Isochronous Sequential Presentation Helps Children Orient Their Attention in Time

Rethinking attention in time: Expectancy violations reconcile contradictory developmental evidence

In environments with many concurrent sound sources, it is often possible to hear out individual sounds and identify their sources. To accomplish this perceptual organization of the sound sources, listeners analyze the mixture of sounds to estimate the constituent components that correspond to one acoustic sound source. Signal components that are likely to come from the same source are grouped into an auditory object, that is segregated from the acoustic complex. The grouping of signal components into sources is based on identifying shared features of the components, like common spectral cues (the same fundamental frequency or frequency modulation), temporal cues (the same temporal envelope), or spatial cues (the same interaural differences). When signal components’ onsets fall within such a time window that they are perceived as being synchronous, the components are combined to form a new auditory object, that is monitored across time on cues that sustain their grouping. Given that spatial cues are inherent to every sound and already present at the onset, and that they enhance detection of a sound by a spatial release from masking, it is unclear whether and how much temporal perception depends on the presence of spatial cues. The research presented here addressed the contribution of the binaural hearing system, which processes a sound’s spatial cues, to the processing of its temporal cues, and the contribution of the sounds’ temporal cues to the processing of their spatial cues. In order to assess the contribution of spatial cues to temporal perception, experiments were conducted in which the temporal position of a target sound’s onset was controlled by the subjects to find its desired position relative to a regular series of reference sound onsets. Manipulation of the target’s interaural differences, its sensation level, and the target and reference sounds’ durations allowed comparison of their effects on temporal perception of the target’s onset. The main finding was that temporal perception precision degraded below a critical level, depending on the absolute target and masker levels and the difference in spatial configuration between target and masker that facilitated perception at much lower signal-to-noise ratios. The implication of a sound’s signal-to-noise ratio getting below this critical level is that, when the temporal window for grouping signal components’ onsets is enlarged due to the degraded precision, there is an increased probability for signal components to be grouped incorrectly into an auditory object, or to be prevented from grouping into a new auditory object and remain part of the acoustic complex until other evidence is gathered for the existence of their source. This may be a contributing factor to the decrease of speech intelligibility in noisy environments, where precise temporal perception of transients is required for the processing of speech signals. In order to assess the contribution of temporal cues to binaural processing, thresholds were measured for discrimination between the spatial configurations of two sounds that had identical spectral range and onset and offset times, but differed in their temporal envelope structure and had equally-sized directional information to opposite sides of the medial plane. The measured minimum interaural differences in time or level at which the sounds’ spatial configurations could successfully be discriminated represented the ability to process binaural cues, and allowed comparison between the effects of the various manipulations of bandwidths, center frequencies, and temporal envelopes to the sounds. The main findings were that discrimination based on interaural level differences was good for all tested conditions (although absolute thresholds depended on the specific conditions), and that discrimination based on interaural time differences was only possible when the temporal envelopes of the sounds were sufficiently different. The binaural system must, therefore, have been capable of processing the interaural differences within short periods of time when one of the sounds was dominant in the monaural temporal envelopes of the combined signals at each ear. Analysis of the monaural temporal envelopes influences the ability to use the binaural information to separate individual signal components, and allow tracking across time of the signals components with identical spatial cues to form a perceptual unity, the auditory object. In conditions where discrimination was not possible, the temporal envelopes of the individual sounds were too similar and such periods did not occur systematically in the temporal envelopes of the combined sounds. This finding suggests that a monaural analysis of a composite signal’s temporal envelope is a prerequisite for the binaural processing of the constituent signal components’ interaural time differences. The implication is that, if the signals’ temporal envelopes are too similar, their signal components may not be correctly grouped into separate and individually lateralized auditory objects, but remain fused as a single object with an averaged spatial image.

Weber ratios were obtained for visual velocity discrimination under three topographic conditions with the same subjects and psychophysical procedures. The conditions differed regarding the presence of either temporal or spatial cues, these being correlated in magnitude with stimulus velocity. Systematic effects of the cues upon the level of velocity discrimination were noted.

Visual snow syndrome (VSS) is a poorly understood neurological disorder that features a range of disabling sensory changes. Visual processing changes revealed previously in VSS appear consistent with poor attentional control, specifically, with difficulty controlling environmentally driven shifts of attention. This study sought to confirm this proposal by determining whether these changes were similarly evident where attention is internally driven. Sixty seven VSS patients and 37 controls completed two saccade tasks: the endogenously cued saccade task and saccadic Simon task. The endogenously cued saccade task correctly (valid trial) or incorrectly (invalid trial) pre-cues a target location using a centrally presented arrow. VSS patients generated significantly shorter saccade latencies for valid trials (p = 0.03), resulting in a greater magnitude cue effect (p = 0.02), i.e. the difference in latency between valid and invalid trials. The saccadic Simon task presents a peripheral cue which may be spatially congruent or incongruent with the subsequent target location. Latencies on this task were comparable for VSS patients and controls, with a normal Simon effect, i.e. shorter latencies for saccades to targets spatially congruent with the preceding cue. On both tasks, VSS patients generated more erroneous saccades than controls towards non-target locations (Endogenously cued saccade task: p = 0.02, saccadic Simon task: p = 0.04). These results demonstrate that cued shifts of attention differentially affect saccade generation in VSS patients. We propose that these changes are not due to impairment of frontally-mediated inhibitory control, but to heightened saccade-related activity in visual regions. These results contribute to a VSS ocular motor signature that may provide clinical utility as well as an objective measure of dysfunction to facilitate future research.

