Feeling and Looking Down: Impact of Depressive Symptoms on the Allocation of Vertical Attention.

Background: Emotions and moods are often expressed using verbal, vertical spatial metaphors (eg, "I'm feeling down"). The reason for using these vertical metaphors is unknown; however, when individuals experience depressive symptoms, they often become self-reflective and ruminative. These mental activities are associated with activation of the default network, including the parietal lobes. The parietal lobes are a critical component of the dorsal visual attentional network, which allocates attention downward. Therefore, activation of the default network may create a downward bias of vertical attention.

Objective: To investigate whether depressive mood disposition, as measured by the number of depressive symptoms experienced by an individual, influences their allocation of vertical attention.

Methods: We used the Hospital Anxiety and Depression Scale to evaluate depressive symptoms in 48 right-handed individuals with a mean age of 57.31 (±17.14) years. We also asked the participants to mark the center (bisect) of 24 vertical and 24 horizontal lines.

Results: Overall, the individuals deviated their bisections of vertical lines upward (M=2.66 mm; SD=3.85). A stepwise linear regression analysis revealed that the number of depressive symptoms an individual experienced was significantly associated with a reduction in the magnitude of this upward vertical bias (P=0.009; R=0.138), such that the number of depressive symptoms was associated with the reduction (lowering) of their upward bias.

Conclusion: Depressive symptoms may be associated with a relative lowering of the vertical attentional bias, and this lowering may be related to increased activation of portions of the default network.