Measures Of Cognitive Processes Research Articles

Investigation of the impact of two verbal instruction formats and prior knowledge on student learning in a simulation-based learning environment

This study investigated how the format of verbal instructions in computer simulations and prior knowledge (PK) affected 8th graders' cognitive load (CL) level and achievement in a multimedia learning environment. Although PK was not found to significantly affect student performance and CL level, instruction format was found to impact both. Students who used narrative simulations were found to have a greater CL but also to perform better than those using simulations with on-screen text instructions. However, no significant differences were found between the cognitive efficiency of the two groups. The difficulty of the subject matter and limitations in students' prior content-related knowledge may have increased the intrinsic CL, such that students had difficulty in interpreting the content even if their PK was relatively high. The narrative instructions were more likely than the on-screen text information to reduce the extraneous CL and promote understanding of content. A new measure of cognitive processing is needed to identify the types of CL involved in e-learning and determine the properties of adequate e-learning materials. Finally, the findings of the study are discussed and suggestions for future studies and instructional design are provided.

The Prefrontal Model Revisited: Double Dissociations Between Young Sleep Deprived and Elderly Subjects on Cognitive Components of Performance

The prefrontal model suggests that total sleep deprivation (TSD) and healthy aging produce parallel cognitive deficits. Here we decompose global performance on two common tasks into component measures of specific cognitive processes to pinpoint the source of impairments in elderly and young TSD participants relative to young controls and to each other. The delayed letter recognition task (DLR) was performed in 3 studies. The psychomotor vigilance task (PVT) was performed in 1 of the DLR studies and 2 additional studies. For DLR, young TSD (n=20, age=24.60 ± 0.62 years) and young control (n=17, age=24.00 ± 2.42); elderly (n=26, age=69.92 ± 1.06). For the PVT, young TSD (n=18, age=26.65 ± 4.57) and young control (n=16, age=25.19 ± 2.90); elderly (n=21, age=71.1 ± 4.92). Both elderly and young TSD subjects displayed impaired reaction time (RT), our measure of global performance, on both tasks relative to young controls. After decomposing global performance on the DLR, however, a double dissociation was observed as working memory scanning speed was impaired only in elderly subjects while other components of performance were impaired only by TSD. Similarly, for the PVT a second double dissociation was observed as vigilance impairments were present only in TSD while short-term response preparation effects were altered only in the elderly. The similarity between TSD and the elderly in impaired performance was evident only when examining global RT. In contrast, when specific cognitive components were examined double dissociations were observed between TSD and elderly subjects. This demonstrates the heterogeneity in those cognitive processes impaired in TSD versus the elderly.

Written expression performance in adolescents with attention-deficit/hyperactivity disorder (ADHD)

We examined written expression performance in a sample of adolescents with ADHD and subthreshold ADHD using two different strategies: examining performance on standardized measures of written expression and using other indicators of written expression developed in this study. We examined associations between standardized measures of written expression, cognitive processing measures (working memory, processing speed, language, fine motor ability, and reading efficiency) and behavioral ratings of ADHD by parents and teachers. We also developed a coding scheme for a writing sample to measure productivity and the ratio of self-corrections to errors. The results indicated that written expression performance was most consistently associated with cognitive processing measures and not behavioral ratings of ADHD, based on correlational and simultaneous regression analyses. These results were consistent in the analyses with both the standardized measures and the coding scheme measures of written expression. Findings generally remained robust, regardless of whether participants who met criteria for a learning disability were included or excluded in the analyses. The current results suggest that written expression difficulties in adolescents with ADHD are attributable to processing difficulties that may be associated with ADHD, not to ADHD reported symptoms. Implications for assessment and intervention are discussed.

