Randolph C. Grace

Behavioral momentum and the Law of Effect

In the metaphor of behavioral momentum, the rate of a free operant in the presence of a discriminative stimulus is analogous to the velocity of a moving body, and resistance to change measures an aspect of behavior that is analogous to its inertial mass. An extension of the metaphor suggests that preference measures an analog to the gravitational mass of that body. The independent functions relating resistance to change and preference to the conditions of reinforcement may be construed as convergent measures of a single construct, analogous to physical mass, that represents the effects of a history of exposure to the signaled conditions of reinforcement and that unifies the traditionally separate notions of the strength of learning and the value of incentives. Research guided by the momentum metaphor encompasses the effects of reinforcement on response rate, resistance to change, and preference and has implications for clinical interventions, drug addiction, and self-control. In addition, its principles can be seen as a modern, quantitative version of Thorndikes (1911) Law of Effect, providing a new perspective on some of the challenges to his postulation of strengthening by reinforcement.

Prevalence of traumatic brain injury among children, adolescents and young adults: Prospective evidence from a birth cohort

Background: Little is known about the incidence and prevalence of traumatic brain injury (TBI), particularly for infants, children and young adults. Primary objective: The purpose of this study was to provide an accurate estimate of the incidence and prevalence of TBIs for individuals between 0–25 years of age. Method and procedures: A birth cohort of 1265 individuals was used, for which information regarding TBI events, both hospitalized and non-hospitalized, had been recorded. Main outcomes and results: The average incidence for this age group ranged from 1.10–2.36 per 100 per year, with an overall prevalence of ∼30%. The most common source of injury was falls for individuals 0–14 years of age and contact sports and motor vehicle accidents for 15–25 year olds. Approximately one third of the individuals who experienced a TBI went on to have one or more additional injuries. Conclusions: The incidence rates reported here are much higher than those previously found. It is clear that TBIs constitute a major health issue and therefore it is important to have accurate information to enable planning for primary healthcare services and to inform prevention programmes.

Assessment of Community Reintegration Planning for Sex Offenders Poor Planning Predicts Recidivism

Poor planning for reintegrating child molesters from prison to the community is a likely risk factor for sexual recidivism. The quality of reintegration planning was retrospectively measured for groups of recidivist (n = 30) and nonrecidivist (n = 30) child molesters who were individually matched on static risk level and time since release. Recidivists had significantly poorer reintegration planning scores than nonrecidivists, consistent with a previous study by the authors. Data from both studies were combined (total N = 141), and survival analyses showed that poor reintegration planning predicted an increased rate of recidivism. Accommodation, employment, and social support planning combined to predict recidivism, with predictive validity comparable to static risk models (area under the curve = .71). Summing these items yielded a scale of reintegration planning quality that differentiated well between recidivists and nonrecidivists and may have practical utility for risk assessment as an adjunct to static models.

Adolescent psychiatric symptoms following preschool childhood mild traumatic brain injury: evidence from a birth cohort.

ObjectiveTo determine whether childhood mild traumatic brain injury (MTBI) is associated with behavioral problems in adolescence. ParticipantsChildren from a longitudinal birth cohort (initial N = 1265) were assigned to 1 of 3 groups: (1) inpatient group (n = 19) comprised children admitted to hospital for MTBI before age 5 years; (2) outpatient group (n = 57), children with any incidence of MTBI before age 5 seen by a general practitioner or at an accident and emergency department and sent home; (3) reference control group (n = 839). Outcome measuresMaternal and self-report regarding attention deficit/hyperactivity disorder, conduct disorder, anxiety disorder, mood disorder, and alcohol or illicit substance abuse/dependence obtained using Diagnostic and Statistical Manual of Mental Disorders (Third Edition Revised) criteria. ResultsAt age 14 to 16 years, children who had been hospitalized for MTBI during preschool years were significantly more likely to show symptoms of attention deficit/hyperactivity disorder (odds ratio = 4.2), conduct disorder/oppositional defiant disorder (odds ratio = 6.2), substance abuse (odds ratio = 3.6), and mood disorder (odds ratio = 3.1) but not anxiety disorder. ConclusionsPreschool MTBI is associated with persistent negative effects on psychosocial development. These continuing problems are consistent with the view that preschool years represent a period of particular vulnerability following MTBI.

The Quality of Community Reintegration Planning for Child Molesters: Effects on Sexual Recidivism

Research on the causal factors underlying sex offender recidivism has not considered the success or failure of the reintegration process by which the offender rejoins the community after prison. The authors developed a coding protocol to measure the quality and comprehensiveness of reintegration planning for sex offenders. The protocol was retrospectively applied to groups of recidivists and nonrecidivists who were matched on static risk level and follow-up time. The protocol demonstrated adequate reliability. Compared to nonrecidivists, recidivists had significantly lower scores relating to accommodation, employment, and the Good Lives Model secondary goods, as well as lower total reintegration plan scores. ANCOVAs showed that when IQ and level of sexual deviance were controlled for, accommodation (a place to live) was significantly related to sexual recidivism and the Good Lives Model—secondary goods was significantly related to any recidivism. These results suggest that poor reintegration planning may be a risk factor for recidivism.

Characteristics of executive function impairment in Parkinson's disease patients without dementia.

