AIDS prevention for intravenous drug users in the community: Street-based education and risk behavior

Conducted a study of behavior change associated with a street-based AIDS education project targeted to intravenous (IV) drug users in San Francisco. Two cross-sections were sampled from drug detoxification clinics and street locations in 1986 (n = 438) and 1987 (n = 623). Significant increases were reported in the percentage of IV drug users who used bleach to decontaminate syringes, who did not share needles in past year, and in condom use. A significant reduction in an index of the number of needle-sharing partners was reported. Respondents ranked treatment program as most important source of AIDS information prior to implementation of the program, and ranked outreach workers as most important after implementation. Findings suggest that this community-based outreach program had at least some impact on knowledge about AIDS and may have led to reductions in behaviors known to transmit HIV.     

Individual differences in working memory during reading with and without parafoveal information: a moving-window study

We examined individual differences in working memory appearing in the effective visual field size while reading Japanese text. Working memory capacity was measured by a Japanese reading span test, and the subjects were divided into high- and low-score groups. Reading performance was measured by reading time, comprehension, and eye movements using a variable moving window through which the subject could read areas of the Japanese text. As the window size decreased, the reading time increased significantly. High-span subjects showed better performance in reading time, comprehension, and fixation duration than low-span subjects even in small visual fields. Interestingly, high-span subjects appear to show better information integration during reading, whereas low-span subjects showed less integration without parafoveal vision. These findings suggest that reading performance was better for subjects with larger working memory resources in a parafoveal restriction condition.     

Robust Improvements on Reasoning Performance Following Discussion in Japan

Group discussion significantly improves performance on intellective problems. However, most experiments have been conducted in Western cultures. Cross‐cultural psychology suggests that members of Eastern cultures might be less likely to benefit from group discussion. One experiment in Japan suggested that this was not the case, but this experiment suffered from some limitations. To address these limitations, Japanese participants were asked to solve an intellective task four times: individually (pre‐test), in small discussion groups (test), individually again (transfer task, post‐test), and individually after a delay (delayed post‐test). The results revealed a robust improvement during group discussion. Groups in which at least one member had found the correct answer individually agreed on it during the discussion. Moreover, and in contrast with results obtained in Western cultures, most groups with no such member also found the correct answer. The gains obtained during discussion were maintained in the transfer tasks. This result provides further evidence that the improvement of reasoning performance in group discussion is a universal phenomenon, and provides support for the practice of collaborative learning in Japan.     

Some determinants of remote behavioral history effects in humans

Undergraduates were exposed to a series of reinforcement schedules: first, to a fixed-ratio (FR) schedule in the presence of one stimulus and to a differential-reinforcement-of-low-rate (DRL) schedule in the presence of another (multiple FR DRL training), then to a fixed-interval (FI) schedule in the presence of a third stimulus (FI baseline), next to the FI schedule under the stimuli previously correlated with the FR and DRL schedules (multiple FI FI testing), and, finally, to a single session of the multiple FR DRL schedule again (multiple FR DRL testing). Response rates during the multiple FI FI schedule were higher under the former FR stimulus than under the former DRL stimulus. This effect of remote histories was prolonged when either the number of FI-baseline sessions was small or zero, or the time interval between the multiple FR DRL training and the multiple FI FI testing was short. Response rates under these two stimuli converged with continued exposure to the multiple FI FI schedule in most cases, but quickly differentiated when the schedule returned to the multiple FR DRL.     

Factors influencing infants’ ability to update object representations in memory

Remembering persisting objects over occlusion is critical to representing a stable environment. Infants remember hidden objects at multiple locations and can update their representation of a hidden array when an object is added or subtracted. However, the factors influencing these updating abilities have received little systematic exploration. Here we examined the flexibility of infants’ ability to update object representations. We tested 11-month-olds in a looking-time task in which objects were added to or subtracted from two hidden arrays. Across five experiments, infants successfully updated their representations of hidden arrays when the updating occurred successively at one array before beginning at the other. But when updating required alternating between two arrays, infants failed. However, simply connecting the two arrays with a thin strip of foam-core led infants to succeed. Our results suggest that infants’ construal of an event strongly affects their ability to update memory representations of hidden objects. When construing an event as containing multiple updates to the same array, infants succeed, but when construing the event as requiring the revisiting and updating of previously attended arrays, infants fail.     

Rorschach Comprehensive System data for a sample of 190 Japanese nonpatient children at five ages

This study is a part of our series of studies of nonpatient, Japanese children. In total, 346 children were administered the Rorschach. Thirty-two children had fewer than 10 responses, 112 children had more than 10 but fewer than 14 responses, and 12 children were maladjusted or mentally retarded, for a total of 156. In this study, we analyzed the remaining 190 children not excluded by the above criteria in the following age groups: 5 years (n = 24), 8 years (n = 43), 9 years (n = 42), 12 years (n = 42), and 14 years (n = 39). Japanese children showed few responses generally, with an average of 18 ~ 20 responses. In addition to having fewer responses, other features of Japanese children are high Lambda, low EA, very high X-%, and low X+%. The fact that the Rorschach test depends on verbal expression may be one factor in all these features, and we should consider this study in view of these Japanese cultural factors. Interrater reliability findings and Rorschach Comprehensive System (CS; Exner, 1995; Matsumoto, 2003; Matsumoto et al., 2002) data are presented.     

