UZH-Logo

Maintenance Infos

Frontal midline theta reflects individual task Performance in a working memory task


Maurer, Urs; Brem, Silvia; Liechti, Martina; Maurizio, Stefano; Michels, Lars; Brandeis, Daniel (2015). Frontal midline theta reflects individual task Performance in a working memory task. Brain Topography, 28(1):127-134.

Abstract

Frontal midline (fm-)theta activity has been related to working memory (WM) processes, as it typically increases with WM load. The robustness of this effect, however, varies across studies and subjects, putting limits to its interpretation. We hypothesized that variation in the fm-theta effect may reflect individual differences in task difficulty with increasing WM load as indicated by behavioural responses. We further tested whether effects in the alpha range are robust markers of WM load. We recorded 64-channel EEG from 24 healthy adults while they memorized either 2 or 4 unfamiliar symbols (low vs. high WM load) in a modified Sternberg task. The last 2 s of the retention phase were analyzed for WM load-related changes in the theta (5-7 Hz) and alpha range (lower: 8-10 Hz, upper: 10.5-12.5 Hz). Higher WM load led to less accurate and slower responses. The increase of fm-theta with WM load was most pronounced at fm electrodes, localized to anterior cingulate regions, and correlated with the participants' decrease in accuracy due to higher WM load. Alpha peak frequency increased in the high compared to the low WM load condition, corresponding to a decrease in lower alpha range across all channels. The results demonstrate that previously reported variation in fm-theta workload effects can partly be explained by variation in task difficulty indexed by individual task accuracy. Moreover, the results also demonstrate that alpha WM load effects are prominent when separating upper and lower alpha.

Frontal midline (fm-)theta activity has been related to working memory (WM) processes, as it typically increases with WM load. The robustness of this effect, however, varies across studies and subjects, putting limits to its interpretation. We hypothesized that variation in the fm-theta effect may reflect individual differences in task difficulty with increasing WM load as indicated by behavioural responses. We further tested whether effects in the alpha range are robust markers of WM load. We recorded 64-channel EEG from 24 healthy adults while they memorized either 2 or 4 unfamiliar symbols (low vs. high WM load) in a modified Sternberg task. The last 2 s of the retention phase were analyzed for WM load-related changes in the theta (5-7 Hz) and alpha range (lower: 8-10 Hz, upper: 10.5-12.5 Hz). Higher WM load led to less accurate and slower responses. The increase of fm-theta with WM load was most pronounced at fm electrodes, localized to anterior cingulate regions, and correlated with the participants' decrease in accuracy due to higher WM load. Alpha peak frequency increased in the high compared to the low WM load condition, corresponding to a decrease in lower alpha range across all channels. The results demonstrate that previously reported variation in fm-theta workload effects can partly be explained by variation in task difficulty indexed by individual task accuracy. Moreover, the results also demonstrate that alpha WM load effects are prominent when separating upper and lower alpha.

Citations

8 citations in Web of Science®
3 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

58 downloads since deposited on 16 Apr 2014
48 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > University Children's Hospital Zurich > Medical Clinic
04 Faculty of Medicine > University Hospital Zurich > Clinic for Neuroradiology
04 Faculty of Medicine > Center for Child and Adolescent Psychiatry
04 Faculty of Medicine > Center for Integrative Human Physiology
06 Faculty of Arts > Institute of Psychology
Dewey Decimal Classification:570 Life sciences; biology
150 Psychology
610 Medicine & health
Date:2015
Deposited On:16 Apr 2014 13:17
Last Modified:05 Apr 2016 17:49
Publisher:Springer
ISSN:0896-0267
Additional Information:The final publication is available at link.springer.com.
Publisher DOI:https://doi.org/10.1007/s10548-014-0361-y
PubMed ID:24687327
Permanent URL: https://doi.org/10.5167/uzh-95201

Download

[img]
Preview
Content: Accepted Version
Language: English
Filetype: PDF
Size: 1MB
View at publisher

TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.

Author Collaborations