A novel, implicit treatment for language comprehension processes in right hemisphere brain damage: Phase I data

Background: This manuscript reports the initial phase of testing for a novel, “Contextual constraint” treatment, designed to stimulate inefficient language comprehension processes in adults with right hemisphere brain damage (RHD). Two versions of treatment were developed to target two normal comprehension processes that have broad relevance for discourse comprehension and that are often disrupted by RHD: coarse semantic coding and suppression. The development of the treatment was informed by two well-documented strengths of the RHD population. The first is consistently better performance on assessments that are implicit, or nearly so, than on explicit, metalinguistic measures of language and cognitive processing. The second is improved performance when given linguistic context that moderately-to-strongly biases an intended meaning. Treatment consisted of providing brief context sentences to prestimulate, or constrain, intended interpretations. Participants made no explicit associations or judgments about the constraint sentences; rather, these contexts served only as implicit primes. Aims: This Phase I treatment study aimed to determine the effects of a novel, implicit, Contextual Constraint treatment in adults with RHD whose coarse coding or suppression processes were inefficient. Treatment was hypothesized to speed coarse coding or suppression function in these individuals. Methods & Procedures: Three adults with RHD participated in this study, one (P1) with a coarse coding deficit and two (P2, P3) with suppression deficits. Probe tasks were adapted from prior studies of coarse coding and suppression in RHD. The dependent measure was the percentage of responses that met predetermined response time criteria. When pre-treatment baseline performance was stable, treatment was initiated. There were two levels of contextual constraint, Strong and Moderate, and treatment for each item began with the provision of the Strong constraint context. Outcomes & Results: Treatment-contingent gains were evident after brief periods of treatment, for P1 on two treatment lists, and for P2. P3 made slower but still substantial gains. Maintenance of gains was evident for P1, the only participant for whom it was measured. Conclusions: This Phase I treatment study documents the potential for considerable gains from an implicit, Contextual constraint treatment. If replicated, this approach to treatment may hold promise for individuals who do poorly with effortful, metalinguistic treatment tasks, or for whom it is desirable to minimize errors during treatment. The real test of this treatment's benefit will come from later phase studies of study, which will test broad-based generalization to various aspects of discourse comprehension.

SMART-T: a system for novel fully automated anticipatory eye-tracking paradigms.

Anticipatory eye movements (AEMs) are a natural and implicit measure of cognitive processing and have been successfully used to document such important cognitive capacities as learning, categorization, and generalization, especially in infancy (McMurray & Aslin, Infancy, 6, 203-229, 2004). Here, we describe an improved AEM paradigm to automatically assess online learning on a trial-by-trial basis, by analyzing eye gaze data in each intertrial interval of a training phase. Different measures of learning can be evaluated simultaneously. We describe the implementation of a system for designing and running a variety of such AEM paradigms. Additionally, this system is capable of a wider variety of gaze-contingent paradigms, as well as implementations of standard noncontingent paradigms. Our system, Smart-T (System for Monitoring Anticipations in Real Time with the Tobii), is a set of MATLAB scripts with a graphical front end, written using the Psychophysics Toolbox. The system gathers eye gaze data using the commercially available Tobii eye-trackers via a MATLAB module, Talk2Tobii. We report a pilot study showing that Smart-T can detect 6-month-old infants' learning of simple predictive patterns involving the disappearance and reappearance of multimodal stimuli.

Fitness, fatness, cognition, behavior, and academic achievement among overweight children: Do cross-sectional associations correspond to exercise trial outcomes?

Background This study examined associations of fitness and fatness with cognitive processes, academic achievement, and behavior, independent of demographic factors, at the baseline of an exercise trial. Methods Overweight, sedentary but otherwise healthy 7–11 year olds (N = 170) participated in a study of health, cognition and achievement in the Augusta, GA area from 2003–2006. Children underwent evaluations of fatness and fitness, psychological assessments of cognition and academic achievement, and behavior ratings by parents and teachers. Partial correlations examined associations of fitness and fatness with cognitive and achievement scores and behavior ratings, controlling for demographic factors. Results Fitness was associated with better cognition, achievement and behavior, and fatness with worse scores. Specifically, executive function, mathematics and reading achievement, and parent ratings of child behavior were related to fitness and fatness. Teacher ratings were related to fitness. Conclusion These results extend prior studies by providing reliable, standardized measures of cognitive processes, achievement, and behavior in relation to detailed measures of fitness and fatness. However, cross-sectional associations do not necessarily indicate that improving one factor, such as fatness or fitness, will result in improvements in factors that were associated with it. Thus, randomized clinical trials are necessary to determine the effects of interventions.

