Attentional capture during attentional awakening
2015-10-09 02:00:00 AM
Abstract
We investigated whether attentional set is available at the beginning of a trial or whether it develops gradually within a trial. Thus, we manipulated the time from the onset of a trial to a target and observers’ search strategy. We also observed the effect of the presence or absence of distractors as an index of the temporal development of attentional set. Participants identified a target letter embedded in a stream of rapidly presented nontargets while ignoring peripheral distractors. Baseline accuracy when no peripheral distractor was presented increased as the target appeared later in the stream, suggesting attentional awakening. Identification accuracy was impaired by the presence of peripheral distractors (i.e., attentional capture) early in the stream only when observers adopted the feature search mode. The magnitude of attentional capture increased over the course of the first 1,000 ms of a trial under the singleton detection and feature search modes. These results suggest that singleton detection mode requires time for a bottom-up signal to be effective in capturing attention, whereas the feature search mode does not require such a warm-up period to be effective and is available from the beginning of viewing the stream.Retraction Note to: The plateau in mnemonic resolution across large set sizes indicates discrete resource limits in visual working memory
2015-10-01 02:00:00 AM
News from the field
2015-10-01 02:00:00 AM
Visual search is influenced by 3D spatial layout
2015-10-01 02:00:00 AM
Abstract
Many activities necessitate the deployment of attention to specific distances and directions in our three-dimensional (3D) environment. However, most research on how attention is deployed is conducted with two dimensional (2D) computer displays, leaving a large gap in our understanding about the deployment of attention in 3D space. We report how each of four parameters of 3D visual space influence visual search: 3D display volume, distance in depth, number of depth planes, and relative target position in depth. Using a search task, we find that visual search performance depends on 3D volume, relative target position in depth, and number of depth planes. Our results demonstrate an asymmetrical preference for targets in the front of a display unique to 3D search and show that arranging items into more depth planes reduces search efficiency. Consistent with research using 2D displays, we found slower response times to find targets in displays with larger 3D volumes compared with smaller 3D volumes. Finally, in contrast to the importance of target depth relative to other distractors, target depth relative to the fixation point did not affect response times or search efficiency.Association between a color and a manual response activation modulates the response planning of typically developing children in a subsequent Simon task
2015-10-01 02:00:00 AM
Abstract
The Simon effect usually refers to the observation that responding to a nonspatial feature of a stimulus is faster when the position of the stimulus (task-irrelevant) matches the position of the to-be-executed response. The Simon effect can disappear when the Simon task is preceded by a spatial compatibility task with an incompatible mapping. In this experiment, during a preliminary phase, 20 children had to decide whether the outline of a colored stimulus was dotted or continuous. Green stimuli were presented exclusively on the right, whereas red stimuli were presented on the left (the color was task-irrelevant). The participants then had to perform a Simon task. When the instructions required them to press either the left or the right button for red or green stimuli, respectively (Group A), the Simon effect on response latencies was not significant. With the opposite instructions (the right or left button for red or green stimuli, respectively; Group B), the Simon effect was significant on response latencies. The Simon effect was significant on movement times for both groups. These results suggest that during the preliminary phase, each color became associated with the manual response automatically activated by that color’s position. In the subsequent Simon task, the presentation of the color activated the associated response. This modulated the planning of the to-be-executed response.Attentional cartography: mapping the distribution of attention across time and space
2015-10-01 02:00:00 AM
Abstract
Decades of research have shown that the orienting of attention follows a reliable pattern of facilitation and then inhibition following a peripheral cue. However, the literature lacks a high-resolution spatiotemporal map of this pattern. Moreover, the use of visual placeholders to highlight potential stimulus locations is inconsistent. This is puzzling, given attention’s well-known predilection for objects. In this article, we remedy these outstanding issues with a large-scale investigation charting the spatiotemporal distribution of attention. Participants detected targets presented at 121 possible locations 100, 200, 400, or 800 ms following an uninformative peripheral cue. The cued locations were presented with or without placeholders. With placeholders, the classic pattern of early facilitation and late inhibition was observed for targets appearing within the placeholders, and the spread of inhibition was severely limited to within the placeholders. Without placeholders, we observed inhibition shortly after cue presentation, upsetting the famously reliable effect of facilitation following a cue. Moreover, inhibition spread from the cued location, unlike when placeholders were present. This investigation has produced an eminently detailed spatiotemporal map of attentional orienting and illustrated the consequences of placeholder stimuli, with surprising results.Gait transition dynamics are modulated by concurrent cognitive activity
