Possible olfaction-based mechanisms in human kin recognition and inbreeding avoidance

Three studies explored kin recognition through olfaction. In Study I, adults (N=22) were tested for ability to identify the odors of themselves; their mother; their father; a sister; a brother; a familiar, unrelated individual; and a stranger. Acquaintances were identified as accurately as biological kin, implicating an association mechanism. However, biological kin were often confused, implicating phenotypic matching. Same-sex kin were confused more than opposite-sex kin, but mainly when same-sex kin had odors of similar intensity. Study II implicated phenotypic matching. Mothers (N=18) could identify their biological children but not their stepchildren. The preadolescent children (N=37) identified their full siblings but not half-siblings or stepsiblings. Thus, olfactory cues may help mediate favoritism of blood relatives. In Study III, mutual olfactory aversion occurred only in the father-daughter and brother-sister nuclear family relationships. Recognition occurred between opposite-sex siblings but not same-sex siblings. Thus, olfaction may help mediate the development of incest avoidance during childhood (the Westermarck effect).     

Facilitation of Sodium Aversion Learning in Sodium-Deprived Rats

Two experiments with rats explored the effects of sodium deprivation induced by furosemide injections upon acquisition of taste aversion to sodium chloride (NaCl). In Experiment 1, rats under either sodium deprivation or a balanced nutrition condition were given access to a limited amount of NaCl solution prior to poisoning. When all rats were tested under sodium repletion, the previously sodium-deprived rats consumed less NaCl than did the nondeprived rats. This finding was replicated in Experiment 2A in which ingestion of a compound solution of NaCl and hydrochloric acid (HCl) was followed by poisoning. Consumption of HCl, however, showed the opposite pattern: the sodium-deprived rats drank more HCl than did the nondeprived rats, a result that was replicated in Experiment 2B. These results suggest that sodium deprivation strengthens the salience of NaCl, thereby facilitating acquisition of aversion to this taste and strongly overshadowing that to a simultaneously presented taste.     

Drug discrimination using a conditioned taste-aversion paradigm in rhesus monkeys.

The development of drug discrimination was assessed in rhesus monkeys using the conditioned taste-aversion paradigm. Monkeys were initially trained to respond under a fixed-ratio 30-response schedule of food-pellet delivery to assess the rate-decreasing effects of alprazolam (0.03 to 3 mg/kg, i.m., 60 min presession). Alprazolam decreased responding at doses greater than 0.1 mg/kg. Discriminative stimulus effects of alprazolam were then assessed by giving 0.03 mg/kg before sessions in which 1.8 mEq/kg lithium chloride was given immediately after the session (alprazolam/lithium session). On intervening days, saline was given before and after the session (saline/saline session). Rates of responding decreased over successive alprazolam/lithium sessions and also during the saline/saline session that immediately followed an alprazolam/lithium session. During subsequent saline/saline sessions, rates of responding returned to levels near baseline rates within two to four sessions. The discriminative stimulus effects of alprazolam were then assessed by giving 0.1 mg/kg before sessions in which 1 mg/kg d-amphetamine was given immediately after the session (alprazolam/d-amphetamine session). Rates of responding decreased during subsequent alprazolam/d-amphetamine sessions in drug-experienced monkeys, but did not decrease during intervening saline/saline sessions. These findings demonstrate that drug stimuli associated with postsession drug injections can rapidly develop control over behavior and suggest that similar methods be explored in the assessment of drug discrimination.     

Food choice in rats (Rattus norvegicus): the effect of exposure to a poisoned conspecific

Three experiments were conducted to examine the effects of exposure to a poisoned conspecific on subsequent food aversion in rats. In Experiment 1A, rats that had been aversively conditioned to a cocoa-flavored food were exposed to a poisoned conspecific that had eaten the same food. On the subsequent choice test, the animals increased their aversion to that food. These results were reconfirmed in Experiment 1B, in which a cinnamon-flavored food was used as the stimulus. In Experiment 2, subjects were first exposed to a poisoned conspecific and then conditioned to the food which the conspecific had eaten. On the test, they showed no sign of increased aversion to that food.     

