Effects of classification context on categorization in natural categories

The patterns of classification of borderline instances of eight common taxonomic categories were examined under three different instructional conditions to test two predictions: first, that lack of a specified context contributes to vagueness in categorization, and second, that altering the purpose of classification can lead to greater or lesser dependence on similarity in classification. The instructional conditions contrasted purely pragmatic with more technical/quasi-legal contexts as purposes for classification, and these were compared with a no-context control. The measures of category vagueness were between-subjects disagreement and within-subjects consistency, and the measures of similarity-based categorization were category breadth and the correlation of instance categorization probability with mean rated typicality, independently measured in a neutral context. Contrary to predictions, none of the measures of vagueness, reliability, category breadth, or correlation with typicality were generally affected by the instructional setting as a function of pragmatic versus technical purposes. Only one subcondition, in which a situational context was implied in addition to a purposive context, produced a significant change in categorization. Further experiments demonstrated that the effect of context was not increased when participants talked their way through the task, and that a technical context did not elicit more all-or-none categorization than did a pragmatic context. These findings place an important boundary condition on the effects of instructional context on conceptual categorization.     

Does Marital Status Predict the Odds of Suicidal Death in Taiwan? A Seven‐Year Population‐Based Study

Using nationwide, 7-year population-based data for 1997-2003, we examined marital status to see if it predicted suicide among the ethnic Chinese population of Taiwan. Using cause of death data, with a case-control design, two groups-total adult suicide deaths, n = 17,850, the study group, and adult deaths other than suicide, n = 71,400 (randomly selected from age, sex, and geographic region matched controls, four per suicide)-were studied. Using multiple logistic regression analysis including age-marital status interaction, adjusted estimates show divorced status to be the most detrimental for suicide propensity, with males showing stronger effect size. Females never married, aged below 35 and 65-plus, and widowed 65-plus had lower suicide odds.     

On the generality of the contingent orienting hypothesis

The contingent-orienting hypothesis states that attentional capture by a task-irrelevant stimulus is contingent on whether that stimulus shares a feature property that is critical to the task at hand [Folk, C. L., Remington, R. W., & Johnston, J. C. (1992). Involuntary covert orienting is contingent on attentional control settings. Journal of Experimental Psychology: Human Perception and Performance, 18, 1030-1044]. Studies supporting this hypothesis have mostly used set size four displays throughout the experiment and thus constrict its ecological validity, since conclusions drawn from experiments using fixed set-size displays may not be generalized to other conditions with different set sizes. We used a spatial cueing paradigm in which a non-informative onset or color cue preceded an onset or a color target, and manipulated set size as a within- or between-subject factor. In four experiments, the original finding of Folk et al. (1992) was replicated only when a fixed set size (four) was used throughout. When both set-size four and eight were used in an experiment, stimulus-driven capture by onset in search of a color target was found even for set-size four displays. These results raise doubts as to the generality of the contingent-orienting hypothesis and help to delineate the boundary conditions on this hypothesis.     

小学儿童互选友谊的发展趋势及攻击行为的影响：3年追踪研究

对小学3、4年级的285名儿童进行了3年追踪调查,分析了儿童分别与男、女生互选友谊数的变化趋势及其在个体间的差异,探讨了外部攻击和关系攻击分别对两类互选友谊数的影响。结果表明：（1）儿童的男、女生互选友谊数在3年时间内都有显著的增加趋势,并表现出显著的性别差异,儿童与同性互选友谊数显著多于他们与异性的互选友谊数,男生与女生互选友谊数的增加速度比女生与女生互选友谊数增加速度慢,儿童与男生的互选友谊数越多,他/她与女生的互选友谊数就越少,表明了性别隔离现象的存在。（2）在控制了关系攻击的影响后,儿童的外部攻击对他们在各时间点测得的与女生的互选友谊数有显著的消极影响,而对他们与男生的互选友谊数影响不显著;在控制了外部攻击的影响后,儿童的关系攻击对他们在各时间点测得的与女生的互选友谊数有显著的积极影响,而对他们与男生的互选友谊数影响不显著。这说明外部攻击和关系攻击对儿童互选友谊数的影响存在性别差异     

Memory impairments and hippocampal modifications in adult rats with neonatal isolation stress experience

Early life events have profound consequences. Our research demonstrates that the early life stress of neonatal isolation (1-h individual isolation on postnatal days 2-9) in rats has immediate and enduring neural and behavioral effects. Recently, we showed neonatal isolation impaired hippocampal-dependent context conditioned fear in adult rats. We now expand upon this finding to test whether neonatal isolation impairs performance in inhibitory avoidance and in the non-aversive, hippocampal-dependent object recognition task. In addition to assessments of hippocampal-dependent memory, we examined if neonatal isolation results in cellular alterations in the adult hippocampus. This was measured with antibodies that selectively label calpain-mediated spectrin breakdown product (BDP), a marker of cytoskeletal modification that can have neuronal consequences. Neonatally isolated male and female rats showed impaired performance in both memory tasks as well as elevated BDP levels in hippocampal immunoblot samples. In tissue sections stained for BDP, the cytoskeletal fragmentation was localized to pyramidal neurons and their proximal dendrites. Interestingly, the hippocampal samples also exhibited reduced staining for the postsynaptic marker, GluR1. Neonatal isolation may render those neurons involved in memory encoding to be vulnerable to calpain deregulation and synaptic compromise as shown previously with brain injury. Together with our prior research showing enhanced striatal-dependent learning and neurochemical responsivity, these results indicate that the early experience of neonatal isolation causes enduring yet opposing region-specific neural and behavioral alterations.     