2015-10-01 02:00:00 AM
Abstract
In tasks with two categorically distinct behavioral possibilities a person beginning with one option will typically switch to the other at a higher value of a control parameter in an ascending (increasing) sequence than in a descending (decreasing) sequence. For example, the switch from walking to running on an accelerating treadmill occurs at a higher speed than the switch from running to walking on a decelerating treadmill. The reported research posed the question of whether this variant of behavioral hysteresis was affected by concurrent cognitive activity. Participants walked or ran on a treadmill with a constant acceleration or deceleration while counting backwards by sevens or ones, or not counting. The degree of hysteresis, the difference between walk-to-run and run-to-walk transition speeds, increased with cognitive difficulty. Specifically, the increased hysteresis was shown to be due to lower run-to-walk transition speeds for the more difficult concurrent cognitive tasks. These results support the hypothesis that cognitive load occupies attentional resources that contribute to triggering human gait transitions.Strength of object representation: its key role in object-based attention for determining the competition result between Gestalt and top-down objects
2015-10-01 02:00:00 AM
Abstract
It was found in previous studies that two types of objects (rectangles formed according to the Gestalt principle and Chinese words formed in a top-down fashion) can both induce an object-based effect. The aim of the present study was to investigate how the strength of an object representation affects the result of the competition between these two types of objects based on research carried out by Liu, Wang and Zhou [(2011) Acta Psychologica, 138(3), 397–404]. In Experiment 1, the rectangles were filled with two different colors to increase the strength of Gestalt object representation, and we found that the object effect changed significantly for the different stimulus types. Experiment 2 used Chinese words with various familiarities to manipulate the strength of the top-down object representation. As a result, the object-based effect induced by rectangles was observed only when the Chinese word familiarity was low. These results suggest that the strength of object representation determines the result of competition between different types of objects.The time course of explicit and implicit categorization
2015-10-01 02:00:00 AM
Abstract
Contemporary theory in cognitive neuroscience distinguishes, among the processes and utilities that serve categorization, explicit and implicit systems of category learning that learn, respectively, category rules by active hypothesis testing or adaptive behaviors by association and reinforcement. Little is known about the time course of categorization within these systems. Accordingly, the present experiments contrasted tasks that fostered explicit categorization (because they had a one-dimensional, rule-based solution) or implicit categorization (because they had a two-dimensional, information-integration solution). In Experiment 1, participants learned categories under unspeeded or speeded conditions. In Experiment 2, they applied previously trained category knowledge under unspeeded or speeded conditions. Speeded conditions selectively impaired implicit category learning and implicit mature categorization. These results illuminate the processing dynamics of explicit/implicit categorization.Strategic top-down control versus attentional bias by previous reward history
2015-10-01 02:00:00 AM
Abstract
Rewards modify performance so that attentional priority is given to stimuli associated with a higher probability of reward. A stimulus associated with reward attracts attention even when it is no longer relevant. In this study, we explored whether or not strategic top-down control can be employed to overcome the attentional bias from a recent reward–stimulus association. Four groups of 12 participants completed a spatial-cueing task involving two phases, in which the cue associated with the target location changed from Phase 1 to Phase 2. Attentional-bias effects toward a previously rewarded cue were demonstrated when the rewarded cue from Phase 1 interfered with the orienting toward a nonrewarded but valid cue in Phase 2. Associating the Phase 2 cue with a higher reward than had been used in Phase 1 resulted in a rapid orientation of attention to the new cue. These findings suggest that pathologies characterized by maladaptive attentional biases (e.g., addiction) may be counteracted by treatments that manipulate motivation by enhancing the subjective relevance of rewards that are less harmful.Mapping the spatiotemporal dynamics of interference between two visual targets
