Is there a function between loss of memory and time? I have 2 related questions with regards to memory capabilities and time:


"Is there a function (e.g. $e^{-\Delta Time}$) with regards to memory loss?" Everyone is bound to forget over time. Is there a function that describes this decay?
"Is there a function between time spent looking at something and remembering it?" The more the time I spend trying to remember something, the better I will be at it. Is there any correlation between the two?
There is substantial research on both the functional relationship relationship between practice and retention and between time away from task and forgetting (e.g., see forgetting curve).
In general, retention is a monotonically increasing and monotonically decelerating function of  practice. And retention is a monotonically decreasing function of time where the rate of deceleration is decreasing. This general finding is tremendously robust, but there is substantial debate about the best fitting functional form for these two relationships.

Averell and Heathcote (2011) provide a good review of forgetting curve functions. See equations 2, 3, and 4 in the article for instances of pareto, power, exponential functions. They concluded:


  Our analysis revealed that, although for individual participant data
  the exponential function with an above chance asymptote had the best
  fit among the models we considered, this advantage was due to its
  extra flexibility (complexity). When we adjusted for complexity using
  a range of model selection techniques that varied in the degree to
  which they adjusted for complexity, in every case a power function
  with an above chance asymptote provided the best description of
  forgetting. Interestingly, previous analyses of retention functions
  without an asymptote (Lee, 2004) found that the power model was more
  complex than the exponential. Our findings suggest that the addition
  of asymptote parameters adds more complexity to the exponential
  function than the power function.


References


Averell, L., &amp; Heathcote, A. (2011). The form of the forgetting curve and the fate of memories. Journal of Mathematical Psychology, 55(1), 25-35. PDF