The role of intermittent food in the induction of attack in pigeons

The present experiments evaluated whether transitions in reinforcer probability are necessary to induce attack in pigeons. In Experiment I, three of six pigeons exposed to response-contingent constant-probability food schedules and a photograph of a conspecific as a target exhibited sustained postreinforcement attack on the target. The postreinforcement pattern of attack developed over the course of the experiment and was accompanied by a reduction in the rate of postreinforcement key pecking and an increase in the postreinforcement pause in key pecking. These effects on key pecking resulted in unprogrammed variations in the probability of reinforcement which may have been responsible for the induction of attack. In Experiment II, the attack-inducing properties of a constant-probability response-independent food schedule were compared to a periodic food schedule matched for overall rate of food delivery and to a no-food condition. In addition to attack, the spatial location of the subjects was monitored during each interfood interval. The periodic and aperiodic food schedules generated very different patterns of spatial location. Postfood attack was induced by both food schedules, although the constant-probability schedule induced attack in fewer birds. The no-food condition was not effective in inducing attack in any birds. These experiments indicate that intermittent food schedules without reductions in reinforcer probability are sufficient to induce attack in some pigeons, although not as effective as schedules with transitions in reinforcer probability.     

Cognitive Behavioral Treatment of PTSD with Comorbid Panic Attacks

Many individuals that experience traumatic events such as sexual and physical assault develop posttraumatic stress disorder (PTSD). More recently, research has indicated that a significant proportion of PTSD sufferers may also have comorbid panic attacks. Although there are several effective treatments that focus on alleviating PTSD symptoms, until now there were no treatments that focused on also treating comorbid panic attacks. Multiple channel exposure therapy (M-CET) is the first treatment developed to specifically treat comorbid PTSD and panic attacks. It is also unique in that it has been used to treat women who have multiple trauma histories as well as a wide range of different types of traumatic event exposure in a group format. This treatment is described in a session by session format and special considerations in implementing the treatment are discussed.     

Sexual and aggressive play fighting of sibling Richardson’s ground squirrels

Play fighting in many species of squirrels can involve sexual play and aggressive play, both of which can lead to wrestling which appears superficially similar. Such convergence can make scoring of the relative frequencies of these two types of play difficult and can lead to the mistaken conclusion that they grade into one another. In this study, both staged laboratory encounters between sibling pairs and spontaneous encounters between siblings in free‐living litters of Richardson’s ground squirrels (Spermophilus richardsonii) were videotaped. Frame‐by‐frame analyses using the Eshkol‐Wachman Movement Notation were employed to record the correlated movements of attack and defense by the partners and to reveal the body areas targeted during each play bout. Whereas sexual play was organized around access to the rump, aggressive play was organized around the shoulders. Although in most cases the defender’s tactics blocked access to the respective target, when contact did occur, it involved mounting in sexual play and nosing or biting in aggressive play. Eighty‐six percent of play fights could be unambiguously categorized as either sexual or aggressive play. Of these, the majority (?80%) involved sexual play. The sex of the participants did not affect the frequency of aggressive play, but in sexual play, males initiated more attacks than females. Once initiated, each form of play fighting remained distinct—if a bout began as sexual play, it would end as sexual play. Furthermore, a counterattack following sexual play was significantly more likely to be sexual than aggressive, and vice versa for counterattacks following aggressive play. Therefore, all the evidence suggested that the two forms of play fighting were not intermixed in Richardson’s ground squirrels. Aggr. Behav. 27:323–337, 2001. © 2001 Wiley‐Liss, Inc.     

Naloxone differentially alters parental aggression by female mice towards conspecific intruders of differing sex

Lactating mice respond differently to male and female conspecific intruders, displaying defensive attack towards the former and offensive attack towards the latter. Two studies are reported in which the effects of naloxone on this differential response pattern were assessed. In the first study, lactating residents were pretreated with saline or naloxone (0.5, 2.5 mg/kg) and consecutively confronted with intruders of differing sex. Results suggested that attack (offensive) against female conspecifics is more sensitive to the inhibitory effects of opiate-receptor blockade than attack (defensive) on males. This conclusion was strengthened in a follow-up study, in which independent groups of lactating residents were used to further examine the effects of naloxone (0.5 mg/kg) on response to male and female intrusion. Analysis indicated that this low dose of naloxone significantly inhibited attack on female, but not on male, intruders. Indeed, in response to male, but not to female, intrusion, naloxone-treated residents showed a significant increase in fear-related behaviour. Findings are discussed in relation to the motivational differences in the response of lactating mice to intruders of differing sex and to possible mechanisms underlying the reported differential effects of opiate-receptor blockade.     