WHAT'S THE MATTER WITH CUE‐INDUCED CRAVING? A COMMENTARY ON PERKINS

Perkins [1] argues that smoking cue-induced craving has not been demonstrated to have clinical predictive utility, and concludes that it is premature to focus upon this model until it has been demonstrated to predict smoking persistence or other indices of dependence. However, whether this apparent failure of the model is due to limitations of the model itself, or other features of laboratory studies of smoking behavior, is only partially addressed. The concept of ‘craving’, and the use of smokers who are not currently seeking treatment as participants, may be equally problematic. Failure to address these issues may invalidate much laboratory research and limit the applicability of any findings to clinical studies. Despite being used as the primary outcome measure in most laboratory studies, the meaning of subjective craving remains controversial and poorly understood. While it is widely assumed that cravings may precipitate relapse to smoking, measures of self-reported craving predict relapse only weakly, particularly when measured at a single time-point, but even when assessed at regular intervals in ambulatory monitoring studies [2]. The global construct of subjective craving may therefore be of limited utility in predicting relapse; by extension, laboratory studies which focus upon craving may not translate to the real world. An important distinction may be between what might be termed tonic craving (i.e. background levels) and phasic craving (i.e. episodic spikes) [3], the former stimulated primarily by withdrawal states and the latter primarily by cues associated with tobacco use. Intense, brief episodes of craving can occur even after background levels have diminished once withdrawal symptomatology resolves [4], and variability in craving may be more predictive than mean level [5]. The true situation is likely to be more complicated than a simple distinction between tonic and phasic craving, with interactions between craving classes (e.g. conditioned emotional states), but this framework provides a starting point that allows the measurement of multiple components of craving, and at different levels of temporal resolution. It remains to be seen whether parsing these components of craving will enhance the validity of laboratory studies. An alternative is to use implicit biobehavioural measures: smokers show increased vigilance for smoking-related cues (sometimes referred to as attentional bias) compared with non-smokers [6], and this may predict relapse following cessation [7], while measures of smoking topography have also been reported to predict relapse in adolescents [8] and adults [9]. However, these measures often correlate only weakly with self-reported craving [10], and their value in predicting clinically relevant outcomes such as relapse to smoking has not yet been established fully. Another difficulty may be the use of short-term abstinence as a model for smoking cessation. Studies of this kind ‘. . . usually involve smokers who are not interested in quitting permanently but participate for monetary payment’ ([1], p. 2). Biologically, the use of acute abstinence to model withdrawal seems plausible, given the short half-life of nicotine. However, there are important differences between this withdrawal state and that associated with a cessation attempt. In the former case the smoker knows that it will be possible to smoke again shortly, and perceived availability has been shown to modify cue-reactivity. Craving increases more when there is an expectation of an opportunity to smoke [11], although this may depend upon degree of dependence [12], while neural response to cigarette cues varies according to perceived availability [13]. Cue-induced craving has been found to be associated with various proxy indices of tobacco dependence, but not severity of dependence (a key index of relapse risk) [1]. However, laboratory measures unrelated to cue-reactivity do seem to predict relapse. These include measures of physical distress tolerance (such as breath-holding) that have been found to offer predictive utility beyond known risk factors for early smoking lapses [14]. More research is needed to evaluate the possibility that ‘various non-self report correlates of craving in response to cues are stronger predictors of relapse than self-reported craving’ ([15], p. 4). Promising targets include cognitive processing measures such as those mentioned earlier, neural imaging of reactivity to cues, and especially acute changes in smoking behavior (i.e. aspects of smoking topography, such as depth of inhalation) as promising directions to assess cue-reactivity. MM has received nicotine replacement products from GlaxoSmithKline and Pfizer Inc. for distribution to study participants. BH has provided consultancy to Pinney Associates, subcontracted by GlaxoSmithKline and Pfizer Inc.

