There are several complex emotions within the poem which contribute to its depressive atmosphere as the narrator moves through what appear to be the processes of a mental breakdown. There is an eerie calm as the narrator compares the loss of her reason to the ritual of the funeral.
The poem is uncomfortable for the reader, as the description gives physical sensation to this decline of the mind. It is placed within the 'brain', causing us to imagine that organ in a pain that is akin to death. Feelings are magnified as the reader visualises the physical effect of the repeated 'treading' through the narrator's thoughts.
There is some hope at the end of the first stanza as the pacing motion seems to suggest that sanity and relief are on their way-
That Sense was breaking through
However, the repeated beat becomes 'like a Drum', and brings numbness, rather than renewed vitality. The intensity of sound is highlighted to an excruciating level as the body becomes an 'Ear' and the Heavens a 'Bell'. There is an agony implied in this description, and the reader is as keen as the narrator to escape this image and reach peace.
The unresolved ending of the poem leaves the reader wondering whether death, relief or both has been reached by the narrator, or whether she has simply become nothingness. It is an intense and bewildering emotion to be left with.