Received August 12, 2005; accepted October 14, 2005

Transcription

1 Prevention Science ( C 2006) DOI: /s The Mediational Role of Neurocognition in the Behavioral Outcomes of a Social-Emotional Prevention Program in Elementary School Students: Effects of the PATHS Curriculum Nathaniel R. Riggs, 1,4 Mark T. Greenberg, 2 CarolA.Kusché, 3 and Mary Ann Pentz 1 Received August 12, 2005; accepted October 14, 2005 Neuropsychology is one field that holds promise in the construction of comprehensive, developmental models for the promotion of social competence and prevention of problem behavior. Neuropsychological models of behavior suggest that children s neurological functioning affects the regulation of strong emotions, as well as performance in social, cognitive, and behavioral spheres. The current study examines the underlying neurocognitive conceptual theory of action of one social-emotional development program. Hypothesized was that inhibitory control and verbal fluency would mediate the relationship between program condition and teacher-reported externalizing and internalizing behavior problems. Participants were 318 regular education students enrolled in the second or third grade. A series of regression analyses provided empirical support for (a) the effectiveness of the PATHS Curriculum in promoting inhibitory control and verbal fluency and (b) a partial mediating role for inhibitory control in the relation between prevention condition and behavioral outcomes. Implications are that programs designed to promote social and emotional development should consider comprehensive models that attend to neurocognitive functioning and development. Lack of consideration of neurocognitive pathways to the promotion of social competence may ignore important mechanisms through which prevention affects youth outcomes. Furthermore, the findings suggest that developers of social-emotional preventions should design curricula to explicitly promote the developmental integration of executive functioning, verbal processing, and emotional awareness. Doing so may enhance prevention outcomes particularly if those preventions are implemented during a time of peak neurocognitive development KEY WORDS: neuro-cognition; social-emotional development; mediation. Youth problem behavior can place children and adolescents at considerable risk for the development of serious future problems including delinquency, substance abuse, and school dropout (Cairns et al., 1989; Flory et al., 2003; Galaif et al., 2001; Lahey et al., 1997; Moffitt & Caspi, 1998;Whiteet al., 2001). 1 The Institute for Prevention Research, University of Southern California, California. 2 The Prevention Research Center, Pennsylvania State University, Pennsylvania. 3 Department of Psychology, University of Washington, District of Columbia. 4 Correspondence should be directed to Mark T. Greenberg, Institute for Prevention Research, University of Southern California, 1000 S. Fremont Ave., Unit #8, Alhambra, California, 90813; e- mail: nriggs@usc.edu. Consequently, recent decades have experienced a rapid increase in the number of prevention programs targeting the promotion of social-emotional competence in young people as one strategy to decrease risk for behavior and mental health problems (Drug Strategies, 1998; Greenberg et al., 1999; U.S. Department of Health and Human Services, 1999). Many of these programs strive to promote competencies in a number of developmentally appropriate skills including inhibition of impulsive behavior, awareness and regulation of feelings, accurate perception of the perspectives of others, correct identification of problems, and development of positive and informed problem solutions and goals (Zins et al., 2000). In turn, it is believed that these skills allow children to modify and integrate behaviors, actions, /06 C 2006 Society for Prevention Research

2 Riggs, Greenberg, Kusché, and Pentz and emotions in order to handle developmentally relevant social tasks (Weissberg et al., 1989). Children who demonstrate mastery of these developmentally appropriate social tasks are generally considered socially and emotionally competent. A number of skills that social-emotional development interventions attempt to promote are presumed to be dependant upon parallel constructs at the neurocognitive level (Riggs & Greenberg, 2004). For example, inhibiting impulsive behavior presumably requires mediation by associated neuroanatomical areas in the prefrontal cortex to control impulsive thoughts and actions. Similarly, children s ability to verbally mediate problem situations depends in part upon verbal fluency, which in turn requires left hemispheric processing in most individuals. A question of substantial interest is whether a social-emotional preventive intervention designed to affect both neurocognitive capacity as well as social behavior can do so. The current study examines the question with regard to one of these programs, The Promoting Alternative Thinking Strategies (PATHS) Curriculum (Kusché & Greenberg, 1994), a research proven program for social-emotional development. In doing so, the paper tests a conceptual theory of action that underlies the curriculum model (Greenberg & Kusché, 1993; Greenberg et al., 2004). Neurocognition and Problem Behavior Neuropsychology is one field that holds promise in the construction of comprehensive, developmental models for the promotion of social competence and prevention of problem behavior (Paschall & Fishbein, 2002; Riggs & Greenberg, 2004). Among other things, neuropsychological models of behavior suggest that children s neurological functioning affects the regulation of strong emotions, as well as performance in social, cognitive, and behavioral spheres (Greenberg et al., 2004). Empirical research supports neuropsychological models of behavior. Specifically, studies have demonstrated links between neurocognition and the development of multiple problem behaviors including conduct disorder (Hill, 2002; Lahey et al., 1995; Lynam & Henry, 2001), delinquency (Brickman et al., 1984; Lynam et al., 1993; Moffitt & Henry, 1989; Spellacy, 1977; White et al., 1994), and substance abuse (Giancola et al., 1996; Giancola et al., 1998; Giancola & Tarter, 1999). One neural region of special research interest is the frontal cortex, beginning anterior to the central sulcus of the human brain. This region of the brain is considered to be very important in the management and organization of two related neurocognitive capacities associated with social and behavioral development; executive cognitive function (ECF) and verbal ability. First, the frontal lobes of the brain are considered to be the seat of the brain s self-control processes, often referred to as ECF (Pennington & Ozonoff, 1996; Welsh et al., 1991). Executive cognitive function is understood as an umbrella term encompassing a number of