The enhancement of retention induced by vasopressin in mice may be mediated by an activation of central nicotinic cholinergic mechanisms.

Immediate post-training subcutaneous administration of lysine vasopressin (LVP, 0.003-1.00 microgram/kg) enhanced retention, whereas the vasopressin antagonist AAVP (0.01-0.30 microgram/kg) impaired it, in male Swiss mice tested 48 h after training in an inhibitory avoidance task. Both effects were dose-dependent. Neither LVP nor AAVP affected response latencies in mice not given the footshock on the training trial. The simultaneous administration of AAVP at a dose (0.01 microgram/kg) which had no effect on retention shifted the dose-response curve of LVP to the right. Nicotine (1.0-30.0 micrograms/kg, sc), a central nicotinic cholinergic agonist, also facilitated retention in a dose-related manner without affecting the retention performance of unshocked mice. The effect of nicotine was prevented by the central acting nicotinic cholinergic receptor antagonist mecamylamine (5 mg/kg, sc.). In contrast, neither hexamethonium (5 mg/kg, sc), a peripheral acting nicotinic receptor blocker, nor atropine (0.5 mg/kg, sc) or methylatropine (0.5 mg/kg, sc), two anticholinergic drugs which are known to act on muscarinic cholinergic receptors, prevented the effect of post-training nicotine. The effects of LVP and nicotine were time-dependent, suggesting that both treatments enhanced retention by influencing post-training processes involved in memory storage. Low doses of nicotine (1.50 microgram/kg, sc) or the central anticholinesterase physostigmine (35 micrograms/kg, sc) and LVP (0.003 microgram/kg, sc), which had no effect on retention when administered alone, produced a synergistic interaction when given together following training. The influence of LVP (0.03 microgram/kg, sc) on retention was prevented not only by AAVP (0.01 microgram/kg, sc) but also by mecamylamine (5 mg/kg, sc), whereas the effects of nicotine (10.0 micrograms/kg, sc) were prevented only by mecamylamine. These results suggest that the enhancement of retention induced by vasopressin is probably due to an activation of central nicotinic cholinergic mechanisms which are critical for memory formation.     

Scratching as a behavioral index of anxiety in macaque mothers.

The aim of this study was to assess the validity of the notion that anxiety influences maternal style in monkeys. To this end, we investigated the correlations between measures of the quality of mother-infant relationship and scratching, a behavior pattern that reflects a state of anxiety. The subjects were seven group-living macaque mothers and their infants observed during the first 12 weeks postpartum. Postpartum scratching by the mothers was positively correlated with both maternal possessiveness and maternal warmth, two composite measures of the quality of mother-infant relationship that reflect a possessive and attentive maternal style. Evaluation of the correlations between maternal rank and scratching before and after parturition indicated that interactions with their infants, not those with other group companions, were the main source of anxiety for the mothers. These results support the notion that anxiety influences maternal style in monkeys and suggest that studies aimed at investigating physiological and social correlates of maternal emotionality in nonhuman primates could use scratching as a useful and simple behavioral measure.     

Effects of verbal labeling and exposure duration on implicit memory for visual patterns.

The present study investigated the role of verbal labeling and exposure duration in implicit memory for novel visual patterns. Encoding condition was varied in Experiment 1. Two encoding conditions discouraged verbal labeling and a third required it. In Experiment 2, exposure duration was manipulated to determine whether a new memory representation could be formed after a single 1-s exposure. The results suggest that verbal labeling is not necessary to support priming. Type of encoding did not affect implicit memory, but had a pronounced effect on explicit memory. Furthermore, a single 1-s exposure was sufficient to support priming, and priming was not further enhanced by longer stimulus exposures. In contrast, recognition performance was enhanced by a longer stimulus duration. Thus, priming effects with these novel figures are likely to be supported by newly acquired representations rather than by preexisting memory representations.     

Perceived benefits of marathon running in males and females

The differences in both perceived benefits and attitudes toward running between male and female runners, and between runners who classified themselves as competitive runners (CR) or recreational runners (RR), was the focus of this study. Four-hundred and two runners completed the Ten-Minute Survey for Runners within two weeks of completing a marathon. RR, more so than CR, perceived greater benefits from running. However, CR expressed a more positive attitude toward running and its role in their lives than did RR. Men perceived running to be more beneficial to them than women. However, women, more so than men, felt running had a positive effect on self-image and their lives were richer because of running. Future research concerns on the effects of competition on the lives of women are explored.     

Suicidal behavior in Italy: data, trends and guidelines for a suicide intervention/prevention policy.

