Concurrent second-order schedules: some effects of variations in response number and duration

To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second-order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed-interval schedule, with one further response completing the fixed-interval schedule. The fixed-ratio and fixed-interval requirements comprising the first-order operant units were systematically and independently varied under three pairs of concurrent variable-interval schedules to produce differences in the first-order response and duration requirements (response and duration differentials). These manipulations produced consistent changes in response, time, and operant-unit biases. A 1:4 response differential biased the time and operant-unit measures towards the smaller fixed ratio, but to a degree less than the imposed response differential. The response-based biases favored the larger fixed ratio. Duration differentials of 4:1 and 8:1 biased the response and operant-unit measures towards the shorter fixed interval, again less than the imposed duration differential, but the time biases remained close to zero. Both sorts of differentials acted to bias operant-unit completions more systematically than the other measures, but undermatching to the differentials occurred. The undermatching appears to have arisen from a pattern of fix and sample (in which visits to the less preferred alternative involved only a single completed operant unit) under combinations of unequal operant-unit requirements and reinforcer rates. The response and time bias measures appeared to arise as by-products of the changes in operant-unit completions.     

Neural correlates of a default response in a delayed go/no-go task

Working memory, the ability to temporarily retain task-relevant information across a delay, is frequently investigated using delayed matching-to-sample (DMTS) or delayed Go/No-Go tasks (DGNG). In DMTS tasks, sample cues instruct the animal which type of response has to be executed at the end of a delay. Typically, performance decreases with increasing delay duration, indicating that working memory fades across a delay. However, no such performance decrease has been found when the sample cues exist of present vs. absent stimuli, suggesting that pigeons do not rely on working memory, but seem to respond by default in those trials. We trained 3 pigeons in a DGNG task and found a similar default response pattern: The diverging slopes of the retention functions on correct Go and No-Go trials suggested that pigeons by default omitted their response following No-Go stimuli, but actively retained task-relevant information across the delay for successful responses on Go trials. We conducted single-cell recordings in the avian nidopallium caudolaterale, a structure comparable to the mammalian prefrontal cortex. On Go trials, many neurons displayed sustained elevated activity during the delay preceding the response, replicating previous findings and suggesting that task-relevant information was neurally represented and maintained across the delay. However, the same units did not show enhanced delay activity preceding correct response suppressions in No-Go trials. This activation-inactivation pattern presumably constitutes a neural correlate of the default response strategy observed in the DGNG task.     

Differential acquisition of lever pressing in inbred and outbred mice: comparison of one-lever and two-lever procedures and correlation with differences in locomotor activity

Recent progress in mouse genetics has led to an increased interest in developing procedures for assessing mouse behavior, but relatively few of the behavioral procedures developed involve positively reinforced operant behavior. When operant methods are used, nose poking, not lever pressing, is the target response. In the current study differential acquisition of milk-reinforced lever pressing was observed in five inbred strains (C57BL/6J, DBA/2J, 129X1/SvJ, C3H/HeJ, and BALB/cJ) and one outbred stock (CD-1) of mice. Regardless of whether one or two levers (an "operative" and "inoperative" lever) were in the operant chamber, a concomitant variable-time fixed-ratio schedule of milk reinforcement established lever pressing in the majority of mice within two 120-min sessions. Substantial differences in lever pressing were observed across mice and between procedures. Adding an inoperative lever retarded acquisition in C57BL/6J, DBA/2J, 129X1/SvJ, and C3H/HeJ mice, but not in CD-1 and BALB/cJ mice. Locomotor activity was positively correlated with number of lever presses in both procedures. Analyses of durations of the subcomponents (e.g., time to move from hopper to lever) of operant behavior revealed further differences among the six types of mice. Together, the data suggest that appetitively reinforced lever pressing can be acquired rapidly in mice and that a combination of procedural, behavioral, and genetic variables contributes to this acquisition.     

Variation, repetition, and choice

Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a response sequence in the terminal link was reinforced only if it differed from the n previous sequences (lag criterion). The REPEAT contingency generated low, constant levels of sequence variation whereas the VARY contingency produced levels of sequence variation that increased with the lag criterion. Preference for the REPEAT alternative tended to increase directly with the degree of variation required for reinforcement. Experiment 2 examined the potential confounding effects in Experiment 1 of immediacy of reinforcement by yoking the interreinforcer intervals in the REPEAT alternative to those in the VARY alternative. Again, preference for REPEAT was a function of the lag criterion. Choice between varying and repeating behavior is discussed with respect to obtained behavioral variability, probability of reinforcement, delay of reinforcement, and switching within a sequence.     