interrelated subskills necessary for purposeful, goal-directed activity. These capacities include the ability to shift attention from one task to another, plan, initiate tasks, and utilize working memory (Luria, 1966; Pennington & Ozonoff, 1996), all of which are important for socialcognitive and behavioral development. One important component of ECF that has received some research attention is inhibitory control. Most of the research linking inhibitory control to behavior has focused on positive cross-sectional associations between executive abilities and both child and adolescent behavioral development (see Pennington & Ozonoff, 1996 for review). However, a few studies have demonstrated longitudinal relationships between early inhibitory control and later problem behaviors (Nigg et al., 1998). Similarly, children s verbal abilities have been hypothesized to play a key role in their behavioral development. Verbal labeling, for example, aids in the accurate perception of emotional experiences and in the retrieval of associated memories. In addition, the ability to verbally represent and internally assess behavior allows children to inhibit problem actions (Henry & Moffitt, 1997). Thus, as children develop throughout early childhood, self-control becomes less dependent upon the mediation of external caregivers and increasingly regulated via internal forms of mediation such as internal verbal representation (Greenberg et al., 1991). Therefore, there appears to be at least a functional link between the development of inhibitory control and verbal abilities. An inability to perform these verbal tasks has been shown to preclude children from being able to plan and perform prosocial objectives, leaving them at-risk for problem behavior (Greenberg & Kusché, 1993; Pine 1985). Research has consistently demonstrated a link between youth verbal deficits and behavior problems (Kusché et al., 1993; Lynam & Henry, 2001; Moffitt, 1990; Moffitt & Lynam, 1994; Lahey et al., 1995; Lynam et al., 1993).

3 Effects of the PATHS Curriculum Promoting Neurocognitive Capacities Related to Problem Behavior Studies linking executive cognitive and verbal skills to social and behavioral development imply that prevention and intervention programs might enhance the effectiveness of these skills in preventing behavior and mental health problems. However, only rarely (Greenberg & Kusché, 1993; Marlowe, 2001) are children s ECF and verbal capacities considered important factors when developing prevention models. Therefore, little is known regarding the ability of prevention programs to affect these neurocognitive functions. The potential for beneficial effects on youth neurocognition through intervention, however, is supported by research demonstrating the ability of the environment to influence each stage of neural development, from neural birth or neurogenesis (Altman & Bayer, 1997; Miller, 1996), to neuronal degeneration (Ikonomidou et al., 2000). Although much of the research illustrating environmental impacts on brain development has been based on nonhuman research, there is also growing evidence that social experience is strongly linked to both temporary and permanent alterations in the structure and function of the human brain (Cicchetti & Tucker, 1994; Fishbein, 2001; Ito et al., 1998; McEwen, 1997; Sapolsky, 1996; Stein et al., 1997). Limited research has linked children s experience in schools, with neurocognitive development. One study demonstrated a positive association between school experience and executive development in a cross-sectional investigation of 7 9-yearold children (McCrea et al., 1999). In a second study forty-nine 3- and 4-year-old children with inhibitory control problems were randomly assigned into ECF Training and Control groups (Dowsett & Livesey, 2000). Results demonstrated that executive skills were significantly enhanced via experience with tasks requiring executive processes. In sum, there appears to be a potential for the enhanced environments resulting from successful prevention programs to improve children s neurocognitive functioning related to social and behavioral development. However, few prevention programs explicitly integrate neurocognitive models into more general theories of change. Broader, more comprehensive models of behavior change that include cognition, affect, and behavior, while taking into account neuropsychology could provide valuable insights into the potential of prevention to promote neurocognitive development. The PATHS Curriculum: Conceptual Relations to Neurocognitive Development The PATHS Curriculum is a universal schoolbased prevention curriculum aimed at reducing aggression and behavior problems by promoting the development of social-emotional competence in children during the elementary school years. PATHS is based on the Affective-Behavioral- Cognitive-Dynamic (ABCD) model of development (Greenberg & Kusché, 1993). The ABCD model of development places primary importance on the developmental integration of cognition, affect and emotion language, and behavior in the promotion of social competence. A fundamental concept in the ABCD model is that as youth mature, emotional development precedes most forms of cognitive development. That is, young children experience emotions and react to them long before they can verbalize their experiences. Early in life, emotional development is an important precursor to other ways of thinking and must be integrated with cognitive and linguistic abilities, which are much slower to develop. Then, during the elementary years, further developmental integration occurs between affect, behavior, and cognition/language. This is important in achieving socially competent action and healthy peer relations. The PATHS Curriculum places special attention on neurocognitive models of development. Of significant importance are the concepts of vertical control and horizontal communication. Here, two neural structures important for social and behavioral development are the prefrontal cortex and the limbic system. These two structures interact with each other in a dynamic and mutually influential fashion. Vertical control refers to higher-order cognitive processes that take place in the prefrontal cortex exerting control over lower-level limbic impulses. In adults, emotional information is rapidly perceived in the emotion centers of the brain (i.e. the limbic system). This information is then sent via ascending neurons to the frontal cortex for higher-order processing and interpretation. Finally, this information is sent back to the limbic system to alter emotional signals. However, in young children, the neural connections between the frontal cortex and limbic system are not completely developed. Therefore, children often react impulsively to challenging social situations without facilitation from higher-order processing skills.