2015-10-01 02:00:00 AM
Abstract
A major thread of visual cognition has been to explore the characteristics of the attention system by presenting two targets and observing how well they can both be reported as a function of their temporal and spatial separation. This method has illuminated effects such as the attentional blink, the attentional dwell time, competitive interference, sparing temporal order errors, and localized attentional interference. However, these different effects are typically explored separately, using quite distinct experimental paradigms. In an effort to consolidate our understanding of these various effects into a more comprehensive theory of attention, we present a new method for measuring spatial gradients of interference at different temporal separations between two targets without creating specific expectations about target location. The observed data support theories that there are multiple sources of interference within the visual system. A theoretical model is proposed that illustrates how three distinct forms of interference could arise through the processes of identifying, attending, and encoding visual targets.Simple reaction time to the onset of time-varying sounds
2015-10-01 02:00:00 AM
Abstract
Although auditory simple reaction time (RT) is usually defined as the time elapsing between the onset of a stimulus and a recorded reaction, a sound cannot be specified by a single point in time. Therefore, the present work investigates how the period of time immediately after onset affects RT. By varying the stimulus duration between 10 and 500 msec, this critical duration was determined to fall between 32 and 40 milliseconds for a 1-kHz pure tone at 70 dB SPL. In a second experiment, the role of the buildup was further investigated by varying the rise time and its shape. The increment in RT for extending the rise time by a factor of ten was about 7 to 8 msec. There was no statistically significant difference in RT between a Gaussian and linear rise shape. A third experiment varied the modulation frequency and point of onset of amplitude-modulated tones, producing onsets at different initial levels with differently rapid increase or decrease immediately afterwards. The results of all three experiments results were explained very well by a straightforward extension of the parallel grains model (Miller and Ulrich Cogn. Psychol. 46, 101–151, 2003), a probabilistic race model employing many parallel channels. The extension of the model to time-varying sounds made the activation of such a grain depend on intensity as a function of time rather than a constant level. A second approach by mechanisms known from loudness produced less accurate predictions.Gender identification from high-pass filtered vowel segments: The use of high-frequency energy
2015-10-01 02:00:00 AM
Abstract
The purpose of this study was to examine the use of high-frequency information for making gender identity judgments from high-pass filtered vowel segments produced by adult speakers. Specifically, the effect of removing lower-frequency spectral detail (i.e., F3 and below) from vowel segments via high-pass filtering was evaluated. Thirty listeners (ages 18–35) with normal hearing participated in the experiment. A within-subjects design was used to measure gender identification for six 250-ms vowel segments (/æ/, /ɪ /, /ɝ/, /ʌ/, /ɔ/, and /u/), produced by ten male and ten female speakers. The results of this experiment demonstrated that despite the removal of low-frequency spectral detail, the listeners were accurate in identifying speaker gender from the vowel segments, and did so with performance significantly above chance. The removal of low-frequency spectral detail reduced gender identification by approximately 16 % relative to unfiltered vowel segments. Classification results using linear discriminant function analyses followed the perceptual data, using spectral and temporal representations derived from the high-pass filtered segments. Cumulatively, these findings indicate that normal-hearing listeners are able to make accurate perceptual judgments regarding speaker gender from vowel segments with low-frequency spectral detail removed via high-pass filtering. Therefore, it is reasonable to suggest the presence of perceptual cues related to gender identity in the high-frequency region of naturally produced vowel signals. Implications of these findings and possible mechanisms for performing the gender identification task from high-pass filtered stimuli are discussed.Modulation of spatial attention by goals, statistical learning, and monetary reward
2015-10-01 02:00:00 AM
Abstract
