We measured the supernumerary spacing parameter of the first- and second-order rainbows of two glass rods, each having an approximately elliptical cross section, as a function of the rod's rotation angle. We attribute large fluctuations in the supernumerary spacing parameter to small local inhomogeneities in the rod's refractive index. The low-pass filtered first-order rainbow experimental data...

Does varying the spacing of repetitions over intervals as long as I week affect recall? The answer from three experiments is yes. Subjects incidentally processed words repeated within a single list and words repeated in separate lists at list spacings of up to I week. Memory was tested by free recall shortly after the second presentations or after retention intervals of up to I week. Recall of ...

In pattern masking, the target and mask are presented at the same location and follow one another very closely in time. When the observer attends to the target, he or she must also attend to the mask, as the switching time for attention is quite slow. In a series of experiments, we present mask-target-mask sequences staggered in time and location (Cavanagh, Holcombe, & Chou, 2008) that allow pa...

The spacing of a fixed amount of study time across multiple sessions usually increases subsequent test performance*a finding known as the spacing effect. In the spacing experiment reported here, subjects completed multiple learning trials, and each included a study phase and a test. Once a subject achieved a perfect test, the remaining learning trials within that session comprised what is known...

Discussions about fertility in developed countries refer almost exclusively to the period Total Fertility Rate (TFR). We argue that the use of this indicator frequently leads to incorrect interpretations of period fertility levels and trends, resulting in distorted policy conclusions and, potentially, in misguided policies. We illustrate this with four policy-relevant examples, drawn from conte...

Recent research has suggested that words presented with a slightly increased interletter spacing are identified faster than words presented with the default spacing settings (i.e., casino is faster to identify than casino; see Perea, Moret-Tatay, & Gomez, 2011). To examine the nature of the effect of interletter spacing in visual-word recognition (i.e., affecting encoding processes vs. quality ...

Repeating an item in a list benefits recall performance, and this benefit increases when the repetitions are spaced apart (Madigan, 1969; Melton, 1970). Retrieved context theory incorporates 2 mechanisms that account for these effects: contextual variability and study-phase retrieval. Specifically, if an item presented at position i is repeated at position j, this leads to retrieval of its cont...

We investigated the effect of varying interstimulus spacing on an upright among inverted face search and a red-green among green-red bisected disk search. Both tasks are classic examples of serial search; however, spacing affects them very differently: As spacing increased, face discrimination performance improved significantly, whereas performance on the bisected disks remained poor. (No effec...