4 Riggs, Greenberg, Kusché, and Pentz Horizontal communication refers to the process of communication between the two hemispheres of the human cortex via the corpus callosum. The left and right hemispheres specialize in processing different types of information (de Hann et al., 1998). The left hemisphere is responsible for processing receptive and expressive language and expressive positive affect. The right hemisphere specializes in processing both comfortable and uncomfortable receptive affect and uncomfortable expressive affect (Bryden & Ley, 1983). Therefore, in order to verbally label emotional experiences and become consciously aware of them, information must be transmitted from the right hemisphere of the brain to the left. However, the left and right hemispheres can only communicate with one another via the corpus callosum. PATHS attempts to teach youth skills that promote the age-appropriate development of vertical control and horizontal communication. The curriculum attempts to promote the development of vertical control by providing youth with opportunities to practice conscious strategies for self-control including verbal mediation (self-talk) and inhibitory control. This is achieved via instruction with curriculum lessons and the integration of the Control Signals Poster (CSP; Weissberg et al., 1988). The CSP is modeled after a traffic signal, with red, yellow, and green lights. The red light signals children to Stop Calm Down. Here, youth are instructed that as challenging social situations occur they should first take a long deep breath, calm down, and say the problem and how they feel. The yellow light signals children to Slow Down Think. Here, youth make a plan by considering possible solutions and then selecting the best option. Finally, the green light signals children to Go Try My Plan. Below the illustration of the stoplight are the words Evaluate How Did My Plan Work? Students may then formulate and try new plans if necessary. PATHS attempts to improving hemispheric integration by assisting youth in verbally identifying and labeling feelings and emotions in order to manage them. This is achieved with curriculum lessons and the integration of Feeling Face cards. Feeling Face cards include both facial drawings of affective states (recognition of which is mediated by the right hemisphere) along with their printed label (which is mediated by the left hemisphere). They are further color-coded as comfortable (yellow) or uncomfortable (blue) feelings. In addition to the curriculum lessons, children are encouraged to talk about emotional experiences to further strengthen neural integration. Program Efficacy of The PATHS Curriculum A number of trials have demonstrated the effectiveness of The PATHS Curriculum. Using the same sample reported in the present study (but also including children in special needs classrooms), Greenberg et al. (1995) reported that the PATHS prevention led to significant improvements in the understanding of emotions, fluency in discussing emotions, and perceived efficacy in managing emotions. Moreover, in a large, randomized trial utilizing 48 schools in four US communities (Conduct Problems Prevention Research Group, 1992), PATHS was utilized as the universal prevention model of the Fast Track Program. Initiated at the beginning of first grade, results after six months (spring of first grade) indicated significant effects on child aggressive and disruptive behavior by peer sociometric reports and improved quality of classroom atmosphere as reflected in ratings by independent observers. Reports of the efficacy of the PATHS Curriculum have also involved special needs students. In a study of profoundly deaf children (Greenberg & Kusché, 1998), results indicated that the prevention led to significant improvement in students social problem-solving skills, emotional recognition skills, and teacher and parent-rated social competence. One and two-year posttest results indicated maintenance of effects. Finally, recent findings indicate significant effects of PATHS on teacher reports of internalizing and externalizing behavior problems as well as self-report of child depression in special needs children (Kam et al., 2004). Hypothesis The main research question of the current study centers on the relation between children s neurocognitive abilities and teacher-reported behavior problems following random assignment into either the Promoting Alternative Thinking Strategies (PATHS) Curriculum or a control group. The specific hypothesis is that, after taking other important factors into account, inhibitory control and verbal fluency will mediate the relationship between prevention/control group assignment and teacher-reported externalizing and internalizing behavior problems.

5 Effects of the PATHS Curriculum Fig. 1. Mediation model. A third variable is considered to be a mediator if there is a significant indirect relationship between an independent variable and a dependent variable via two causal paths shown in Fig. 1 (MacKinnon et al., 2000). One path (Path γ) links the independent variable with the dependent variable directly. The other links the independent variable to the dependent variable through Paths α and β. An indirect or mediated effect suggests that the independent variable causes the mediator, which, in turn causes the dependent variable (Holland, 1988; MacKinnon et al., 2000). Participants METHOD Participants were drawn from second and third grade regular education classrooms in four schools in the Seattle School District. These schools were representative of the district profile, with the exception of having a lower percentage of Asian American students. The prevention model was initially described to principals and teachers at each school. After faculty discussion, buildingbased decisions were made regarding participation. Schools were aware that once they decided to participate, they had a 50% chance of being randomized as a comparison school. All four schools that were approached decided to participate and two were randomly assigned to receive the prevention. A letter was sent to all English-speaking families requesting their child s participation in the assessment phase of the prevention. As active consent was necessary for participation, only those children who returned consents were included in the study; this involved 64% of the children in these classrooms. We believe these students to be representative of their schools as they showed differences of less than 10% as compared to the composition of their entire school on the variables of sex, ethnic minority status, and percentage of children receiving free or reduced-fee lunch. The total recruited sample included 329 students enrolled in the second or third grade at the time of pretesting (spring). Eleven students were not included in analyses due to the fact that there was no data regarding experimental or control group assignment. Thus, the final sample was 318 participants. Ages ranged from 7 years 1 month to 9 years 2 months at pretest, with a mean age of 8 years 0 months. One hundred and fifty-three (48%) of these participants were in the experimental group and 165 were in the control group. Fifty percent of participants were girls, 55% were Caucasian, 33% African-American, and 22% either Asian-American, Native American, or of other racial background. Prevention Design Teacher Training and Consultation The prevention teachers attended a 3-day training workshop and received weekly consultation and observation from project staff. Each teacher received a copy of the curriculum, which included detailed scripts and accompanying materials that focused on teaching skills related to self-control, the management and recognition of feelings, and interpersonal problem-solving. In addition to the lessons, teachers utilized techniques to generalize skills learned during PATHS lessons in other contexts during the classroom day. The PATHS lessons were taught approximately three times per week, with each lesson lasting min. Teachers began to teach the lessons in early October and finished in early April. Weekly consultations with each teacher were completed to enhance the quality of implementation through modeling, coaching, and providing ongoing feedback regarding program delivery. Fidelity was assessed through monthly ratings of quality of implementation made by the consultants. Although there was wide variation in the quality of implementation, most teachers completed the curriculum. The mean

