Recognition memory for item information (single words) and associative information (word pairs) was tested immediately and after retention intervals of 30 min and 1 day (Experiment 1) and 2 days and 7 days (Experiment 2) using Tulvmg's (1985) remember/lmow response procedure. Associative recognition decisions were accompanied by more "remember" responses and less "know" responses than item recognition decisions. Overall recognition performance and the proportion of remember responses declined at similar rates for item and associative information. The pattern of results for item recognition was consistent with Donaldson's (1996) single-factor signal detection model of remember/lmow responses, as comparisons based on A' between overall item recognition and remember item recognition showed no significant differences. For associative recognition, however, A' for remember responses was reliably greater than for overall recognition. The results show that recollection plays a significant role in associative recognition.

An experiment was conducted to determine the effect of aging on sound localization. Seven groups of 16 subjects, aged 10-81 years, were tested. Sound localization was assessed using six different arrays of four or eight loudspeakers that surrounded the subject in the horizontal plane, at a distance of 1 m. For two 4-speaker arrays, one loudspeaker was positioned in each spatial quadrant, on either side of the midline or the interaural axis, respectively. For four 8-speaker arrays, two loudspeakers were positioned in each quadrant, one close to the midline and the second separated from the first by 15 degrees, 30 degrees, 45 degrees, or 60 degrees. Three different 300-ms stimuli were localized: two one-third-octave noise bands, centered at 0.5 and 4 kHz, and broadband noise. The stimulus level (75 dB SPL) was well above hearing threshold for all subjects tested. Over the age range studied, percent-correct sound-source identification judgments decreased by 12%-15%. Performance decrements were apparent as early as the third decade of life. Broadband noise was easiest to localize (both binaural and spectral cues were available), and the 0.5-kHz noise band, the most difficult to localize (primarily interaural temporal difference cue available). Accuracy was relatively higher in front of than behind the head, and errors were largely front/back mirror image reversals. A left-sided superiority was evident until the fifth decade of life. The results support the conclusions that the processing of spectral information becomes progressively less efficient with aging, and is generally worse for sources on the right side of space.

A mirror effect was found for a stimulus manipulation introduced at test. When subjects studied a set of normal faces and then were tested with new and old faces that were normal or wearing sunglasses, the hit rate was higher and the false alarm rate was lower for normal faces. Hit rate differences were reflected in remember and sure recognition responses, whereas differences in false alarm rates were largely seen in know and unsure judgments. In contrast, when subjects studied faces wearing sunglasses, the hit rate was greater for test faces with sunglasses than for normal faces, but there was no difference in false alarm rates. These findings are problematic for single-factor theories of the mirror effect, but can be accommodated within a two-factor account.The mirror effect refers to the regularity of recognition memory in which classes of stimuli that are relatively easy to identify as old when old are also relatively easy to classify as new when new. In other words, the difference in discriminability is observed in both hit and false alarm rates rather than in only one of these measures. Glanzer and Adams (1985), in a review of80 recognition experiments, showed that the mirror effect can be seen for a variety of stimulus manipulations (e.g., natural language word frequency, concreteness, meaningfulness, and pictures vs. words) and that it holds for both yes/no and forced-choice recognition test procedures.The mirror effect has been extended to tests of associative recognition (Greene, 1996;Hockley, 1994) as well as discriminations of order (Greene, 1996) and frequency (Greene & Thapar, 1994); it is also reflected in measures ofresponse latency (Hockley, 1994). Hintzman, Caulton, and Curran (1994) have further demonstrated that dividing attention at test, or using a response-signal procedure to control processing time at retrieval, does not eliminate or attenuate the mirror effect. Hintzman et al. concluded that the mirror effect "may best be attributed to the inherent nature of the retrieval and judgment processes that underlie recognition memory" (p. 286). Hintzman et al. (1994) further noted that the mirror effect has proven to be difficult to account for in the context of most current models of recognition memory. This is because most models view recognition memory in terms

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