody>
</table>
Table 1. Descriptive statistics for the cognitive tasks&#39; results.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td></td>
			<td colspan="3" rowspan="2">Pre- to post-training effect</td>
			<td colspan="3" rowspan="2">Training group effect</td>
			<td colspan="4" rowspan="2">Interaction effect 
			&#160;(time x training group)</td>
		</tr>
		<tr>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td>F (1,83)</td>
			<td>&#951;p2&#160;</td>
			<td>p</td>
			<td>F (1,83)</td>
			<td>&#951;p2&#160;</td>
			<td>p</td>
			<td>F (1,83)</td>
			<td>&#951;p2&#160;</td>
			<td>p</td>
			<td>significant within-group effects:</td>
		</tr>
		<tr>
			<td>OSPAN Task</td>
			<td>3.67</td>
			<td>0.04</td>
			<td>0.06</td>
			<td>13.01*</td>
			<td>0.14</td>
			<td>0.01</td>
			<td>1.49</td>
			<td>0.19</td>
			<td>0.22</td>
			<td>Nback (T1 vs.T2): 5,00*</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Syllogisms Task</td>
			<td>31,22*</td>
			<td>0.27</td>
			<td>0</td>
			<td>0.01</td>
			<td>0</td>
			<td>0.95</td>
			<td>0.35</td>
			<td>0.01</td>
			<td>0.56</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Memory SPAN Task</td>
			<td>3.13</td>
			<td>0.04</td>
			<td>0.08</td>
			<td>7,72*</td>
			<td>0.09</td>
			<td>0.01</td>
			<td>0.04</td>
			<td>&#60; .001</td>
			<td>0.85</td>
			<td>T1 (N-back vs. Quiz): 0,09*</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td>T2 (N-back vs. Quiz): 0,10*</td>
		</tr>
		<tr>
			<td>Sternberg&#8217;s Task</td>
			<td>3.56</td>
			<td>0.04</td>
			<td>0.06</td>
			<td>0.78</td>
			<td>0.01</td>
			<td>0.38</td>
			<td>0.62</td>
			<td>0.01</td>
			<td>0.43</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td rowspan="2">Attention Switching Task</td>
			<td>5,79*</td>
			<td>0.07</td>
			<td>0.02</td>
			<td>0.75</td>
			<td>0.01</td>
			<td>0.39</td>
			<td>0.02</td>
			<td>&#60; .001</td>
			<td>0.87</td>
			<td>Nback (T1 vs.T2): -0,08</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Go/no-go Task</td>
			<td>0.01</td>
			<td>&#60; .001</td>
			<td>0.93</td>
			<td>0.21</td>
			<td>0.01</td>
			<td>0.65</td>
			<td>2.82</td>
			<td>0.03</td>
			<td>0.09</td>
			<td>T1 (N-back vs. Quiz): -0,01</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td>T2 (N-back vs. Quiz): -0,02</td>
		</tr>
		<tr>
			<td colspan="3">* statistically significant effect (p &#60; .05)</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">T1 vs. T2 -&#160; difference in means between 1st and 2nd session;</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">N-back vs. Quiz - difference in means between training groups;</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>
Table 2. Outcome measures: main and interaction effects from MANOVA with training type (n-back vs. Quiz) and time (pre vs post training) as factors.
WMC as a predictor of WM training effectiveness 
In a subsequent analysis, performed on the n-back training group only, we used a more refined method - multilevel modeling (MLM) - to observe the learning process during the experimental training. The hierarchical structure of the data was accommodate to the model: at level 1 - repeated measurements, nested within participants (level 2)34. The MLM dataset consisted of 1,050 observations gathered from 42 participants from experimental group within each of 25 training sessions. The model provided for both fixed and random effects: the regression intercept and slope for the average person, and between-subject variability around the average. In the Model 1, the change in the number of points scored in the n-back task over time (number of the training sessions) was modeled. The time variable was centered at 1st day of the intervention. Compared to Model 1, Model 2 added on predicting and moderating effects of a baseline OSPAN score (between-subjects predictor - level 2) on within-subject variability (level 1). Those predictors were tested independently to avoid multicollinearity. In all models, a linear and quadratic effects for the slope were tested, however the quadratic one was subsequently removed because its fixed effects and variance components were not significant. The restricted maximum likelihood served as the estimator. -2 Restricted log likelihood ratio (-2LL) and the Akaike Information Criterion (AIC) were used to assess the goodness of fit for all models. Given the common proximal autocorrelation in the daily data35 we decided to base on a first-order autoregressive [AR(1)] covariance structure.