6 Riggs, Greenberg, Kusché, and Pentz number of lessons taught by the teachers was 53. The actual number of classroom sessions devoted to PATHS teaching was 68 (some lessons required more than one class session). Measures IQ IQ was estimated using a two subtest short form of the Wechsler Intelligence Scale for Children- Revised (WISC-R; Wechsler, 1974) which included Vocabulary and Block Design. Estimated IQ score was normed based on demographically corrected data (M = 100, SD = 15). Inhibitory Control The Stroop Test (Golden, 1981) consisted of three trials (words written in black, colored Xs, and colored words written in conflicting colors of ink). Only the score from the Color Words trial was included in the current analyses. In this trial children were presented with a color word such as red, blue, or green. However, this word was presented in a color of ink that conflicted with the written label (e.g., the word red printed in green ink). Children were asked to ignore the word, itself, and instead to identify the color of the ink in which the word was printed. High scores indicate greater inhibitory functioning. The Stroop consistently activates the anterior cingulated in adults, which is a neural region that interacts with both limbic and prefrontal function. Because disruption in this task involves susceptibility to a competing response tendency, the Stroop Color Word Test is considered to be a measure of inhibitory control (Pennington & Ozonoff, 1996) and a highly reliable neurocognitive test (Spreen & Strauss, 1991). Verbal Fluency The Verbal Fluency Subtest of the McCarthy Scales of Children Abilities (McCarthy, 1972) requires children to name as many items as they can in the four common categories (things to eat, animals, things to wear, and things to ride). There is a 20-s time limit for each of the four categories, thus emphasizing speed of response. This test assesses verbal concept formation, logical classification, verbal expression, and creativity. Child Behavioral Checklist Child behavior problems were assessed using the Teacher Report Form (TRF) of the Child Behavioral Checklist (CBCL; Achenbach, 1991). Teachers were given a list of symptomatic behaviors and were asked to rate each child on these items by denoting whether a given behavior was not true (0), sometimes or somewhat true (1), or very true or often true (2), now or within the past 6 months. For the current study, age corrected scores for the externalizing and internalizing subscales were examined. Preliminary Analyses RESULTS Distributions of test scores and behavior outcomes were examined for outliers and normality. Missing data were considered to be missing at random and were replaced with sample means. Due to a lack of age corrected normative data on the Stroop Color Word task and Verbal Fluency, raw scores for all measures of executive function were converted to standardized scores based on sample distributions (M = 10, SD = 2.00). Table 1 illustrates pretest mean scores for continuous variables and correlation analyses. The Estimated IQ of the participants was one standard deviation above standardized norms. Due to the fact that ethnicity was not related to any independent or dependent variables, it was excluded from future analyses. Finally, paired samples t-tests were performed to test for significant differences between prevention and control groups. Group differences were found for Verbal Fluency and Estimated IQ at pretest with control group children having significantly greater Verbal Fluency and Estimated IQ as compared to the intervention children. As a result, pretest neurocognitive scores were controlled for in future analyses. Data Analytic Model In order for a mediational hypothesis to be supported three conditions must be satisfied. Each

7 Effects of the PATHS Curriculum Table 1. Correlation Among Variables Variable M SD Ethnicity 2. Age (months) Estimated IQ Verbal fluency Stroop color word Internalizing Externalizing p < 01; p <.001. of these conditions can be supported with regression analyses. First, two hierarchical linear regression models were performed to determine the effect of the PATHS Curriculum on teacher-reported behavior outcomes (test of Path γ in Fig. 1). Covariates for these models included pretest behavior scores, age, and IQ. Experimental condition was entered last in the model as the independent variable of primary interest. Second, hierarchical linear regression models were performed to determine the effect of the PATHS Curriculum on children s inhibitory control and verbal fluency nine months later (test of Path α). For these models, covariates included pretest neurocognitive scores, age, and IQ. The independent variable of primary interest was again experimental condition. The third regression models regressed behavior problems onto both intervention condition and posttest neurocognitive mediators (test of Path β). For these models, covariates included pretest behavior scores, age, and IQ. In order for a mediational hypothesis to be supported, regression model three must demonstrate a direct effect of the mediator on the behavioral outcome, and the previously significant relation between intervention condition and outcome (Path γ) must be significantly attenuated. Sobel tests for indirect effects were employed to determine whether this attenuation was significant. Results Effects of the PATHS Curriculum on Teacher-Reported Behavior and Neurocognitive Mediators Tests for significance of Paths γ & α. Prevention condition was significantly related to both teacher-reported externalizing (t = 3.26, p <.01) and internalizing (t = 2.23, p <.05) at 1- year follow-up. Children that participated in the PATHS Curriculum demonstrated fewer behavior problems. Regression analyses indicated that there was a significant prevention effect on both inhibitory control (t = 2.80, p <.01) and verbal fluency (t = 2.79, p <.01). Here, children who participated in the PATHS Curriculum demonstrated greater inhibitory control and verbal fluency at posttest than did children in the control group. Table 2 shows unstandardized betas and standard errors for these analyses. Effects of Neurocognition on Behavioral Outcomes: Test for significance of Path β Models were then run that included intervention condition, posttest inhibitory control, and Table 2. Program Effects on Behavioral Outcomes and Neurocognition Externalizing behavior b (SE) Internalizing behavior b (SE) Inhibitory control b (SE) Verbal fluency b (SE) Pretest.54 (.05).30 (.06).38 (.05).32 (.06) Age (months).11 (.05).05 (.05).01 (.01).07 (.02) IQ.06 (.03).08 (.03).02 (.01).04 (.01) Program 2.95 (.91) 2.15 (.96).53 (.19).77 (.27) Note. Program was coded as 1 = program, 0 = control, b = Unstandardized beta coefficient, SE = standard error. p <.10; p <.01; p <.001; p <.0001.