Parents' emotion‐related beliefs and behaviours in relation to children's coping with the 11 September 2001 terrorist attacks

To assess relationships between parental socialization of emotion and children's coping following an intensely emotional event, parents' beliefs and behaviours regarding emotion and children's coping strategies were investigated after a set of terrorist attacks. Parents (n=51) filled out the Parents' Beliefs about Negative Emotions questionnaire and were interviewed within two weeks of the attacks. Their elementary and middle school‐aged children were interviewed eight weeks later. First, parents' beliefs were related to two kinds of parental behaviours. Parents' beliefs about both the value of and the danger of children's emotions were positively related to their discussion with their children. Parents' belief about children's emotions as dangerous was also negatively related to parents' expressiveness with their children. Second, parents' beliefs were related to five kinds of coping strategies reported by their children. Parents' belief about children's emotions as valuable predicted children's problem‐solving, emotion‐oriented, and support‐seeking coping following the terrorist attacks. Parents' belief about children's emotions as dangerous predicted children's avoidance and distraction coping following the attacks. Parents' beliefs about the importance of children's emotions may foster a family atmosphere that facilitates children's coping with intensely emotional events. Results support differentiated, multi‐faceted analysis of the broader construct of parental beliefs. Copyright © 2008 John Wiley & Sons, Ltd.     

CTPI和CTA在椎底动脉系统TIA诊断中的互补性

研究CT灌注成像（CTPI）和CT血管造影（CTA）对椎底动脉系统短暂性脑缺血发作（TIA）的诊断价值。采用64排螺旋CT对30例患者进行常规CT、CT灌注成像和CT血管造影检查。30例CT平扫无责任病灶。CT灌注成像正常14例,异常16例。CTA正常4例,异常26例。CT灌注成像和CT血管造影联合应用有利于椎底动脉系统短暂性脑缺血发作的诊断和治疗方案的选择。     

Variables affecting establishment of schedule-induced attack on pictorial targets in White King pigeons.

White King pigeons exposed to food schedules before introduction of a colored photograph of a pigeon showed sustained schedule-induced attack on that image; additional birds given an early introduction to both the photograph and the schedule subsequently attacked the image at lower rates. Other pigeons attacked a second photograph of a pigeon regardless of whether it was introduced early or late. The late-introduction procedure was also effective in establishing attack on a projected image of a conspecific. The combined results showed that 14 of 17 White King pigeons given a late introduction to a pictorial target exhibited sustained attack against it and that a pigeon's initial reaction to a photograph of a conspecific when introduced early was a good predictor of subsequent schedule-induced attack on it.     

The effects of two response-elimination procedures on reinforced and induced aggression.

Pecks against a stuffed pigeon were reinforced according to a fixed-interval schedule for one group of pigeons and a variable-interval schedule for a second group. Red and green stimulus lights were alternately illuminated. Subsequently, food deliveries no longer occurred during one color (extinction). In the presence of the other color, food was presented only when no attack occurred for 30 sec. When attack produced food, all pigeons generally exhibited characteristic fixed-interval or variable-interval response patterns. Two birds in each group frequently exhibited postreinforcement schedule-induced aggression. Attack was reduced to low levels at approximately the same rate by extinction and differential reinforcement of other behavior. For birds that had previously exhibited schedule-induced aggression the initial reduction of attack during the second experimental phase was followed by induced attack immediately after food delivery in the differential-reinforcement-of-other-behavior component and upon onset of the extinction component, Either extinction or differential reinforcement of other behavior may eliminate reinforced aggression but may be relatively ineffective for reducing induced attack.     

Brief exposure to contingent reinforcement produces a sustained increment in the strength of an elicited response.

Squirrel monkeys' lever pressing produced by response-independent shock was measured before, and for an extended period following, exposure to a shock-avoidance procedure. Following avoidance training, the frequency of responding increased by multiples of 10 to 50 across subjects and evidence little or no decrement for up to 6 months of postreinforcement testing. Manual responding produced by intense environmental stimulation may be substantially strengthened by a brief history of reinforcement, such that it is sustained over long periods without reinforcement.     

Does coping predict CO2-induced panic in patients with panic disorder?

Patients with panic disorder (PD) show maladaptive coping but the role of coping in the pathogenesis of panic is unclear. This study examined general coping and panic-specific coping as predictors of fear responding to CO2 inhalation. Subjective and physiological responses including panic attacks were assessed in 45 patients with PD and 45 matched nonclinical controls. Measures of coping were the primary predictors used in the analyses. Consistent with other reports, patients with PD reported increased emotion-focused coping and there was an association between emotion-focused coping and subjective reactivity. However, only panic-specific coping predicted panic attacks in response to the CO2 challenge.