The impact of wearing a KN95 face mask on human brain function: evidence from resting state functional magnetic resonance imaging

Abstract

BackgroundFace masks are widely used in daily life because of the COVID-19 pandemic. The objective of this study was to explore the impact of wearing face masks on brain functions by using resting-state functional MRI (RS-fMRI).MethodsScanning data from 15 healthy subjects (46.20 ± 6.67 years) were collected in this study. Each subject underwent RS-fMRI scans under two comparative conditions, wearing a KN95 mask and natural breathing (no mask). The amplitude of low frequency fluctuation (ALFF) and functional connectivity under the two conditions were analyzed and then compared using the paired t-test.ResultsCompared with those of the no-mask condition, the ALFF activities when wearing masks were increased significantly in the right middle frontal gyrus, bilateral precuneus, right superior marginal gyrus, left inferior parietal gyrus, and left supplementary motor area and decreased significantly in the anterior cingulate gyrus, right fusiform gyrus, left superior temporal gyrus, bilateral lingual gyrus, and bilateral calcarine cortex (p < 0.05). Taking the posterior cingulate cortex area as a seed point, the correlations with the occipital cortex, prefrontal lobe, and motor sensory cortex were sensitive to wearing masks compared with not wearing masks (p < 0.05). Taking the medial prefrontal cortex region as a seed point, the functional connectivity with the bilateral temporal lobe, bilateral motor sensory cortex, and occipital lobe was influenced by wearing a KN95 mask (p < 0.05).ConclusionThis study demonstrated that wearing a KN95 face mask can cause short-term changes in human resting brain function. Both local neural activities and functional connectivity in brain regions were sensitive to mask wearing. However, the neural mechanism causing these changes and its impact on cognitive function still need further investigation.

Wearing a KN95/FFP2 facemask has no measureable effect on functional activity in a challenging working memory n-back task

“…More recently, Wu et al examined the amplitude of low frequency fluctuation (ALFF) and functional connectivity at rest in 15 middle-aged healthy subjects wearing a KN95 mask and natural breathing. In contrast to the previous observations, they reported significant increases and decreases of ALFF as well as significant alterations of functional connectivity of posterior cingulate and medial prefrontal areas when wearing masks ( Wu et al, 2023 ). These first fMRI studies in this field were performed with no or no significant cognitive challenge so that it was not possible to comment on a possible deleterious effect of the facemask in highly demanding situations.…”

Advantages and disadvantages of maintaining the mandatory use of masks in health centers and nursing homes in Spain. How and when is it justified to maintain it?

“…Smiles and facial stimuli are not seen, and are necessary for the relationship with patients. The increased listening effort required when wearing masks is also associated with a higher cognitive load for patients and healthcare professionals [ 19 , 20 ]. The prolonged use of masks has contributed to the harmful trend, already present before the pandemic, of medical practice progressive dehumanization [ 21 ].…”