This study documented the relative strength of task goals, visual statistical learning, and monetary reward in guiding spatial attention. Using a difficult T-among-L search task, we cued spatial attention to one visual quadrant by (i) instructing people to prioritize it (goal-driven attention), (ii) placing the target frequently there (location probability learning), or (iii) associating that quadrant with greater monetary gain (reward-based attention). Results showed that successful goal-driven attention exerted the strongest influence on search RT. Incidental location probability learning yielded a smaller though still robust effect. Incidental reward learning produced negligible guidance for spatial attention. The 95 % confidence intervals of the three effects were largely nonoverlapping. To understand these results, we simulated the role of location repetition priming in probability cuing and reward learning. Repetition priming underestimated the strength of location probability cuing, suggesting that probability cuing involved long-term statistical learning of how to shift attention. Repetition priming provided a reasonable account for the negligible effect of reward on spatial attention. We propose a multiple-systems view of spatial attention that includes task goals, search habit, and priming as primary drivers of top-down attention.Contralateral delay activity tracks the influence of Gestalt grouping principles on active visual working memory representations
2015-10-01 02:00:00 AM
Abstract
Recent studies have demonstrated that factors influencing perception, such as Gestalt grouping cues, can influence the storage of information in visual working memory (VWM). In some cases, stationary cues, such as stimulus similarity, lead to superior VWM performance. However, the neural correlates underlying these benefits to VWM performance remain unclear. One neural index, the contralateral delay activity (CDA), is an event-related potential that shows increased amplitude according to the number of items held in VWM and asymptotes at an individual’s VWM capacity limit. Here, we applied the CDA to determine whether previously reported behavioral benefits supplied by similarity, proximity, and uniform connectedness were reflected as a neural savings such that the CDA amplitude was reduced when these cues were present. We implemented VWM change-detection tasks with arrays including similarity and proximity (Experiment 1); uniform connectedness (Experiments 2a and 2b); and similarity/proximity and uniform connectedness (Experiment 3). The results indicated that when there was a behavioral benefit to VWM, this was echoed by a reduction in CDA amplitude, which suggests more efficient processing. However, not all perceptual grouping cues provided a VWM benefit in the same measure (e.g., accuracy) or of the same magnitude. We also found unexpected interactions between cues. We observed a mixed bag of effects, suggesting that these powerful perceptual grouping benefits are not as predictable in VWM. The current findings indicate that when grouping cues produce behavioral benefits, there is a parallel reduction in the neural resources required to maintain grouped items within VWM.The effects of simulated vision impairments on the cone of gaze
2015-10-01 02:00:00 AM
Abstract
Detecting the gaze direction of others is critical for many social interactions. We explored factors that may make the perception of mutual gaze more difficult, including the degradation of the stimulus and simulated vision impairment. To what extent do these factors affect the complex assessment of mutual gaze? Using an interactive virtual head whose eye direction could be manipulated by the subject, we conducted two experiments to assess the effects of simulated vision impairments on mutual gaze. Healthy subjects had to demarcate the center and the edges of the cone of gaze—that is, the range of gaze directions that are accepted for mutual gaze. When vision was impaired by adding a semitransparent white contrast reduction mask to the display (Exp. 1), judgments became more variable and more influenced by the head direction (indicative of a compensation strategy). When refractive blur was added (Exp. 1), the gaze cone shrank from 12.9° (no blur) to 11.3° (3-diopter lens), which cannot be explained by a low-level process but might reflect a tightening of the criterion for mutual gaze as a response to the increased uncertainty. However, the overall effects of the impairments were relatively modest. Elderly subjects (Exp. 2) produced more variability but did not differ qualitatively from the younger subjects. In the face of artificial vision impairments, compensation mechanisms and criterion changes allow us to perform better in mutual gaze perception than would be predicted by a simple extrapolation from the losses in basic visual acuity and contrast sensitivity.Fixation Not Required: Characterizing Oculomotor Attention Capture for Looming Stimuli
2015-10-01 02:00:00 AM
Abstract
A stimulus moving toward us, such as a ball being thrown in our direction or a vehicle braking suddenly in front of ours, often represents a stimulus that requires a rapid response. Using a visual search task in which target and distractor items were systematically associated with a looming object, we explored whether this sort of looming motion captures attention, the nature of such capture using eye movement measures (overt/covert), and the extent to which such capture effects are more closely tied to motion onset or the motion itself. We replicated previous findings indicating that looming motion induces response time benefits and costs during visual search Lin, Franconeri, & Enns(Psychological Science 19(7): 686–693, 2008). These differences in response times were independent of fixation, indicating that these capture effects did not necessitate overt attentional shifts to a looming object for search benefits or costs to occur. Interestingly, we found no differences in capture benefits and costs associated with differences in looming motion type. Combined, our results suggest that capture effects associated with looming motion are more likely subserved by covert attentional mechanisms rather than overt mechanisms, and attention capture for looming motion is likely related to motion itself rather than the onset of motion.Selective visual scaling of time-scale processes facilitates broadband learning of isometric force frequency tracking
