Avijja is ignorance of the four noble truths. It makes ordinary people blind to the impermanence and insubstantiality of sense objects. So they think, speak and act in the hope of securing happiness in the present life or hereafter. These deeds in thought, word or bodily actions are either wholesome or unwholesome and they are also called sankharas (kamma formation).
The sankharas give rise to new existence. The dying person has flashbacks of his kammic deeds and visions of future life that impress him and condition his new consciousness in a new life. In the absence of any special object that concerns the new consciousness, the latter occurs repeatedly with the death bed impression of his previous life as its object.
This bhavanga citta becomes active at the moment of seeing, etc. Then, there arises eye consciousness that is dependent on the eye and visual form. It is part of the state of consciousness, that is, the whole mental life as conditioned by sankhara. What we see, hear, etc., may be pleasant or unpleasant and the corresponding nature of eye consciousness, ear consciousness, etc., is due to the ethical character of our past deeds, that is the wholesomeness or unwholesomeness of the kammas in the past existence.
This applies to all of the six types of consciousness that arise from six sense objects. The last type of consciousness, implicit in mental activity comprising thinking, imagining, willing, etc., is dependent on bhavanga citta, avajjana citta (mental advertence), the physical basis and the mental image. This mental activity (manovinnana) involves seven thought moments (javana) and two other thought moments (tadarammana). Here tadarammana is the product of good or bad kamma. Javana is not such a product, but in Abhidhamma it is labelled sankhara based vinnana in that it arises from bhavanga, the product of sankhara.
Together with the arising of vinnana, there also arises other concomitant psycho physical phenomena (cetasika and rupas). Thus vinnana leads to nama rupa, but vinnana is followed also by the six ayatana (sense organs) and six phassa (sense impressions). Phassa means the conjunction of the mind, the mind object and the sense organ. It gives rise to vedana (feeling) which may be pleasant or unpleasant or neither pleasant nor unpleasant. The last kind of feeling which is called upekkhavedana, gives us the impression of the absence of any feeling, but according to Abhidhamma, it is in fact a kind of subtle pleasure that implies only the absence of unbearable pain.