Cathodal tDCS of the Left Posterior Parietal Cortex Increases Proprioceptive Drift

In aiming movements the limb position drifts away from the defined target after some trials without visual feedback, a phenomenon defined as proprioceptive drift (PD). There are no studies investigating the association between the posterior parietal cortex (PPC) and PD in aiming movements. Therefore, cathodal and sham transcranial direct current stimulation (tDCS) were applied to the left PPC concomitantly with the performance of movements with or without vision. Cathodal tDCS applied without vision produced a higher level of PD and higher rates of drift accumulation while it decreased peak velocity and maintained the number of error corrections, not affecting movement amplitude. The proprioceptive information seems to produce an effective reference to movement, but with PPC stimulation it causes a negative impact on position.     

Effects of bilingualism, aging, and semantic relatedness on memory under divided attention.

We examined how encoding and retrieval processes were affected by manipulations of attention, and whether the degree of semantic relatedness between words in the memory and distracting task modulated these effects. We also considered age and bilingual status as mediating factors. Monolingual and bilingual younger and older adults studied a list of words from a single semantic category presented auditorily, and later free recalled them aloud. During either study or retrieval, participants concurrently performed a distracting task requiring size decisions to words from either the same or a different semantic category as the words in the memory task. The greatest disruptions of memory from divided attention (DA) were for encoding rather than retrieval. The effect of semantic relatedness was significant only for DA at encoding. Older age and bilingualism were associated with lower recall scores in all conditions, but these factors did not influence the magnitude of memory interference. The results suggest that encoding is more sensitive to semantic similarity in a distracting task than is retrieval. The role of attention at encoding and retrieval is discussed.     

Comparing language lateralization determined by dichotic listening and fMRI activation in frontal and temporal lobes in children with epilepsy

We investigated the relationship between ear advantage scores on the Fused Dichotic Words Test (FDWT), and laterality of activation in fMRI using a verb generation paradigm in fourteen children with epilepsy. The magnitude of the laterality index (LI), based on spatial extent and magnitude of activation in classical language areas (BA 44/45, 21/22, 39) differed significantly for patients classified with unilateral left, compared to bilateral, language representation based on FDWT scores. Concordance with fMRI was higher for those classified with unilateral left, than bilateral language representation on the FDWT. Of note, asymmetry in temporal lobe, rather than frontal lobe, activation was more strongly related to the LI from the dichotic listening test. This study shows that the FDWT can provide a quick and valid estimate of lateralization in pre-surgical candidates, which can be readily adopted for other clinical or research purposes when an estimate of language dominance is desired.     

Changing the focus of attention: The interacting effect of valence and arousal

We examined how valence and arousal of an image influence visual attention. “Spotlight of attention” theory suggests that positive affect broadens, and negative affect narrows, one's aperture of attention, whereas the arousal theory literature suggests that arousal level is what modulates attentional focus, with highly arousing affect capturing attention, regardless of valence. In two experiments, a digit parity task was used to index the influence of valence, and arousal, on visual attention. Positive or negative images were displayed centrally on each trial, with single digits presented more peripherally (Experiment 1) or more centrally (Experiment 2) to the image. In both Experiments participants were slower, and less accurate at making parity decisions (e.g., both digits odd or both even) when the image was negative relative to positive, and of high arousal. For low arousal images, positive, relative to negative, valence images led to greater impairment of the digit parity task. Findings suggest that arousal level of images modulates the influence of valence on distribution of visual attention. Highly negative emotional images may command or capture attention, but there are other factors that can lead to attention capture, even in low arousing positive stimuli.     

Age-Related Changes in the use of Study Context to Increase Recollection

ABSTRACT

We examined how context presented at study affects recollection of words in younger and older adults. In Experiment 1, participants studied words presented with a picture of a face (context-rich condition) or a rectangle (context-weak condition), and subsequently made ‘Remember’, ‘Know’, or ‘New’ judgments to words presented alone. Younger, but not older, adults showed higher Remember accuracy following rich- than weak-context trials. In Experiment 2, we manipulated the type of processing engaged during the encoding of context–word pairs. Younger and older adults studied words presented with a picture of a face under a surface feature (gender) or binding feature (match) instruction condition. Both age groups showed higher Remember accuracy in the binding than surface instruction condition. Results suggest that providing rich contextual detail at encoding boosts later item recollection in younger adults. Older adults, however, do not spontaneously engage in the processes required to boost recollection, though instructional manipulation during encoding lessens this deficit.     

Age-related differences in attentional bias for emotional faces

Past research suggests an aging-related positivity effect in orienting to faces. However, these studies have eschewed direct comparison of orienting when positive and negative faces are presented simultaneously, thereby potentially underestimating the degree to which emotional valence influences such effects. In the current study younger and older adults viewed face pairs for 1000 ms, and upon face-pair offset indicated the location of a dot that appeared in the former location of one of the faces, to assess attentional orienting. When shown negative–neutral pairs, both age groups were biased to attend to negative faces, but when shown positive–negative pairs only younger adults showed a bias toward negative; older adults showed a lack of orienting toward either emotional face. Results suggest younger adults have a negativity bias in attention orienting regardless of the valence of nearby stimuli, whereas older adults show an absence of this bias when positive information is present.     

Ethnic and Gender Variation in Religious Involvement: Patterns of Expression in Young Adulthood

This study used latent class analysis (LCA) to empirically derive profiles of religious involvement among a sample of 808 young adults and describe ethnic and gender differences within such religious involvement patterns. Items on the Duke Religion Index (DRI) were included as part of a larger longitudinal survey of emotional, physical, and behavioral health. The scale measured the organizational, nonorganizational, and intrinsic dimensions of religiosity (Koenig et al. in Handbook of religion and health, Oxford University Press, Oxford, 2001) in a sample of young adults at two waves of the study—age 27 and age 30. At age 27, five religious profiles were distinguishable in the sample while at age 30 six profiles emerged. Ethnic differences were found for each of the religious profiles where religious involvement manifested in different ways. Religious profiles between ages 27 and 30 changed over time and were affected by gender and ethnicity.