DIFFERENTIAL REINFORCEMENT OF OTHER BEHAVIOR AND NONCONTINGENT REINFORCEMENT AS CONTROL PROCEDURES DURING THE MODIFICATION OF A PRESCHOOLER'S COMPLIANCE1

Differential reinforcement of other behavior (DRO) and noncontingent reinforcement were compared as control procedures during the modification of a 3-yr-old preschooler's compliance. The recorded reinforcer was teacher proximity (within 3 ft (0.9 m) of the subject for at least 5 sec) which was often accompanied by positive verbal comments that varied in content across experimental conditions. The verbal content during contingent reinforcement might have been: “Thank you for picking up the blocks”; during noncontingent reinforcement: “You're wearing a pretty dress”; and during DRO: “I don't blame you for not picking up because it isn't any fun”. Contingent reinforcement increased compliance in all manipulation conditions. Noncontingent reinforcement decreased compliance during two reversal conditions. However, the behavior was variable and did not decrease to the low levels reached during the two DRO reversals.     

Memory consolidation effects on memory stabilization and item integration in older adults

This study examined the differential effects of aging on consolidation processes that strengthen newly acquired memory traces in veridical form (memory stabilization) versus consolidation processes that are responsible for integrating these memory traces into an existing body of knowledge (item integration). Older adults learned 13 nonwords and were tested on their memory for the nonwords, and on whether these nonwords impacted upon processing of similar-sounding English words immediately and 24 hours later. Participants accurately recognized the nonwords immediately, but showed significant decreases in delayed recognition and recall. In comparison, the nonwords impacted upon processing of similar-sounding words only in the delayed test. Together, these findings suggest that memory consolidation processes may be more evident in item integration than memory stabilization processes for new declarative memories in older adults.     

Learning in the absence of experience-dependent regulation of NMDAR composition

Olfactory discrimination (OD) learning consists of two phases: an initial N-methyl-D-aspartate (NMDA) receptor-sensitive rule-learning phase, followed by an NMDA receptor (NMDAR)-insensitive pair-learning phase. The rule-learning phase is accompanied by changes in the composition and function of NMDARs at synapses in the piriform cortex, resulting in a high level of the NR2a subunit relative to NR2b. Here we show that the learning-induced changes in NMDAR composition in the adult piriform cortex are due to a decrease in the level of the NR2b subunit protein, rather than an increase in the level of NR2a. Chronic administration of an NMDAR open channel blocker during training delays OD learning and blocks learning-induced changes in NMDAR subunit composition. However, the animals still learn the OD task. Our data demonstrate that learning can occur in the absence of activity-dependent regulation of NMDAR composition, suggesting differences in the mechanism for long-term maintenance of NMDAR-dependent and NMDAR-independent learning.     

Dear diary, is plastic better than paper? I can't remember: Comment on Green, Rafaeli, Bolger, Shrout, and Reis (2006)

In this commentary, the authors discuss the implications of A. S. Green, E. Rafaeli, N. Bolger, P. E. Shrout, and H. T. Reis's (2006) diary studies with respect to memory. Researchers must take 2 issues into account when determining whether paper-and-pencil or handheld electronic diaries gather more trustworthy data. The first issue is a matter of prospective memory, and the second is a matter of reconstructive memory. The authors review the research on these issues and conclude that regardless of the type of diary researchers use, several factors can conspire to produce prompt--but inaccurate--data.     

On the importance of being ethnic: coping with the threat of prostate cancer in relation to prostate cancer screening

The relation between coping with a possible prostate cancer diagnosis and screening behavior was examined in men from seven precise ethnic groups. Five coping styles differed in their likelihood of use across ethnic groups and had somewhat different associations with frequency of prostate-specific antigen (PSA) testing. As expected, PSA test frequency differed among men from different ethnic groups and was differentially predicted by coping styles. Analyzing the results using typical groups of White, Black, and Hispanic, rather than precise ethnic groups, obscured these results. Researchers investigating psychological variables in preventive health behaviors must analyze diversity within the framework provided by ethnic specificity. Such an approach will guide the development and provision of interventions that are more sensitive to the characteristics of specific ethnic groups of at risk men.     

Infant word segmentation revisited: edge alignment facilitates target extraction

In a landmark study, Jusczyk and Aslin (1995) demonstrated that English-learning infants are able to segment words from continuous speech at 7.5 months of age. In the current study, we explored the possibility that infants segment words from the edges of utterances more readily than the middle of utterances. The same procedure was used as in Jusczyk and Aslin (1995); however, our stimuli were controlled for target word location and infants were given a shorter familiarization time to avoid ceiling effects. Infants were familiarized to one word that always occurred at the edge of an utterance (sentence-initial position for half of the infants and sentence-final position for the other half) and one word that always occurred in sentence-medial position. Our results demonstrate that infants segment words from the edges of an utterance more readily than from the middle of an utterance. In addition, infants segment words from utterance-final position just as readily as they segment words from utterance-initial position. Possible explanations for these results, as well as their implications for current models of the development of word segmentation, are discussed.     

Gender effects on reaction time variability and trial-to-trial performance: reply to Deary and Der (2005)

Deary and Der (2005) reported significant gender effects on intraindividual variability in choice reaction time (CRT), and suggested several potential causes. In their procedure it was not possible to examine RTs on a trial-to-trial basis. We therefore investigate an additional possible cause: that men and women differ in their rate of performance improvement across trials, creating an apparent difference in variability. Using data from a large online CRT study, we replicate the finding that women are more variable in RT than men. However, we also demonstrate an interaction between gender and trial number for RT: women were initially slower than men, but became faster than men across a block. When the first two trials of the block are excluded, the gender effects on RT variability disappear.