A new look at the relationship between perceptual and motor responses

A visual stimulus may affect a motor response although its visibility is prevented by a mask. This implies that the sensorimotor system is more susceptible to stimulation than the perceptual system. We report data that are contrary to this intuition. Experiments where both the observer's perceptual state related to the presence/absence of a masked stimulus and the motor behaviour elicited by the same stimulus were jointly assessed on a trial-by-trial basis show that masked visual stimulation at constant visibility (d′) has two types of effect on the motor system. When the physical energy of the masked stimulus is weak, it affects the motor response only if it exceeds the observer's perceptual response criterion. It is only when the physical energy of the masked stimulus is relatively strong that its impact on the motor response is independent of the state of the perceptual system. This indicates that reflex, “nonconscious” behaviour has a high energy threshold.     

Differential time course of implicit and explicit cueing by colour and orientation in visual search

Using a cued conjunction search task, Anderson, Heinke, and Humphreys (2010) demonstrated larger effects from cueing target colour than from cueing target orientation. In this study, we separated the implicit (nonexpectation-dependent) and explicit (expectation-dependent) effects of orientation and colour visual cues. In Experiment 1, we replicated the original findings for short cue durations (100–200 ms), demonstrating that cues matching the physical property of the target on 80% of trials exert a rapid effect on search. These early cueing effects on reaction times were supported by evidence of guidance from cues on early eye movements. Experiment 2 introduced a feature to the cue that randomly matched the colour or orientation of the target. When cue orientation was predictive, there were strong implicit effects based on whether the colour of the cue and target matched. When cue colour was predictive, there were only weak effects from the cue's orientation. Implicit effects from cue colour remained when orientation-predictive cues were used and colour was unlikely to predict the target (Experiment 3). The data suggest that strong effects of colour cueing result from a combination of implicit and explicit processes, whereas effects from orientation cues are largely limited to the explicit guidance of visual search.     

Rewards shape attentional search modes

Visual attention can be configured for specific stimulus features (feature search mode) or it can be non-specifically set for salient pop-outs (singleton detection mode). Additionally, monetary rewards have been shown to bias attention toward specific features, but it is unknown whether secondary reinforcers (images of US$) can shape global attention via search modes. In a between-group study, we trained participants to value one search mode over the other. In a testing phase, a salient distractor captured the attention of the value-singleton group; however, the value feature group was completely unaffected. This suggests that rewards automatically bias global attention mechanisms and potentially mediate the handoff between stimulus-driven and goal-directed attentional control.     

The impacts of task relevance and cognitive load on adults’ decision information search

ABSTRACT

Higher relevance may increase older adults’ engagement in cognitively demanding activities; however, whether this effect will maintain when available cognitive resources are limited? Consequently, we investigated the joint impact of task relevance and cognitive load on older and younger adults’ decision search behaviors. We adopted a 2 (age: young/old) × 2 (cognitive load: without load/with load) × 2 (task relevance: high/low) mixed design. Sixty-one younger and 63 older adults completed high-relevance and low-relevance decisions. Our results revealed that older (vs. younger) adults took more time and more alternative-based search before decision-making. Both age groups sampled less information with an additional memory task. Additionally, they spent more time and effort to sample more information on high-relevance (vs. low-relevance) decisions; however, such differences disappeared when with an additional memory task. Task relevance promoted both age groups' search engagement, but this effect was subjected to their available cognitive resources.     

Ontogenetic Emergence of Cognitive Reference Comprehension

Prelinguistic cognitive reference comprehension is foundational to language acquisition and higher cognitive functions. However, its ontogenetic origins in the first year of life are currently not well understood. The current study pitted cognitivist against social interactionist views. We worked with infants monthly from 10 to 13 months of age and observed their behavioral search during a reference comprehension task. Our goal was to first establish the age at which infants begin to cognitively expect an occluded object in one of two locations following a communicative pointing cue. We then tested whether infants' cognitive referential expectations would prospectively predict social interaction skills and experiences (as assessed by spontaneous infant and parent pointing) or, conversely, be predicted by social interaction skills and experiences. Results revealed a linear increase in cognitive reference comprehension, with clear above chance performance, individual stability in month-to-month correlations, and a synchronous correlation to referential pointing all emerging at 12 months but not earlier. Regarding developmental predictions, infants' cognitive referential expectations were not predictive of social interaction skills and experiences; on the contrary, they were predicted by social interaction skills and experiences. Findings suggest that a nonverbal cognitive understanding of reference to occluded entities is neither early emerging, hard wired, nor causal to infants' or caregivers' referential pointing. Instead, this foundational skill is predicted by earlier social interaction. Findings are consistent with the view that cognitive reference comprehension develops via a social construction process in the first year of life.     

Search and rescue operation in flooded areas: A survey on emerging sensor networking-enabled IoT-oriented technologies and applications

The climate and weather dynamics in the past few years has driven a massive increase in the number and intensity of flood disasters, which severely claim casualties in human, goods and properties. Aimed to reduce these casualties, emerging software-defined internet protocol-based communication technologies in the form of Internet of Things (IoT) have attracted strong interests from disaster mitigation stakeholders to rapidly locate victims and acquire their relevant information, which in turn can boost up the efficiency and effectiveness of Search and Rescue (SAR) missions. In order to capture state-of-the-art development and technological challenges, this paper presents an extensive review on the flood SAR systems, highlighting some of the key emerging IoT technologies that prove or are potentially useful in improving the SAR operation by the rescuers. Furthermore, a comprehensive study on different existing communication technologies for SAR is provided, covering the system architecture, communication network compositions and applications. Based on the critical analysis of existing works, this paper puts forward a proposal on an IoT-aided integrated flood management framework to support SAR in the flood-catchment areas, leveraging upon three-domain (ground, water and air) collaborative wireless networks.