Abstract
Scholars have extensively studied the electroencephalography (EEG) correlates of associative working memory (WM) load. However, the effect of stimulus modality on EEG patterns within this process is less understood. To fill this research gap, the present study re-analyzed EEG datasets recorded during visual and audiovisual equivalence learning tasks from earlier studies. The number of associations required to be maintained (WM load) in WM was increased using the staircase method during the acquisition phase of the tasks. The support vector machine algorithm was employed to predict WM load and stimulus modality using the power, phase connectivity, and cross-frequency coupling (CFC) values obtained during time segments with different WM loads in the visual and audiovisual tasks. A high accuracy (>90%) in predicting stimulus modality based on power spectral density and from the theta–beta CFC was observed. However, accuracy in predicting WM load was higher (≥75% accuracy) than that in predicting stimulus modality (which was at chance level) using theta and alpha phase connectivity. Under low WM load conditions, this connectivity was highest between the frontal and parieto-occipital channels. The results validated our findings from earlier studies that dissociated stimulus modality based on power-spectra and CFC during equivalence learning. Furthermore, the results emphasized the importance of alpha and theta frontoparietal connectivity in WM load.
Highlights
Working memory (WM) is a cognitive process that enables the retention of information ‘‘in the mind’’ after the physical stimuli that introduced it is no longer available (Atkinson and Shiffrin, 1968; Baddeley, 1992)
As all prediction accuracies were significantly different from the chance level, this section reports the results of a one-way analysis of variance (ANOVA) test, i.e., if the prediction accuracies were significantly different across frequency bands
The study found that prediction accuracy was highest in the power spectra of the theta frequency band if the intention is to simultaneously predict stimulus modality and working memory (WM) load
Summary
Working memory (WM) is a cognitive process that enables the retention of information ‘‘in the mind’’ after the physical stimuli that introduced it is no longer available (Atkinson and Shiffrin, 1968; Baddeley, 1992). Activities in these areas increase during WM tasks. The ventral PFC is engaged in lower WM load (Paulesu et al, 1993; Awh et al, 1996); dorsal PFC activations occur with increased WM load, typically in a bilateral manner. Functional neuroimaging studies have revealed that default mode network activity is decreased during WM tasks (Esposito et al, 2009), and such a decrease is correlated with WM load (Medendorp et al, 2011)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.