New protocol for dissociating visuospatial working memory ability in reaching space and in navigational space

Several studies have demonstrated that the processing of visuospatial memory for locations in reaching space and in navigational space is supported by independent systems, and that the coding of visuospatial information depends on the modality of the presentation (i.e., sequential or simultaneous). However, these lines of evidence and the most common neuropsychological tests used by clinicians to investigate visuospatial memory have several limitations (e.g., they are unable to analyze all the subcomponents of this function and are not directly comparable). Therefore, we developed a new battery of tests that is able to investigate these subcomponents. We recruited 71 healthy subjects who underwent sequential and simultaneous navigational tests by using an innovative sensorized platform, as well as comparable paper tests to evaluate the same components in reaching space (Exp. 1). Consistent with the literature, the principal-component method of analysis used in this study demonstrated the presence of distinct memory for sequences in different portions of space, but no distinction was found for simultaneous presentation, suggesting that different modalities of eye gaze exploration are used when subjects have to perform different types of tasks. For this purpose, an infrared Tobii Eye-Tracking X50 system was used in both spatial conditions (Exp. 2), showing that a clear effect of the presentation modality was due to the specific strategy used by subjects to explore the stimuli in space. Given these findings, the neuropsychological battery established in the present study allows us to show basic differences in the normal coding of stimuli, which can explain the specific visuospatial deficits found in various neurological conditions.     

Effect of achievement motivation on cognitive control adaptations

Previous research addressing motivational effects on cognitive control adaptations primarily manipulated external rewards. In the present study, we examined whether achievement motivation, reflecting intrinsic motivation, modulates cognitive control adaptations. In each of two experiments, students were divided into a high achievement motivation group (HAM; Experiment 1: N?=?36; Experiment 2: N?=?39) and a low achievement motivation group (LAM; Experiment 1: N?=?30; Experiment 2: N?=?39) on the basis of the Achievement Motivation Scale. Cognitive control adaptations were assessed by sequential congruency effects (SCEs) in Flanker tasks. Using a standard Flanker task in Experiment 1 and examining response times, the HAM but not LAM participants showed evidence of cognitive control adaptations. Because SCEs in a standard Flanker task may reflect lower-level, bottom-up processes rather than cognitive control adaptations, we used an adapted version of the Flanker task in Experiment 2 that controlled for the potential influence of such processes. Experiment 2 again revealed evidence of SCEs in the HAM but not LAM participants. These results suggest that cognitive control adaptions may be modulated by achievement motivation. Such potential modulation could be taken into account when evaluating results of previous and future fundamental and applied studies on cognitive control adaptations.     

The role of observer strategy in the single-target AB paradigm

Identification of the second of two targets (T1, T2) inserted in a stream of distractors is impaired when presented 200–500 ms after the first (attentional blink, AB). An AB-like effect has been reported by Nieuwenstein, Potter, and Theeuwes, Journal of Experimental Psychology: Human Perception and Performance, 35, 159-169, (2009, Experiment 2), with a distractor stream that contained only one target and a gap just before the target. Nieuwenstein et al. hypothesized that the gap enhanced the salience of the last distractor, causing it to be processed much like T1 in conventional AB studies. This hypothesis can also account for Lag-1 sparing (enhanced target performance when presented directly after the last distractor, without an intervening gap). We propose an alternative account of the Lag-1 sparing in the single-target paradigm based on observer strategy, and test it by presenting the single-target and dual-target conditions to separate groups (Experiment 2) instead of mixed across trials (Experiment 1 and Nieuwenstein et al.'s study). The single-target condition exhibited Lag-1 sparing when it was mixed with the dual-target condition, but Lag-1 deficit when it was done in isolation. This outcome is consistent with an observer-strategy account but not with an enhanced salience account of the Lag-1 sparing effect in the single-target condition.     

The effects of valence and arousal on the emotional modulation of time perception: evidence for multiple stages of processing

Previous research has demonstrated that both emotional valence and arousal can influence the subjective experience of time. The current research extends this work by (1) identifying how quickly this emotional modulation of time perception can occur and (2) examining whether valence and arousal have different effects at different stages of perception. These questions were addressed using a temporal bisection task. In each block of this task, participants are trained to distinguish between two different exposure durations. Participants are then shown stimuli presented at a number of durations that fall between the two learned times, and are asked to indicate whether the test stimulus was closer in duration to the shorter or longer learned item. In the current study, participants completed blocks of trials in which the durations were "Short" (100-300 ms) or "Long" (400-1600 ms). Stimuli consisted of neutral photographs as well as four categories of emotional images: high-arousal negative, high-arousal positive, low-arousal negative, and low-arousal positive. In Short blocks, arousing and nonarousing negative images were judged to have been shown for shorter durations than they actually were (i.e., the duration was underestimated); this effect occurred at durations as brief as 133 ms. In Long blocks, the display time for highly arousing negative items was overestimated, whereas durations were underestimated for highly arousing positive items and less arousing negative items. These data suggest that arousal and valence have different effects at different stages of perception, possibly due to the different neural structures involved at each stage of the emotional modulation of time perception.     

