Variation in the standard deviation of the lure rating distribution: Implications for estimates of recollection probability.

In word recognition semantic priming of test words increased the false-alarm rate and the mean of confidence ratings to lures. Such priming also increased the standard deviation of confidence ratings to lures and the slope of the z-ROC function, suggesting that the priming increased the standard deviation of the lure evidence distribution. The Unequal Variance Signal Detection (UVSD) model interpreted the priming as increasing the standard deviation of the lure evidence distribution. Without additional parameters the Dual Process Signal Detection (DPSD) model could only accommodate the results by fitting the data for related and unrelated primes separately, interpreting the priming, implausibly, as decreasing the probability of target recollection (DPSD). With an additional parameter, for the probability of false (lure) recollection the model could fit the data for related and unrelated primes together, interpreting the priming as increasing the probability of false recollection. These results suggest that DPSD estimates of target recollection probability will decrease with increases in the lure confidence/evidence standard deviation unless a parameter is included for false recollection. Unfortunately the size of a given lure confidence/evidence standard deviation relative to other possible lure confidence/evidence standard deviations is often unspecified by context. Hence the model often has no way of estimating false recollection probability and thereby correcting its estimates of target recollection probability.

Dimensional interaction in distance judgment.

Participants decided under speed stress whether or not the horizontal distances between pairs of frontal locations exceeded a criterion distance. The error rate reflected parallel effects of the horizontal and vertical distance between the locations. Whereas dimensional interaction in perceptual judgment has previously been attributed either to the perception of the stimulus or to the response decision concerning the stimulus, here dimensional interaction was attributed to the process of distance assessment regarding the test locations. Under the proposed account, the horizontal distance between the locations could not be assessed independently of the vertical distance. Only the overall distance between the locations could be assessed. However, because the horizontal and vertical positions of the locations could be independently assessed, the horizontal distance between the locations was available to the extent that the vertical positions of the locations were weighted so as to minimize vertical distance prior to the assessment of overall distance. In support of this account, parallel effects of horizontal and vertical distance were not observed when participants decided whether or not pairs of locations had the same horizontal position.

Getting completely turned around: how disorientation impacts subjective straight ahead.

In manipulating a pointer to indicate subjective straight ahead (SSA), participants were more variable after a series of whole-body rotations in conjunction with external sensory blockade than after external sensory blockade alone. The variability of reported SSA did not increase consequent to a temporal delay matched to the time taken by the rotation procedure. These results suggest that an observer's egocentric reference frame is more complex and less stable than has previously been thought.