Motion onset really does capture attention

Moving spiders do not boost visual search in spider fear

Previous research on attention to fear-relevant stimuli has largely focused on static pictures or drawings, and thus did not consider the potential effect of natural motion. Here, we aimed to investigate the effect of motion on attentional capture in spider-fearful and non-fearful participants by using point-light stimuli and naturalistic videos. Point-light stimuli consist of moving dots representing joints and thereby visualizing biological motion (e.g. of a walking human or cat) without needing a visible body. Spider-fearful (n = 30) and non-spider-fearful (n = 31) participants completed a visual search task with moving targets (point-light/naturalistic videos) and static distractors (images), static targets and moving distractors, or static targets and static distractors. Participants searched for a specified animal type (snakes, spiders, cats, or doves) as quickly as possible. We replicated previous findings with static stimuli: snakes were detected faster and increased distraction, while spiders just increased distraction. However, contrary to our hypotheses, spider targets did not speed up responses, neither in the group of control nor in the group of spider-fearful participants. Interestingly, stimuli-specific effects were toned down, abolished, or even changed direction when motion was introduced. Also, we demonstrated that point-light stimuli were of similar efficiency as naturalistic videos, indicating that for testing effects of motion in visual search, "pure" motion stimuli might be sufficient. As we do show a substantial modulation of visual search phenomena by biological motion, we advocate for future studies to use moving stimuli, equivalent to our dynamic environment, to increase ecological validity.

Attentional spatial cueing of the stop-signal affects the ability to suppress behavioural responses

The ability to adapt to the environment is linked to the possibility of inhibiting inappropriate behaviours, and this ability can be enhanced by attention. Despite this premise, the scientific literature that assesses how attention can influence inhibition is still limited. This study contributes to this topic by evaluating whether spatial and moving attentional cueing can influence inhibitory control. We employed a task in which subjects viewed a vertical bar on the screen that, from a central position, moved either left or right where two circles were positioned. Subjects were asked to respond by pressing a key when the motion of the bar was interrupted close to the circle (go signal). In about 40% of the trials, following the go signal and after a variable delay, a visual target appeared in either one of the circles, requiring response inhibition (stop signal). In most of the trials the stop signal appeared on the same side as the go signal (valid condition), while in the others, it appeared on the opposite side (invalid condition). We found that spatial and moving cueing facilitates inhibitory control in the valid condition. This facilitation was observed especially for stop signals that appeared within 250ms of the presentation of the go signal, thus suggesting an involvement of exogenous attentional orienting. This work demonstrates that spatial and moving cueing can influence inhibitory control, providing a contribution to the investigation of the relationship between spatial attention and inhibitory control.

Rotating objects cue spatial attention via the perception of frictive surface contact

We report a new attentional cueing effect, which shows how attention models the physical force of friction. Most objects we see are in frictive contact with a 'floor', such that clockwise rotation causes rightward movement and counterclockwise rotation leftward movement. Is this regularity encoded in spatial orienting responses? In Experiment 1, seeing a clockwise-rotating 'wheel' produced faster responses to subsequent targets appearing on the right vs. left (and vice versa for counterclockwise rotation). Thus, when viewing a lone rotating wheel, we orient attention toward where we predict it will move next, assuming frictive floor contact. But what happens if the rotating wheel is seen touching another visible surface? In Experiment 2, rotational cueing was stronger for wheels touching a visible floor, was abolished for wheels near but not touching another surface, and reversed for wheels touching a ceiling. We conclude that the visual system makes an assumption of frictive floor contact, and rapidly analyzes visual cues to frictive contact with other surfaces, in order to orient attention toward where objects are likely to move next.

Humans, fish, spiders and bees inherited working memory and attention from their last common ancestor