人类社会认知的神经机制:来自社会脑研究的证据

社会认知是指从环境互动的过程中推测他人意图、情感和思想等内部状态的心理加工过程。社会脑假说认为,包括人类在内的灵长类大脑内肯定存在着一个旨在认识和理解他人表情的神经机制,在社会交往中通过该中枢迅速处理与他人相互作用的各种信息。本文通过回顾社会脑的构成与基本功能,镜像神经元的发现及功能,以及社会脑、镜像神经元对社会认知影响的相关研究,提出了人类社会认知不同于其他物种的三个主要区别。     

Central executive system impairment in traumatic brain injury

The aim of the present study was to identify cognitive functions affected by traumatic brain injury (TBI) and to verify the mechanism underlying cognitive impairment. More precisely, cognitive deficits following TBI can be considered as a consequence of (a) a speed processing deficit, that is a general slowing of perceptual, motor and cognitive subroutines; (b) an impairment of the Central Executive System of working memory (CES).Thirty-seven patients were submitted to a neuropsychological battery, aimed to evaluate different cognitive functions.Results showed severe deficits in speed processing, divided attention,working memory, executive functions and long term memory.Regression analyses, performed to test the two hypotheses, showed that the working memory deficit hypothesis is able to explain divided attention, executive functions and long term memory deficits more than speed processing hypothesis.     

The state of the psychological contract and its relation with employees' psychological health

In the present paper the role of the state of the psychological contract to predict psychological health results is studied in a sample of 385 employees of different Spanish companies. Results indicate that the state of the psychological contract significantly predicts life satisfaction, work-family conflict and well-being beyond the prediction produced by the content of the psychological contract. In addition, trust and fairness, two dimensions of the state of psychological contract, all together contribute to explain these psychological health variables adding value to the role as predictor of fulfillment of the psychological contract. The results support the approach argued by Guest and colleagues.     

Crossing the pillars of Hercules: the role of spatial frames of reference in error making

This paper introduces a perspective accounting for errors that may occur as a result of the human interaction with the three-dimensional (3D) space. Particularly, we are interested in errors that are caused by cognitively crossing the boundary between peripersonal and extrapersonal space. Several behavioural, neurophysiological, and neuropsychological perspectives are reviewed in order to develop the theoretical framework on which our ideas are founded. We argue that cognitively crossing the boundary implies switching from one frame of reference to another, which, as a consequence, implies specific costs. The results of five experiments (overall involving 76 participants) support our hypothesis, suggesting the existence of different action-oriented spatial frames of reference.     

Frames and MV-algebras

We describe a class of MV-algebras which is a natural generalization of the class of “algebras of continuous functions”. More specifically, we're interested in the algebra of frame maps Hom (Ω(A), K) in the category T of frames, where A is a topological MV-algebra, Ω(A) the lattice of open sets of A, and K an arbitrary frame. Given a topological space X and a topological MV-algebra A, we have the algebra C (X, A) of continuous functions from X to A. We can look at this from a frame point of view. Among others we have the result: if K is spatial, then C(pt(K), A), pt(K) the points of K, embeds into Hom (Ω(A), K) analogous to the case of C (X, A) embedding into Hom (Ω(A), Ω (X)). 1991 Mathematics Subject Classification: 06F20, 06F25, 06D30 Presented by Ewa Orlowska     

The attentional blink: Resource depletion or temporary loss of control?

Identification of the second of two targets is impaired if it is presented less than about 500 ms after the first. Theoretical accounts of this second-target deficit, known as attentional blink (AB), have relied on some form of limited attentional resource that is allocated to the leading target at the expense of the trailing target. Three experiments in the present study reveal a failure of resource-limitation accounts to explain why the AB is absent when the targets consist of a stream of three items belonging to the same category (e.g., letters or digits). The AB is reinstated, however, if an item from a different category is inserted in the target string. This result, and all major results in the AB literature, is explained by the hypothesis that the AB arises from a temporary loss of control over the prevailing attentional set. This lapse in control renders the observer vulnerable to an exogenously-triggered switch in attentional set.