Simultaneous and Sequential Cognitive Processing in Monolingual and Bilingual Children in South Africa

Academic success is correlated with simultaneous and sequential cognitive processing. The cognitive processing skills of bilingual children have come under scrutiny. Cognitive processing may be mediated by level of orthographic transparency, level of bilingualism, and language of instruction at school. Given the imperative of assessing the impact of bilingualism and multilingualism on learning, the performance of 30 monolingual English and 30 bilingual Afrikaans-English third grade children was compared on the Kaufman Assessment Battery for Children (K-ABC) simultaneous and sequential processing standard scales. The K-ABC is relatively culture fair with low language requirements. We did not find any significant differences between the two groups on the global simultaneous-sequential scales, but significant differences were found on two specific subtests of the K-ABC: Hand Movements and Matrix Analogies. Findings provide overall support for the usefulness of the K-ABC as a measure of cognitive processing for children from diverse cultural-linguistic backgrounds, but with the understanding that a monolingual and a bilingual literacy-learning environment influences cognitive processing skills on specific cognitive tasks on the K-ABC. Importantly, the unchanged Hand Movements subtest and a modified version of the Matrix Analogies subtest (i.e. Pattern Recognition) is used in the K-ABC II, not yet widely used in South Africa. This study has important implications for using the K-ABC and K-ABC II across cultural-linguistic groups, for educational purposes.

Moderate vagal withdrawal in 3.5-year-old children is associated with optimal performance on executive function tasks.

Vagal tone (measured via respiratory sinus arrhythmia, RSA) and vagal withdrawal (measured by decreases in RSA) have been identified as physiological measures of self-regulation, but little is known how they may relate to the regulation of cognitive activity as measured through executive function (EF) tasks. We expected that baseline measures of vagal tone, thought to be an indicator of attention, would correlate with EF performance. We also predicted that vagal withdrawal would allow for the reorientation of attention that is needed to succeed on EF tasks, but too much withdrawal would be detrimental. RSA measured at baseline was indeed related to EF performance in 220 3.5-year-old children, and those who exhibited a moderate decrease in RSA during the EF tasks outperformed children whose RSA decreased by too little or too much. These findings implicate vagal tone withdrawal as a psychophysiological measure of higher cognitive processes, most likely substantiated through increases in the levels of focused attention.

Waiting is the hardest part: Anticipating medical test results affects processing and recall of important information

Waiting for medical test results that signal physical harm can be a stressful and potentially psychologically harmful experience. Despite this, interventionists and physicians often use this wait time to deliver behavior change messages and other important information about the test, possible results and its implications. This study examined how "bracing" for a medical test result impacts cognitive processing, as well as recall of information delivered during this period. Healthy U.S. university students (N = 150) were tested for a deficiency of a fictitious saliva biomarker that was said to be predictive of long-term health problems using a 2 (Test Result) x 2 (Expected immediacy of result: 10 min, 1 month) factorial design. Participants expecting to get the test result shortly should have been bracing for the result. While waiting for the test results participants completed measures of cognitive processing. After participants received the test result, recall of information about the biomarker was tested in addition to cognitive measures. One week later, participants who were originally told they did not have the deficiency had their recall assessed again. Results showed that anticipating an imminent test result increased cognitive distraction in the processing of information and lowered recall of information about the test and the biomarker. These results suggest that delivering critical information to patients after administering a test and immediately before giving the results may not be optimal.

Transtorno do Déficit de Atenção/Hiperatividade: o que nos informa a investigação dimensional?

