Eye movement correlates of younger and older adults' strategies for complex addition

This study examined performance measures and eye movements associated with complex arithmetic strategies in young and older adults. Participants added pairs of three-digit numbers using two different strategies, under choice and no-choice conditions. Older adults made more errors but were not significantly slower than young adults, and response times and errors showed no interaction between age and the number of carries. Older adults chose strategies less adaptively than young adults. Eye movements were consistent with use of required strategies on no-choice trials and reported strategies on choice trials. Eye movement data also suggested that young adults more successfully distinguished between strategies. Implications of these findings for understanding aging effects in complex arithmetic are discussed.     

Dimensions and Categories Underlying Thinking About College Student Types1

Previous work on implicit personality theory and the college student culture suggests that thinking about college student types should include academic involvement and social involvement dimensions. Further, positive and negative social, positive academic, and oppositional clusters of types were predicted based on studies of high school crowds. Using 85 college student type labels as stimuli, a free‐sorting method coupled with multidimensional scaling and hierarchical clustering analyses provided support for these hypotheses. Also, the results suggest convergence in the cognitive structure underlying perception of college student types across major demographic categories.     

Repeated cocaine experience facilitates sucrose-reinforced operant responding in enriched and isolated rats

The purpose of the present experiment was to determine whether repeated cocaine exposure differentially affects sucrose-reinforced operant responding in rats raised in an enriched condition (EC) or an isolated condition (IC). Specifically, the performance of EC and IC rats pressing a lever for sucrose under a high fixed-ratio schedule (FR 30) prior to and after 10 days of exposure to cocaine (15 mg/kg, i.p.) or saline was compared. Regardless of rearing condition, rats repeatedly exposed to cocaine had shorter reacquisition latencies to complete a sucrose-reinforced FR 30 task than saline controls. The results suggest that cocaine exposure may have cross-sensitized both EC and IC rats to the reinforcing effects of sucrose or sucrose-associated cues, thus facilitating reacquisition of operant responding.     

How Do Relationships Support Parenting? Effects of Attachment Style and Social Support on Parenting Behavior in an At‐Risk Population

The importance of supportive relationships for new parents has been the focus of both research and parenting interventions. Attachment style, typically viewed as a relatively stable trait reflecting one's comfort in social relationships, as well as social support, or one's perception of the social context, have both been found to be important for fostering engaged, involved parenting. Less is known, however, about how these variables work together to influence parenting behavior, especially in families at higher risk for negative child outcomes. Data were collected from 152 urban, predominantly African American, low-income parents when their children were 14 and 36 months of age. Results suggest that parents with more social support show greater increases in the frequency of positive parent-child activities over time, but that this effect is mediated by mothers' attachment style, specifically, their level of anxious/ambivalent attachment. Mothers with more social support tended to be less anxious/ambivalent about close relationships, and this in turn led to increases over time in the frequency of parent-child interactions. Mothers' tendency to avoid close relationships, however, while correlated with social support, was unrelated to changes in parenting behavior. Implications of these findings for program development, parenting, and the malleability of attachment style based on social context are discussed.     

Ghosts from the past: an examination of romantic relationships and self-discrepancy

Researchers have previously reported a negative association between romantic involvement and the discrepancy between the actual self and the ideal self. The authors present a schema-based model of romantic involvement and self-discrepancy to help explain this association, focusing on the impact of terminated relationships--"ghosts from the past." In Study 1, participants primed with a past relationship reported increased self-discrepancy relative to participants primed with a present relationship. Study 2 indicated that this increased self-discrepancy was the result of reexperiencing emotionally negative past romantic relationships. Study 3 revealed the role of depressive affect in negative past romantic relationships. Finally, Study 4 indicated that depressive affect mediated the relation between reexperiencing negative past romantic relationships and experiencing self-discrepancy.     

Pigeons' preferences for stimulus information: effects of amount of information

A concurrent-chain procedure was used to study pigeons' preferences as a function of amount of information. Pigeons chose between two terminal links. Both terminal links ended in food reinforcement with probability (p) and in blackout with probability (1–p). One terminal link (noninformative link) was signalled by a stimulus uncorrelated with either food or blackout. The other terminal link (informative link) was signalled by stimuli correlated with these outcomes. Amount of information conveyed by these stimuli was varied across conditions by changing the probability of reinforcement (p) and blackout (1–p). The pigeons strongly preferred the informative link, and preferences were greater at p values above 0.50 than for their complements. The pigeons engaged in different behaviors during the stimulus periods, suggesting that the value of informative stimuli may be in their function as discriminative stimuli for interim activities and terminal responses.     

A comparison of method-of-adjustment and forced-choice procedures in frequency discrimination

Reported estimates of the frequency difference limen (DL) for tones show considerable variability. To determine the extent that the differences are dependent on psychophysical method, three estimates of the DL at 1,000 Hz were obtained from the same subjects for each of three psychophysical procedures. The three estimates were: (1) the standard deviation of final settings in a methbd of adjustment, (2) the average of several reversals in an adaptive two-interval forced-choice procedure, and (3) the 76%-correct point in a two-interval forced-choice procedure using constant stimuli. The two forced-choice procedures yielded very similar DLs. The adjustment procedure yielded significantly smaller estimates. Possible reasons for the different values produced by adjustment procedures and the nature of the underlying decision process are discussed.     

A Follow-up Dual-Task Investigation of Lateralized Effects in Right- and Left-Handed Males

A dual-task follow-up investigation examined the influence of sample size and ideational complexity of cognitive tasks on lateralized effects. With a larger sample (n = 128), results showed a "manual dominance effect" for relaxed and paced nonideational vocalized tasks. A hierarchy of ideational verbal tasks yielded the expected lateralized effects which corresponded with increasingly greater interference in concurrent tapping, but not in strength of lateralized effect. Instead of a trend seen in the earlier work (Steiner, Green, & White, 1992), results revealed a significant difference between handedness groups for one complex spatial task. Finally, outcomes for the other spatial task highlight the importance of assessing tradeoffs in attention.