Evaluation of Students' Conceptual Organization of Neuroscience May Depend on the Expert Referent.

The Structural Assessment of Knowledge (SAK) is an implicit form of evaluation, which examines the organization of knowledge structures or networks. The current study investigates variability in expert knowledge structures of neuroscience concepts, and whether different expert referents affect undergraduate students' learning of neuronal physiology and structure and function relationships across different course levels. Experts and students made pairwise ratings of terms on their relatedness. Students completed the ratings before and after learning in the classroom. Using Pathfinder software, students' networks were compared to three expert networks: their individual professor, an average of neuroscience professors at their institution, and an average of neuroscience professors in the field across multiple institutions. Neuroscience experts had large variability in the number of links in their networks. Furthermore, an exploratory analysis suggests experts' training may differentiate knowledge structures for some concepts. For student knowledge structures, the type of expert referent interacted with the type of class for neuronal physiology, but not structure and function relationships. More specifically, for neuronal physiology, advanced students were more similar to their professor than professors at their institution or professors in the field, but introductory students' similarity did not vary by expert referent. These findings highlight the role factors such as type of class, type of expert referent, and type of knowledge may play in comparisons using SAK. These issues may be more complex in interdisciplinary fields like neuroscience.

The Role of Musical Experience in Hemispheric Lateralization of Global and Local Auditory Processing.

The global precedence effect is a phenomenon in which global aspects of visual and auditory stimuli are processed before local aspects. Individuals with musical experience perform better on all aspects of auditory tasks compared with individuals with less musical experience. The hemispheric lateralization of this auditory processing is less well-defined. The present study aimed to replicate the global precedence effect with auditory stimuli and to explore the lateralization of global and local auditory processing in individuals with differing levels of musical experience. A total of 38 college students completed an auditory-directed attention task while electroencephalography was recorded. Individuals with low musical experience responded significantly faster and more accurately in global trials than in local trials regardless of condition, and significantly faster and more accurately when pitches traveled in the same direction (compatible condition) than when pitches traveled in two different directions (incompatible condition) consistent with a global precedence effect. In contrast, individuals with high musical experience showed less of a global precedence effect with regards to accuracy, but not in terms of reaction time, suggesting an increased ability to overcome global bias. Further, a difference in P300 latency between hemispheres was observed. These findings provide a preliminary neurological framework for auditory processing of individuals with differing degrees of musical experience.

Use of Structural Assessment of Knowledge for Outcomes Assessment in the Neuroscience Classroom.

Outcomes assessment of undergraduate neuroscience curricula should assess the ability to think integratively about basic neuroscience concepts based on two of the core competencies established by the Faculty for Undergraduate Neuroscience. The current study investigated whether the structural assessment of knowledge (SAK) approach, which evaluates the organization of an individual's knowledge structures, is effective for demonstrating learning of basic neuroscience concepts. Students in an introductory psychology course (n = 29), an introductory neuroscience course (n = 19), or an advanced behavioral neuroscience course (n = 15) completed SAK before and after learning gross brain anatomy and neuronal physiology. All students showed improvements in their SAK after short-term dissemination for gross brain anatomy, but not for neuronal physiology, concepts. Therefore, research is needed to determine whether the effectiveness of SAK in outcomes assessment depends on the content or teaching style. Additional research using SAK should also explore effectiveness for learning over longer time frames and correlations with student performance in the course. However, the results suggest SAK is a promising technique for outcomes assessment of undergraduate neuroscience curricula.

Effective use of computer simulations in an introductory neuroscience laboratory.

Introductory Neuroscience courses are being offered more regularly at diverse institutions. On the other hand, the creation of an independent laboratory curriculum for introductory neuroscience courses puts a strain on financial and human resources of a small college. A solution to this situation might be presented through the use of relevant simulation software in order to eliminate the binding of resources; but nevertheless, provide sufficient, effective, and engaging education to students. This paper suggests the use of a combination of different software during Introductory Neuroscience laboratory sessions, which are finely tuned with the material presented during lecture. Two student cohorts were evaluated and compared using three types of measures: exam grades, course evaluations, and software evaluations. The results show that the use of software simulations had a positive effect on the performance of students on exams, and on the favorability of course ratings. The findings suggest the use of software simulations for Introductory Neuroscience courses to be beneficial for the learning experience of the students.

Domain specific attentional impairments in children with chromosome 22q11.2 deletion syndrome.

One of the defining cognitive characteristics of the chromosome 22q deletion syndrome (DS22q11.2) is visuospatial processing impairments. The purpose of this study was to investigate and extend the specific attentional profile of children with this disorder using both an object-based attention task and an inhibition of return task. A group of children with the disorder was compared in these tasks with a group of age-matched typically developing children. The children with DS22q11.2 demonstrated impaired spatially based orienting which is consistent with previous findings in this group. Strikingly, the children with DS22q11.2 also demonstrated an improved ability to use object-based cues, relative to the typically developing group. Finally, the children with DS22q11.2 demonstrated an intact inhibition of return system, however, it appears to be delayed developmentally.

