An examination of sex differences in social support among older men and women

This paper is designed to empirically investigate sex differences in social support. Several types of sex differences are examined, including quantity and quality of support, the relationship between quantitative and qualitative measures of support, the number and source of support provided and received, and the relative predictive power of quality and quantity of support on well-being. The data are taken from the Supports of the Elderly, a national survey of older people (Kahn and Antonucci, 1984). Included in the present study are 214 men and 166 women ranging in age from 50 to 95 who are married and have at least one child. The analyses reveal that women have larger networks and receive supports from multiple sources, while men tend to rely on their spouses exclusively. Men report greater satisfaction with marriage than women. Quantitative supports are more related to qualitative supports for women than for men. For both sexes, the quality of support rather than the quantity of support has significantly greater effects on well-being; both the quantity and quality of social support have a greater impact on the well-being of women compared to men.     

Efficient visual search without top-down or bottom-up guidance

Two types of mechanisms have dominated theoretical accounts of efficient visual search. The first are bottom-up processes related to the characteristics of retinotopic feature maps. The second are top-down mechanisms related to feature selection. To expose the potential involvement of other mechanisms, we introduce a new search paradigm whereby a target is defined only in a context-dependent manner by multiple conjunctions of feature dimensions. Because targets in a multiconjunction task cannot be distinguished from distractors either by bottom-up guidance or top-down guidance, current theories of visual search predict inefficient search. While inefficient search does occur for the multiple conjunctions of orientation with color or luminance, we find efficient search for multiple conjunctions of luminance/size, luminance/shape, and luminance/topology. We also show that repeated presentations of either targets or a set of distractors result in much faster performance and that bottom-up feature extraction and top-down selection cannot account for efficient search on their own. In light of this, we discuss the possible role of perceptual organization in visual search. Furthermore, multiconjunction search could provide a new method for investigating perceptual grouping in visual search.     

Recognition memory of retrieved sequences of words

The subject was asked to retrieve words belonging to a given category, natural or artificially created. After n words were retrieved, a recognition task was given either immediately after or after a delay (4 hours, 7, 14, or 28 days). Several probe words were presented and the subject had to decide whether each had been retrieved or not. The length of retrieval sequence, n, was systematically varied. Results of three experiments showed that, in general, mean decision time was almost independent of n. Namely, recognition regarding self-generated lists of words seems to be due to a different information processing than recognition regarding lists of words presented by the experimenter to memorize. Implications of the findings for retrieval from long term memory were discussed.     

Association of race and color with mean IQ across nations

This study investigated the correlation of both race and skin color in the distribution of mean IQ for 129 countries with primarily indigenous populations. Skin color correlated most highly with mean IQ across the Caucasoid countries (r = -.86), somewhat less across the Mongoloid countries (r = -.66), and nonsignificantly across the Negroid countries (r = .06). When the Negroid and Caucasoid countries were combined, both race and skin color yielded high correlations with IQ (r = .87, -.95, respectively). When the Negroid and Mongoloid countries were combined, both race and skin color yielded high correlations with IQ (r = .91, -.91, respectively). When Caucasoid and Mongoloid countries were combined, skin color yielded a high correlation, but race did not correlate significantly with IQ. The greater importance of Negroid race was regarded as congruent with the 1998 generalization of Jensen that the genetic distance between Mongoloids and Caucasoid is less than the genetic distance of these two groups from Negroid.     

The roles of sequencing and verbal working memory in sentence comprehension deficits in Parkinson's disease

Studies of sentence comprehension deficits in Parkinson's disease (PD) patients suggest that language processing involves circuits connecting subcortical and cortical regions. Anatomically segregated neural circuits appear to support different cognitive and motor functions. To investigate which functions are implicated in PD comprehension deficits, we tested comprehension, verbal working memory span, and cognitive set-switching in a non-linguistic task in 41 PD patients; we also obtained speech measurements reflecting motor sequencing processes that may be involved in articulatory rehearsal within working memory. Comprehension of sentences with center-embedded or final relative clauses was impaired when they could not be understood from lexical semantic content alone. Overall comprehension error rates correlated strongly with impaired set-switching and significantly with reduced working memory span and speech motor sequencing deficits. Correlations with comprehension of different sentence structures indicate that these impairments do not represent a single deficit; rather, PD comprehension deficits appear to arise from several independent mechanisms. Deficits in cognitive set-switching or underlying inhibitory processes may compromise the ability to process relative clauses. Deficits in verbal working memory appear to impair comprehension of long-distance dependencies. Speech sequencing correlated with neither set-switching nor verbal working memory span, consistent with their being supported by independent, segregated cortico-subcortical circuits.     