MLM results showed that OSPAN scores from the pre-training measurement were a significant predictor of the first n-back outcome from the 1 session. Baseline OSPAN level turned out to be a moderator of the whole training course (Table 2). When compared, groups of participants with high or low OSPAN points had similar N-level at the first training session: approx. 2.00 units on a 1+&#8734; scale (low OSPAN = 1.93; high OSPAN = 2.31). A significant difference manifested in the post-training measurement, when the participants with low initial OSPAN results achieved a .01 unit increase in n-back task, whereas those with the high initial OSPAN scores recorded a .04 point improvement. The observed result clearly indicates the existence of a positive association between the initial OSPAN level and training effectiveness. The n-back scores in the 1st session and a learning curve of a training are higher and stepper for the participants with initially higher OSPAN result (p &#60; .001).
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Time - linear</td>
			<td>.031</td>
			<td>(.005)***</td>
			<td></td>
			<td>.016</td>
			<td>(.007)*</td>
		</tr>
		<tr>
			<td>&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; (centered at 1st day)</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Initial OSPAN score</td>
			<td>---</td>
			<td>---</td>
			<td></td>
			<td>.038</td>
			<td>(.183)*</td>
		</tr>
		<tr>
			<td>&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; ~ (high / low)</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Time &#215; Initial OSPAN score</td>
			<td>---</td>
			<td>---</td>
			<td></td>
			<td>.026</td>
			<td>(.008)**</td>
		</tr>
		<tr>
			<td>Random effects 
			([co-]variances)</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Level 2 (between-person)</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;&#160;&#160;&#160; Intercept</td>
			<td>.285</td>
			<td>(.073)***</td>
			<td></td>
			<td>.286</td>
			<td>(.075)***</td>
		</tr>
		<tr>
			<td>&#160;&#160;&#160;&#160; Time - linear</td>
			<td>.001</td>
			<td>(.001)***</td>
			<td></td>
			<td>.001</td>
			<td>(.001)***</td>
		</tr>
		<tr>
			<td>&#160;Intercept and time</td>
			<td>.006</td>
			<td>(.003)*</td>
			<td></td>
			<td>.004</td>
			<td>(.002) &#176;</td>
		</tr>
		<tr>
			<td>Level 1 (within-person)</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Residual</td>
			<td>.151</td>
			<td>(.009)***</td>
			<td></td>
			<td>.149</td>
			<td>(.009)***</td>
		</tr>
		<tr>
			<td>&#160;Autocorrelation</td>
			<td>.339</td>
			<td>(.039)***</td>
			<td></td>
			<td>.328</td>
			<td>(.040)***</td>
		</tr>
		<tr>
			<td>Model fit</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;&#160;&#160; &#8722;2 log likelihood (&#967;2)</td>
			<td>1069.32</td>
			<td></td>
			<td></td>
			<td>1046.37</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;&#160;&#160; Akaike&#8217;s Information 
			&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Criterion (AIC)</td>
			<td>1083.32</td>
			<td></td>
			<td></td>
			<td>1056.37</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td colspan="6">Results from multilevel modeling. Unstandardized regression coefficients&#160; with standard errors in parenthesis.</td>
		</tr>
		<tr>
			<td colspan="3">&#176;p=0.1, *p&#60;.05, **p&#60;.01, ***p&#60;.001; All p-values are two-tailed</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>~ the predictor is dichotomous</td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>
Table 3. Multilevel analysis of the training data (n-back task performance as a dependent variable). Models with training sessions (time) only (MODEL 1) and training sessions plus initial working memory capacity level as a predictor and a moderator, respectively (MODEL 2).

