Complex effects of NMDA receptor antagonist APV in the basolateral amygdala on acquisition of two-way avoidance reaction and long-term fear memory

Although much has been learned about the role of the amygdala in Pavlovian fear conditioning, relatively little is known about an involvement of this structure in more complex aversive learning, such as acquisition of an active avoidance reaction. In the present study, rats with a pretraining injection of the N-methyl-D-aspartate (NMDA) receptor antagonist, 2-amino-5-phosphonopentanoic acid (APV), into the basolateral amygdala (BLA) were found to be impaired in two-way active avoidance learning. During multitrial training in a shuttle box, the APV-injected rats were not different from the controls in sensitivity to shock or in acquisition of freezing to contextual cues. However, APV injection led to impaired retention of contextual fear when tested 48 h later, along with an attenuation of c-Fos expression in the amygdala. These results are consistent with the role of NMDA receptors of the BLA in long-term memory of fear, previously documented in Pavlovian conditioning paradigms. The APV-induced impairment in the active avoidance learning coincided with deficits in directionality of the escape reaction and in attention to conditioned stimuli. These data indicate that normal functioning of NMDA receptors in the basolateral amygdala is required during acquisition of adaptive instrumental responses in a shuttle box but is not necessary for acquisition of short-term contextual fear in this situation.     

Decoding digit symbol: speed,memory, and visual scanning

The authors evaluated the relative contributions of speed, memory, and visual scanning to Digit Symbol score in a sample of young adults (N = 87). Speed (Symbol Copy) explained 35% of Digit Symbol variance; only half of this was attributable to graphomotor speed (Name Printing), implying a role for perceptual speed. Visual-scanning tests (e.g., Symbol Scan) explained (on average) 34% of Digit Symbol variance, much of which was independent of perceptual-motor speed, establishing an important role for visual-scanning efficiency in Digit Symbol performance. By contrast, memory tests (on average) explained only 4% to 5% of Digit Symbol variance: statistically significant but clearly subsidiary, although a visual memory composite correlated more strongly with Digit Symbol. The Digit Symbol incidental learning procedures did, however, correlate moderately with other memory measures, suggesting that they are valid memory screening devices.     

Psychopathy scores predict adolescent inpatient aggression

This prospective study found that psychopathy scores predicted aggressive behavior among 72 adolescent psychiatric inpatients, even after controlling for age, sex, socioeconomic status, length of hospital stay, and independent self-report measures of impulsivity and conduct problems. Psychopathy was assessed within 3 days of hospital admission by clinical raters trained in the use of Hare's Psychopathy Checklist-Revised. Aggressive behavior was recorded by clinical staff members who were unaware of psychopathy ratings. Adolescents rated higher in psychopathy exhibited higher frequencies of both reactive and instrumental aggressive behavior than adolescents rated lower in psychopathy. Post hoc regression analyses revealed that psychopathy had incremental validity in predicting aggression beyond the contribution of clinical diagnosis or scores on the Millon Adolescent Clinical Inventory.     

Parenting of children with attention-defecit/hyperactivity disorder (ADHD): the role of parental ADHD symptomatology

OBJECTIVE: The present study examined the relation between parental ADHD symptomatology and parent-child behavior among 46 mothers and 26 fathers of ADHD children. RESULTS: Fathers' self-reports of inattention and impulsivity were strongly associated with self-reports of lax parenting both before and after parent training, and with self-reports of overreactivity after parent training. Fathers' impulsivity was also associated with more arguing during audiotaped observations of parent-child interactions prior to parent training. Mothers' self-reports of inattention were modestly associated with self-reports of laxness before and after parent training. Prior to parent training, there were non-linear relations between mothers' inattention and observations of mother-child behavior, with mothers who reported moderate levels of inattention engaging in the most negative parent-child interactions. After parent training, these relations were linear, with the mothers who reported the most inattention engaging in the most negative parent-child interactions. These results were weakened but were generally still significant when parental depression and alcohol use were controlled.     