Even though in Italy, as in the majority of Mediterranean countries, the increase in suicide rates is not among the highest in Europe, between 1969 and 1989 it showed a sharp upswing (+43% among males and +31% among females). In terms of geographical differences, the regions with the highest suicide rate are the northern ones (up to twice the national average). The age groups with the highest suicide risk are those over 74 years (in 1989 the rate among males over 65 was the highest of all: 31.3 per 100,000). The differences in the between-sexes distribution show that among females over 65 years old the suicide rate rose by 70% between 1974 and 1989, versus 77% for males of the same age. The preliminary epidemiological results of one of two Italian centers are presented. These centers are collaborating with the WHO/EURO Multicenter Study on Parasuicide; parasuicide rates are higher for females than for males (55.9 per 100,000, as against 38.1 for males), while the age group at highest risk is seen to be young women (15-24 years), with a specific rate of 115.6.     

AIDS-related factors predictive of suicidal ideation of low and high intent among gay and bisexual men.

AIDS-related stressors were studied in relationship to suicidal ideation and suicide intent among 778 gay and bisexual men (none with AIDS). Over the previous six months, 27% (n = 212) reported suicidal ideation. Subjects who reported suicidal ideation (compared to those who did not) were more likely to report recent (last 6 months) bereavement of partner, recent ARC diagnosis, and multiple close friends with ARC. Suicide ideators were divided by a median split on a self-report scale of suicide intent into low (n = 105) and high (n = 107) intent suicide ideators. News of HIV seropositivity was specifically related to low intent suicidal ideation. High intent suicidal ideation was associated with having a partner with AIDS or ARC, or multiple close friends with AIDS, or having ARC. Generally speaking, while temporally discrete AIDS-related events were associated the report of suicidal ideation, ongoing stressors which may more greatly challenge adaptational capacities were more associated with high intent suicidal ideation.     

An investigation into the relationships between gender and language

The present investigation focused upon the impact of gender and various powerful and less powerful linguistic features on the communication of unfamiliar male and female college students. Same-sex and mixed-sex dyads were recorded as they engaged in discussions regarding suggestions for a bogus freshman orientation booklet. Although few gender differences were found, the result of a factor analysis yielded three factors: questions, suggestions, and process variables. These factors are consistent with a power perspective in the use of various linguistic features. However, the present findings suggest that gender and power alone cannot explain differences in communication styles. Rather, the results suggest the need to consider other aspects of the speaker to explain differences that occur in the use of language.     

Effect of intrauterine position and social density on age of first reproduction in wild-type female house mice (Mus musculus)

In laboratory strains of mice, reproductive maturation is influenced by both the fetal and the peripubertal social environments experienced by females. Intrauterine position (IUP) for female fetuses is identified by the number of adjacent males; where 0M have zero, 1M have one, and 2M have two male neighbors. We sought to confirm, using wild-type female house mice (Mus musculus), the previous finding in the CF-1 strain of laboratory mouse that males prefer 0M over 2M females as mates. We recorded the age at first reproduction for females of known IUP housed either individually with a male or in a group of 6 females and a male. In neither housing condition were there significant differences in age of first reproduction among females of different IUPs, but 0M females that were group housed had perforate vaginas at an earlier age than other group-housed females. Mean (+/- SE) age at first reproduction was 58.1 (+/- 3.3) for paired and 126.6 (+/- 5.1) for group-housed females. The reproductive suppression observed in the grouped females was probably due to the interaction of inhibitory urinary chemosignals, low body weights, and female dominance hierarchies.     

Subliminal Self-Help Tapes and Academic Achievement: An Evaluation

Marketing claims of effectiveness in improving academic achievement through the use of commercially prepared subliminal audiotapes were investigated. Students enrolled in a career development class were randomly assigned to an active treatment group (n=25), an inactive treatment group (n=26), or a control group (n=22). Participants in the treatment group listened to tapes with subliminal affirmations masked by ocean waves. The inactive treatment group listened to placebo tapes with ocean waves but no subliminal messages. Dependent variables used were final examination scores from the class and current semester grade point average. No treatment differences on either dependent measure were found. The implications of these findings are discussed.     

Effects of short-term retrieval on adult age differences in long-term recall of actions.

In Experiment 1 young and elderly subjects either recalled or repeated after every block of 4 actions, whereas control subjects received neither interpolated short-term recall nor action repetition. On a later long-term memory test, experimental subjects, regardless of age or condition, recalled slightly more actions than control subjects. In Experiment 2 young adult and elderly subjects received 12 short-term memory trials in which 2 actions were performed on each trial, but only 1 was cued for recall after a brief retention interval filled with a distracting activity. On a later long-term memory test for the actions performed on the short-term trials, both young and elderly subjects recalled significantly more previously cued than noncued actions. The Age X Cuing Condition interaction was negligible. Prior retrieval of actions appears to enhance later recall regardless of age but seemingly only when prior retrieval requires considerable cognitive effort (as in Experiment 2).