Effects of the periodic administration of odor or vibration on a 3-hr. vigilance task

The present study examined performance during 3 hr. of simulated sentry duty with and without the intermittent administration of low-level sensory stimuli (odor or vibration). For odor and control conditions, target-detection latency increased steadily over the course of the 3-hr. session. Administration of a tactile stimulus reduced the increase in detection latency compared to that found in odor and control conditions. For all conditions, there were no significant differences in target-detection frequency, shot accuracy, or friend-foe discrimination. Across all conditions, restlessness (motor activity) increased significantly the first hour and remained elevated for the rest of the session. Subjective measures of workload (NASA-TLX) indicated that the 3-hr. task rated high on physical demand, mental demand, frustration, and overall workload. These findings suggest that the intermittent delivery of a clearly detectable tactile stimulus can reduce reaction-time decrements that occur as time on task increases.     

Infants' comprehension of toy replicas as symbols for real objects

Infants' understanding of toy model-real exemplar relations was assessed through preferential looking and habituation tasks. Results from the preferential looking task suggest that 18-month toddlers are just beginning to demonstrate comprehension of symbolic relations between iconic models and their real object counterparts. Performance of 10- and 14-month-old infants in the preferential looking task did not improve when across-domain pairs of videos were used in place of within-domain pairs. Habituation task results indicated that 10-month-olds do not comprehend symbolic relations between miniature toy replicas and their "real" counterparts, but that such understanding begins to emerge by age 14 months. Interactions between symbolic processing and early lexical development are considered, as are methodological implications for the study of infant categorization.     

Gender, grade, and relationship differences in emotional closeness within adolescent friendships

Previous research has examined gender and grade differences in the emotional closeness of adolescents' same- and cross-sex friendships. However, findings from these studies have been inconsistent because they have failed to (1) differentiate between cross-sex friendships and romantic relationships and (2) compare same- and cross-sex friendships. In an attempt to clarify previous findings, gender and grade differences in adolescent reports of emotional closeness within same- and cross-sex friendships were examined in the current study. Responses from two hundred seventy adolescents indicated gender differences in reports of time spent with their friends daily and levels of relationship closeness, cohesion, and commitment. Further, grade moderated relationship differences in reports of relationship cohesion and closeness. Differences in predictors of intimacy support previous studies that have found grade and gender differences in levels of intimacy in adolescents' same- and cross-sex friendships. Results also elaborate on previous research by indicating grade differences in adolescents' perceptions of cohesion and closeness in their same- and cross-sex friendships. Findings are discussed in terms of understanding differences in adolescent reports of intimacy within same- and cross-sex friendships.     

Prevention opportunities in health care settings

Psychologists have an opportunity to offer their expertise at a time when health care settings are beginning to recognize the importance of behaviorally based interventions for improving health and health care. The authors review the changing patterns of health and illness that have led to an increased interest in the role of patient and provider behavior and discuss the many advantages of using health care settings as prevention sites. Examples of successful behaviorally based prevention programs are presented, along with the evidence supporting the cost-effectiveness of such programs. Challenges presented by working in health care settings are described. Throughout, the authors emphasize the multiple opportunities for psychologists' involvement across a wide variety of health care delivery sites.     

The "what" and "where" of object representations in infancy

Four-month-olds' memory for surface feature and location information was tested following brief occlusions. When the target objects were images of female faces or monochromatic asterisks infants showed increased looking times following a change in identity or color but not following a change in location or combinations of feature and location information. When the target objects were images of manipulable toys, the infants showed increased looking times following a change in location but not identity or the binding of location and identity information. This evidence is consistent with the idea that young infants are unable to maintain the information processed separately in both the dorsal and ventral visual streams during occlusions. Our results suggest that it is the target's affordance for action that determines whether the dorsal or ventral information is selectively maintained during occlusion.     

The effects of presession attention on problem behavior maintained by different reinforcers

The effect of presession attention on the later occurrence of problem behavior was examined with elementary-school children with a range of disabilities. Results of analogue functional analyses suggested an escape function, an attention function, or both. Following the analogue functional analyses, the effects of two antecedent conditions (10-min ignore vs. 10-min attention) were compared on problem behavior in subsequent test conditions. For participants who displayed attention-maintained problem behavior, the test condition involved contingent attention for problem behavior. For participants who displayed escape-maintained problem behavior, the test condition involved contingent escape for problem behavior. Results indicated that participants who displayed attention-maintained problem behavior displayed less problem behavior following presession exposure to attention than when ignored. No such effect was found for presession attention on escape-maintained problem behavior. We discuss matching antecedent-based interventions to the results of functional analysis.     

Infants perceiving and acting on the eyes: tests of an evolutionary hypothesis

It has been hypothesized that an evolutionarily ancient mechanism underlies the ability of human infants to detect and act upon the direction of eye gaze of another human face. However, the evidence from behavioral studies with infants is also consistent with a more domain-general system responsive to the lateral motion of stimuli regardless of whether or not eyes are involved. To address this issue three experiments with 4-month-old infants are reported that utilize a standard face-cueing paradigm. In the first experiment an inverted face was used to investigate whether the motion of the pupils elicits the cueing effect regardless of the surrounding face context. In the second experiment pupil motion and eye gaze direction were opposed, allowing us to assess their relative importance. In a third experiment, a more complex gaze shift sequence allowed us to analyse the importance of beginning with a period of mutual gaze. Overall, the results were consistent with the importance of the perceived direction of motion of pupils. However, to be effective in cueing spatial locations this motion needs to be preceded by a period of direct mutual gaze (eye contact). We suggest that evolution results in information-processing biases that shape and constrain the outcome of individual development to eventually result in adult adaptive specializations.     

Remembering chosen and assigned options

Recent studies have shown systematic choice-supportive memory for past choices, wherein people tend to overattribute positive features to options they chose and negative features to unchosen options (Mather & Johnson, 2000, Mather, Shafir, & Johnson, 2000). In contrast, the present experiments showed no choice-supportive memory bias for assigned options. Rather than having a general motivation to recall the chosen or the assigned option in a more positive light, people appear to be influenced by heuristics that vary with context: In recalling past choices, people expect the chosen option to contain more positive and fewer negative features than do its competitors. In recalling past assignments, in contrast, people expect the assigned option to be remembered better than the unassigned alternatives. This vividness heuristic leads to systematic misattribution of new features to unassigned alternatives, but not in a manner supportive of the assigned option. Some implications of these findings are discussed.     

Inferring the mental processes of other minds

In 4 experiments, the authors examined how several variables influence the quality and quantity of information that people use to make judgments about other people. The results showed that when possible, participants consistently responded appropriately to variables that influenced information that they used to make inferences about other minds. The results also suggested that under circumstances with no opportunity to contrast behavior in different situations, people might not be sensitive to the quality and quantity of information present. The authors interpreted results to mean that under most circumstances, people make inferences in a way that efficiently uses information about the causes of behavior.