2015-10-01 02:00:00 AM
Abstract
The experiment investigated the effect of selectively augmenting faster time scales of visual feedback information on the learning and transfer of continuous isometric force tracking tasks to test the generality of the self-organization of 1/f properties of force output. Three experimental groups tracked an irregular target pattern either under a standard fixed gain condition or with selectively enhancement in the visual feedback display of intermediate (4–8 Hz) or high (8–12 Hz) frequency components of the force output. All groups reduced tracking error over practice, with the error lowest in the intermediate scaling condition followed by the high scaling and fixed gain conditions, respectively. Selective visual scaling induced persistent changes across the frequency spectrum, with the strongest effect in the intermediate scaling condition and positive transfer to novel feedback displays. The findings reveal an interdependence of the timescales in the learning and transfer of isometric force output frequency structures consistent with 1/f process models of the time scales of motor output variability.Capture by colour: Evidence for dimension-specific singleton capture
2015-10-01 02:00:00 AM
Abstract
Previous work on attentional capture has shown the attentional system to be quite flexible in the stimulus properties it can be set to respond to. Several different attentional “modes” have been identified. Feature search mode allows attention to be set for specific features of a target (e.g., red). Singleton detection mode sets attention to respond to any discrepant item (“singleton”) in the display. Relational search sets attention for the relative properties of the target in relation to the distractors (e.g., redder, larger). Recently, a new attentional mode was proposed that sets attention to respond to any singleton within a particular feature dimension (e.g., colour; Folk & Anderson, 2010). We tested this proposal against the predictions of previously established attentional modes. In a spatial cueing paradigm, participants searched for a colour target that was randomly either red or green. The nature of the attentional control setting was probed by presenting an irrelevant singleton cue prior to the target display and assessing whether it attracted attention. In all experiments, the cues were red, green, blue, or a white stimulus rapidly rotated (motion cue). The results of three experiments support the existence of a “colour singleton set,” finding that all colour cues captured attention strongly, while motion cues captured attention only weakly or not at all. Notably, we also found that capture by motion cues in search for colour targets was moderated by their frequency; rare motion cues captured attention (weakly), while frequent motion cues did not.On the costs and benefits of repeating a nonspatial feature in an exogenous spatial cuing paradigm
2015-10-01 02:00:00 AM
Abstract
Recent research using the Posner cuing paradigm to explore inhibition of return seems to suggest that repetition of a nonspatial feature modulates cue-related facilitatory and inhibitory aftereffects differently in detection and discrimination tasks. Because the cues were unrelated to the final response in the detection task but parallel to (not orthogonal with) the final response in the discrimination task, it is unclear whether the different patterns of results were caused by the complexity of the decision (detection vs. discrimination) or by the task relevance of the feature that might or might not repeat from cue to target. Using a paradigm modeled on previous work, in Experiment 1 (detection task) and 2 (discrimination task) we replicated the previous patterns: No early feature repetition benefit but reduced IOR for feature mismatch trials in the detection task; and large early feature repetition benefit but no effect of feature match upon the later IOR in the discrimination task. In Experiment 3 (discrimination task), we used an “orthogonal-cuing” method: the feature (color) that could repeat or not from cue to target was not on the dimension being discriminated (shape). The pattern of results was very similar to what is observed in detection tasks. These results demonstrate that it is not the task but the task relevance of the repeating feature that modulates facilitation and inhibition effects. The findings are generally consistent with a habituation account of the inhibitory aftereffects of orienting but do not rule out the contribution of other mechanisms.
Thursday, October 15, 2015
Attention, Perception, & Psychophysics
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