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G J Iverson

Publications and source records attributed to G J Iverson.

2 recordsLinked to original sources

The regularities of recognition memory.

Three regularities in recognition memory are described with supporting data: the mirror effect, the order of receiver operating characteristic slopes, and the symmetry of movement of underlying distributions. The derivation of these regularities from attention/likelihood theory is demonstrated. The theory's central concept, which distinguishes it from other theories, is the following: Ss make recognition decisions by combining information about new and old items, the combination made in the form of likelihood ratios. The central role of the likelihood ratios extends the implications of signal detection theory for recognition memory. Attention/likelihood theory is fitted to data of 2 series of experiments. One series involves yes-no tests and confidence ratings, the other forced-choice experiments. It is argued that the regularities require a revision of most current theories of recognition memory.

Aging↗

Invariant characteristics of partial masking: implications for mathematical models.

The loudness of a tone in a noisy background increases very rapidly above its threshold with increasing intensity of the tone. The particular curve describing loudness growth as measured by a loudness matching paradigm depends on the level of the background noise. We introduce the hypothesis that an increment in masking noise induces a shift of the loudness matching curve in a diagonal direction (the matching curve being plotted in conventional log--log coordinates). This shift invariance is shown here to hold empirically for individual subjects within a monaural loudness matching task, based on a 2IFC paradigm using 1000-Hz tones and a wide band Gaussian noise. Shift invariance places considerable restrictions on models feasible for such data. In conjunction with a very general class of models involving the notion of gain control, the shift invariance property determines all parametric forms possible for the loudness matching functions. The fit of such parametric expressions to the data reported here yields very satisfying results. The resulting model is also found to be consistent with relevant results in the literature.

Humans↗