Qian

Spatial organisation between targets and cues affects the sequence effect of symbolic cueing

Previous studies have found that attention orienting is influenced by the orienting processes of previous trials in a spatial cueing paradigm. This sequence effect is due to the fact that performance is facilitated when cue validity (valid or invalid) repeats between trials. This study investigated the sequence effect of arrow cueing with four possible display locations. Therefore, there are two spatial organisation conditions between targets and cues for an invalid trial: opposite (i.e., targets appeared in the opposite location of the cue directions) and adjacent (i.e., targets appeared in the adjacent locations of the cues). The results showed that the sequence effects were enhanced when the spatial organisation conditions repeated between trials. The results suggest that not only the cue validity status but also the spatial organisation conditions of targets and cues are encoded in the memory representation to form the sequence effect.

Spatial Correspondence Learning is Critical for the Sequence Effects of Symbolic Cueing

Attention orienting has been found to be influenced by the previous cueing status in a spatial cueing paradigm. The purpose of this study was to determine whether the cue predictive values or the spatial correspondence learning between cues and targets could influence the sequence effect of symbolic cueing. The findings revealed that the predictive values of arrow or word cues do not lead to different sequence effects, but that visually asymmetrical letter cues, which allow spatial correspondence learning between cues and targets, induce stronger sequence effects than visually symmetrical letter cues. In addition, visually symmetrical directional word cues can induce sequence effects. The results suggest that spatial correspondence learning, although not obligatory, is critical for the sequence effects of symbolic cueing. The findings support the feature-integration hypothesis, rather than the strategic adjustments account.

Starvation avoidance mobile energy replenishment for wireless rechargeable sensor networks

The breakthrough progress of wireless charging technology provides a significant opportunity to solve the energy constrained problem in wireless sensor networks. However, most of existing mobile energy replenishment schemes either cannot well adapt to the high diversity of energy consumption or leave out of consideration about the fairness of charging response, and thus may still suffer from non-negligible performance degradation resulted from energy starvation. Particularly when there is a large number of charging requirements, the energy starvation may bring about quite a number of sensor nodes invalid due to energy depletion. In this paper, we explore the energy starvation issue while provisioning energy for wireless sensor networks and propose a Starvation Avoidance Mobile Energy Replenishment scheme (SAMER) which can avoid energy starvation through calculating and considering the maximum tolerable latency of each charging requirement. The simulation results show that SAMER scheme can effectively solve the energy starvation problem and achieve efficient mobile energy supplement for wireless sensor networks.

When Smart Phone Meets Vehicle: A New On-Board Unit Scheme for VANETs

As the most main part of constituting Vehicular Ad Hoc Networks (VANETs), On-Board Unit (OBU) which is installed on vehicle is crucial to the development and popularization of such networks. In this paper, we propose a New OBU (NOBU) scheme of combining smart phone with Customized 802.11p Device. Since smart phone is generally equipped with powerful computing and storing device, GPS and electronic map, in our proposed scheme, it is utilized as a platform to run routing strategy and all kinds of applications of VANETs. By USB cable, the smart phone can readily connect with a customized 802.11p device, and thus access VANETs. As smart phones have been becoming so popular that almost every driver own one, the scheme will provide vehicles, especially for low-and middle-price ones, with a chance to access VANETs in a feasible, low-cost and efficient way. Simulation results based on a real map demonstrated the effectiveness of the proposed scheme.

Influence of Previous Cueing Validity on Gaze-Evoked Attention Orienting

Perception of an averted gaze can automatically shift an observer’s attention toward the location gazed at. The present study intended to investigate the sequential processes between trials in gaze-cueing paradigm. The results showed that cueing effects for the group of trials that was preceded by a valid trial are larger than that for the group of trials that was preceded by an invalid trial. This sequence effect is due to the fact that repeating a trial type (valid or invalid) quickens reaction time (RT), and switching a trial type slows RT. The results also showed that similar sequence effect patterns are induced by both gaze cues and arrow cues. The present results suggest that symbolic cues, no matter biologically significant or not, can induce sequence effects, and sequential processes are common mechanisms in human attention orienting systems.

Sequence effects of the involuntary and the voluntary components of symbolic cueing

The orienting of attention has been found to be influenced by the previous cueing status in a spatial-cueing paradigm. The explanation for this sequence effect remains uncertain. This study separated the involuntary and the voluntary components of arrow cueing by manipulating the predicted target locations. For example, a left arrow cue may have indicated that the target was more likely to appear at the up location. Therefore, three trial types were repeated or switched between trials: cued (targets appeared along the direction of the arrows), predicted (targets appeared at the locations predicted by the arrows), and unrelated (targets appeared at the other two locations, neither cued nor predicted). RTs of cued trials were found to be significantly facilitated after a previous cued trial; however, the same effect was not observed for predicted trials. The results suggest that significant sequence effects are induced only in the involuntary component of arrow cueing. The findings support the feature-integration hypothesis for the sequence effect of symbolic cueing.

Gazes Induce Similar Sequential Effects as Arrows in a Target Discrimination Task

Symbolic cueing paradigm has been widely used to investigate the attention orienting induced by centrally-presented gaze or arrow cues. Previous studies have found a sequence effect in this paradigm when arrows are used as central cues and simple detection tasks are included. The present study investigated the universality of the sequence effect with gaze cues and in discrimination tasks. It was found that sequence effects are not limited to specific cue types or specific tasks, and the sequence effect can even generalize across different cue types (from gaze to arrow, or from arrow to gaze). In addition, the sequence effect is not influenced by the repetition and switch of target identities (along with response keys). The results suggest that sequential processing is a common mechanism in attention orienting systems, and support the automatic retrieval hypothesis more than the strategy adjustment account.

The Change of Expression Configuration Affects Identity-Dependent Expression Aftereffect but Not Identity-Independent Expression Aftereffect.

The present study examined the influence of expression configuration on cross-identity expression aftereffect. The expression configuration refers to the spatial arrangement of facial features in a face for conveying an emotion, e.g., an open-mouth smile vs. a closed-mouth smile. In the first of two experiments, the expression aftereffect is measured using a cross-identity/cross-expression configuration factorial design. The facial identities of test faces were the same or different from the adaptor, while orthogonally, the expression configurations of those facial identities were also the same or different. The results show that the change of expression configuration impaired the expression aftereffect when the facial identities of adaptor and tests were the same; however, the impairment effect disappears when facial identities were different, indicating the identity-independent expression representation is more robust to the change of the expression configuration in comparison with the identity-dependent expression representation. In the second experiment, we used schematic line faces as adaptors and real faces as tests to minimize the similarity between the adaptor and tests, which is expected to exclude the contribution from the identity-dependent expression representation to expression aftereffect. The second experiment yields a similar result as the identity-independent expression aftereffect observed in Experiment 1. The findings indicate the different neural sensitivities to expression configuration for identity-dependent and identity-independent expression systems.