The effects of a pre-time-out stimulus on matching-to-sample of humans,

In each of two experiments human subjects were intermittently reinforced with money on a fixed-ratio schedule for emitting correct matching responses. A pre-time-out stimulus which signaled removal of positive reinforcement was periodically superimposed. In the first experiment the superimposed pre-time-out stimulus was paired with a 1-min or 4-min response-independent time out. In the second experiment the pre-time-out stimulus was paired with a 1-min or 4-min time out contingent on the incorrect responses. The pre-time-out stimulus did not markedly influence performance when the time out was response independent. In contrast, the pre-time-out stimulus markedly suppressed incorrect responding when the time out was contingent on the incorrect responses. When duration of this time-out was increased from 1-min to 4-min, suppression of incorrect responding increased and correct responding was suppressed. Therefore, behavioral suppression by a pre-time-out stimulus was obtained only when the signaled aversive event-time out-was response produced. In this case, suppression was influenced by time-out duration.     

Characteristics of Suicidality Among Adolescents

The identification of high-risk adolescent suicide attempters in a population of depressed and suicidal adolescents is of crucial importance. This retrospective study examined characteristics of suicidality (recent and lifetime, active and passive) and psychopathology (depression, aggression, impulsivity, stressful life events, SCL-90 dimensions) among four groups of depressed adolescent outpatients: (1) suicide attempters who required medical treatment (n = 84), (2) suicide attempters who did not require medical treatment (n = 57), (3) suicidal ideators who had never made a suicide attempt (n = 40), and (4) nonsuicidal patients (n = 44). Results indicate that the nonsuicidal group could be differentiated from the three suicidal groups on the basis of suicidality and psychopathology, and that the three suicidal groups could be differentiated from one another on the basis of suicidality but not psychopathology. These findings are discussed in terms of the usefulness of certain self-report measures of suicidality for identifying suicidal adolescents and for differentiating among them. Furthermore, the findings suggest that psychopathological factors do not determine which suicidal adolescents make a medically dangerous suicide attempt and which do not.     

The bed nucleus of the stria terminalis is required for the expression of contextual but not auditory freezing in rats with basolateral amygdala lesions

Previous data suggest that overtraining can overcome fear conditioning deficits in rats with lesions of the basolateral complex of the amygdala (BLA). We have previously shown that the central nucleus of the amygdala (CEA) is essential for the acquisition and expression of conditional fear to both contextual and auditory conditioned stimuli (CSs) after overtraining. This provides strong evidence that the CEA can compensate for the loss of the BLA. Another brain area that may compensate for the loss of the BLA is the bed nucleus of the stria terminalis (BNST). We explored this possibility by examining the consequences of lesions or reversible inactivation of the BNST on the expression of overtrained fear in rats with BLA lesions. We demonstrate that lesions or inactivation of the BNST block the expression of freezing to the conditioning context, but not to an auditory conditional stimulus. These results reveal that the BNST has a critical role in the expression of contextual fear, but not fear to an auditory CS, and is therefore not the essential locus of compensation for fear learning in the absence of the BLA.     

How similar is false recognition to veridical recognition objectively and subjectively?

Three recognition memory experiments were conducted using modified Deese-Roediger-McDermott (DRM) and DRM paradigms. In Experiment 1, the reaction time (RT) of the false alarms to critical nonpresented words (false memory) was compared with the RT of hits to the critical presented words and with the RT of hits to the studied list words (true memory). The RT of the false alarms to the critical nonpresented words was significantly longer than that of the hits to the critical words and than that of the studied list words. In Experiment 2, in addition to RT, participants' confidence level was measured on a 4-point scale for a yes or no response. Confidence rating was significantly higher for the hits to the critical presented words and to the list words than for the false alarms to the critical non-presented words. Experiment 3 further showed that how similar false memory experience was to that of true memory was a function of retention size (number of lists of words retained in memory). In all three experiments, the participants' recognition RTs distinguished false memory from veridical memory, and in Experiments 2 and 3, so did their confidence ratings. Therefore, false memory and veridical memory differ at both the objective and the subjective levels. The results are consistent with a single familiarity dimension model of recognition memory.     

Self-presentations of happiness: sincere, polite, or cautious?

Two studies addressed the meaning of expressed happiness in social relationships. In the first study, men expected to interact with a socially desirable or a socially undesirable woman. It was predicted that (a) when about to meet a socially undesirable woman, men would display more happiness publicly than is felt privately and (b) when about to meet a socially desirable woman, men would display less happiness publicly than felt privately. Results supported the former and tended to support the latter prediction. In the second study, the authors predicted that women would mistrust men's expressions of happiness upon meeting them such that (a) unattractive women would suspect men of inflating happiness and (b) attractive women would suspect men of suppressing happiness. Results supported the former but not the latter hypothesis. Taking relationship-specific goals into account appears to be important in determining whether emotion will be accurately conveyed and can be trusted.     

Capacities, context and moral status of animals

According to a widely shared intuition, normal adult humans require greater moral concern than normal, adult animals in at least some circumstances. Even the most steadfast defenders of animals' moral status attempt to accommodate this intuition, often by holding that humans' higher-level capacities (intellect, linguistic ability, and so on) give rise to a greater number of interests, and thus the likelihood of greater satisfaction, thereby making their lives more valuable. However, the moves from capacities to interests, and from interests to the likelihood of satisfaction, have up to now gone unexamined and undefended. I argue that context plays a morally significant role both in the formation of an individual's capacities, and in the determination of the individual's interests and potential for satisfaction based on those capacities. Claims about an individual's capacities and interests are typically presented as unconditional; but on closer examination, they are revealed to be contingent on tacit assumptions about context. Until we develop an understanding of how to account for the role of context within our moral theories, attempts to defend special moral concern for human beings based on their superior capacities are less firmly grounded than is commonly thought.     

A closer look at preschoolers' freely produced labels for facial expressions

Children's performance on free labeling of prototypical facial expressions of basic emotions is modest and improves only gradually. In 3 data sets (N = 80, ages 4 or 5 years; N = 160, ages 2 to 5 years; N = 80, ages 3 to 4 years), errors remained even when method factors (poor stimuli, unavailability of an appropriate label, or the difficulty of a production task) were controlled. Children's use of emotion labels increased with age in a systematic order: Happy, angry, and sad emerged early and in that order, were more accessible, and were applied broadly (overgeneralized) but systematically. Scared, surprised, and disgusted emerged later and often in that order, were less accessible, and were applied narrowly.     

Screening for principal versus comorbid conditions in psychiatric outpatients with the Psychiatric Diagnostic Screening Questionnaire

In examining the performance of screening scales, a distinction should be made between principal and additional diagnoses. The Psychiatric Diagnostic Screening Questionnaire (PDSQ) is a brief, psychometrically strong self-report scale designed to screen for the most common Diagnostic and Statistical Manual of Mental Disorders (4th ed; DSM-IV) Axis I disorders encountered in outpatient mental health settings. In the present report, the authors compared the performance of the PDSQ in identifying principal and comorbid disorders. Seven hundred ninety-nine psychiatric outpatients completed the PDSQ and were interviewed with the Structured Clinical Interview for DSM-IV. The sensitivity and negative predictive values of the PDSQ subscales were similar for principal and additional diagnoses.