Approximating the ZPD? Young children's judgements of appropriate task level for learning.

This research examined how 3-6-year-olds judge appropriate levels of counting games based on a person's ability, desire for learning and degree of difficulty. Study 1 found that 3-year-olds did not consider a character's ability or desire, whereas older children gave high ability characters large number games and low ability characters small number games when the characters wanted to play a manageable game. However, older children gave large number games to characters who wanted to learn counting, regardless of their ability.

Mechanism of action of cholecystokinin on colonic motility in isolated, vascularly perfused rat colon.

Background/aims: It is generally believed that cholecystokinin (CCK) stimulates colonic motility, although there are controversial reports. It has also been suggested that postprandial peptide YY (PYY) release is CCK-dependent. Using a totally isolated, vascularly perfused rat colon, we investigated: (1) the roles of CCK and PYY on colonic motility, (2) to determine if CCK modulates PYY release from the colon to influence the motility and (3) to clarify whether the action of CCK and PYY on colonic motility is mediated via the influence of cholinergic input.