The role of priming in conjunctive visual search

To assess the role of priming in conjunctive visual search tasks, we systematically varied the consistency of the target and distractor identity between different conditions. Search was fastest in the standard conjunctive search paradigm where identities remained constant. Search was slowest when potential target identity varied predictably for each successive trial (the 'switch' condition). The role of priming was also demonstrated on a trial-by-trial basis in a 'streak' condition where target and distractor identity was unpredictable yet was consistent within streaks. When the target to be found was the same for a few trials in a row, search performance became similar to that when the potential target was the same on all trials. A similar pattern was found for the target absent trials, suggesting that priming is based on the whole search array rather than just the target in each case. Further analysis indicated that the effects of priming are sufficiently strong to account for the advantage seen for the conjunctive search task. We conclude that the role of priming in visual search is underestimated in current theories of visual search and that differences in search times often attributed to top-down guidance may instead reflect the benefits of priming.     

Categorical perception of face identity in noise isolates configural processing.

Neuropsychological evidence suggests that face recognition based on configural (holistic) information can occur in isolation from recognition based on local feature cues. The present study shows that configural processing can be isolated experimentally in normal subjects. A phenomenon is reported that exists only for upright whole faces, namely categorical perception (CP) of face identity in noise. Three discrimination tasks (ABX, better likeness, and similarity ratings) were used to test for perceptual distortion across the category boundary predicted from binary classification of face morphs. Noise was added such that any single local region provided unreliable cues to identity. Under these conditions, CP was found for upright faces but not for inverted faces or single features, even with more than 10,000 trials. The CP-in-noise signature phenomenon was then used to show that configural processing survives image plane rotations of 45 degrees-90 degrees.     

Visual short-term memory benefit for objects on different 3-D surfaces

Visual short-term memory (VSTM) plays an important role in visual cognition. Although objects are located on different 3-dimensional (3-D) surfaces in the real world, how VSTM capacity may be influenced by the presence of multiple 3-D surfaces has never been examined. By manipulating binocular disparities of visual displays, the authors found that more colored objects could be held in VSTM when they were placed on 2 rather than on 1 planar 3-D surfaces. This between-surface benefit in VSTM was present only when binding of objects' colors to their 3-D locations was required (i.e., when observers needed to remember which color appeared where). When binding was not required, no between-surface benefit in VSTM was observed. This benefit in VSTM could not be attributed to the number of spatial locations attended within a given surface. It was not due to a general perceptual grouping effect either, because grouping by motion and grouping by different regions of the same surface did not yield the same benefit. This increment in capacity indicates that VSTM benefits from the placement of objects in a 3-D scene.     

Phase-dependent synaptic changes in the hippocampal CA1 field underlying extinction processes in freely moving rats

Recent studies focus on the functional significance of a novel form of synaptic plasticity, low-frequency stimulation (LFS)-induced synaptic potentiation in the hippocampal CA1 area. In the present study, we elucidated dynamic changes in synaptic function in the CA1 field during extinction processes associated with context-dependent fear memory in freely moving rats, with a focus on LFS-induced synaptic plasticity. Synaptic transmission in the CA1 field was transiently depressed during each extinction trial, but synaptic efficacy was gradually enhanced by repeated extinction trials, accompanied by decreases in freezing. On the day following the extinction training, synaptic transmission did not show further changes during extinction retrieval, suggesting that the hippocampal synaptic transmission that underlies extinction processes changes in a phase-dependent manner. The synaptic potentiation produced by extinction training was mimicked by synaptic changes induced by LFS (0.5 Hz) in the group that previously received footshock conditioning. Furthermore, the expression of freezing during re-exposure to footshock box was significantly reduced in the LFS application group in a manner similar to the extinction group. These results suggest that LFS-induced synaptic plasticity may be associated with the extinction processes that underlie context-dependent fear memory. This hypothesis was supported by the fact that synaptic potentiation induced by extinction training did not occur in a juvenile stress model that exhibited extinction deficits. Given the similarity between these electrophysiological and behavioral data, LFS-induced synaptic plasticity may be related to extinction learning, with some aspects of neuronal oscillations, during the acquisition and/or consolidation of extinction memory.     

On the Functional Role of Implicit Visual Memory for the Adaptive Deployment of Attention Across Scenes

Although very little visual information is explicitly retained across views, some continuity of processing is afforded by implicit visual memory traces of previous views. These memory traces interact with attentional mechanisms to guide eye movements, cognition, and action. Two different memory mechanisms are described here. First, the deployments of focal attention and eye movements are facilitated towards recently attended features and locations (priming of popout). Second, attention is guided by implicit memory traces of specific visual contexts experienced in the past (contextual cueing). Compared to the visual memory tapped by change blindness tasks, the implicit memory mechanisms of priming of popout and contextual cueing do not require conscious intervention and may exhibit greater memory capacity, longer durability, and higher discriminability. Thus, these implicit traces of past views guide attention and eye movements to allow for effective access (indexing) to a scene's details, hence providing context and continuity to ongoing interactions with the perceptual world.