Elevation and reduction of plasma tryptophan and their effects on aggression and perceptual sensitivity in normal males

Data from experimental animals suggest that 5-hydroxytryptamine (5HT) may have an inhibitory effect on aggression, while clinical studies have found a correlation between pathological aggression and low brain 5HT. To investigate this relationship further we used amino acid mixtures designed to raise or lower the levels of the 5HT precursor, tryptophan. Normal male subjects were given tryptophan-depleted, balanced, or tryptophan-supplemented ammo acid mixtures and tested for aggression 5 hours later. The balanced amino acid mixture served as a control for the tryptophan depletion and supplementation. Testing for aggression was done using the Buss paradigm in which subjects deliver electric shocks to a (nonexistent) partner in response to stimulus tones. Duration and intensity of shock delivered were the measures of aggression, while responsivity to the stimulus tones was the measure of perceptual sensitivity. Neither tryptophan supplementation nor tryptophan depletion had any effect on these measures of aggression or perceptual sensitivity. We conclude that raising or lowering the synthesis of brain 5HT through alterations in tryptophan availability does not influence aggression in normal males as measured by the Buss task.     

Psychoanalytic patients in the U.S., CANADA,and Australia: I. DSM-III-R disorders,indications, previous treatment,medications, and length of treatment

To determine the demographics, DSM-III-R disorders diagnosed, indications used in recommending psychoanalysis, previous treatment histories, use of medication, and length of treatment in patients in psychoanalysis in the U.S., Canada, and Australia, a mail survey of practice was sent to every other active member of the American Psychoanalytic Association and every member of the Australian Psychoanalytical Society. This supplemented an earlier survey sent to all Ontario psychoanalysts. The response rates were 40.1 % (n = 342) for the U.S., 67.2% (n = 117) for Canada, and 73.9% (n = 51) for Australia. Respondents supplied data on 1,718 patients. The employment rate for patients increases as analysis progresses (p < .0001). The mean number of concurrent categories of disorders (Axis I, Axis II, and Disorders First Evident in Childhood) per patient at the start of treatment is 5.01 (SD = 3.66; median = 4; mode = 3). There are no statistically significant differences across countries. Mood, anxiety, sexual dysfunction, and personality disorders are most common. American Psychiatric Association / American Psychoanalytic Association peer review criteria for indicating psychoanalysis are followed for 86.5% of patients. Over 80% of patients in all three countries had undergone previous treatments prior to analysis. In the U.S., 18.2% of analysands are on concurrent psychoactive medication; in Australia, 9.6%. The mean length of analyses conducted in the U.S. is 5.7 years, in Australia 6.6, and in Canada 4.8. Psychoanalytic patients in all three countries have similar rates of DSM-III-R psychopathology, and many indications of chronicity.     

Dispelling the illusion of invulnerability: the motivations and mechanisms of resistance to persuasion

Three studies examined the impact of a treatment designed to instill resistance to deceptive persuasive messages. Study 1 demonstrated that after the resistance treatment, ads using illegitimate authority-based appeals became less persuasive, and ads using legitimate appeals became more persuasive. In Study 2, this resistance generalized to novel exemplars, persevered over time, and appeared outside of the laboratory context. In Study 3, a procedure that dispelled participants' illusions of invulnerability to deceptive persuasion maximized resistance to such persuasion. Overall, the present studies demonstrate that attempts to confer resistance to appeals will likely be successful to the extent that they install 2 conceptual features: perceived undue manipulative intent of the source of the appeal and perceived personal vulnerability to such manipulation.     

Perceptions of another person's heavy drinking as a function of one's relationship to the drinker a pilot study

Of 301 participants in a telephone survey, 201 could identify a problem drinker within their social networks. In 67 cases the drinker was a partner, in 45 another family member, in 61 a friend, and in 28 a work colleague. Another person's heavy drinking was reported as most disrupting to one's life when that person was a partner or other family member or if one was living in the same residence as the drinker. The exception to this was that reported disruption to respondents' work life was greatest when the drinker was a work colleague. While there appear to be problems for friends and work colleagues, partners and other family members appear to report the most disruption so providing services to family members seems appropriate.     

Background beliefs in Bayesian inference

We report five experiments in which the role of background beliefs in social judgments of posterior probability was investigated. From a Bayesian perspective, people should combine prior probabilities (or base rates) and diagnostic evidence with equal weighting, although previous research shows that base rates are often underweighted. These experiments were designed so that either piece of information was supplied either by personal beliefs or by presented statistics, and regression analyses were performed on individual participants to assess the relative influence of information. We found that both prior probabilities and diagnostic information significantly influenced judgments, whether supplied by beliefs or by statistical information, but that belief-based information tended to dominate the judgments made.     

