(HealthDay News) – Emotional contagion, the tendency for two individuals to emotionally converge, increases as individuals progress from healthy to mild cognitive impairment to Alzheimer’s disease, which correlates with smaller structures in the temporal lobe, according to a study published online May 28 in the Proceedings of the National Academy of Sciences.

Virginia E. Sturm, PhD, from the University of California San Francisco, and colleagues measured emotional contagion and depressive symptoms, and performed structural magnetic resonance imaging in 62 patients with mild cognitive impairment, 64 patients with Alzheimer’s disease, and 111 healthy controls.

The researchers found that both emotional contagion and depressive symptoms significantly increased with increasing disease progression. Only the higher emotional contagion significantly correlated with smaller volumes in the right inferior, middle, and superior temporal gyri, after correction for multiple comparisons. Higher emotional contagion also significantly correlated with smaller volumes in the right temporal pole, anterior hippocampus, parahippocampal gyrus, and left middle temporal gyrus, but the correlations did not survive correction.

“These findings suggest that in mild cognitive impairment and Alzheimer’s disease, neurodegeneration of temporal lobe structures important for affective signal detection and emotion inhibition are associated with up-regulation of emotion-generating mechanisms,” Sturm and colleagues conclude.

Full Text (subscription or payment may be required)