The role of explicit and implicit standards in visual speed discrimination

Five experiments were designed to investigate visual speed discrimination. Variations of the method of constant stimuli were used to obtain speed discrimination thresholds in experiments 1, 2, 4, and 5, while the method of single stimuli was used in experiment 3. The observers' thresholds were significantly influenced by the choice of psychophysical method and by changes in the standard speed. The observers' judgments were unaffected, however, by changes in the magnitude of random variations in stimulus duration, reinforcing the conclusions of Lappin et al (1975 Journal of Experimental Psychology: Human Perception and Performance 1 383 394). When an implicit standard was used, the observers produced relatively low discrimination thresholds (7.0% of the standard speed), verifying the results of McKee (1981 Vision Research 21 491-500). When an explicit standard was used in a 2AFC variant of the method of constant stimuli, however, the observers' discrimination thresholds increased by 74% (to 12.2%), resembling the high thresholds obtained by Mandriota et al (1962 Science 138 437-438). A subsequent signal-detection analysis revealed that the observers' actual sensitivities to differences in speed were in fact equivalent for both psychophysical methods. The formation of an implicit standard in the method of single stimuli allows human observers to make judgments of speed that are as precise as those obtained when explicit standards are available.     

The influence of partial‐match cues on event‐based prospective memory

In event‐based prospective memory tasks people form an intention to respond when an environmental cue signals that conditions are appropriate to fulfil an intended activity. In the ongoing activity the authors embedded partial‐match cues that only partially, but not completely, satisfied the conditions required to make a prospective response. The consequence of encountering these partial‐match cues was to increase responses to appropriate prospective memory cues encountered later. This outcome occurred both with semantic and orthographic cues, but only the former led to longer processing latencies of the partial‐match cues. This asymmetry suggests that partial‐match cues may not need to be processed consciously in order to benefit event‐based prospective memory. A parametric manipulation of the number of partial‐match cues resulted in numerically but not statistically better prospective memory. Consequently, partial‐match cues may function as overt reminders of the intention to respond or they may serve to engage participants in self‐initiated remindings of the intention.     

Imaginary Worlds in Middle Childhood: A Qualitative Study of Two Pairs of Coordinated Paracosms

Imagining alternatives to actual experiences is an important part of everyday life that can take many forms. One manifestation in middle childhood is the creation of elaborate imaginary worlds, called paracosms. Retrospective reports of adults indicate that having a childhood paracosm is more commonly reported in individuals acknowledged for being highly creative. In this study, we interviewed four children aged 10 to 12 years with interconnected paracosms about the details of their imagined worlds. Our findings indicated that paracosms served as a platform for social activity with friends, a way to explore real world interests (e.g., geography, language), and a vehicle for engaging in creative pursuits (e.g., drawing, storytelling).     

Pursuit of comfort and pursuit of harmony: culture, relationships, and social support seeking

This research examined whether people from collectivistic cultures are less likely to seek social support than are people from individualistic cultures because they are more cautious about potentially disturbing their social network. Study 1 found that Asian Americans from a more collectivistic culture sought social support less and found support seeking to be less effective than European Americans from a more individualistic culture. Study 2 found that European Americans' willingness to seek support was unaffected by relationship priming, whereas Asian Americans were willing to seek support less when the relationship primed was closer to the self. Study 3 replicated the results of Study 2 and found that the tendency to seek support and expect social support to be helpful as related to concerns about relationships. These findings underscore the importance of culturally divergent relationship patterns in understanding social support transactions.     

Postpartum feeding attitudes, maternal depression, and breastfeeding in Barbados

Maternal feeding attitudes, maternal moods and infant feeding practices during the first 6 months postpartum were assessed in 226 healthy, well-nourished Barbadian mother-infant dyads. Factor analysis of the feeding attitudes questionnaire resulted in six independent factors. The belief that breastfeeding was better than bottle-feeding was associated with higher family income, more information seeking behavior and older maternal age at the time of her first pregnancy. Women who believed that breastfeeding was better at 7 weeks postpartum were also more likely to breastfeed at concurrent and later ages, up to 6 months postpartum. This belief was also associated with less maternal depression at 7 weeks and 6 months. The association between feeding attitudes and actual feeding practices was significant even after correcting for maternal moods and other background variables. Conversely, after controlling for feeding attitudes, maternal mood at 7 weeks was still significantly associated with infant feeding practices at 6 months. Thus, feeding attitudes and maternal moods were closely linked, but each contributed independently and uniquely to different aspects of breastfeeding, especially at 6 months. These findings suggest that early intervention addressing maternal feeding attitudes, may improve the extent of breastfeeding and the health of children in this setting.     

Experience with songs in adulthood reduces song-induced gene expression in songbird auditory forebrain

Male songbirds learn to produce song within a limited phase early in life; however they continue to learn to recognize songs in adulthood. Studies looking at Zenk activation after exposure to songs learned early in life for song production and songs learned in adulthood show opposite patterns of activation, suggesting distinct neural mechanisms may be involved in these two forms of learning. In this study, we look at IEG Zenk activation in auditory regions NCM and CMM of song sparrows (Melospiza melodia) to see whether recent exposure to song in adulthood leads to greater or decreased Zenk activation upon hearing that song versus a novel song. We found significantly lower activation in birds exposed to previously heard songs versus novel songs in vNCM but not dNCM, though further analysis suggest an overall trend in NCM. We found no significant difference in the amount of activation to previously heard songs vs. novel songs in CMM. These results support previous findings suggesting that activation is reduced to learned stimuli; we discuss possible implications of these findings in relation to song production learning early in life and song recognition learning in adulthood.     

Frequency effects in spoken and visual word recognition: evidence from dual-task methodologies

The authors report 3 dual-task experiments concerning the locus of frequency effects in word recognition. In all experiments, Task 1 entailed a simple perceptual choice and Task 2 involved lexical decision. In Experiment 1, an underadditive effect of word frequency arose for spoken words. Experiment 2 also showed underadditivity for visual lexical decision. It was concluded that word frequency exerts an influence prior to any dual-task bottleneck. A related finding in similar dual-task experiments is Task 2 response postponement at short stimulus onset asynchronies. This was explored in Experiment 3, and it was shown that response postponement was equivalent for both spoken and visual word recognition. These results imply that frequency-sensitive processes operate early and automatically.     

Sequential modulations of interference evoked by processing task-irrelevant stimulus features

Compatibility level repetition benefits in interference paradigms have been taken to reflect enhanced processing selectivity in response to cognitive conflict elicited by a task-irrelevant stimulus feature. The authors demonstrate such sequential effects in the Simon task which (a) occur independent of previous behavioral conflict effects and (b) cannot be accounted for by selectivity enhancement. Furthermore, when presenting more than one type of irrelevant stimulus features, compatibility level repetition effects occurred in a type-specific manner. The results do not support the notion that cognitive conflict results in enhanced processing selectivity and favor a feature integration account.