味觉厌恶性条件反射与条件反射性免疫抑制的研究

以环磷酰胺的注射为非条件刺激（ＵＣＳ）,糖精水的摄入为条件刺激（ＣＳ）,并以血白细胞和淋巴细胞数量及脾淋巴细胞的转化反应为免疫指标,糖精水的饮用量为行为指标,通过改变条件刺激与非条件刺激结合的次数来观察条件反射性厌恶行为与条件反射性免疫抑制的反应。结果表明不管是一次性的还是两次性的ＣＳ－ＵＣＳ结合训练都能使动物明显地建立起味觉厌恶性条件反射,然而条件反射性免疫抑制只在两次性ＣＳ－ＵＣＳ结合训练后才     

Parental loss of close family members and propensities towards absorption in offspring

Parental unresolved/disorganized responses to loss assessed in the Adult Attachment Interview predict infant disorganized (D) attachment. Parental experiences of loss near the birth of an infant should therefore increase the likelihood of D attachment to that parent. Liotti (1992) suggested that D attachment may increase tendencies to altered states of consciousness, and some support for this hypothesis has been obtained in clinical and high-risk samples. Here, Tellegen's Absorption Scale was used to measure propensities to altered consciousness in two low-risk samples of young adults (N=136, N=308). In both studies, participants whose parents experienced familial loss within two years of their birth showed elevated levels of absorption. These outcomes (a) support the proposed connection between disorganized attachment and tendencies to altered consciousness, and (b) suggest that queries regarding parental loss experiences should be further explored as a ‘rough and ready’ estimate of disorganized attachment in large-scale studies.     

Ambiguity seeking in multi-attribute decisions: Effects of optimism and message framing

This paper investigates the influence of message framing and personality variables on preferences over ambiguity in the context of multi-attribute decision scenarios. Undergraduate subjects responded to scenarios in which one of two medical treatments was associated with ambiguous probabilities of treatment effects. Probabilities were either positively or negatively framed. Subjects indicated their degree of preference for one treatment over the other. Subjects' optimism, trait anxiety, health locus of control, need for cognitive structure, and current mood were measured. In two separate studies, subjects preferred ambiguity when probabilities were positively framed, and were neutral toward ambiguity when probabilities were negatively framed. Also, in both studies the preference for ambiguity in positively framed scenarios was greater for more optimistic subjects. The unexpected finding of ambiguity seeking may be associated with the use of different decision strategies in multi-attribute versus single-attribute decisions.     

THEORETICAL,PRACTICAL, AND SOCIAL ISSUES IN BEHAVIORAL TREATMENTS OF OBESITY

Although showing superior maintenance, behavioral treatments of obesity typically produce small weight losses at a decelerating rate. Rather than reflecting poor compliance with treatment, these findings are consistent with known compensatory metabolic changes that operate to slow weight loss and promote regain. Other problems associated with dieting include failure of caloric regulation, hyper-responsivity to food palatability, and hunger, which is greatest under conditions of moderate restriction and unpredictability of access to food. The inevitability of treatment failure in many instances must be faced and efforts made to prevent further worsening of the obese patient's self-esteem. Prognosis and treatment planning may be aided by consideration of the historical difficulties of weight loss, the degree of hunger experienced on diets, which may reflect important physiological differences among individuals, and the use of food to optimize arousal level. Full involvement of the patient in setting goals and planning treatment is recommended.     

Contingency-shaped and rule-governed behavior: instructional control of human loss avoidance

Instructions can override the influence of programmed schedules of reinforcement. Although this finding has been interpreted as a limitation of reinforcement schedule control in humans, an alternative approach considers instructional control, itself, as a phenomenon determined by subjects' reinforcement histories. This approach was supported in a series of experiments that studied instructional and schedule control when instructions either did or did not accord with the schedule of reinforcement. Experiment I demonstrated that accurate instructions control discriminative performances on multiple avoidance schedules, and that such control persists in a novel discrimination. Experiments II and III showed that elimination of instruction-following occurs when inaccurate instructions cause subjects to contact a monetary loss contingency. Experiment IV demonstrated the reinforcing properties of accurate instructions. Skinner's view of rule-governed behavior is consistent with these findings, and can be extended to account for many aspects of instructional control of human operant behavior.     

Loss context enhances preferences for generosity but reduces preferences for honesty: Evidence from a combined behavioural-computational approach

The current literature has revealed mixed evidence on whether loss (vs. gain) context promotes or curtails human prosociality. The current study (N=96) aimed to address this issue by examining whether gain/loss context has distinct effects on different prosocial preferences combining computational modelling with Dictator Game and Message Game. These interactive games allow for dissociating preferences for generosity and honesty, which have been respectively associated with intuitive and deliberative systems. Our behavioural and computational modelling results indicate that loss context enhances concerns for generosity but reduces concerns for honesty. These findings support an account under the framework of dual process model asserting that loss facilitates intuitive responses during social decision-making, regardless of whether they are prosocial or proself. The current findings reconcile previous debates on the relationship between loss-gain context and human prosociality and shed light on the design of institutions to promote human prosocial behaviours.