Samskaras & Vasanas
It is the ahamkara (ego, concept/belief that you exist separate from the cosmos) along with the Vijnanamaya, Manomaya & Pranamaya Koshas that continue to live when the Annamaya Kosha dies. All of our previous karmas and vasanas are recorded in Vijnanamaya Kosha, but it is due to our identification with our individuality (ego, Vijnanamaya, Manomaya, Pranamaya, Annamaya) that forces us to be influenced by them. Ramaswami said that the core teachings of the Patanjali's sutras is that "we only have to pay the karma with which we identify". It is through pure identification with the soul, that we no longer are connected with the previous karmas & we attain moksha. Unfortunately, until we merge with source & leave these body's behind, this too is merely conceptualizing. Indeed most of our samskaras that we see playing out, have been taken on during this lifetime. But, look at a young child. They come into this world already knowing what they like and dislike. They come into this world already having a personality of their own, without any outside influence. Granted, the older they get, the more conditioned & influenced they become. Samskara simply means pattern. The seeds might be dormant or fully blossoming. As they blossom, you can experience the samskara penetrating every Kosha, all the way from ego to Annamaya Kosha & into our interactions with the outside world. It may be that when we come into this world the strongest samskaras from the previous birth (ego - Pranamaya) are the ones most readily at the surface. Different things happen during our lifetime that germinate our dormant vasanas & allow them to grow, also we take on a shit load of more seeds from our parents; family; society; etc & due to our upbringing those recently planted seeds blossom faster than the dormant ones.
The mind has previously been trained in the ability to observe itself through pratyahara. This enables Dharana- giving your attention to the samskaras once they have been observed and beginning to try and analyze and understand them. What are they? Where do they come from? The bridge between Dharana and Dhyana lies in these inquiries. In order to find the answer, we have to gaze upon the object (in this case, the samskara) for a prolonged period of time, to the exclusion of everything else-the conscious mind must operate as a pure laser-beam point of focus upon the object of inquiry- then it is Dhyana.
Once this laser beam of concentration (Dharana) is no longer a struggle to maintain, it then becomes meditation (Dhyana).
Once this occurs, you begin to perceive the object as it is, rather than as you perceive it to be after it has been filtered through your entire memory, semantic and conceptual and emotional networks that project all kinds of attributes and qualities onto it. Only then do you begin to gain a true understanding of it. This is where you recognize the samskara for what it is and discover that its root lies deeper than the conscious mind. As you gaze with full intensity and focus upon the object, the duality between subject/object continues to dissipate, and you begin to move in to the subconscious mind to recognize its root cause.
As the distinction between subject/object dissipates, we become rooted in Dhyana. Samadhi is the higher states of consciousness & the realizations that come through, after prolonged periods of Dhyana.
The conscious mind (manas) exists to serve as our control board as we interact with our external environments... but as we move into the subconscious mind, it is no longer necessary. We are moving deeper within-shifting from identification with manomaya kosha towards identification with vijnyanamaya kosha, where our deeper issues and wisdom lie. The vijnyanamaya kosha is where unresolved karma from all of our past lives survives in the form of DNA memory from our ancestral lineage since time immemorial. This is where the VASANAS are found- the instinctual desires, the DNA memory, evolutionary knowledge, unmanifest samskaras. the seeds of future karma. Vasanas constitute the entire store of the evolutionary memory of the species as well as the unresolved karma that has been passed on to us by our ancestors. Think of the vasanas as seeds, lying in the subconscious mind. These seeds lie dormant until an external event triggers them or creates a fertile situation for them to germinate. Once this germination occurs, they sprout into samskaras and enter into our conscious mind as behavioral/neural patterns. In other words, the Vasana is the seed, and the samskara is the sprouted seedling. This sprouted seedling will continue to grow as the psychic or behavioral pattern is strengthened, fortified and legitimized through repetition. This is how behavioral patterns, addictions, etc form.
Indeed, the conscious mind & the emotions (Manomaya) at the surface have literally manifested from our deeper subconscious beliefs (vasanas within Vijnanamaya). These beliefs allow certain emotional states to arise that color our perception. These emotions act as parameters for the conscious thought trajectory. If we want to think of something else, identify the emotion that is influencing our thought parameters. Once we identify the emotion, we can look deeper into Vijnanamaya & find the correlating belief that is being activated (vasana that is sprouting & growing) & determined whether or not it is useful & act accordingly (burn it up or let it grow).
