Activation of the Prefrontal Cortex in Working Memory and Interference Resolution Processes Assessed with Near-Infrared Spectroscopy

Abstract

Background/Aims: The present study investigated cortical correlates of top-down processes in visual-object working memory with multi-channel near-infrared spectroscopy. Methods: The activity of the prefrontal cortex (PFC) was investigated while performing an n-back task with sequentially presented task-relevant and task-irrelevant faces. The activation patterns in the PFC associated with working memory and interference resolution were examined in 20 healthy adults. Results: We found a bilateral enhancement of oxygenated haemoglobin in the lateral PFC for remembering relevant faces and in the right lateral PFC for ignoring irrelevant faces. Oxygenation for relevant and irrelevant faces did not differ significantly, indicating that memory pro- cesses and interference resolution were interdependent functions, which were subserved by comparable prefrontal regions. Conclusion: This supports the notion that the prefrontal activity during working memory tasks reflects not only maintenance processes but also attentional monitoring and selection processes.

Hemodynamic Changes in the Prefrontal Cortex during Digit Span Task: A Near-Infrared Spectroscopy Study

“…Therefore, digit span backward is associated with executive function working memory rather than transient working memory [26] . Many studies -including lesion studies, neuroimaging studies [27] , and NIRS studies [13,28,29] -have shown that the PFC plays a role in the executive function working memory. Thus, our results indicate that digit span backward is related to executive functioning, and consequently requires greater PFC activation as compared to the digit span forward task.…”

“…It is possible to use NIRS measurements to assess brain activation in the human cortex during cognitive tasks [7][8][9][10][11][12][13] . NIRS is a noninvasive technique with high time resolution.…”

The frontal cortex is activated during learning of endoscopic procedures

“…Atkeson et al [15] reported that movements are unskilled, highly feedback dependent, and require strong demands on attention during the early phase of motor learning. Activation of prefrontal areas is commonly reported to be involved in the sensorimotor association [16] and working memory [17] during the initial stages of explicit motor learning. Hatakenaka et al [18] also demonstrated that task-related increases in oxy-Hb levels in frontal regions actively change with acquisition of motor skills.…”

Load-dependent brain activation assessed by time-domain functional near-infrared spectroscopy during a working memory task with graded levels of difficulty

“…In particular, multichannel fNIRS can measure cortical activation during cognitive processing without interfering with task procedure; indeed, it has been successfully employed in protocols evaluating psychological and emotional pressure 22 and in pediatric studies. 23 Schreppel et al 24 investigated the effects of interference resolution processes on activation of the PFC in a WM task by means of fNIRS. Shibuya-Tayoshi et al 25 and Nakahachi et al 26 employed fNIRS devices to obtain a mapping of the activation of the PFC during the visuospatial WM Trail Making Test.…”