Adolescent Psychopathy and Personality Theory—the Interpersonal Circumplex: Expanding Evidence of a Nomological Net

The construct validity of psychopathy was examined in a sample of 114 male and female young offenders (M_age = 15.16) at a southeastern detention center. The interpersonal circumplex served as a framework of general personality from which to examine the construct of adolescent psychopathy. A supplementary analysis of the psychopathy measures and the Big 5 factors of personality was also conducted using a matrix approach. Measures included: (a) Antisocial Process Screening Device (P. J. Frick & R. D. Hare, 2001); (b) Child Psychopathy Scale (D. R. Lynam, 1996); (c) Psychopathy Checklist—Youth Version (A. E. Forth, D. S. Kosson, & R. D. Hare, 2003); and (d) Interpersonal Adjective Scales Revised—Big 5 Version (P. Trapnell & J. S. Wiggins, 1991; J. S. Wiggins, 1995). Results showed substantial convergence among the three psychopathy measures. In addition, meaningful associations between psychopathy and constructs within the interpersonal circumplex and broader domains of the Big 5 were obtained. Two psychopathy scales correlated to a higher degree than expected with neuroticism. These findings provide evidence linking personality theory to the concept of child and adolescent psychopathy, thereby adding to its construct validity. However, they do so with the caveat that youth may also be displaying some characteristics of neuroticism, suggesting that worry and anxiety may accompany psychopathic features in earlier developmental stages. The implications of the current study are discussed.     

The Impact of the Big Five Personality Traits on Reports of Child Behavior Problems by Different Informants

The present study compared ratings of a standardized sample of child behavior problems across informants and examined the effects of informant personality traits on child behavior ratings by mothers, teachers, and group-care workers. Participants were 55 clinic-referred children, aged 6–12 years. All informants watched and rated the same 17-min videotaped behavior sample of a familiar target child. Independent trained observers rated the same videotapes to provide criterion ratings. Informants personality traits were assessed using the NEO Five Factor Personality Inventory. Results showed that mothers reported fewer behavior problems than did the professionals, that the informants who were familiar with the child reported more behavior problems than did the independent observers, and that higher levels of informant neuroticism were related to higher ratings of child behavior problems in the case of the professionals, but not in the case of the mothers. In addition, group-care workers who were less extraverted and open were likely to report more child behavior problems than group-care workers with normal levels of extraversion and openness. Finally, no relations were found between agreeableness or conscientiousness and ratings of child behavior. Findings suggest that professionals who work with children are not immune to distortions based on their own personality.     

师生关系与中小学生学校适应性的关系

师生关系作为儿童人际关系的一部分,是儿童社会化的重要内容,对儿童的学校适应产生重要影响。本研究运用问卷法、访谈法等对6个年级867名中小学生进行测查,以了解中小学生师生关系对学生学校适应性的影响。结果表明:(1)中小学生学校适应性与师生关系之间存在显著正相关;(2)师生关系是影响学生学校适应性的重要因素。其影响程度从大到小依次为:亲密性、主动性、合作性;年龄也影响学生的学校适应性,但程度较小。     

Interpersonal Dependency in Child Abuse Perpetrators and Victims: A Meta-Analytic Review

Meta-analysis of studies assessing interpersonal dependency in child abuse perpetrators (N of studies = 7) and victims (N of studies = 9) indicated that perpetrators have higher dependency levels than nonabusing controls (d = 0.43), and child abuse victims have higher dependency levels in early adulthood than people who were not abused as children (d = 0.47). An array of other personality traits and disorders showed comparable associations with abuse suggesting that in both populations increased dependency reflects a generalized increase in pathology and distress. Theoretical implications of these results are discussed, and suggestions for future research on dependency and abuse are offered.     

Measurement of Cruelty in Children: The Cruelty to Animals Inventory

Cruelty to animals may be a particularly pernicious aspect of problematic child development. Progress in understanding the development of the problem is limited due to the complex nature of cruelty as a construct, and limitations with current assessment measures. The Children and Animals Inventory (CAI) was developed as a brief self- and parent-report measure of F. R. Ascione's (1993) 9 parameters of cruelty. The CAI emerged as a reliable, stable, and readily utilized measure of cruelty using parent and child reports. Children (especially the older children) reported higher rates of cruelty than their parents and boys reported more cruelty than girls. Self- and parent-reports showed good convergence with independent observations of cruelty versus nurturance during free interactions with domestic animals. The results indicate that cruelty to animals can be reliably measured using brief child and parent report measures.