fitDPSDsource: Estimation of recollection and familiarity by fitting source...

In nklange/fullDPROC: Fitting Dual-Process model to recognition and source memory data

Description

This function allows to estimate recollection and familiarity for source memory data by fitting data to the DPSD model. The optimization is attempted by minimizing the summed log-likelihood using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm in optim. The function uses random start values on each iteration in order to find the set of parameters, which fit the data best by returning the values with the lowest total squared difference. Optional arguments in the function allow the user to specify an equal-variance model and/or specify if recollection is to be estimated as a separate parameter for both target and lure items. Recollection is bounded to be between 0 and 1, Familiarity and the standard deviation of the target distribution to be positive. Criteria are ordered. A high number of iterations is necessary to avoid local minima.

Usage

fitDPSDsource(falseAlarms, hit, iterations = iterations, eqVar = eqVar,
  eqRecollection = eqRecollection)

Arguments

falseAlarms	A vector containing the number of false alarms per source category rating.
hit	A vector containing the number of hits per source category rating.
iterations	A numeric value specifying the number of iterations. Default is set to 200.
eqVar	A boolean value specifying if the standard deviation of the target distribution is equal to that of the lure distribution (i.e. = 1) (TRUE) or estimated separately (FALSE). Default is set to TRUE.
eqRecollection	A boolean value specifying if recollection is set equal for the target and lure source (TRUE) or is estimated separately for both sources (FALSE). Default is set to FALSE.

Value

The function returns a dataframe with components:

(parameters)	The estimated parameters (recollection_target, recollection_lure, familiarity, sd_target, criteria) for the iteration with the lowest SumSquareError
negLL	negative Log Likelihood

Author(s)

Nicholas Lange, [e-mail]

References

Yonelinas, A. P. (1999). The Contribution of Recollection and Familiarity to Recognition and Source-Memory Judgments: A Formal Dual-Process Model and an Analysis of Receiver Operating Characteristics. Journal of Experimental Psychology: Learning, Memory, and Cognition, 25(6), 1415 - 1434. http://doi.org/10.1037//0278-7393.25.6.1415

nklange/fullDPROC documentation built on May 26, 2019, 2:34 a.m.