N‐back training and transfer effects revealed by behavioral responses and EEG

Abstract

IntroductionCognitive function performance decreases in older individuals compared to young adults. To curb this decline, cognitive training is applied, but it is not clear whether it improves only the trained task or also other cognitive functions. To investigate this, we considered an N‐back working memory (WM) training task and verified whether it improves both trained WM and untrained cognitive functions.MethodsAs EEG studies have noted task difficulty and age‐related changes in time‐locked EEG responses, called event‐related potentials (ERPs), we focused on the relation between the P300 ERP component, task difficulty level, and behavior response accuracy and reaction time (RT) in young and older healthy adults. We used two groups of young and older healthy participants to assess the effect of N‐back training: cognitive training group (CTG) and passive control group (PCG). Before and after training, cognitive tests were administered to both groups to evaluate transfer effects.ResultsDespite the observed age‐related differences in the P300 ERP component and in terms of RT and accuracy, our findings demonstrate a stronger improvement in the trained task for older CTGs compared to younger CTGs, larger near‐ and far‐transfer effect to WM and fluid intelligence for both younger and older CTGs, and a far‐transfer effect to attention but only for older adults. Significant differences in response accuracy were shown between young and older subjects in spatial memory and attention tests.ConclusionThe application of a WM training is a promising tool for both healthy adults, and in particular for older subjects, as it showed physiological and behavioral differences in cognitive plasticity across life span and evidence of benefits in the trained task and near‐/far‐transfer effects to other cognitive functions.

Working memory updating training modulates a cascade of event-related potentials depending on task load

“…As in previous studies (Oelhafen et al 2013, Pergher et al 2018, we observed P3 amplitude increase in the WM training group. However, while Oelhafen et al (2013) and Pergher et al (2018) reported this effect also in a difficult WM task, we observed P3 increase only in the easier 1-back task.…”

“…As in previous studies (Oelhafen et al 2013, Pergher et al 2018, we observed P3 amplitude increase in the WM training group. However, while Oelhafen et al (2013) and Pergher et al (2018) reported this effect also in a difficult WM task, we observed P3 increase only in the easier 1-back task. Nevertheless, we would like to note that direct comparison between our results and those of previous studies should not be made because the analyses were not similar (e.g., we conducted direct comparisons between pre and post targets, while Pergher et al 2018 analyzed training effects for target vs.…”

“…Our findings, suggesting that early and late ERPs are differentially affected by Training-related modulation of the P2-N2-P3 complex: In our study, training-induced changes were observed already 200-300 ms after the stimulus onset. Such modulations of early responses, especially N2 and P3 responses, have been observed also in prior studies using differential experimental approaches either in training or in measuring its effects (Shiran and Brezniz 2011, Oelhafen et al 2013, Liu et al 2017, Covey et al 2018, Pergher et al 2018, Covey et al 2019. We did observe a significant session × group interaction already at P2 latency, although when the groups were examined separately a pre-post comparison showed an effect only in the control group.…”

N-Back Related ERPs Depend on Stimulus Type, Task Structure, Pre-processing, and Lab Factors

“…1 Eight of these participants were included in N-Back training study conducted by Pergher et al (2018). They received a payment of 20 euros for participating in two experiments.…”

“…One of the commonly used techniques to probe WM is the N-Back task, a complex task that requires storage, maintenance, and manipulation of information (Chen et al, 2008 ; Jaeggi et al, 2008 ) as well as inhibitory and interference control (Oberauer, 2005 ; Kane et al, 2007 ). The N-Back task has been used in single-session behavioral (Jaeggi et al, 2010 ; Brouwer et al, 2012 ) and neurophysiological (Krause et al, 2000 ; Pesonen et al, 2007 ; Esposito et al, 2009 ; Scharinger et al, 2017 ) studies as well as in multi-session behavioral (Jaeggi et al, 2008 , 2014 ; Minear et al, 2016 ; Blacker et al, 2017 ) and neurophysiological (Chen and Mitra, 2009 ; Dong et al, 2015 ; Pergher et al, 2018 ) training studies, to name a few. Many N-Back studies focus on task difficulty at different N-levels, indicating lower ERP amplitudes for more difficult tasks (Brouwer et al, 2012 ; Herff et al, 2014 ; Scharinger et al, 2017 ; Pergher et al, 2019b ) and/or stimulus type , such as the use of spatial (for instance when the target stimulus occurs in different locations on the screen) vs. verbal (for instance when the presented stimulus is word or syllable) stimuli.…”