Investiga-se o Transtorno do Déficit de Atenção/Hiperatividade (TDAH) em contexto escolar adotando a perspectiva dimensional. Participaram 107 crianças com idade média de 12,37 anos. Utilizou-se a Escala de TDAH - versão para professores, uma versão adaptada para pais e tarefas computadorizadas de processamento cognitivo. A prevalência de Hiperatividade pelo relato de professores e pais foi condizente com aquela apontada pela literatura (4,7%). O Déficit de Atenção, avaliado por pais e professores, correlacionou com todas as medidas de processamento de informação. Hiperatividade e Comportamento Anti-social correlacionaram com as medidas de memória de trabalho quando a primeira foi avaliada pelos professores e a segunda pelos pais, refletindo baixa concordância entre o relato de informantes a respeito das dimensões comportamentais do TDAH. Entretanto, as respostas dos professores parecem estar mais de acordo com a literatura. Conclui-se que a perspectiva dimensional de investigação pode fornecer informações relevantes sobre as características demográficas e cognitivas do TDAH.

Temporal Stability of Music Perception and Appraisal Scores of Adult Cochlear Implant Recipients

An extensive body of literature indicates that cochlear implants (CIs) are effective in supporting speech perception of persons with severe to profound hearing losses who do not benefit to any great extent from conventional hearing aids. Adult CI recipients tend to show significant improvement in speech perception within 3 mo following implantation as a result of mere experience. Furthermore, CI recipients continue to show modest improvement as long as 5yr postimplantation. In contrast, data taken from single testing protocols of music perception and appraisal indicate that CIs are less than ideal in transmitting important structural features of music, such as pitch, melody, and timbre. However, there is presently little information documenting changes in music perception or appraisal over extended time as a result of mere experience. This study examined two basic questions: (1) Do adult CI recipients show significant improvement in perceptual acuity or appraisal of specific music listening tasks when tested in two consecutive years? (2) If there are tasks for which CI recipients show significant improvement with time, are there particular demographic variables that predict those CI recipients most likely to show improvement with extended CI use? A longitudinal cohort study. Implant recipients return annually for visits to the clinic. The study included 209 adult cochlear implant recipients with at least 9 mo implant experience before their first year measurement. Outcomes were measured on the patient's annual visit in two consecutive years. Paired t-tests were used to test for significant improvement from one year to the next. Those variables demonstrating significant improvement were subjected to regression analyses performed to detect the demographic variables useful in predicting said improvement. There were no significant differences in music perception outcomes as a function of type of device or processing strategy used. Only familiar melody recognition (FMR) and recognition of melody excerpts with lyrics (MERT-L) showed significant improvement from one year to the next. After controlling for the baseline value, hearing aid use, months of use, music listening habits after implantation, and formal musical training in elementary school were significant predictors of FMR improvement. Bilateral CI use, formal musical training in high school and beyond, and a measure of sequential cognitive processing were significant predictors of MERT-L improvement. These adult CI recipients as a result of mere experience demonstrated fairly consistent music perception and appraisal on measures gathered in two consecutive years. Gains made tend to be modest, and can be associated with characteristics such as use of hearing aids, listening experiences, or bilateral use (in the case of lyrics). These results have implications for counseling of CI recipients with regard to realistic expectations and strategies for enhancing music perception and enjoyment.

Emotional sensitivity measurement in cognitive tasks with emotional stimuli

The present study was designed in the theoretical framework of indirect measurement of emotional sensitivity as a component of emotional intelligence (EI) via speeded simple cognitive tasks. Two different subtests were constructed to calculate the indexes reflecting changes in task performance caused specifically by emotional processing. Response latencies obtained from the subtests with neutral and emotional stimuli were analyzed in their relationships with other measures of processing speed and scales of EI. The results allow discussing such approach as a productive way to measure some emotional processing ability that differs from the measures of simple cognitive processing and reflects some components of emotional intelligence.