All brain processes that generate behaviour, apart from reflexes, operate with information that is in an "activated" state. This activated information, which is known as working memory (WM), is generated by the effect of attentional processes on incoming information or information previously stored in short-term or long-term memory (STM or LTM). Information in WM tends to remain the focus of attention; and WM, attention and STM together enable information to be available to mental processes and the behaviours that follow on from them. WM and attention underpin all flexible mental processes, such as solving problems, making choices, preparing for opportunities or threats that could be nearby, or simply finding the way home. Neither WM nor attention are necessarily conscious, and both may have evolved long before consciousness. WM and attention, with similar properties, are possessed by humans, archerfish, and other vertebrates; jumping spiders, honey bees, and other arthropods; and members of other clades, whose last common ancestor (LCA) is believed to have lived more than 600 million years ago. It has been reported that very similar genes control the development of vertebrate and arthropod brains, and were likely inherited from their LCA. Genes that control brain development are conserved because brains generate adaptive behaviour. However, the neural processes that generate behaviour operate with the activated information in WM, so WM and attention must have existed prior to the evolution of brains. It is proposed that WM and attention are widespread amongst animal species because they are phylogenetically conserved mechanisms that are essential to all mental processing, and were inherited from the LCA of vertebrates, arthropods, and some other animal clades.

Classical center-surround receptive fields facilitate novel object detection in retinal bipolar cells

Antagonistic interactions between center and surround receptive field (RF) components lie at the heart of the computations performed in the visual system. Circularly symmetric center-surround RFs are thought to enhance responses to spatial contrasts (i.e., edges), but how visual edges affect motion processing is unclear. Here, we addressed this question in retinal bipolar cells, the first visual neuron with classic center-surround interactions. We found that bipolar glutamate release emphasizes objects that emerge in the RF; their responses to continuous motion are smaller, slower, and cannot be predicted by signals elicited by stationary stimuli. In our hands, the alteration in signal dynamics induced by novel objects was more pronounced than edge enhancement and could be explained by priming of RF surround during continuous motion. These findings echo the salience of human visual perception and demonstrate an unappreciated capacity of the center-surround architecture to facilitate novel object detection and dynamic signal representation.

Spatial task relevance modulates value-driven attentional capture

Attention tends to be attracted to visual features previously associated with reward. To date, nearly all existing studies examined value-associated stimuli at or near potential target locations, making such locations meaningful to inspect. The present experiments examined whether the attentional priority of a value-associated stimulus depends on its location-wise task relevance. In three experiments we used an RSVP task to compare the attentional demands of a value-associated peripheral distractor to that of a distractor associated with the top-down search goal. At a peripheral location that could never contain the target, a value-associated color did not capture attention. In contrast, at the same location, a distractor in a goal-matching color did capture attention. The results show that value-associated stimuli lose their attentional priority at task-irrelevant locations, in contrast to other types of stimuli that capture attention.

Contributions of gains and losses to attentional capture and disengagement: evidence from the gap paradigm

It is known that movements of visual attention are influenced by features in a scene, such as colors, that are associated with value or with loss. The present study examined the detailed nature of these attentional effects by employing the gap paradigm-a technique that has been used to separately reveal changes in attentional capture and shifting, and changes in attentional disengagement. In four experiments, participants either looked toward or away from stimuli with colors that had been associated either with gains or with losses. We found that participants were faster to look to colors associated with gains and slower to look away from them, revealing effects of gains on both attentional capture and attentional disengagement. On the other hand, participants were both slower to look to features associated with loss, and faster to look away from such features. The pattern of results suggested, however, that the latter finding was not due to more rapid disengagement from loss-associated colors, but instead to more rapid shifting of attention away from such colors. Taken together, the results reveal a complex pattern of effects of gains and losses on the disengagement, capture, and shifting of visual attention, revealing a remarkable flexibility of the attention system.

People's sensitivity to content vs. formal properties of visual stimuli: Evidence from category construction

When people are asked to classify visual stimuli, they are often insensitive to formal properties, such as their 3D coherence or symmetry. We investigated whether this pattern of formal insensitivity would also be found using more familiar stimuli and properties: paintings that differ in their artistic style and words printed in two different typefaces. The experiments used the category formation paradigm in which subjects freely sort items into groups that seem most natural to them. They could sort each stimulus set up to three times. Only about half of the subjects in Experiment 1 ever sorted the paintings by artistic style, and only 12% did so on their first sort. Only 36% ever sorted by typeface, with many of the subjects stopping after two sorts and saying that no further categories were possible. Experiment 2 repeated the test of typeface using actual words cut out of newspapers and advertisements. Half the words were printed in boldface and half not. These items lacked any strong semantic connections, yet only 30% of subjects ever sorted the items into the bold and non-bold words. The results suggest that many people are not sensitive to the formal properties of stimuli that also have semantic content. Spontaneously noticing those differences may require a particular task with explicit instructions or experience in that domain (e.g., copyeditors or art students).