Amygdala and hippocampal activity during acquisition and extinction of human fear conditioning

Previous functional magnetic resonance imaging (fMRI) studies have characterized brain systems involved in conditional response acquisition during Pavlovian fear conditioning. However, the functional neuroanatomy underlying the extinction of human conditional fear remains largely undetermined. The present study used fMRI to examine brain activity during acquisition and extinction of fear conditioning. During the acquisition phase, participants were either exposed to light (CS) presentations that signaled a brief electrical stimulation (paired group) or received light presentations that did not serve as a warning signal (control group). During the extinction phase, half of the paired group subjects continued to receive the same treatment, whereas the remainder received light alone. Control subjects also received light alone during the extinction phase. Changes in metabolic activity within the amygdala and hippocampus support the involvement of these regions in each of the procedural phases of fear conditioning. Hippocampal activity developed during acquisition of the fear response. Amygdala activity increased whenever experimental contingencies were altered, suggesting that this region is involved in processing changes in environmental relationships. The present data show learning-related amygdala and hippocampal activity during human Pavlovian fear conditioning and suggest that the amygdala is particularly important for forming new associations as relationships between stimuli change.     

Wais-III matrix reasoning: instruction effects on task perception and performance

Instructions for the Matrix Reasoning subtest of the WAIS-III do not communicate to examinees that the subtest is untimed. The present study examined what percentage of participants (34 women, 26 men, M age = 20.1; 55 Caucasian, 3 African American, 2 Hispanic) made the assumption that Matrix Reasoning was timed, and its effect on examinees' scores. 55% of participants receiving standard instructions retrospectively reported assuming the subtest was timed, and those who did not assume Matrix Reasoning was timed scored significantly higher than participants who did. Participants receiving additional instructions that clarified the untimed nature of Matrix Reasoning scored significantly higher than those receiving standard instructions who believed the subtest was timed.     

Visual implicit memory in the left hemisphere: evidence from patients with callosotomies and right occipital lobe lesions

Identification of visually presented objects and words is facilitated by implicit memory for past visual experiences with those items. Several behavioral and neuroimaging studies suggest that this form of memory is dependent on perceptual processes localized in the right occipital lobe. We tested this claim by examining implicit memory in patients with extensive right occipital lobe lesions, using lexical-decision, mirror-reading, picture-fragment, and word-fragment-completion tests, and found that these patients exhibited normal levels of priming. We also examined implicit memory in patients with complete callosotomies, using standard and divided-visual-field word-fragment-completion procedures, and found that the isolated left hemisphere exhibited normal priming effects. The results indicate that the right occipital lobe does not play a necessary role in visual implicit memory, and that the isolated left hemisphere can support normal levels of visual priming in a variety of tasks.     

Measuring Coping in Low-Income European American,African American,and Mexican American Adolescents: An Examination of Measurement Equivalence

We examined the cross-ethnic and cross-language equivalence of the Children's Coping Strategies Checklist (Ayers, T.S., Sandler, I.N., West, S.G. and Roosa, M.W. (1996). A dispositional and situational assessment of children's coping: Testing alternative models of coping. Journal of Personality , 64 (4), 923-958) by assessing item, functional, and scalar equivalence in a sample of 319 European American, African American, and Mexican American adolescents from low-income inner-city families. Depression, as measured by Children's Depression Inventory, was the criterion in the analyses of scalar equivalence. The results suggest considerable cross-ethnic and cross-language measurement equivalence of the Children's Coping Strategies Checklist. The findings also suggest some caution in using the Children's Depression Inventory in comparative studies of African American and Mexican American adolescents or in studies that treat these groups as homogeneous samples.     

The Effect of Education on Age-Related Functional Activation During Working Memory

Education has been suggested to play a protective role against the development of age-related dementias. Accordingly, we examined modulation of functional activation during working memory by age and education. Eight older individuals with a college education, six older individuals with a high school education, and eight younger individuals with a college education performed a working memory task during O¹⁵ [water] PET scanning. In a voxel-by-voxel whole brain search, older participants with less education demonstrated greater left frontal activation relative to older participants with more education. Older participants with more education demonstrated greater right precuneus activation relative to older participants with less education. This suggests that older less educated participants may have used additional frontal resources to compensate for dysfunctional parietal cortex. These results occurred in the context of similar activation in well-educated younger and older participants. Younger participants had one unique area of activation in the left posterior parietal cortex and no differences in frontal activation were observed between these two groups. The results of this study indicate the need to consider education in age-related neuroimaging studies.     

Junior Tennis Players’ Preferences for Parental Behaviors

The purpose of this study was to identify junior tennis players’ preferences for parental behaviors at competitions. Eleven focus groups were conducted with 42 high performance Canadian tennis players (M age = 13.5 yrs, SD = 1.2 yrs). Analysis revealed several themes describing athletes’ views of supportive parental behaviors. Specific preferences were that parents should not provide technical and tactical advice, but they should comment on effort and attitude, provide practical advice, respect tennis etiquette, and match nonverbal behaviors with supportive comments. By providing a children's perspective, these findings offer guidance to enhance parental involvement in tennis.     

COPY AND RECALL PERFORMANCE OF 6–8-YEAR-OLD CHILDREN AFTER STANDARD VS. STEP-BY-STEP ADMINISTRATION OF THE REY-OSTERRIETH COMPLEX FIGURE

Turner syndrome (TS) is a genetic disorder in females characterized by the complete or partial absence of one X chromosome. Its most consistent physical features include short stature and ovarian dysgenesis. TS individuals demonstrate a characteristic neurocognitive profile involving weaknesses in visuospatial processing. The hypothesis of defective right hemisphere specialization has been offered to explain the visuospatial deficits in TS. In contrast, an alternative explanation proposes a more uniform dysfunction of the left and right hemispheres, based on findings of symmetrical abnormalities. This article presents an overview of the two hypotheses, along with relevant findings on hemispheric specialization with respect to TS. The impact of the genetic and hormonal mechanisms on the neurocognitive profile of TS is also discussed and directions for further empirical research are identified.