Reading Disabilities in Adults: A Selective Meta-Analysis of the Literature

This article synthesizes the experimental literature that compares the academic, cognitive, and behavioral performance of adults with reading disabilities to those of average-achieving adult readers. The central question posed by this review is to what extent and in what manner do adults with reading disabilities differ from adults without reading disabilities on measures assumed to relate to overall reading competence. In all, 52 studies met criteria for a meta-analysis, yielding 776 effect sizes (ESs) with an overall a weighted ES of 0.72 ( SD = 0.54). Moderate to high ESs in favor of adults without reading disabilities emerged on measures of cognition (naming speed [ M = 0.96], phonological processing [ M = 0..87], verbal memory [ M = 0.62]) and achievement (word attack [ M = 1.33], math [ M = 0.75], vocabulary [ M = 0.71], spelling [ M = 1.57], and writing [ M = 0.72]). Hierarchical linear modeling indicated that verbal IQ, vocabulary, math, spelling, and specific cognitive process measures (naming speed, phonological processing, and verbal memory) significantly moderated overall group ES differences. Significantly larger ESs emerged for studies with relatively higher IQ scores when compared to studies with IQ and reading scores in the same low range. Overall, the results support the notion that reading achievement and cognitive deficits in adults with reading disabilities are persistent across age.

Angry Thoughts and Response to Provocation: Validity of the Angry Cognitions Scale

Recently, Martin and Dahlen (J Ration Emot Cogn Behav Ther 25:155–173, 2007) developed the Angry Cognitions Scale (ACS), a theoretically derived instrument designed to measure the cognitive processes related to anger. This instrument has the potential to inform clinical and research perspectives of anger. Although preliminary evidence for the reliability and validity of the ACS was positive, further research is required regarding the ACS’s temporal stability and predictive validity. The current project sought to address this concern by assessing the six-week test–retest reliability of the ACS, exploring relationships between the ACS subscales and the experience and expression of anger, and assessing the ability of the ACS to predict cognitive and emotional responses to provocation. The ACS demonstrated adequate test–retest reliability and predicted hostile thoughts and state anger following provocation. Thus, results contribute to the literature on the ACS and support its use as a measure of cognitive processes associated with anger.

Maladaptive cognitive appraisals mediate the evolution of posttraumatic stress reactions: A 6-month follow-up of child and adolescent assault and motor vehicle accident survivors.

A prospective longitudinal follow-up study (n = 59) of child and adolescent survivors of physical assaults and motor vehicle accidents assessed whether cognitive processes predicted posttraumatic stress symptomatology (PTSS) at 6 months posttrauma in this age group. In particular, the study assessed whether maladaptive posttraumatic appraisals mediated the relationship between initial and later posttraumatic stress. Self-report measures of PTSS, maladaptive appraisals, and other cognitive processes, as well as structured interviews assessing for acute stress disorder and posttraumatic stress disorder (PTSD), were completed at 2-4 weeks and 6 months posttrauma. PTSS and PTSD at 6 months were associated with maladaptive appraisals and other cognitive processes but not demographic or objective trauma severity variables. Only maladaptive appraisals were found to associate with PTSS/PTSD after partialing out initial symptoms/diagnosis and to mediate between initial and later PTSS. It was argued that, on this basis, maladaptive appraisals are involved in the development and maintenance of PTSS over time, whereas other cognitive processes (e.g., subjective threat, memory processes) may have an effect only in the acute phase. The implications of this study for the treatment of PTSS in youths are discussed.

Asymmetry and non-zero mean of neuronal oscillations: What is essential for the generation of evoked responses?