8 Riggs, Greenberg, Kusché, and Pentz Table 3. Program and Neurocognition Effects on Behavioral Outcomes Externalizing behavior b (SE) Internalizing behavior b (SE) Pretest.52 (.05).29 (.06) Age (months).13 (.05).09 (.06) IQ.04 (.03).04 (.03) Inhibitory.72 (.26).72 (.27) control Verbal fluency.16 (.18).44 (.19) Program 2.47 (.91) 1.59 (.95) Note. Program was coded as 1 = program, 0 = control. b = unstandardized beta coefficient, SE = standard error. p <.05; p <.01; p <.001; p < posttest verbal fluency demonstrated. Here, posttest inhibitory control was negatively related to teacherreported externalizing (t = 2.80, p <.01) and internalizing (t = 2.69, p <.01) behavior at 1-year follow-up. Posttest verbal fluency was negatively related to teacher ratings of internalizing (t = 2.28, p <.05) behavior problems at 1-year follow-up. That is children who had greater inhibitory control at posttest demonstrated fewer externalizing and internalizing behavior problems and children who were more verbally fluent demonstrated fewer internalizing behavior problems at 1-year follow-up. After taking these neurocognitive variables into account intervention condition continued to have a significant effect on externalizing behavior (t = 2.73, p <.01) and internalizing behavior (t = 1.66, p <.05). Table 3 shows unstandardized betas and standard errors for these analyses. Tests of Mediation Sobel tests for mediation (Sobel, 1982) were employed to determine whether children s neurocognitive abilities mediated the relation between experimental condition and behavior outcomes. A Sobel test for mediation assesses whether the direct effect of the mediators significantly reduces the relation between the intervention and the outcome. The formula for the Sobel test for mediation is as follows: z = α β/sqrt(β 2 s α 2 + α 2 s β 2 ), where α and β are the unstandardized beta coefficients for Paths α and β respectively, and sα and sβ are the standard errors of Paths α and β respectively. Sobel tests for mediation demonstrated that inhibitory control at immediate posttest significantly mediated the relation between experimental condition and both teacher-reported externalizing (z = 1.98, p <.05) and internalizing (z = 1.98, p <.05) behavior at 1-year follow-up. These findings demonstrate that the direct effect of the PATHS program on inhibitory control significantly reduced the relation between PATHS and both outcomes. However, a Sobel test of mediation demonstrated that the mediating role of verbal fluency in the relation between experimental condition and teacher-reported internalizing behavior only approached significance (z = 1.80, p <.10). Both PATHS mediational models, with standardized betas, are presented in Fig. 2. DISCUSSION The current study provides empirical support for the conceptual theory of action that underlies the PATHS Curriculum model. Specifically, child neurocognitive functioning played a partial mediating role in the relation between prevention condition and behavioral outcomes. In short, current findings suggest the effectiveness of the PATHS Curriculum in promoting inhibitory control and verbal fluency, two theoretically and empirically supported mediators of social competence (Nigg et al., 1998; Riggs et al., 2003). In turn, inhibitory control was related to externalizing behavior and both inhibitory control and verbal fluency were related to internalizing behavior. Finally, inhibitory control mediated the relation between program condition and both externalizing and internalizing behavior. Contrary to hypothesis, verbal fluency was not related to teacher-reported externalizing behaviors. This may be due to verbally expressive young children being better at talking back or verbally ridicule peers. Furthermore, verbal fluency s mediating relation only approached significance for that between program condition and internalizing behavior. Therefore, it appears that inhibitory control is the main generative mechanism in the relation between PATHS and behavioral outcomes. These findings have significant implications for the development of programs that attempt to promote positive social-emotional development. First, the current study is one of few to demonstrate the ability of a prevention program to purposefully promote neurocognitive function during a period of peak neural development. Second, it is the first to our knowledge to demonstrate that the effects of a prevention program are mediated via inhibitory control. From a theoretical perspective, the current findings support the use of neurocognitive models for

9 Effects of the PATHS Curriculum Fig. 2. PATH mediation models. understanding behavior change. In other words, programs designed to promote social and emotional development should consider comprehensive models that attend to neurocognitive functioning and development. Lack of consideration of neurocognitive pathways to the promotion of social competence may ignore important mechanisms through which prevention affects youth outcomes. Furthermore, the findings suggest that developers of social-emotional preventions should design curricula to explicitly promote the developmental integration of executive functioning, verbal processing, and emotional awareness. Doing so may enhance prevention outcomes particularly if those preventions are implemented during a time of peak neurocognitive development (Greenberg et al., 2004; Riggs & Greenberg, 2004). Although there is not absolute consensus as to when the period of rapid neural development in the frontal areas ends, the implementation of curricula during early and middle childhood may be more beneficial in promoting optimal neurocognitive functioning and positive behavioral development than programs offered during adolescence or adulthood. Findings that the PATHS Curriculum can enhance these aspects of neurocognitive development may also be important for programs that attempt to promote other developmental outcomes, such as academic achievement (Burchinal et al., 1997), substance use resistance (Kirisci et al., 2004), and healthy dietary choices (Davis et al., 2004), that are presumed to rely on the same or similar neurocognitive capacities. Although there is less research investigating the link between neurocognition and these outcomes, the identification of common neurocognitive mediators to multiple problem outcomes would support the argument for translating research proven programming for social development to programming for academic failure, substance use, and obesity prevention. Programs that target common mediators to multiple outcomes may be particularly useful for