So, going back to the analogy, the sprouted seedling continues to grow, becoming ingrained in our psyche as neural pathways, affecting our behavior. This behavior that occurs as a result of our samkaras is the fruit of the plant. Our actions are the fruit.
"Our actions are the fruit" - Thought, word & deed. Karma is three fold.
And as we know, all action results in karma... the fruits of our actions bearing more seeds (Vasanasas) of future karma for us to repeat indefinitely, even passing on to our offspring, until we identify and eliminate them with great effort. Of course not all of the vasanas are negative- they are also the survival instincts that have been passed on to us- the primal, hair-raising fear you feel when you hear the sound of a rattlesnake in your proximity is a useful function of the vasanas, for example. This is where wisdom is required... to discern the vasanas that keep us safe from danger from the vasanas that sprout into samskaras that control our behavior and end up enslaving us and turning us into mechanical robots instead of free, divine beings. So this is where the vijnyanamaya kosha comes into play... the Wisdom Sheath. This is where true discernment can be accessed, whereas the manas is merely the information processing unit.
Precisely
Our bodies have been steadied through asana and our nervous system has been controlled through pranayama, our senses tamed through pratyara, our concentration refined with dharana, and our subject/object filters dissolved with dhyana... we're now working from vijnyanamaya kosha, deep in the subconscious mind, in the realm of the vasanas. Once the subject/object duality between you and your object of contemplation is dissolved completely, this is Samadhi. You are one with your object of contemplation. There is no "you" or "it," it is merely pure perception.
Yes
The object is experienced completely objectively through the direct discernment of vijnyanamaya kosha, untainted by any notions or associations or stories or concepts that our sensory perceptions are filtered through, obscuring and plaguing our interactions with the external world and thus preventing direct perception. However, this is only the first stage of samadhi... in this first samadhi, Sabeeja Samadhi, the conception of time and space still exist, and thus there is still the conception of subjectivity vs. objectivity. Ahamkara (ego) and thus duality are still hanging on by a thread, albeit only in potential form.
Yes
The next phase, Nirbeeja Samadhi, is when even the vasanas are eliminated. The entire universe is experienced completely objectively. Superconsciousness. Hence the terms, Sabeeja-"with seed" & Nirbeeja="without seed."
If all vasanas were elimated, your body would cease to continue living. And while that's perfectly fine if you want to merge with source & leave the cosmic Lila behind. But, if you are on the path of the Bodhisattva, the only vasanas that you allow to remain are those needed for your continued separate existence, in order to teach & lead as many people to that last final doorway to merge with the Absolute. Only after every last soul has merged, will you eliminate those last few vasanas & walk through that doorway yourself & attain Maha Samadhi. Until then, Nirbeeja Samadhi can be attained through identification with the soul (which is an electrical switch to plug into the Supersoul) & dis-identifying with the ahamkara, Vijnanamaya, Manomaya, Pranamaya & Annamaya koshas. If we are on the path of the bodhisattva, and the essential vasanas remain. We can obtain Nirbeeja samadhi by not allowing these vasanas to affect our own internal state of consciousness. This is done by re-identification with the soul & by not identifying with the ego or these vasanas. That way, they have limited power & influence. At the Anandamaya Kosha level, it is a matter of identification. If we are truly identifying with the soul, we stop suffering & we become liberated while still alive and we become the Bodhisattva. That's why all of the great saints and yogis appear on the outside to be interacting with the world & doing great things & suffering & dying etc. But on this inside they are not affected, because of their deep identification with the soul (objective awareness) - this automatically keeps the ego (subjective awareness) from getting unnecessary power. It is when the ego gets unnecessary power that we begin to suffer; that's because we are identifying with Vijnanamaya, Manomaya, Pranamaya, Annamaya as if they were who we are. When in fact we are none of those things. All these koshas are simply our tools to do our life's work, to uplift & heal the local, global & universal community & to finally unite the cosmos back to it's original dormant state - only for it to explode outward into an infinitely faceted jewel & thus repeat the whole cycle over again. Who are we then? We are the observer of all these layers & interactions. The soul is unnaffected by all things nor is it able to affect anything, it is simply the ability to objectively observe.
Or something like that ;)