Executive function impairments in Parkinsons disease (PD) are well documented. However, uncertainties remain regarding the impact of these deficits on other areas of cognitive functioning. The goal of this study was to provide a comprehensive assessment of cognitive characteristics in patients with PD without dementia and to assess how any such deficits affected other areas of cognitive functioning. Forty PD patients without dementia were compared to healthy controls using measures of attention and speed of processing and a comprehensive set of executive function tests including working memory, planning, and problem solving. Measures of memory/learning and visuospatial skills were also included to examine the relationship between aspects of executive function and other areas of cognition. Patients with PD showed deficits on measures of executive function, problem solving, and visuospatial skills. However, they were unimpaired on measures of planning, attention, and memory/learning. Deficits in problem solving were only evident for tasks with a high visuospatial content and were no longer significant when visuospatial skills were controlled for. While deficits in executive function and visuospatial skills were apparent for PD patients compared to controls, many aspects of cognition remained intact. These can provide a focus for cognitive intervention strategies that can be effective in delaying decline for PD patients.

Long-term behavioural outcomes of pre-school mild traumatic brain injury.

Abstract Background Mild traumatic brain injury (MTBI) is a leading cause of injury for children during their pre-school years. However, there is little information regarding the long-term outcomes of these injuries. Method We used fully prospective data from an epidemiological study of a birth cohort to examine behavioural effects associated with MTBI during the pre-school years. Cases of confirmed MTBI were divided into two groups, those that had received outpatient medical attention, and those that had been admitted to hospital for a brief period of observation (inpatient cases). The remainder of the cohort served as a reference control group. Results Mother/teacher ratings for behaviours associated with attention deficit/hyperactivity disorder and oppositional defiant/conduct disorder, obtained yearly from age 7 to 13, revealed evidence of deficits after inpatient MTBI (n = 21), relative to more minor outpatient injury MTBI (n = 55) and the reference control group (n = 852). For the inpatient group there was evidence of increasing deficits over years 7-13. Conclusions More severe pre-school MTBI may be associated with persistent negative effects in terms of psychosocial development. The vulnerability of pre-school children to MTBI signals a pressing need to identify high-risk cases that may benefit from monitoring and early intervention.

Resistance to extinction: Contingency termination and generalization decrement

We present an algebraic model of resistance to extinction that is consistent with research on resistance to change. The model assumes that response strength is a power function of reinforcer rate and that extinction involves two additive, decremental processes: (1) the termination of the reinforcement contingency and (2) generalization decrement resulting from reinforcer omission. The model was supported by three experiments. In Experiment 1, 4 pigeons were trained on two-component multiple variable-interval (VI) 60-sec, VI 240-sec schedules. In two conditions, resistance to change was tested by terminating the response-reinforcer contingency and presenting response-independent reinforcers at the same rate as in training. In two further conditions, resistance to change was tested by prefeeding and by extinction. In Experiment 2, 6 pigeons were trained on two-component multiple VI 150-sec schedules with 8-sec or 2-sec reinforcers, and resistance to change was tested by terminating the response-reinforcer contingency in three conditions. In two of those conditions, brief delays were interposed between responses and response-independent reinforcers. In both Experiments 1 and 2, response rate was more resistant to change in the richer component, except for extinction in Experiment 1. In Experiment 3, 8 pigeons were trained on multiple VI 30-sec, VI 120-sec schedules. During extinction, half of the presentations of each component were accompanied by a novel stimulus to produce generalization decrement. The extinction data of Experiments 1 and 3 were well described by our model. The value of the exponent relating response strength and reinforcement was similar in all three experiments.

Treatment Gain for Sexual Offenders Against Children Predicts Reduced Recidivism: A Comparative Validity Study

OBJECTIVE To determine whether pro-social treatment change in sexual offenders would predict reductions in recidivism beyond static and dynamic risk factors measured at pretreatment and whether different methods for assessing change based on self-reports and structured clinical rating systems would show convergent validity. METHOD We compared 3 methods for assessing treatment change with a sample of adult male sexual offenders against children (n = 218) who completed a prison-based cognitive-behavioral treatment program between 1993 and 2000. The methods were measures of change derived from offender self-reports on a psychometric battery administered both pre- and posttreatment, change across treatment on the Violence Risk Scale: Sexual Offender Version (VRS:SO; Olver, Wong, Nicholaichuk, & Gordon, 2007), and posttreatment ratings on the Standard Goal Attainment Scaling for Sex Offenders (SGAS; Hogue, 1994). Offenders were followed up for an average of 12.24 years after release. RESULTS All measures of treatment gain were positively correlated, and all significantly predicted reductions in sexual recidivism, with values for the area under the receiver-operating characteristic curve ranging from .66 (SGAS) to .70 (VRS:SO). Survival analyses showed that measures of change based on the psychometric battery significantly predicted recidivism after controlling for both static and dynamic factors measured at pretreatment, while results for the VRS:SO were similar but failed to reach significance. CONCLUSIONS Measures of treatment change based on offender self-reports and structured clinical rating systems show convergent and predictive validity, which suggests that effective treatment that targets dynamic risk factors leads to a reduction in sexual recidivism.

Social Desirability and Sexual Offenders A Review

Social desirability—the desire to make a favorable impression on others—poses a significant threat to the validity of self-reports. This review examines research on social desirability in both forensic and nonforensic populations with the goal of identifying how best to minimize threats to the validity of research with sexual offenders. Although social desirability has long been a major research topic in personality, consensus has not been reached on key questions such as its dimensional structure and whether social desirability constitutes a trait or a response bias. Research with offenders has shown that social desirability is negatively related to recidivism and that different offender subtypes vary in the degree to which social desirability appears to influence self-reports, with child molesters exhibiting the strongest tendency to “fake good.” Several methods of controlling for social desirability have been proposed, but the effectiveness of these methods in increasing validity of offender self reports is questionable. Given the lack of consensus in the personality literature, a fresh start is needed in which basic questions regarding social desirability are revisited with respect to offender populations.