10 Riggs, Greenberg, Kusché, and Pentz overburdened schools as they would allow teachers to simultaneously address a variety of areas such as academic progress, substance use, obesity, and behavior problem prevention with the application of a core social-emotional curriculum. Although the challenge of developing core curricula that reduce risk factors related to a spectrum of behavioral concerns is significant, programs that explicitly take into account common mediators of multiple problem behaviors, whether neurocognitive or otherwise, should be among the most promising for optimizing classroom time while achieving concurrent success in multiple areas. Current findings should be considered in light of study limitations. Here, only a limited number of indicators of inhibitory control and verbal fluency were used. These tasks, although previously validated to tap the inhibitory control and verbal fluency, are limited in that they assess relatively gross measures of neurocognitive functioning. Future studies should determine whether performance on neurocognitive tasks presumed to tap neurocognitive functioning are paralleled by changes in cortical function and structure. Such changes, although beyond the scope of the current study can be determined via neural imaging techniques such a functional magnetic resonance imaging (fmri) or positron emission tomography (PET) scans. Studies of this nature could better determine the specific neurological correlates of interventions, such as changes in neural density, regional blood flow, or glucose metabolism in the areas of the brain associated with emotion and behavior. This research would compliment the current literature that has focused on cognitive testing indicators of neurocognitive functioning. In summary, the results demonstrated the effectiveness of PATHS in positively altering the developmental trajectories of both neurocognition and behavior among children during the elementary school years. Further, these findings and others in neuroscience point to the importance of considering social-emotional development as best understood within broader theories that take into account how children s experiences and relationships affect their brain organization, structuralization, and development (Fishbein, 2001). Although these findings have documented that 1 year of a school-based prevention is of considerable value, the evaluation of more comprehensive models that are sustained across multiple years and grade levels will be necessary to discover the true potential of social-emotional education (Weissberg & Greenberg, 1998). REFERENCES Achenbach, T. M. (1991). Manual for the child behavior checklist and 1991 profile. Burlington: Department of Psychiatry, University of Vermont. Altman, J., & Bayer, S. A. (1997). Development o the cerebellar system: In relation to its evolution, structure, and functions. Boca Raton, FL: CRC Press. Brickman, A. S., McManus, M., Grapentine, W. L., & Alessi, N. (1984). Neuropsychological assessment of seriously delinquent adolescents. Journal of the American Academy of Child Psychiatry, 23, Bryden, M. P., & Ley, R. G. (1983). Right-hemispheric involvement in the perception and expression of emotion in normal humans. In K. M. Heilman & P. Satz (Eds.), Neuropsychology of human emotion (pp. 6 44). New York: Guilford Press. Burchinal, M. R., Campbell, F. A., Bryant, D. M., Wasik, B. H., & Ramey, C. T. (1997). Early intervention and mediating processes in cognitive performance of children of lowincome African American families. Child Development, 68, Cairns, R. B., Cairns, B. D., Neckerman, H. J., Ferguson, L. L., & Gariepy, J. L. (1989). Growth and aggression: I. Childhood to early adolescence. Developmental Psychology, 25, Cicchetti, D., & Tucker, D. (1994). Development and selfregulatory structures of the mind. Development and Psychopathology, 6, Conduct Problems Prevention Research Group. (1992). A developmental and clinical model for the prevention of conduct disorders: The FAST Track Program. Development and Psychopathology, 4, Davis, C., Strachan, S., & Berkson, M. (2004). Sensitivity to reward: Implications for overeating and overweight. Appetite, 42, Dowsett, S. M., & Livesey, D. J. (2000). The development of inhibitory control in preschool children: Effects of executive skills training. Developmental Psychobiology, 36, Drug Strategies (1998). Safe schools, safe students: A guide to violence prevention strategies. Washington, DC: Drug Strategies. Fishbein, D. (2001). The importance of neurobiological research to the prevention of psychopathology. Prevention Science, 1, Flory, K., Milich, R., Lynam, D. R., Leukefeld, C., & Clayton, R. (2003). Relation between childhood disruptive behavior disorders and substance use and dependence symptoms in young adulthood: Individuals with symptoms of attentiondeficit/hyperactivity disorder are uniquely at risk. Psychology of Addictive Behaviors, 17, Galaif,E.R.,Hser,Y.I.,Grella,C.E.,&Joshi,V.(2001).Prospective risk factors and treatment outcomes among adolescents in DATOS-A. Journal of Adolescent Research, 16, Giancola, P., Martin, C., Tarter, R., Pelham, W., & Moss, H. (1996). Executive cognitive functioning and aggressive behavior in preadolescent boys at high risk for substance abuse/dependence. Journal of Studies on Alcohol, 59, Giancola, P., Mezzich, A., & Tarter, R. (1998). Disruptive, delinquent and aggressive behavior in adolescent female substance abusers: Relation to executive cognitive functioning. Journal of Studies on Alcohol, 59, Giancola, P., & Tarter, R. (1999). Executive cognitive functioning and risk for substance abuse. Psychological Science, 10, Golden, C. J. (1981). The Luria-Nebraska children s battery: Theory and formulation. In G. W. Hynd & J. E. Obrzut (Eds.), Neuropsychological assessment and the school-age child (pp ). New York: Grune & Stratton.