Many visual tasks have been shown to be influenced by the attentional state of the observer. However the conditions under which attention has effects is still unclear. Here we report upon a series of experiments where the observer has to react to changes in the luminance of a target amongst many distractors. We have systematically manipulated the nature of the cue (endogenous vs exogenous) and the task to be performed (detection of changes vs discrimination of direction of change). Stimuli consisted of a number of circles upon a screen. At some point in time one of the circles changed in luminance and subjects reacted as quickly as possible. Typically half the circles were red and half green. Subjects could be cued to attend to a particular colour by instruction (endogenous) or by a brief flash of the lines that joined the same coloured elements (exogenous). In most cases the cue was appropriate on 80% of the trials and hence we could compare response times between valid and invalid trials. Our results show that (1) for simple detection endogenous cues were ineffective whereas exogenous cues provided a small advantage for the valid trials, and (2) for discrimination of direction of change endogenous cues provided a small advantage, whereas exogenous cues provided a large advantage for the valid trials. It appears that both cueing type and task type modulate the attentional effects on this ‘preattentive’ task.

Video salient object detection (VSOD) aims to locate and segment the most attractive object by exploiting both spatial cues and temporal cues hidden in video sequences. However, spatial and temporal cues are often unreliable in real-world scenarios, such as low-contrast foreground, fast motion, and multiple moving objects. To address these problems, we propose a new framework to adaptively capture available information from spatial and temporal cues, which contains Confidence-guided Adaptive Gate (CAG) modules and Dual Differential Enhancement (DDE) modules. For both RGB features and optical flow features, CAG estimates confidence scores supervised by the IoU between predictions and the ground truths to re-calibrate the information with a gate mechanism. DDE captures the differential feature representation to enrich the spatial and temporal information and generate the fused features. Experimental results on four widely used datasets demonstrate the effectiveness of the proposed method against thirteen state-of-the-art methods.

Top-down attention to spatial and temporal cues has been thoroughly studied in the visual domain. However, because the neural systems that are important for auditory top-down temporal attention (i.e., attention based on time interval cues) remain undefined, the differences in brain activity between directed attention to auditory spatial location (compared with time intervals) are unclear. Using fMRI (magnetic resonance imaging), we measured the activations caused by cue-target paradigms by inducing the visual cueing of attention to an auditory target within a spatial or temporal domain. Imaging results showed that the dorsal frontoparietal network (dFPN), which consists of the bilateral intraparietal sulcus and the frontal eye field, responded to spatial orienting of attention, but activity was absent in the bilateral frontal eye field (FEF) during temporal orienting of attention. Furthermore, the fMRI results indicated that activity in the right ventrolateral prefrontal cortex (VLPFC) was significantly stronger during spatial orienting of attention than during temporal orienting of attention, while the DLPFC showed no significant differences between the two processes. We conclude that the bilateral dFPN and the right VLPFC contribute to auditory spatial orienting of attention. Furthermore, specific activations related to temporal cognition were confirmed within the superior occipital gyrus, tegmentum, motor area, thalamus and putamen.

Recent works have proved that combining spatial and temporal visual cues can significantly improve the performance of various vision-based robotic systems. However, for the ultrasonic sensors used in most robotic tasks (e.g. collision avoidance, localization and navigation), there is a lack of benchmark ultrasonic datasets that consist of spatial and temporal data to verify the usability of spatial and temporal ultrasonic cues. In this paper, we are the first to propose a Spatio-Temporal Ultrasonic Dataset (STUD), which aims to develop the ability of ultrasonic sensors by mining spatial and temporal information from multiple ultrasonic measurements. In particular, we first propose a novel Spatio-Temporal (ST) ultrasonic data gathering scheme, in which an innovatory data instance is designed. Besides, part of the data in the STUD is collected in a robot simulator, in which a well-designed corridor map is utilized to increase the data diversity. Then a selection algorithm is proposed to find a proper length of data sequences to obtain the best description of the navigation environments. Finally, we present an end-to-end learning benchmark model that learns driving policies by extracting spatial and temporal ultrasonic cues from the STUD. With the help of our STUD and this benchmark model, more powerful deep neural networks can be trained for addressing the tasks of indoor navigation or motion planning of mobile robots, which is unachievable by using the existing ultrasonic datasets. Comparison experiments verified the effectiveness of spatial and temporal ultrasonic cues for the robot driving policy learning.