Bayesian generalized structured component analysis

Generalized structured component analysis (GSCA) is a component-based approach to structural equation modelling, which adopts components of observed variables as proxies for latent variables and examines directional relationships among latent and observed variables. GSCA has been extended to deal with a wider range of data types, including discrete, multilevel or intensive longitudinal data, as well as to accommodate a greater variety of complex analyses such as latent moderation analysis, the capturing of cluster-level heterogeneity, and regularized analysis. To date, however, there has been no attempt to generalize the scope of GSCA into the Bayesian framework. In this paper, a novel extension of GSCA, called BGSCA, is proposed that estimates parameters within the Bayesian framework. BGSCA can be more attractive than the original GSCA for various reasons. For example, it can infer the probability distributions of random parameters, account for error variances in the measurement model, provide additional fit measures for model assessment and comparison from the Bayesian perspectives, and incorporate external information on parameters, which may be obtainable from past research, expert opinions, subjective beliefs or knowledge on the parameters. We utilize a Markov chain Monte Carlo method, the Gibbs sampler, to update the posterior distributions for the parameters of BGSCA. We conduct a simulation study to evaluate the performance of BGSCA. We also apply BGSCA to real data to demonstrate its empirical usefulness.     

Bereavement and Coping of south Asian Families post 9/11

Eleven first‐generation South Asian family members who lost a relative in the World Trade Center attacks on September 11, 2001, were interviewed about their loss and their coping strategies. Data were analyzed using consensual qualitative research (CQR) methodology. Participant responses clearly delineated bereavement reactions and coping within a cultural framework. Once miembros de una familia surasiática de primera generación que perdieron a un pariente en el atentado contra el World Trade Center el 11 de septiembre de 2001 fueron entrevistados acerca de su pérdida y las estrategias que emplearon para soportarla. Los datos se analizaron siguiendo una metodología de investigación cualitativa consensuada (CQR, por sus siglas en inglés). Las respuestas de los participantes delinearon con claridad sus reacciones ante el dolor sufrido y cómo lo sobrellevaron dentro de un marco cultural.     

Late expression of brain-derived neurotrophic factor in the amygdala is required for persistence of fear memory

In many instances, increase in neuronal activity can induce biphasic secretion of a modulator. The initial release of the modulator triggers the induction of synaptic plasticity, whereas the second-phase release reinforces the efficacy of synaptic transmission and growth of dendrites and axons. In this study, we showed that fear conditioning not only induced the first but also a second peak of brain-derived neurotrophic factor (BDNF) expression. Fluorescent immunohistostaining confirmed that BDNF expression increased at 1 and 12 h after conditioning and returned to baseline at 30 h after conditioning. Mature BDNF expression increased in a similar manner. TrkB-IgG or K252a infusion before training impaired fear memory on days 1 and 7 after training. In contrast, TrkB-IgG or K252a infusion 9 h after fear conditioning did not affect memory retention on day 1 after training but impaired fear memory on day 7 after training. Fear conditioning significantly enhanced Zif268 expression in the amygdala at 12 h after training; this enhanced expression was completely inhibited by TrkB-IgG infusion 9 h after training. The level of growth-associated protein 43 (GAP-43), a marker of newly formed synapses, in the amygdala increased 7 days after fear conditioning. Moreover, conditioned rats had higher AMPA/NMDA ratio than unpaired rats. These results suggest that consolidated memory could be continuously modulated by previous molecular changes produced during memory acquisition.     

Parent-Child Interactions Among Low-Income Mexican American Parents and Preschoolers: Do Clinic-Referred Families Differ From Nonreferred Families?

This study compared low-income Mexican American parents of young children referred for behavior problems to their nonreferred counterparts on an observational measure of parent-child interactions. Referred Mexican American parents demonstrated more negative behaviors than their nonreferred counterparts in both nondirective and highly directive situations. However, no differences were found at moderate levels of directiveness. The most and least directive situations in the Dyadic Parent-Child Interaction Coding System best differentiated referred from nonreferred Mexican American families, and families differed more in their negative behaviors than positive behaviors. Many of the parenting behaviors that have been found to differ between referred and nonreferred Caucasian families were also observed to differ between their Mexican American counterparts.     

Segregation by color and stereoscopic depth in three-dimensional visual space

Two experiments were conducted to investigate how color and stereoscopic depth information are used to segregate objects for visual search in three-dimensional (3-D) visual space. Eight observers were asked to indicate the alphanumeric category (letter or digit) of the target which had its unique color and unique depth plane. In Experiment 1, distractors sharing a common depth plane or a common color appeared in spatial contiguity in thexy plane. The results suggest that visual search for the target involves examination of kernels formed by homogeneous items sharing the same color and depth. In Experiment 2, thexy contiguity of distractors sharing a common color or a common depth plane was varied. The results showed that when target-distractor distinction becomes more difficult on one dimension, the other dimension becomes more important in performing visual search, as indicated by a larger effect on search time. This suggests that observers can make optimal use of the information available. Finally, color had a larger effect on search time than did stereoscopic depth. Overall, the results support models of visual processing which maintain that perceptual segregation and selective attention are determined by similarity among objects in 3-D visual space on both spatial and nonspatial stimulus dimensions.