Men and Women Differ in Object Memory but Not Performance of a Virtual Radial Maze.

The present study examined sex differences in object memory by using 2-dimensional object arrays and in spatial memory by using a computerized virtual 12-arm radial maze. Virtual T-maze and water maze tasks were also used to examine sex differences in the use of spatial and nonspatial strategies during navigation. Women significantly outperformed men in recalling the locations and identities of objects. However, the sexes did not differ in the commission of working memory and reference memory errors in the radial maze or in the use of particular navigational strategies. Because arms in the radial maze may become associated with specific extramaze cues, the superior object memory demonstrated by women may have eliminated the typical male advantage found in spatial navigation tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Hippocampal Role in Spatial Memory and the Familiarity-Recollection Distinction: A Case Study.

Memory for object locations and for events (comprising the receipt of an object) was tested in a case of developmental amnesia with focal hippocampal damage ("Jon"; F. Vargha-Khadem et al., 1997). Tests used virtual reality environments and forced-choice recognition with foils chosen to equalize the performance of control participants across conditions. Memory for the objects received was unimpaired, but the context of their receipt was forgotten. Memory for short lists of object locations was unimpaired when tested from the same viewpoint as presentation but impaired when tested from a shifted viewpoint. Same-view performance was disrupted by changing the background scene. These results are consistent with Jon having preserved matching to fixed sensory-bound representations but impaired reconstructed or manipulable representations underlying shifted-viewpoint recognition and episodic recollection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An fMRI Study of Episodic Memory: Retrieval of Object, Spatial, and Temporal Information.

Sixteen participants viewed a videotaped tour of 4 houses that highlighted a series of objects and their spatial locations. Participants were tested for memory of object, spatial, and temporal-order information while undergoing functional magnetic resonance imaging. Preferential activation was observed in the right parahippocampal gyrus during the retrieval of spatial-location information. Retrieval of contextual information (spatial location and temporal order) was associated with activation in the right dorsolateral prefrontal cortex. In bilateral posterior parietal regions, greater activation was associated with processing of visual scenes regardless of the memory judgment. These findings support current theories positing roles for frontal and medial temporal regions during episodic retrieval and suggest a specific role for the hippocampal complex in the retrieval of spatial-location information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tracking the displacement of objects: A series of tasks with great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, and Pongo pygmaeus) and young children (Homo sapiens).

The authors administered a series of object displacement tasks to 24 great apes and 24 30-month-old children (Homo sapiens). Objects were placed under 1 or 2 of 3 cups by visible or invisible displacements. The series included 6 tasks: delayed response, inhibition test, A not B, rotations, transpositions, and object permanence. Apes and children solved most tasks performing at comparable levels except in the transposition task, in which apes performed better than children. Ape species performed at comparable levels in all tasks except in single transpositions, in which chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) performed better than gorillas (Gorilla gorilla) and orangutans (Pongo pygmeaus). All species found nonadjacent trials and rotations especially difficult. The number of elements that changed locations, the type of displacement, and having to inhibit predominant reaching responses were factors that negatively affected the subjects' performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ethnic Enclaves and the Dynamics of Social Identity on the College Campus: The Good, the Bad, and the Ugly.

The effects of membership in ethnic organizations and fraternities and sororities on intergroup attitudes were examined using a 5-wave panel study at a major, multiethnic university. The results showed that these effects were similar for both minority and White students. Membership in ethnic student organizations for minorities and Greek organizations for Whites was anteceded by the degree of one's ethnic identity, and the effects of membership in these groups were similar, although not identical, for both White and minority students. These effects included an increased sense of ethnic victimization and a decreased sense of common identity and social inclusiveness. Consistent with social identity theory, at least a portion of these effects were mediated by social identity among both White and minority students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Revision and extension of a multidimensional measure of sexual minority identity: The Lesbian, Gay, and Bisexual Identity Scale.

Two studies were conducted to investigate a revised and extended version of the Lesbian and Gay Identity Scale (Mohr & Fassinger, 2000): the 27-item Lesbian, Gay, and Bisexual Identity Scale (LGBIS). This revision features more inclusive and less stigmatizing language than the previous version and includes 2 new subscales assessing identity affirmation and centrality. In Study 1, an exploratory factor analysis (n = 297) and a confirmatory factor analysis (n = 357) supported an 8-factor solution assessing acceptance concerns, concealment motivation, identity uncertainty, internalized homonegativity, difficulty with the identity development process, identity superiority, identity affirmation, and identity centrality. Predicted associations with measures of identity-related constructs and psychosocial functioning provided preliminary validity evidence for LGBIS scores in a college student population. Study 2 (N = 51) provided evidence of the test–retest and internal consistency reliability of LGBIS scores. These studies suggest that the LGBIS may offer researchers an efficient means of assessing multiple dimensions of sexual orientation minority identity. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of Apolipoprotein E Genotype on Spatial Attention, Working Memory, and Their Interaction in Healthy, Middle-Aged Adults: Results From the National Institute of Mental Health's BIOCARD Study.

The cognitive consequences of the apolipoprotein E-ε4 (APOE-ε4) allele were examined in middle age, before likely onset of symptoms of Alzheimer's disease. The authors identified 3 cognitive processes--visuospatial attention, spatial working memory, and the effect of visuospatial attention on working memory--and devised "behavioral assays" of the integrity of components of these processes. Redirecting visuospatial attention, retention of memory for location, and attentional modulation of memory of target location were affected by APOE genotype. Visuospatial attention showed additive effects of ε4 gene dose; each additional ε4 allele inherited further slowed disengagement from invalidly cued space. In contrast, working memory performance was affected only in ε4 homozygotes. Effect sizes for the APOE gene were moderate to large, ranging from 14% to 24%. Effects of APOE genotype on component processes of cognition in healthy, middle-aged adults is consistent with the emergence in adulthood of an APOE-ε4 cognitive phenotype. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Ventral Hippocampus Supports a Memory Representation of Context and Contextual Fear Conditioning: Implications for a Unitary Function of the Hippocampus.

The authors report that either inactivating the ventral hippocampus (VH) with muscimol prior to context preexposure or injecting anisomycin into the VH after preexposure significantly impaired rats' memory for context. Injecting anisomycin into the VH prior to contextual fear conditioning also greatly reduced long-term memory (48-hr retention test) but had no effect on short-term memory (1-hr retention test) for contextual fear. Together with other results, these data suggest that the memory for a novel context is distributed throughout the longitudinal extent of the hippocampus and that this representation helps to support contextual fear conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual Differences in the Inference of Word Meanings From Context: The Influence of Reading Comprehension, Vocabulary Knowledge, and Memory Capacity.

Two studies investigated the ability to use contextual information in stories to infer the meanings of novel vocabulary by 9-10-year-olds with good and poor reading comprehension. Across studies, children with poor reading comprehension were impaired when the processing demands of the task were greatest. In Study 2, working memory capacity was related to performance, but short-term memory span and memory for the literal content of the text were not. Children with poor reading comprehension were not impaired in learning novel vocabulary taught through direct instruction, but children with both weak reading comprehension and vocabulary were. Implications for the relation between vocabulary development and text comprehension are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)