The influence of the global/local probability effect on the neural processing of cues and targets. A functional systems approach.

ABSTRACTSpatial cueing paradigms are popular tools to assess human attention to emotional stimuli, but different variants of these paradigms differ in what participants’ primary task is. In one variant, participants indicate the location of the target (location task), whereas in the other they indicate the shape of the target (identification task). In the present paper we test the idea that although these two variants produce seemingly comparable cue validity effects on response times, they rest on different underlying processes. Across four studies (total N = 397; two in the supplement) using both variants and manipulating the motivational relevance of cue content, diffusion model analyses revealed that cue validity effects in location tasks are primarily driven by response biases, whereas the same effect rests on delay due to attention to the cue in identification tasks. Based on this, we predict and empirically support that a symmetrical distribution of valid and invalid cues would reduce cue validity effects in location tasks to a greater extent than in identification tasks. Across all variants of the task, we fail to replicate the effect of greater cue validity effects for arousing (vs. neutral) stimuli. We discuss the implications of these findings for best practice in spatial cueing research.

Masked stimuli modulate endogenous shifts of spatial attention

While scanning a textured surface with fingers, tactile information is encoded both spatially, by differential activation of adjacent receptors, and temporally, by changes in receptor activation during movements of the fingers across the surface. We used a tactile discrimination task to examine the dependence of human tactile perception on the availability of spatial and temporal cues. Subjects discriminated between spatial frequencies of metal gratings presented simultaneously to both hands. Tactile temporal cues were eliminated by preventing lateral hand movements; tactile spatial cues were eliminated by using gloves with an attached rubber pin. Analysis revealed separation of the subjects into two groups: "spatiotemporal" (ST) and "latent-temporal" (LT). Under normal conditions, the performance of ST subjects was significantly better than that of the LT subjects. Prevention of lateral movements impaired performance of both ST and LT subjects. However, when only temporal cues were available, the performance of ST subjects was significantly impaired, whereas that of the LT subjects either improved or did not change. Under the latter condition, LT subjects changed strategy to scanning with alternating hands, at velocities similar to the velocities normally used by ST subjects. These velocities generated temporal frequencies between 15 and 30 Hz. The LT subjects were unaware of their improved performance. Nine of ten LT subjects significantly improved their performance under normal conditions when trained to scan gratings using alternating hands and velocities similar to those used by ST subjects. We conclude that (1) temporal cues are essential for spatial-frequency discrimination, (2) human subjects vary in the tactile strategies they use for texture exploration, and (3) poor tactile performers can significantly improve by using strategies that emphasize temporal cues.

Covert visual attention in schizophrenia spectrum personality disordered subjects: Visuospatial cuing and alerting effects

ABSTRACTThe present article reviews recent and older literature on the spatial parameters that flowers display, as well as on the capacities of anthophilous insects to perceive and use these parameters for optimizing their foraging success. Although co‐evolution of plants and pollinators has frequently been discussed with respect to floral colours and insect colour vision, it has rarely been assessed with respect to insect spatial vision and spatial floral cues, such as shape, pattern, size, contrast, symmetry, spatial frequency, contour density and orientation of contours. This review is an attempt to fill this gap. From experimental findings and observations on both flowers and insects, we arrive at the conclusion that all of the spatial and spatio‐temporal parameters that flowers offer are relevant to the foraging task and are tuned to the insect's visual capacities and visually guided behaviour. We try, in addition, to indicate that temporal cues are closely related to spatial cues, and must therefore be included when flower–pollinator interactions are examined. We include results that show that colour vision and spatial vision have diverged over the course of evolution, particularly regarding the processing of spatio‐temporal information, but that colour vision plays a role in the processing of spatial cues that are independent of temporal parameters. By presenting this review we hope to contribute to closer collaboration among scientists working in the vast fields of botany, ecology, evolution, ethology and sensory physiology.

Recently, two accounts have attempted to account for the effects of evaluation on performance, the mere effort account (Harkins, 2006; McFall, Jamieson, & Harkins, 2009) and the focus of attention account (Muller & Butera, 2007; Normand, Bouquet, & Croizet, 2014). The focus of attention account suggests that undergoing evaluation causes a reduction in processing capacity, which, in turn, leads individuals to prioritize the most relevant information and disregard less focal information. In support of this notion, Normand, Bouquet, and Croizet (2014) report an experiment in which participants were asked to look at a fixation cross followed by a brief abrupt onset cue that flashed in one of four locations forming a square followed by a display of four letters (three Qs and one O) in the same square. The participants task was to identify the location of the O as quickly and as accurately as possible. The brief onset cue appeared either in the location where the O would appear (valid trials), in a location where the Q would appear (invalid trials), or onsets flashed in all four locations (neutral trials). Normand et al., found that participants subject to evaluation exhibited smaller cueing effects (i.e., the difference between invalid and valid trial reaction times) than their non-evaluated counterparts, which they interpreted as evidence for the cue having less impact on reaction times.