Watch this Scientific Journal Video about Working Memory Training for Older Participants: A Control Group Training Regimen and Initial Intellectual Functioning Assessment at JoVE.com

Working Memory Training for Older Participants: A Control Group Training Regimen and Initial Intellectual Functioning Assessment

A cognitive training intervention in elderly population together with the assessment of the pre training cognitive abilities is presented. We show two versions of training - experimental and active control - and demonstrate their effects on the array of cognitive tests.

The efficacy of cognitive training interventions is recently highly debated. There is no consensus on what kind of training regimen is the most effective. ...

working-memory-training-for-older-participants-control-group-training

Nanyang Technological University

Research

JoVE Journal

Behavior

4.5K Views.  SWPS University of Social Sciences and Humanities. A cognitive training intervention in elderly population together with the assessment of the pre training cognitive abilities is presented. We show two versions of training - experimental and active control - and demonstrate their effects on the array of cognitive tests.

Video: Working Memory Training for Older Participants: A Control Group Training Regimen and Initial Intellectual Functioning Assessment

Training Synesthetic Letter-color Associations by Reading in Color

Synesthesia is a rare condition in which a stimulus from one modality automatically and consistently triggers unusual sensations in the same and/or other modalities. A relatively common and well-studied type is grapheme-color synesthesia, defined as the consistent experience of color when viewing, hearing and thinking about letters, words and numbers. We describe our method for investigating to what extent synesthetic associations between letters and colors can be learned by reading in color in nonsynesthetes. Reading in color is a special method for training associations in the sense that the associations are learned implicitly while the reader reads text as he or she normally would and it does not require explicit computer-directed training methods. In this protocol, participants are given specially prepared books to read in which four high-frequency letters are paired with four high-frequency colors. Participants receive unique sets of letter-color pairs based on their pre-existing preferences for colored letters. A modified Stroop task is administered before and after reading in order to test for learned letter-color associations and changes in brain activation. In addition to objective testing, a reading experience questionnaire is administered that is designed to probe for differences in subjective experience. A subset of questions may predict how well an individual learned the associations from reading in color. Importantly, we are not claiming that this method will cause each individual to develop grapheme-color synesthesia, only that it is possible for certain individuals to form letter-color associations by reading in color and these associations are similar in some aspects to those seen in developmental grapheme-color synesthetes. The method is quite flexible and can be used to investigate different aspects and outcomes of training synesthetic associations, including learning-induced changes in brain function and structure.

Reading in color is a new method for training letter-color associations that are typically found only in grapheme-color synesthetes. It involves an implicit form of training that has potential for long-term associative training methods&#160;because the training is a byproduct of reading and any text can be colored.

Synesthesia is a rare condition in which a stimulus from one modality automatically and consistently triggers unusual sensations in the same and/or other ...

A Cognitive Paradigm to Investigate Interference in Working Memory by Distractions and Interruptions

Goal-directed behavior is often impaired by interference from the external environment, either in the form of distraction by irrelevant information that one attempts to ignore, or by interrupting information that demands attention as part of another (secondary) task goal. Both forms of external interference have been shown to detrimentally impact the ability to maintain information in working memory (WM). Emerging evidence suggests that these different types of external interference exert different effects on behavior and may be mediated by distinct neural mechanisms. Better characterizing the distinct neuro-behavioral impact of irrelevant distractions versus attended interruptions is essential for advancing an understanding of top-down attention, resolution of external interference, and how these abilities become degraded in healthy aging and in neuropsychiatric conditions. This manuscript describes a novel cognitive paradigm developed the Gazzaley lab that has now been modified into several distinct versions used to elucidate behavioral and neural correlates of interference, by to-be-ignored distractors versus to-be-attended interruptors. Details are provided on variants of this paradigm for investigating interference in visual and auditory modalities, at multiple levels of stimulus complexity, and with experimental timing optimized for electroencephalography (EEG) or functional magnetic resonance imaging (fMRI) studies. In addition, data from younger and older adult participants obtained using this paradigm is reviewed and discussed in the context of its relationship with the broader literatures on external interference and age-related neuro-behavioral changes in resolving interference in working memory.