Lateralization of narrow-band noise by blind and sighted listeners

The effects of varying interaural time delay (ITD) and interaural intensity difference (IID) were measured in normal-hearing sighted and congenitally blind subjects as a function of eleven frequencies and at sound pressure levels of 70 and 90 dB, and at a sensation level of 25 dB (sensation level refers to the pressure level of the sound above its threshold for the individual subject). Using an 'acoustic' pointing paradigm, the subject varied the IID of a 500 Hz narrow-band (100 Hz) noise (the 'pointer') to coincide with the apparent lateral position of a 'target' ITD stimulus. ITDs of 0, +/-200, and +/-400 micros were obtained through total waveform delays of narrow-band noise, including envelope and fine structure. For both groups, the results of this experiment confirm the traditional view of binaural hearing for like stimuli: non-zero ITDs produce little perceived lateral displacement away from 0 IID at frequencies above 1250 Hz. To the extent that greater magnitude of lateralization for a given ITD, presentation level, and center frequency can be equated with superior localization abilities, blind listeners appear at least comparable and even somewhat better than sighted subjects, especially when attending to signals in the periphery. The present findings suggest that blind listeners are fully able to utilize the cues for spatial hearing, and that vision is not a mandatory prerequisite for the calibration of human spatial hearing.     

Assault victimization and suicidal ideation or behavior within a national sample of U.S. adults

Data from a nationally representative sample of 5,238 U.S. adults were used to examine the extent to which physical assault victimization was associated with suicidal ideation or behavior (SIB). The results from multivariable logistic regression analyses indicate that physical assault victimization was positively associated with SIB after adjusting for sociodemographic characteristics and alcohol use (OR = 3.6; 95% CI = 2.4-5.5). Those who were injured during the most recent physical assault (OR = 2.7; 95% CI = 1.2-6.0) and those who were assaulted by a relative (OR = 3.4; 95% CI= 1.0-11.0) or intimate partner (OR = 7.7; 95% CI = 2.7-22.5) were significantly more like to report SIB than victims who were not injured or were assaulted by a stranger. Also, those who were victimized but not injured (OR = 5.6; 95% CI = 3.8-8.2) and those who were victimized by a stranger (OR = 2.9; 95% CI = 1.4-6.0) were more likely to report SIB than non-victims. These results highlight the need for legal, medical, mental health, and social service providers to address the co-occurrence of violent victimization and suicidal ideation, particularly, but not exclusively, victimization by family members and intimates.     

Change in cognitive functioning associated with apoE genotype in a community sample of older adults

The influence of a genetic risk factor, apolipoprotein E (apoE) epsilon4 variant, was assessed in older adults aged 70 to 94 on 3 occasions over 7 years. The results of latent growth curve analyses are reported for individuals genotyped for apoE at the 2nd measurement occasion (n = 601) and for a subsample of individuals without probable or definite dementia during the 1st or 2nd occasion (n = 434). ApoE-epsilon4 status was a significant predictor of level and change in memory performance and change in speed performance in the full sample, and of initial level and change in memory performance in the nondemented subsample. These results support previous findings that apoE-epsilon4 is associated with accelerated memory deterioration in individuals without clinical dementia.     

Cruise ships and kayaks: welfare and rehabilitation approaches for women with disabilities in poverty

Women with disabilities have low employment rates and about one-third live in poverty. They represent half of the population using either services of the vocational rehabilitation (VR) system or the welfare system, and many use both. Although both systems have made gains in improving their employment status, neither comprehensively addresses the needs of this population. Welfare policy has encouraged state level innovation and moved large numbers of people into employment in as little as five years. State welfare agencies offer a range of services specifically addressing the needs of families with children. VR agencies have decades of specific experience assisting people with disabilities gain employment. Welfare reform has been the cruise ship moving large numbers of people across an ocean. VR agencies have been the kayak builders designing specialized small craft to move specific people along tributaries. What can they learn from each other? Copyright © 2002 John Wiley & Sons, Ltd.     

Carryover effects associated with the single-trial passive avoidance learning task in the young chick

The single-trial passive avoidance task is a useful procedure for examining learning and memory in the young chick. However, it has recently been suggested that discrepant results reported by different laboratories are due to differences in training procedure. The present study investigated a number of parameters surrounding the passive avoidance task, using day-old White Leghorn, Black Australorp cockerels. The results suggested that presentation of a water-dipped bead immediately after the aversive bead significantly altered retention levels. In addition, when the water-dipped bead was presented after the aversive bead, chicks failed to discriminate between beads for a period of 10 min following exposure to the aversant experience. A novel variant of the passive avoidance procedure, involving pretraining with a water-dipped red bead, training with an aversant-coated red bead, and testing with a dry red bead, was evaluated. A measure of avoidance was calculated using all three trials. It is suggested that the use of a single bead, measured both before and after the training experience and using both aversant- and water-trained controls, results in the most concise characterization of memory-related phenomena in the chick which is not contaminated by a carryover effect from the aversive training experience to the nonaversive bead.