Neurochemical changes correlated with behavior maintained under fixed-interval and fixed-ratio schedules of reinforcement.

Key pecking of 4 pigeons was maintained under a multiple 3-min fixed-interval, 30-response fixed-ratio schedule of food presentation. Only one schedule was in effect during an experimental session, and each was correlated with a different keylight stimulus and location (left vs. right). The different schedule components alternated across days or weeks. Cerebrospinal fluid was collected from chronically implanted intracerebroventricular cannulae following sessions with the different schedules, as well as following sessions in which reinforcement was withheld (extinction), when response-independent food was delivered, and when the experimental chamber was dark and there were no scheduled events. Metabolites of the neurotransmitters serotonin, norepinephrine, and dopamine were assayed in cerebrospinal fluid using high-performance liquid chromatography with electrochemical detection. Compared to the fixed-ratio condition, responding maintained under the fixed-interval schedule resulted in consistently higher levels of the serotonin metabolite 5-hydroxyindoleacetic acid and of the dopamine metabolite homovanillic acid in all pigeons. Levels of 3-methoxy-4-hydroxyphenylethylene glycol, a metabolite of norepinephrine, and dihydroxyphenylacetic acid, another dopamine metabolite, were also higher in 3 of the 4 pigeons following exposure to the fixed-interval schedules when compared to levels of these metabolites after exposure to the fixed-ratio schedule. Extinction of fixed-ratio responding resulted in large increases in 5-hydroxyindoleacetic acid compared to levels of this metabolite under the fixed-ratio schedule, whereas this serotonin metabolite decreased during extinction of responding under the fixed-interval schedule. Control procedures suggested that the neurochemical changes were not related to the rate of responding but were a function of the specific experimental conditions. Distinctive neurochemical changes that accompany schedule-controlled responding show the sensitivity of the neurochemical environment to behavioral contingencies and demonstrate further the profound impact that such contingencies have on biobehavioral processes.     

Examining Attachment to God and Health Risk-Taking Behaviors in College Students

Drawing on insights from attachment theory, this study examined whether three types of attachment to God—secure, avoidant, and anxious—were associated with health-risk behaviors, over and above the effects of religious attendance, peer support, and demographic covariates, in a sample of 328 undergraduate college students. Contrary to prior theory, secure attachment to God is not inversely associated with recent alcohol or marijuana use, or substance use prior to last sexual intercourse. Instead, avoidant and anxious attachment to God are associated with higher levels of drinking; anxious attachment to God is associated with marijuana use; and avoidant attachment to God is associated with substance use prior to last sexual intercourse. These patterns are gender-specific; problematic attachment to God is linked with negative outcomes solely among men.     

The brain basis of emotion: a meta-analytic review

Researchers have wondered how the brain creates emotions since the early days of psychological science. With a surge of studies in affective neuroscience in recent decades, scientists are poised to answer this question. In this target article, we present a meta-analytic summary of the neuroimaging literature on human emotion. We compare the locationist approach (i.e., the hypothesis that discrete emotion categories consistently and specifically correspond to distinct brain regions) with the psychological constructionist approach (i.e., the hypothesis that discrete emotion categories are constructed of more general brain networks not specific to those categories) to better understand the brain basis of emotion. We review both locationist and psychological constructionist hypotheses of brain-emotion correspondence and report meta-analytic findings bearing on these hypotheses. Overall, we found little evidence that discrete emotion categories can be consistently and specifically localized to distinct brain regions. Instead, we found evidence that is consistent with a psychological constructionist approach to the mind: A set of interacting brain regions commonly involved in basic psychological operations of both an emotional and non-emotional nature are active during emotion experience and perception across a range of discrete emotion categories.     

Hurricane Andrew: Psychological distress among shelter victims

This study examined psychological distress and functioning among Hurricane Andrew victims who lost their homes and were living in shelters. Four and one-half weeks after Hurricane Andrew struck southern Florida, 89 (45 males, 44 females) Blacks, Hispanics, and Whites completed a questionnaire. The questionnaire asked for information about psychological and psychophysiological symptoms, use of mental health services, coping responses, and extent of preparation for the storm. The findings suggest that loss of home and property were related to distress and depression. About one-quarter of the sample were moderately depressed. Over one-third of the sample reported experiencing psychological and psychophysiological distress. Approximately one-half of the subjects did not take the hurricane warnings seriously. White subjects began preparing earlier for the storm, and evacuated their homes more frequently than did Black subjects. Implications of the findings and future research directions are discussed.     

The single-mind and many-minds versions of quantum mechanics

There is a long tradition of trying to find a satisfactory interpretation of Everett's relative-state formulation of quantum mechanics. Albert and Loewer recently described two new ways of reading Everett: one we will call the single-mind theory and the other the many-minds theory. I will briefly describe these theories and present some of their merits and problems. Since both are no-collapse theories, a significant merit is that they can take advantage of certain properties of the linear dynamics, which Everett apparently considered to be important, to constrain their statistical laws.     

Religion and Attitudes Toward Family Planning Issues Among US Adults

Although religion is an important influence on a variety of social attitudes, the relationship between religion and views on family planning remains underexplored, especially in terms of attitudes relating to public policy. Using data from a nationally-representative survey (N = 1,500) fielded in 1998, we examine the influence of religious affiliation, subcultural identification, and attendance on three aspects of attitudes toward contraception in the public sphere. Specifically, we explore opinions regarding the public consequences of contraception and the responsibility for making contraception available as part of health care services in the United States. More frequent religious attendance is linked to less-approving opinions about contraception and less support for its provision by the US government and health insurers. Catholic affiliation is not consistently associated with the examined opinions, and we find mixed results for conservative Protestants. Including religious subcultural identities yields additional information, with born-again Christians reporting less positive opinions about the consequences of contraceptive availability, while evangelical identity is linked to negative views on policy aimed at increasing access to family planning services. These findings contribute to knowledge about the relationship between religion and attitudes toward policy-relevant aspects of contraception, as well as the broader social influences of religious subcultural identification.     

Development of the Grief Experience Questionnaire

The development of the Grief Experience Questionnaire (GEQ) is reported. This questionnaire is an instrument for measuring various components of grief, including somatic reactions, general grief reactions, search for explanation, loss of social support, stigmatization, guilt, responsibility, shame, rejection, self-destructive behavior, and reactions to a unique form of death. Initial results with the GEQ suggest its potential to differentiate grief reactions experienced by suicide survivors from those experienced by survivors of accidental death, unexpected natural death, and expected natural death. Conclusions support its use in redressing common methodological criticisms of suicide survivor research. Six additional benefits derived from use of this instrument are discussed.