A novel cognitive paradigm is developed to elucidate behavioral and neural correlates of interference by to-be-ignored distractors versus interference by to-be-attended interruptors during a working memory task. In this manuscript, several variants of this paradigm are detailed, and data obtained with this paradigm in younger/older adult participants is reviewed.

Goal-directed behavior is often impaired by interference from the external environment, either in the form of distraction by irrelevant information that ...

Vision Training Methods for Sports Concussion Mitigation and Management

There is emerging evidence supporting the use vision training, including light board training tools, as a concussion baseline and neuro-diagnostic tool and potentially as a supportive component to concussion prevention strategies. This paper is focused on providing detailed methods for select vision training tools and reporting normative data for comparison when vision training is a part of a sports management program. The overall program includes standard vision training methods including tachistoscope, Brock&#8217;s string, and strobe glasses, as well as specialized light board training algorithms. Stereopsis is measured as a means to monitor vision training affects. In addition, quantitative results for vision training methods as well as baseline and post-testing *A and Reaction Test measures with progressive scores are reported. Collegiate athletes consistently improve after six weeks of training in their stereopsis, *A and Reaction Test scores. When vision training is initiated as a team wide exercise, the incidence of concussion decreases in players who participate in training compared to players who do not receive the vision training. Vision training produces functional and performance changes that, when monitored, can be used to assess the success of the vision training and can be initiated as part of a sports medical intervention for concussion prevention.

This paper describes a protocol to conduct, quantitatively monitor, and assess the success of vision training initiated as part of a sports medical management program including intervention for concussion prevention and performance enhancement.

There is emerging evidence supporting the use vision training, including light board training tools, as a concussion baseline and neuro-diagnostic tool ...

Combined Shuttle-Box Training with Electrophysiological Cortex Recording and Stimulation as a Tool to Study Perception and Learning

Shuttle-box avoidance learning is a well-established method in behavioral neuroscience and experimental setups were traditionally custom-made; the necessary equipment is now available by several commercial companies. This protocol provides a detailed description of a two-way shuttle-box avoidance learning paradigm in rodents (here Mongolian gerbils; Meriones unguiculatus) in combination with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical electrophysiological in vivo recordings. The detailed protocol is applicable to study multiple aspects of learning behavior and perception in different rodent species.
Site-specific ICMS of auditory cortical circuits as conditioned stimuli here is used as a tool to test the perceptual relevance of specific afferent, efferent and intracortical connections. Distinct activation patterns can be evoked by using different stimulation electrode arrays for local, layer-dependent ICMS or distant ICMS sites. Utilizing behavioral signal detection analysis it can be determined which stimulation strategy is most effective for eliciting a behaviorally detectable and salient signal. Further, parallel multichannel-recordings using different electrode designs (surface electrodes, depth electrodes, etc.) allow for investigating neuronal observables over the time course of such learning processes. It will be discussed how changes of the behavioral design can increase the cognitive complexity (e.g. detection, discrimination, reversal learning).

Shuttle-box avoidance learning is well-established in behavioral neuroscience. This protocol describes how shuttle-box learning in rodents can be combined with site-specific electrical intracortical microstimulation (ICMS) and simultaneous chronical in vivo recordings as a tool to study multiple aspects of learning and perception.

Shuttle-box avoidance learning is a well-established method in behavioral neuroscience and experimental setups were traditionally custom-made; the ...

Pavlovian Conditioned Approach Training in Rats

Cues that are contingently paired with unconditioned, rewarding stimuli can acquire rewarding properties themselves through a process known as the attribution of incentive salience, or the transformation of neutral stimuli into attractive, &#34;wanted&#39; stimuli capable of motivating behavior. Pavlovian conditioned approach (PCA) develops after the response-independent presentation of a conditioned stimulus (CS; e.g., a lever) that predicts the delivery of an unconditioned stimulus (US; e.g., a food pellet) and can be used to measure incentive salience. During training, three patterns of conditioned responses (CRs) can develop: sign-tracking behavior (CS-directed CR), goal-tracking behavior (US-directed CR), and an intermediate response (both CRs). Sign-trackers attribute incentive salience to reward-related cues and are more vulnerable to cue-induced reinstatement of drug-seeking as well as other addiction-related behaviors, making PCA a potentially valuable procedure for studying addiction vulnerability. Here, we describe materials and methods used to elicit PCA behavior from rats as well as analyze and interpret PCA behavior in individual experiments.