Social psychology of mental health: the social structure and personality perspective

Previous research has revealed a persistent association between social structure and mental health. However, most researchers have focused only on the psychological and psychosocial aspects of that relationship. The present paper indicates the need to include the social and structural bases of distress in our theoretical models. Starting from a general social and psychological model, our research considered the role of several social, environmental, and structural variables (social position, social stressors, and social integration), psychological factors (self-esteem), and psychosocial variables (perceived social support). The theoretical model was tested working with a group of Spanish participants (N = 401) that covered a range of social positions. The results obtained using structural equation modeling support our model, showing the relevant role played by psychosocial, psychological and social, and structural factors. Implications for theory and intervention are discussed.     

Argumentation and Evidence

This essay explores the role of informal logicand its application in the context of currentdebates regarding evidence-based medicine. This aim is achieved through a discussion ofthe goals and objectives of evidence-basedmedicine and a review of the criticisms raisedagainst evidence-based medicine. Thecontributions to informal logic by StephenToulmin and Douglas Walton are explicated andtheir relevance for evidence-based medicine isdiscussed in relation to a common clinicalscenario: hypertension management. This essayconcludes with a discussion on the relationshipbetween clinical reasoning, rationality, andevidence. It is argued that informal logic hasthe virtue of bringing explicitness to the roleof evidence in clinical reasoning, and bringssensitivity to understanding the role ofdialogical context in the need for evidence inclinical decision making.     

The influence of language exposure on lexical and syntactic language processing

Previous literature has argued that proficient bilingual speakers often demonstrate monolingual-equivalent structural processing of language (e.g., the processing of structural ambiguities; Frenck-Mestre, 2002). In this paper, we explore this thesis further via on-line examination of the processing of syntactically complex structures with three populations: those who classify as monolingual native English speaker (MNES), those who classify as non-native English speakers (NNES), and those who calssify as bilingual native English speakers (BNES). On-line measures of processing of object-relative constructions demonstrated that both NNES and BNES have different patterns of performance as compared to MNES. Further, NNES and BNES speakers perform differently from one another in such processing. The study also examines the activation of lexical information in biasing contexts, and suggests that different processes are at work in the different type of bilinguals examined here. The nature of these differences and the implications for developing sensitive models of on-line language comprehension are developed and discussed.     

Strategic aspects of numerosity judgment: the effect of task characteristics

In previous investigations we documented that people use several strategies to determine different numerosities of blocks that are presented in a square grid. One of these strategies is the clever subtraction strategy, wherein the number of empty squares in the grid is subtracted from the total number of squares in the grid. In the present study we investigated participants' flexibility in strategy use when varying the shape of the grid. Analysis of the results in terms of the theoretical framework of Lemaire and Siegler (1995) regarding strategic change shows that this contextual variable affected the frequency, execution time, and accuracy of subjects' use of the subtraction strategy. The usefulness of this framework for analyzing the nature of the adaptation to contextual variations is discussed. From a methodological point of view, this study documents the potential of Beem's (1993, 1999) segmented linear regression models for assessing subjects' strategy use in cognitive tasks.     

Spatial language and spatial representation: a cross-linguistic comparison

We examined the relationship between spatial language and spatial memory by comparing native English, Japanese, and Korean speakers' naming of spatial locations and their spatial memory for the same set of locations. We focused on two kinds of spatial organization: axial structure of the reference object, and contact/support with respect to its surface. The results of two language (naming) tasks showed similar organization across the three language groups in terms of axial structure, but differences in organization in terms of contact/support. In contrast, the results of two memory tasks were the same across language groups for both axial structure and contact/support. Moreover, the relationship between spatial language and spatial memory in the two sets of tasks did not show a straightforward isomorphism between the two systems. We conclude that spatial language and spatial memory engage the same kinds of spatial properties, suggesting similarity in the foundations of the two systems. However, the two systems appear to be partially independent: the preservation of particular spatial properties was not mandatory across languages, nor across memory tasks, and cross-linguistic differences in spatial language did not lead to differences in the non-linguistic encoding of location. We speculate that the similarity in linguistic and non-linguistic representations of space may emerge as a functional consequence of negotiating the spatial world.