The locus of spatial attention during the temporal integration of visual memories and visual percepts

Temporal integration is a process by which two serially presented visual stimuli are mentally integrated to form a composite representation. In the present research, we explored how spatial selective attention is used during the delay separating stimuli, in order to determine the contents of spatial working memory in this task. A two-task situation was created. On the primary task, two dot arrays were serially presented within a grid, leaving one space empty, which subjects identified. On the secondary task, instead of the second array, a discrimination probe was presented. Integration accuracy increased through delays of 1,500 msec, revealing an estimate of the time required to form an optimal memory trace for integration. Once the memory trace was formed (but not before), response time to the probe was faster if it was presented in a location previously occupied by a dot from Array 1. This indicates that during the delay separating the arrays, the subjects assigned spatial attention to the locations occupied by the first array and actively maintained the leading array in working memory. Implications for theories of visual processing and memory are discussed.     

Diencephalic damage decreases hippocampal acetylcholine release during spontaneous alternation testing

A rodent model of diencephalic amnesia, pyrithiamine-induced thiamine deficiency (PTD), was used to investigate diencephalic-hippocampal interactions. Acetylcholine (ACh) release, a marker of memory-related activation, was measured in the hippocampus of PTD-treated and control rats prior to, during, and after spontaneous alternation test. During behavioral testing, all animals displayed increases in ACh release. However, both the percent increase of ACh release during spontaneous alternation testing and the alternation scores were higher in control rats relative to PTD-treated rats. Thus, when rats are tested on a task with demands dependent on the hippocampus, it appears that the hippocampus is not fully activated after diencephalic damage.     

The ‘redefinition of death’ debate: Western concepts and western bioethics

Biomedicine is a global enterprise constructed upon the belief in the universality of scientific truths. However, despite huge scientific advances over recent decades it has not been able to formulate a specific and universal definition of death: In fact, in its attempt to redefine death, the concept of death appears to have become immersed in ever increasing vagueness and ambiguity. Even more worrisome is that bioethics, in the form of principlism, is also endeavouring to become a global enterprise by claiming neutrality. It appears that the discourse within both disciplines have similarly manipulated the boundaries of death to include the “dying”. This paper argues that the redefinition of death debate in biomedicine reveals a concept of personhood which is profoundly western in origin and which is in accordance to the concept adhered to within principlism. Biomedicine and bioethics do not appear to acknowledge the limitations of their own world view and hence lack an understanding of their applicability and appropriateness in diverse social and cultural contexts; a situation which adds credence to claims as to the hegemonic and imperialistic nature of all such global enterprises. Ms. Jones is an intensive care clinical nursing specialist. Dr. Kessel is a public health physician and medical ethicist.     

Somatosensory processing in the biological relatives of schizophrenia patients: a signal detection analysis of two-point discrimination

This study examined 2-point discrimination performance in 1 st-degree biological relatives (n = 39) of individuals with schizophrenia and normal adult control participants (n = 30) recruited from the community. They completed an objective 2-point discrimination task, adapted for use with a signal detection approach to permit separation of discriminability (i.e., sensitivity, d') from response bias/ criterion (or motivation, lnbeta). Relatives revealed poorer performance on the d' index compared with controls. The 2 groups did not differ on lnbeta, suggesting a genuine difference in sensitivity but not response bias. The sensitivity deficit might reflect decreased spatial acuity and/or impaired intensity cue processing of tactile stimuli. Poor performance on the d' index was most closely associated with 2 schizotypic features, namely "odd beliefs/magical thinking."     

Cultural variations in optimistic and pessimistic bias: do Easterners really expect the worst and Westerners really expect the best when predicting future life events?

The authors compared levels of optimistic and pessimistic bias in the prediction of positive and negative life events between European Americans and Japanese. Study 1 showed that European Americans compared with Japanese were more likely to predict positive events to occur to self than to others. The opposite pattern emerged in the prediction of negative events. Study 2 replicated these cultural differences. Furthermore, positive associations emerged between predictions and occurrence of life events 2 months later for both European Americans and Japanese. Across both studies, results of within-groups analyses indicated that both groups expected negative events to be more likely to occur to others than to self (optimistic bias). In addition, Japanese expected positive events to be more likely to occur to others than to self (pessimistic bias). However, European Americans failed to show the expected optimistic bias for positive events.     

心算加工年老化及其机制研究

以１７２名２０－７９岁成人为被式对心算加工的年老化过程及其机制进行了研究。任务为连续减法心算,依难度分为５种：１０００－１,１０００－３,１０００－１３及１０００－１７。结果表明,年龄与心算难度存在明显的交互作用,且随着年龄增加,不同难度心算效率均以幂函数形式降低。     

心算加工年老化及其机制研究

以172名20－79岁成人为被试对心算加工的年老化过程及其机制进行了研究。任务为连续减法心算,依难度分为5种：1000－1、1000－3、1000－7、1000－13及1000－17。结果表明,年龄与心算难度存在明显的交互作用,且随着年龄增加,不同难度心算效率均以幂函数形式降低。结构方程建模分析发现心算加工年老化过程存在两个中介作用因子,即速度因子和非速度因子,且速度因子对非速度因子存在明显的正效应。     

Peak Performance of Business Leaders: An Experience Parallel to Self-Actualization Theory

To investigate peak performance, 40 business leaders described personal experiences through interviews and the Privette Experience Questionnaire. In order to discriminate processes of peak performance from personality attributes of business leaders, their questionnaire data were compared with parallel data from a sample of 41 university men. Multivariate analyses of variance of factors and items and follow-up analyses indicated that scores differed but not on defining attributes. The peak performance dyad—full focus and clear sense of self—and aspects of peak experience—significance and fulfillment—were endorsed by both samples. Business leaders endorsed sociability and personal discipline and denied playfulness more than the university men, who endorsed fluidity. The relation of peak performance to self-actualization theory is discussed.