Here, we present a protocol to elicit Pavlovian conditioned approach behavior in rats. This procedure can be used to measure individual differences in the tendency to approach and attribute incentive salience to reward-related cues and investigate addiction vulnerability.

Cues that are contingently paired with unconditioned, rewarding stimuli can acquire rewarding properties themselves through a process known as the ...

An Innovative Running Wheel-based Mechanism for Improved Rat Training Performance

This study presents an animal mobility system, equipped with a positioning running wheel (PRW), as a way to quantify the efficacy of an exercise activity for reducing the severity of the effects of the stroke&#160;in rats. This system provides more effective animal exercise training than commercially available systems such as treadmills and motorized running wheels (MRWs). In contrast to an MRW that can only achieve speeds below 20 m/min, rats are permitted to run at a stable speed of 30 m/min on a more spacious and high-density rubber running track supported by a 15 cm wide acrylic wheel with a diameter of 55 cm in this work. Using a predefined adaptive acceleration curve, the system not only reduces the operator error but also trains the rats to run persistently until a specified intensity is reached. As a way to evaluate the exercise effectiveness, real-time position of a rat is detected by four pairs of infrared sensors deployed on the running wheel. Once an adaptive acceleration curve is initiated using a microcontroller, the data obtained by the infrared sensors are automatically recorded and analyzed in a computer. For comparison purposes, 3 week training is conducted on rats using a treadmill, an MRW and a PRW. After surgically inducing middle cerebral artery occlusion (MCAo), modified neurological severity scores (mNSS) and an inclined plane test were conducted to assess the neurological damages to the rats. PRW is experimentally validated as the most effective among such animal mobility systems. Furthermore, an exercise effectiveness measure, based on rat position analysis, showed that there is a high negative correlation between the effective exercise and the infarct volume, and can be employed to quantify a rat training in any type of brain damage reduction&#160;experiments.

This study presents an innovative running wheel-based animal mobility system to quantify an effective exercise activity in rats. A rat-friendly testbed is built, using a predefined adaptive acceleration curve, and a high correlation between the effective exercise rate and the infarct volume suggests the protocol&#39;s potential for stroke prevention experiments.

This study presents an animal mobility system, equipped with a positioning running wheel (PRW), as a way to quantify the efficacy of an exercise activity ...

Assessing Working Memory in Children: The Comprehensive Assessment Battery for Children &#8211; Working Memory (CABC-WM)

The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of working memory in young school-age children. Working memory deficits have been identified in children with language-based learning disabilities, including dyslexia1,2 and language impairment3,4, but it is not clear whether these children exhibit deficits in subcomponents of working memory, such as visuospatial or phonological working memory. The CABC-WM is administered on a desktop computer with a touchscreen interface and was specifically developed to be engaging and motivating for children. Although the long-term goal of the CABC-WM is to provide individualized working memory profiles in children, the present study focuses on the initial success and utility of the CABC-WM for measuring central executive, visuospatial, phonological loop, and binding constructs in children with typical development. Immediate next steps are to administer the CABC-WM to children with specific language impairment, dyslexia, and comorbid specific language impairment and dyslexia.

Working memory predicts a significant amount of variance for a variety of cognitive tasks, including speaking, reading, and writing. However, few tools are available to assess working memory in children. We present an innovative, computer-based battery that comprehensively assesses different components of working memory in school-age children.

The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of ...

