In the passage, what does the term 'by using the truncated senses' most likely refer to?

Directions: Read the following passage and answer the question.
Unlike a long, very long, spiral staircase inside a lighthouse, the top of which, though invisibly lost in the mists of darkness is present, or perhaps a mountain much higher than the highest, but still having a discernable acme, the journey of consciousness does not stop at any level. Like exploring an underwater maze of caves, deep under the sea, in almost pitch darkness, the human soul transcends the boundaries and barriers of time and space. There is no life-line to haul oneself back to safety if lost or paralyzed with fear, the sense of spatial reasoning is in abeyance, the eyes are nearly blind due to the pitch darkness, and yet one must feel one’s way forward by using the truncated senses to the best of one’s ability. The darkness holds unknown fears - real, and those conjured by one’s senses, unseen challenges and pitfalls as well as good and nasty surprises within its bosom and yet the journey must go on because to stop and give up means getting stuck at the same spot for eternity. According to many scientists and philosophers, time and space are the only two anchors that give us a sense of progress, direction and spatial reasoning and if both of these are removed, as they have been suggested by thinkers and visionaries alike to be the props created by humans, then nothing is left. Our world is perhaps the creation of our mind and death erases our mind like a hard drive wiped clean of all data, till the time comes for it to start storing data again on the next plane of consciousness. It is like giving up the familiar comfort of a familiar landing and venturing out in the dark unknown again. Time is relative, we live in different time zones, there is day in one part of the world while another is shrouded by the darkness of the night. The time spent waiting for a lover makes every second seem like an eternity while the same time rushes past when the deadline for some important task approaches.