Hello phinamh, all,
A little information from the Pali-English Dictionary:manasikāra ~ 'attention', 'mental advertence', 'reflection'.
1. As a psychological term, attention belongs to the formation-group (sankhāra-kkhandha; s. Tab. II) and is one of the 7 mental factors (cetasika) that are inseparably associated with all states of consciousness (s. cetanā). In M. 9, it is given as one of the factors representative of mind (nāma) It is the mind's first 'confrontation with an object' and 'binds the associated mental factors to the object.' It is, therefore, the prominent factor in two specific classes of consciousness: i.e. 'advertence (āvajjana, q.v.) at the five sense-doors' (Tab. I, 70) and at the mind-door (Tab. I, 71). These two states of consciousness, breaking through the subconscious life-continuum (bhavanga), form the first stage in the perceptual process (citta-vīthi; s. viññāna-kicca). See Vis.M. XIV, 152.
2. In a more general sense, the term appears frequently in the Suttas as yoniso-manasikāra, 'wise (or reasoned, methodical) attention' or 'wise reflection'. It is said, in M. 2, to counteract the cankers (āsava, q.v.); it is a condition for the arising of right view (s. M. 43), of Stream-entry (s. sotāpattiyanga), and of the factors of enlightenment (s. S. XLVI, 2.49,51). - 'Unwise attention' (ayoniso-manasikāra) leads to the arising of the cankers (s. M. 2) and of the five hindrances (s. S. XLVI, 2.51).http://www.palikanon.com/english/wtb/g_ ... ikaara.htm