Introducing Clicker Training as a Cognitive Enrichment for Laboratory Mice

Establishing new refinement strategies in laboratory animal science is a central goal in fulfilling the requirements of Directive 2010/63/EU. Previous research determined a profound impact of gentle handling protocols on the well-being of laboratory mice. By introducing clicker training to the keeping of mice, not only do we promote the amicable treatment of mice, but we also enable them to experience cognitive enrichment. Clicker training is a form of positive reinforcement training using a conditioned secondary reinforcer, the "click" sound of a clicker, which serves as a time bridge between the strengthened behavior and an upcoming reward. The effective implementation of the clicker training protocol with a cohort of 12 BALB/c inbred mice of each sex proved to be uncomplicated. The mice learned rather quickly when challenged with tasks of the clicker training protocol, and almost all trained mice overcame the challenges they were given (100% of female mice and 83% of male mice). This study has identified that clicker training for mice strongly correlates with reduced fear in the mice during human-mice interactions, as shown by reduced anxiety-related behaviors (e.g., defecation, vocalization, and urination) and fewer depression-like behaviors (e.g., floating). By developing a reliable protocol that can be easily integrated into the daily routine of the keeping of laboratory mice, the lifetime experience of welfare in the mice can be improved substantially.

The development of new refinement strategies for laboratory mice is a challenging task that contributes towards fulfilling the 3R principle. This protocol introduces clicker training as a cognitive enrichment program for laboratory mice.

Establishing new refinement strategies in laboratory animal science is a central goal in fulfilling the requirements of Directive 2010/63/EU. Previous ...

Reducing State Anxiety Using Working Memory Maintenance

The purpose of this protocol is to explain how to examine the relationship between working memory processes and anxiety by combining the Sternberg Working Memory (WM) and the threat of shock paradigms. In the Sternberg WM paradigm, subjects are required to maintain a series of letters in the WM for a brief interval and respond by identifying whether the position of a given letter in the series matches a numerical prompt. In the threat of shock paradigm, subjects are exposed to alternating blocks where they are either at risk of receiving unpredictable presentations of a mild electric shock or are safe from the shock. Anxiety is probed throughout the safe and threat blocks using the acoustic startle reflex, which is potentiated under threat (Anxiety-Potentiated Startle (APS)). By conducting the Sternberg WM paradigm during the threat of shock and probing the startle response during either the WM maintenance interval or the intertrial interval, it is possible to determine the effect of WM maintenance on APS.

This protocol demonstrates how to measure anxiety-potentiated startle during the Sternberg Working Memory paradigm.

The purpose of this protocol is to explain how to examine the relationship between working memory processes and anxiety by combining the Sternberg Working ...

Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury

Skeletal muscle atrophy, increased adiposity and reduced physical activity are key changes observed after spinal cord injury (SCI) and are associated with numerous cardiometabolic health consequences. These changes are likely to increase the risk of developing chronic secondary conditions and impact the quality of life in persons with SCI. Surface neuromuscular electrical stimulation evoked resistance training (NMES-RT) was developed as a strategy to attenuate the process of skeletal muscle atrophy, decrease ectopic adiposity, improve insulin sensitivity and enhance mitochondrial capacity. However, NMES-RT is limited to only a single muscle group. Involving multiple muscle groups of the lower extremities may maximize the health benefits of training. Functional electrical stimulation-lower extremity cycling (FES-LEC) allows for the activation of 6 muscle groups, which is likely to evoke greater metabolic and cardiovascular adaptation. Appropriate knowledge of the stimulation parameters is key to maximizing the outcomes of electrical stimulation training in persons with SCI. Adopting strategies for long-term use of NMES-RT and FES-LEC during rehabilitation may maintain the integrity of the musculoskeletal system, a pre-requisite for clinical trials aiming to restore walking after injury. The current manuscript presents a combined protocol using NMES-RT prior to FES-LEC. We hypothesize that muscles conditioned for 12 weeks prior to cycling will be capable of generating greater power, cycle against higher resistance and result in greater adaptation in persons with SCI.

Spinal cord injury is a traumatic medical condition that may result in elevated risks of chronic secondary metabolic disorders. Here, we presented a protocol using surface neuromuscular electrical stimulation-resistance training in conjunction with functional electrical stimulation-lower extremities cycling as a strategy to ameliorate several of these medical problems.

Skeletal muscle atrophy, increased adiposity and reduced physical activity are key changes observed after spinal cord injury (SCI) and are associated with ...