11 Effects of the PATHS Curriculum Greenberg, M. T., Domitrovich, C., & Bumbarger, B. (1999). Preventing mental disorder in school-aged children: A review of the effectiveness of prevention programs. Report submitted to The Center for Mental Health Services (SAMHSA), Prevention Research Center, Pennsylvania State University (available at Greenberg, M. T., & Kusché, C. A. (1993). Promoting social and emotional development in deaf children: The PATHS project. Seattle: University of Washington Press. Greenberg, M. T., & Kusché, C. A. (1998). Preventive interventions for school-age deaf children: The PATHS curriculum. Journal of Deaf Studies and Deaf Education, 3, Greenberg, M. T., Kusché, C. A., &Riggs, N. (2004). The PATHS Curriculum: Theory and research on neuro-cognitive development and school success. In J. Zins, R. Weissberg, & H. Walber (Eds.), Building school success on social and emotional learning. New York: Teachers College Press. Greenberg, M. T., Kusché, C. A., Cook, E. T., & Quamma, J. P. (1995). Promoting emotional competence in school-aged children: The effects of the PATHS curriculum. Development and Psychopathology. Special Emotions in developmental psychopathology, 7, Greenberg, M. T., Kusché, C. A., & Speltz, M. (1991). Emotional regulation, self-control and psychopathology: The role of relationships in early childhood. In D. Cicchetti & S. Toth (Eds.), Internalizing and externalizing expressions of dysfunction. Rochester Symposium on developmental psychopathology (Vol. 2, pp ). New York: Cambridge University Press. de Hann, M., Nelson, C. A., Gunnar, M. R., & Tout, K. A. (1998). Hemispheric differences in brain activity related to the recognition of emotional expressions by 5-year-old children. Developmental Neuropsychology, 14, Henry, B., & Moffitt, T. E. (1997). Neuropsychological and neuroimaging studies of juvenile delinquency and adult criminal behavior. In D. M. Stoff & J. Breiling (Eds.), Handbook of antisocial behavior (pp ). New York: John Wiley & Sons Inc. Hill, J. (2002). Biological, psychological and social processes in the conduct disorders. Journal of Child Psychology and Psychiatry, 43, Holland, P. W. (1988). Causal inference, path analysis, and recursive structural equations models. Sociological Methodology, 18, Ikonomidou, C., Bittigau, P., Ishimaru, M. J., Wozniak, D. F., Koch, C., & Genz, K. (2000). Ethanol-induced apoptotic neurodegeneration and fetal alcohol syndrome. Science, 287, Ito, Y., Teicher, M. H., Glod, C. A., & Ackerman, E. (1998). Preliminary evidence for aberrant cortical development in abused children: A quantitative EEG study. Journal of Neuropsychiatry and Clinical Neuroscience, 10, Kam, C., Greenberg, M. T., & Kusché, C. A. (2004). Sustained Effects of the PATHS Curriculum on the Social and Psychological Adjustment of Children in Special Education. Journal of Emotional and Behavioral Disorders, 12, Kirisci, L., Tarter, R. E., Vanyukov, M., Reynolds, M., & Habeych, M. (2004). Relation between cognitive distortions and neurobehavior disinhibition on the development of substance use during adolescence and substance use disorder by young adulthood: A prospective study. Drug and Alcohol Dependence, 76, Kusché, C. A., Cook, E. T., & Greenberg, M. T. (1993). The neuropsychological basis of disorders affecting children and adolescents. Journal of Clinical Child Psychology, 22, Kusché, C. A., & Greenberg, M. T. (1994). The PATHS (Promoting alternative thinking strategies) curriculum. South Deerfield, MA: Channing-Bete Co. Lahey, B. B., Loeber, R., Hart, E. L., Frick, P. J., Applegate, B., Zhang, Q., Green, S. M., & Russo, M. F. (1995). Four-year longitudinal study of conduct disorder in boys: Patterns and predictors of persistence. Journal of Abnormal Psychology, 104, Lahey, B. B., Loeber, R., Quay, H. C., Frick, P. J., & Grimm, J. (1997). Oppositional defiant disorder and conduct disorder. In T. A. Widiger, A. J. Frances, H. A. Pincus, R. Ross, M. B. First, & W. Davis (Eds.), DSM-IV sourcebook 3 (pp ). Washington, DC: American Psychiatric Association. Lahey, B. B., Waldman, I. D., & McBurnett, K., (1999). The development of antisocial behavior: An integrative causal model. Journal of Child Psychology and Psychiatry, 40, Luria, A. R. (1966). Higher cortical functions in man. New York: Basic Books. Lynam, D. R., & Henry, V. (2001). The role of neuropsychological deficits in conduct disorders. In J. Hill & B. Maughan (Eds.), Conduct disorders in childhood and adolescence. Cambridge, UK: Cambridge University Press. Lynam, D., Moffitt, T., & Stouthamer-Loeber, M. (1993). Explaining the relation between IQ and delinquency: Class, race, test motivation, school failure, or self-control? Journal of Abnormal Psychology, 102, MacKinnon, D. P., Krull, J. L., & Lockwood, C. M. (2000). Equivalence of the mediation, confounding and suppression effect. Prevention Science, 4, Marlowe, W. B. (2001). An intervention for children with disorders of executive functions. Developmental Neuropsychology, 18, McCarthy, D. (1972). Manual for the McCarthy scales for children s abilities. New York: The Psychological