Differences in adrenocortical secretory and gene expression responses to stimulation in vitro by ACTH or prolactin between high- and low-avoidance Hatano rats

Rats of the Hatano high-avoidance (HAA) and low-avoidance (LAA) strains have been genetically selected on the basis of their two-way active avoidance behavior, and have different endocrine responses to stress. The present study focused on the adrenal steroid hormone responses of the Hatano strains and identifies differences in regulation of the adrenal cortex in vitro of HAA and LAA rats. Although incubation with prolactin (PRL) and/or adrenocorticotrophic hormone (ACTH) resulted in a dose-dependent increase of corticosterone and progesterone release by adrenal cells from both HAA and LAA male rats, the responses were markedly increased for adrenal cells from LAA rats as compared with HAA rats. This finding suggested that adrenal glands of HAA rats are less sensitive to PRL and/or ACTH than adrenals from LAA rats. Several possible intra-adrenal regulators were investigated. The basal level of expression of steroidogenic acute regulatory protein (StAR) and the long form of the PRL receptor (PRLR-L) mRNAs was higher in adrenals of LAA rats. ACTH treatment of adrenal cells from HAA rats resulted in statistically significant increases in melanocortin receptor 2 (MC2R) mRNA expression, while neither ACTH nor PRL altered MC2R mRNA expression in adrenal cells of LAA rats. Conversely, the increase in PRLR-L mRNA expression induced by PRL was observed only in adrenal cells from LAA rats. Treatment of adrenal cells with PRL and/or ACTH increased the expression of StAR and CYP11A1 mRNAs for both Hatano strains. However, the induction of StAR mRNA expression was higher in LAA rats, but the CYP11A1 response was lower. These findings indicate that adrenal cells of the LAA strain have higher sensitivity to secretagogues than those of the HAA strain. These results suggest that PRL may also be important in stimulating secretion of adrenal steroid hormones.     

‘Unwilling’ versus ‘unable’: capuchin monkeys’ (Cebus apella) understanding of human intentional action

A sensitivity to the intentions behind human action is a crucial developmental achievement in infants. Is this intention reading ability a unique and relatively recent product of human evolution and culture, or does this capacity instead have roots in our non‐human primate ancestors? Recent work by Call and colleagues (2004) lends credence to the latter hypothesis, providing evidence that chimpanzees are also sensitive to human intentions. Specifically, chimpanzees remained in a testing area longer and exhibited fewer frustration behaviors when an experimenter behaved as if he intended to give food but was unable to do so, than when the experimenter behaved as if he had no intention of giving food. The present research builds on and extends this paradigm, providing some of the first evidence of intention reading in a more distant primate relative, the capuchin monkey (Cebus apella). Like chimpanzees, capuchin monkeys distinguish between different goal‐directed acts, vacating an enclosure sooner when an experimenter acts unwilling to give food than when she acts unable to give food. Additionally, we found that this pattern is specific to animate action, and does not obtain when the same actions are performed by inanimate rods instead of human hands (for a similar logic, see Woodward, 1998 ). Taken together with the previous evidence, the present research suggests that our own intention reading is not a wholly unique aspect of the human species, but rather is shared broadly across the primate order.     

Reach tracking reveals dissociable processes underlying inhibitory control in 5‐ to 10‐year‐olds and adults

Researchers have proposed that two processes featuring distinct types of inhibition support inhibitory control: a response threshold adjustment process involving the global inhibition of motor output and a conflict resolution process involving competitive inhibition among co‐active response alternatives. To target the development of these processes, we measured the reaching behavior of 5‐ to 10‐year‐olds (Experiment 1) and adults (Experiment 2) as they performed an Eriksen flanker task. This method provided two key measures: initiation time (the time elapsed between stimulus onset and movement onset) and reach curvature (the degree to which a movement deviates from a direct path to the selected target). We suggest that initiation time reflects the response threshold adjustment process by indexing the degree of motoric stopping experienced before a movement is started, while reach curvature reflects the conflict resolution process by indexing the degree of co‐activation between response alternatives over the course of a movement. Our results support this claim, revealing different patterns effects in initiation time and curvature, and divergent developmental trajectories between childhood and adulthood. These findings provide behavioral evidence for the dissociation between global and competitive inhibition, and offer new insight into the development of inhibitory control.     

Neural bases of focusing attention in working memory: An fMRI study based on group differences

Using fMRI, we investigated neural substrates for focusing attention in working memory. To explore this focusing effect, two kinds of reading span test (RST), focused and nonfocused, were performed. In the focused RST (F-RST), the target word to be maintained was the focus word in the sentence. In the nonfocused RST (NF-RST), the target word was not the focus word in the sentence. In both RST conditions, significant activations were found in three main regions: left dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and left superior parietal lobule (SPL). In addition, fMRI signal changes increased in the left SPL in the NF-RST condition. These findings suggest that the neural substrates of focusing attention are based on SPL and ACC-DLPFC networks. Furthermore, there were group differences in the focusing effect between high-span and low-span subjects: High-span subjects showed focusing effects (supported by SPL control) greater than those of low-span subjects.