Evoked responses (ERs) from magneto- and electroencephalographic recordings (MEG/EEG) are the primary real-time objective measures of cognitive and perceptual processes in the human brain. For the past fifty years, only two mechanisms for the generation of ERs have been discussed in the literature: „additive“ responses and „phase resetting“ of ongoing oscillations. Recently we introduced a novel mechanism for the generation of ERs (Nikulin et al., 2007), which can be deduced entirely from the properties of the ongoing neuronal oscillations, e.g., alpha oscillations. We have shown analytically and experimentally that neuronal oscillations with a non-zero mean (i.e., the integrated field of one oscillatory cycle is not zero) is a sufficient prerequisite for oscillations to contribute to evoked responses through a mechanism of amplitude modulation. Recently in another study (Mazaheri and Jensen, 2008) it was proposed that an „amplitude fluctuation asymmetry index“ (AFA, the amplitude asymmetry of peaks and troughs around zero) might reveal whether or not an amplitude modulation of oscillations contributes to ERs. Necessarily, oscillations with a non-zero mean will have a non-zero AFA index. Critically, however, the reverse is not true in general, because – as we show here – the AFA index is sensitive also to the non-sinusoidal (e.g., comb-like) shape of neuronal oscillations. We prove analytically and experimentally that the amplitude modulation of non-sinusoidal oscillations with zero mean cannot give rise to evoked responses. Consequently, it is not possible to infer from the AFA index of an oscillation whether its amplitude modulation will contribute to an evoked response. It is therefore crucial to choose methodological approach that is specifically sensitive to the non-zero-mean properties of neuronal oscillations in order to be able to make conclusions about the contribution of the novel ER mechanism to the measured data.

Self-report and Cognitive Processing Measures of Depressive Thinking Predict Subsequent Major Depressive Disorder

We examined the utility of two measures of cognitive bias—a self-report questionnaire, the Dysfunctional Attitudes Scale (Weissman and Beck 1978), and a cognitive processing task, the Scrambled Sentences Test (Wenzlaff 1988, 1993), in predicting episodes of depression prospectively in a community-based sample of nondepressed women. When examined separately, each measure contributed significantly to predicting a subsequent diagnosis of MDD, supporting the utility of both types of measures as indicators of depression vulnerability. When examined together, each measure made an independent contribution to the prediction of MDD, raising the possibility that questionnaire and processing tasks may assess separate aspects of cognitive vulnerability to depression.

The association of unresolved attachment status and cognitive processes in maltreated adolescents

AbstractThis exploratory investigation sought to gain a better understanding of the mental representations of attachment in maltreated adolescents, and how, if at all, unresolved attachment representations are related to cognitive processes in this population. Measures of cognitive functioning, attachment state of mind and parent ratings on attention were obtained from 38 adolescents with a history of maltreatment. Results showed that maltreated adolescents with unresolved states of mind in regard to attachment scored significantly lower on measures of cognitive processes of attention, working memory and cognitive efficiency, even when intelligence was controlled for in the analyses. Theoretical considerations, implications for future research and clinical implications are discussed. Copyright © 2009 John Wiley & Sons, Ltd.

N-methyl-d-aspartic acid receptor antagonist–induced frequency oscillations in mice recreate pattern of electrophysiological deficits in schizophrenia

Introduction: Electrophysiological responses to auditory stimuli have provided a useful means of elucidating mechanisms and evaluating treatments in psychiatric disorders. Deficits in gating during paired-click tasks and lack of mismatch negativity following deviant stimuli have been well characterized in patients with schizophrenia. Recently, analyses of basal, induced, and evoked frequency oscillations have gained support as additional measures of cognitive processing in patients and animal models. The purpose of this study is to examine frequency oscillations in mice across the theta (4–7.5 Hz) and gamma (31–61 Hz) bands in the context of N-methyl-d-aspartic acid receptor (NMDAR) hypofunction and dopaminergic hyperactivity, both of which are thought to serve as pharmacological models of schizophrenia.Experimental procedures: Electroencephalograms (EEG) were recorded from mice in five treatment groups that consisted of haloperidol, risperidone, amphetamine, ketamine, or ketamine plus haloperidol during an auditory task. Basal, induced and evoked powers in both frequencies were calculated.Results: Ketamine increased basal power in the gamma band and decreased the evoked power in the theta band. The increase in basal gamma was not blocked by treatment with a conventional antipsychotic. No other treatment group was able to fully reproduce this pattern in the mice.Conclusions: Ketamine-induced alterations in EEG power spectra are consistent with abnormalities in the theta and gamma frequency ranges reported in patients with schizophrenia. Our findings support the hypothesis that NMDAR hypofunction contributes to the deficits in schizophrenia and that the dopaminergic pathways alone may not account for these changes.