Corp. McCrea, S. M., Mueller, J. H., & Parrila, R. K. (1999). Quantitative analyses of schooling effects on executive function in young children. Child Neuropsychology, 5, McEwen, B. S. (1997). Possible mechanisms for atrophy of the human hippocampus. Molecular Psychiatry, 2, Miller, M. W. (1996). Limited ethanol exposure selectively alters the proliferation of precursor cells in the cerebral cortex.alcoholism, Clinical and Experimental Research, 20, Moffitt, T. E. (1990). The neuropsychology of delinquency: A critical review of theory and research. In N. Morris & M. Tonry (Eds.), Crime and justice: An annual review of research (Vol. 12, pp ). Chicago: University of Chicago Press. Moffitt, T. E., & Caspi, A. (1998). Annotation: implications of violence between intimate partners for child psychologists and psychiatrists. Journal of Child Psychology and Psychiatry, 39, Moffitt, T. E., & Henry, B. (1989). Neuropsychological assessment of executive function in self-reported delinquents. Development and Psychopathology, 1, Moffitt, T. E., & Lynam, D. R. (1994). The neuropsychology of conduct disorder and delinquency: Implications for understanding antisocial behaviour. In D. Fowles, P. Sutker, & S. Goodman (Eds.), Psychopathy and antisocial personality: A developmental perspective: Vol. 18. Progress in experimental personality and psychopathology research (pp ). New York: Springer. Nigg, J. T., Quamma, J. P., Greenberg, M. T., & Kusché, C. A. (1998). A two-year longitudinal study of neuropsychological and cognitive performance in relation to behavioral problems and competencies in elementary school children. Journal of Abnormal Psychology, 27, Paschall, M. J., & Fishbein, D. H. (2002). Executive cognitive functioning and aggression: A public health perspective. Aggression and Violent Behavior, 7,

12 Riggs, Greenberg, Kusché, and Pentz Pennington, B. F., & Ozonoff, S. (1996). Executive function and developmental psychopathology. Journal of Child Psychology and Psychiatry, 1, Pine, F. (1985). Developmental theory and clinical process. New Haven, CT: Yale University Press. Riggs, N. R., Blair, C. B., & Greenberg, M. T. (2003). Concurrent and 2-year longitudinal relations between executive function and the behavior of 1st and 2nd grade children. Child Neuropsychology, 9, Riggs, N. R., & Greenberg, M. T. (2004). The role of neurocognitive models in prevention research. In D. Fishbein (Ed.): The science, treatment, and prevention of antisocial behaviors: Application to the criminal justice system: Vol. 2. Evidence-based practice. Kingston, NJ: Civic Research Institute. Sapolsky, R. M. (1996). Why stress is bad for your brain. Science, 273, Sobel, M. E. (1982). Asymptotic confidence intervals for indirect effects in structural equation models. In S. Leinhardt (Ed.), Sociological methodology, (pp ). Washington, DC: American Sociological Association. Spellacy, F. (1977). Neuropsychological differences between violent and nonviolent adolescents. Journal of Clinical Psychology, 33, Spreen, O., & Strauss, E. (1991). The relationship between learning disabilities and persisting delinquency. Journal of Learning Disabilities, 26, Stein, M. B., Koverola, C., Hanna, C., Torchia, M. C., & McClarty, B. (1997). Hippocampal volume in women victimized by childhood sexual abuse. Psychological Medicine, 27, U.S. Department of Health and Human Services Mental Health. (1999). A report of the Surgeon General. Rockville, MD. Wechsler, D. (1974). Manual for the Wechsler Intelligence Scale for Children Revised. New York: Psychological Corporation. Weissberg, R. P., Caplan, M. Z., & Bennetto, L. (1988). The Yale- New Haven Middle-School Social Problem Solving (SPS) Program. New Haven, CT: Yale University. Weissberg, R. P., Caplan, M. Z., & Sivo, P. J. (1989). A new conceptual framework for establishing school-based social competence promotion programs. In L. A. Bond & B. E. Compas (Eds.), Primary prevention and promotion in the schools. Primary prevention of psychopathology (Vol. 12, pp ). Thousand Oaks, CA: Sage. Weissberg, R. P., & Greenberg, M. T. (1998). Prevention science and collaborative community action research: Combining the best from both perspectives. Journal of Mental Health, 7, Welsh, M. C., Pennington, B. F., & Groisser, D. B. (1991). A normative-developmental study of executive function: A window of prefrontal function in children. Developmental Neuropsychology, 7, White, J. L., Moffitt, T. E. Caspi, A., Jeglum Bartusch, D., Needles, D. J., & Stouthamer-Loeber, M. (1994). Measuring impulsivity and examining its relationship to delinquency. Journal of Abnormal Psychology, 103, White, H. R., Xie, M., Thompson, W., Loeber, R., Stouthamer- Loeber, M. (2001). Psychopathology as a predictor of adolescent drug use trajectories. Psychology of Addictive Behaviors, 15, Zins, J. E., Elias, M. J., Greenberg, M. T., Weissberg, R. P. (2000). Promoting social and emotional competence in children. In K. M. Minke & G. G. Bear (Eds.), Preventing school problems-promoting school success: Strategies and programs that work (pp ). Bethesda, MD: National Association of School Psychologists.