Specific cerebellar reductions in children with chromosome 22q11.2 deletion syndrome.

Children with chromosome 22q11.2 deletion syndrome commonly are found to have morphological brain changes, cognitive impairments, and elevated rates of psychopathology. One of the most commonly and consistently reported brain changes is reduced cerebellar volume. Here, we demonstrate that, in addition to the global cerebellum reductions previously reported, volumetric reductions of the anterior lobule and the vermal region of the neo-cerebellum in the mid-sagittal plane best differentiate children with the deletion from typically developing children. These results suggest that the morphological changes of specific portions of the cerebellum may be an important underlying substrate of cognitive impairments and increased incidence of psychopathology in this group.

A multilevel analysis of cognitive dysfunction and psychopathology associated with chromosome 22q11.2 deletion syndrome in children.

We present a multilevel approach to developing potential explanations of cognitive impairments and psychopathologies common to individuals with chromosome 22q11.2 deletion syndrome. Results presented support our hypothesis of posterior parietal dysfunction as a central determinant of characteristic visuospatial and numerical cognitive impairments. Converging data suggest that brain development anomalies, primarily tissue reductions in the posterior brain and changes to the corpus callosum, may affect parietal connectivity. Further findings indicate that dysfunction in "frontal" attention systems may explain some executive cognition impairments observed in affected children, and that there may be links between these domains of cognitive function and some of the serious psychiatric conditions, such as attention-deficit/hyperactivity disorder, autism, and schizophrenia, that have elevated incidence rates in the syndrome. Linking the neural structure and the cognitive processing levels in this way enabled us to develop an elaborate structure/function mapping hypothesis for the impairments that are observed. We show also, that in the case of the catechol-O-methyltransferase gene, a fairly direct relationship between gene expression, cognitive function, and psychopathology exists in the affected population. Beyond that, we introduce the idea that variation in other genes may further explain the phenotypic variation in cognitive function and possibly the anomalies in brain development.

Volumetric, connective, and morphologic changes in the brains of children with chromosome 22q11.2 deletion syndrome: an integrative study.

Chromosome 22q11.2 deletion syndrome is a highly prevalent genetic disorder whose manifestations include developmental disability and sometimes mental retardation. The few studies that have examined brain morphology in different samples from this population have found similar general patterns, mostly using region of interest measures. We employed voxel-based techniques to concurrently examine specific morphologic changes in multiple brain tissue measures. Results were similar to previous findings of volumetric reductions in the posterior brain. They also extended them in two ways. First, our methods provided greater specificity in the localization of changes detected. Second, the combination of our measures of gray and white matter along with cerebrospinal fluid volume and fractional anisotropy, which indicates the structure of white matter, showed a posterior displacement of and morphologic changes to the corpus callosum in affected children.

Maladaptive conflict monitoring as evidence for executive dysfunction in children with chromosome 22q11.2 deletion syndrome.

Using an adaptation of the Attentional Networks Test, we investigated aspects of executive control in children with chromosome 22q11.2 deletion syndrome (DS22q11.2), a common but not well understood disorder that produces non-verbal cognitive deficits and a marked incidence of psychopathology. The data revealed that children with DS22q11.2 demonstrated greater difficulty than controls in locating and processing target items in the presence of distracters. Importantly, children with DS22q11.2 showed a deficit in the ability to monitor and adapt to stimulus conflict. These data provide evidence of inadequate conflict adaptation in children with DS22q11.2, a problem that is also present in schizophrenia. The findings of specific executive dysfunction in this group may provide a linkage between particular genetic abnormalities and the development of psychopathology.

Thalamic reductions in children with chromosome 22q11.2 deletion syndrome.

Children with chromosome 22q11.2 deletion syndrome (22q) suffer from physical and behavioral dysfunctions, including neuroanatomical anomalies, visuo-spatial processing deficits, and increased risk for psychopathology. Reduced total brain volume, parietal lobe volume, and cerebellar volumes, enlarged ventricles, and increased basal ganglia volumes have been reported. Since previous literature has related the pulvinar nucleus of the thalamus to visuo-spatial processing, we compared the thalamic volume in children with 22q to typically developing controls. Children with 22q showed a significant reduction of the thalamus compared with normally developing children, specifically in the posterior portion of the thalamus, including the pulvinar nucleus. These results provide the first evidence for a potential relationship between posterior thalamic reductions and the characteristic visuo-spatial deficits demonstrated in this group.