On the spatial distribution of visual attention.

A reanalysis of part of P. Podgorny and R. N. Shepard's (see record 1984-03057-001) data shows that reaction times (RTs) to attended and unattended squares are almost identical when the attended areas are nonunitary and that RTs are related to compactness for unitary attended areas but that this relation breaks down when attention is focused on nonunitary areas. The importance of the actual grid location of probes on RTs is also illustrated. The failure of compactness to reflect these aspects of the spatial nature of attention suggests that this metric is deficient when applied to the study of the spatial determinants of attention. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of action video games on the spatial distribution of visuospatial attention.

The authors investigated the effect of action gaming on the spatial distribution of attention. The authors used the flanker compatibility effect to separately assess center and peripheral attentional resources in gamers versus nongamers. Gamers exhibited an enhancement in attentional resources compared with nongamers, not only in the periphery but also in central vision. The authors then used a target localization task to unambiguously establish that gaming enhances the spatial distribution of visual attention over a wide field of view. Gamers were more accurate than nongamers at all eccentricities tested, and the advantage held even when a concurrent center task was added, ruling out a trade-off between central and peripheral attention. By establishing the causal role of gaming through training studies, the authors demonstrate that action gaming enhances visuospatial attention throughout the visual field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional influences on spatial attention.

The relationships between the anterior-posterior and left-right regions of the brain have been characterized as mutually inhibitory. Whereas the left hemisphere attends to right proximal hemispace and is associated with positive emotions, the right hemisphere attends to left distal hemispace and is associated with negative emotions. Because of the excitatory and inhibitory influences between the left and right frontal and posterior regions of the brain, the expression of emotion will result in an ipsilateral attentional bias. Given these functional systems, we hypothesized that positive emotions would be associated with a bias for left distal hemispace and negative emotions would be associated with a bias for right proximal hemispace. We tested these hypotheses by having 138 undergraduate students place emotionally labeled pegs on a large board. Our results indicated that the positively labeled pegs were placed in left distal hemispace and the relative placement of negatively labeled pegs was rightward and proximally. Whereas numerous research investigations have examined how attention is biased for emotional stimuli, ours is the first investigation to provide evidence that emotions can bias attentional allocation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of rotation on spatial attention

OBJECTIVE: To clarify whether out-of-hours health centre visits and referrals to hospital are equally distributed in the three different duty models being used for health care in southwestern Finland. DESIGN: A medical audit of 2926 health centre visits and 223 referrals to hospitals by general practitioners (GPs) on duty. The duty models were formed on the basis of a possibility to utilize a local health centre during nights and weekends. Two-month follow-up period. SETTING: Primary health care. Population 46438. MAIN OUTCOME MEASURES: Out-of-hours visits to health centres and referrals to hospital, and the effect of age and duty model on referrals and visits. RESULTS: Patients over 64 years of age received most of the referrals although they visited the health care centre less frequently than the 0-14 year-olds (p < 0.001). The people who had an opportunity to utilize their local health centres visited more during out-of-hours than those who did not have this opportunity (p < 0.001). CONCLUSIONS: The health centre visits were not equally distributed in the three examined duty models. The over 64 year-olds in particular had the least visits and the most referrals.     

Cross-modal links in spatial attention

A great deal is now known about the effects of spatial attention within individual sensory modalities, especially for vision and audition. However, there has been little previous study of possible cross-modal links in attention. Here, we review recent findings from our own experiments on this topic, which reveal extensive spatial links between the modalities. An irrelevant but salient event presented within touch, audition, or vision, can attract covert spatial attention in the other modalities (with the one exception that visual events do not attract auditory attention when saccades are prevented). By shifting receptors in one modality relative to another, the spatial coordinates of these cross-modal interactions can be examined. For instance, when a hand is placed in a new position, stimulation of it now draws visual attention to a correspondingly different location, although some aspects of attention do not spatially remap in this way. Cross-modal links are also evident in voluntary shifts of attention. When a person strongly expects a target in one modality (e.g. audition) to appear in a particular location, their judgements improve at that location not only for the expected modality but also for other modalities (e.g. vision), even if events in the latter modality are somewhat more likely elsewhere. Finally, some of our experiments suggest that information from different sensory modalities may be integrated preattentively, to produce the multimodal internal spatial representations in which attention can be directed. Such preattentive cross-modal integration can, in some cases, produce helpful illusions that increase the efficiency of selective attention in complex scenes.     

Figural aftereffects and spatial attention

Distracting attention away from the location of an adaptation figure reduces the positional shift of a displaced test figure in the figural aftereffect (FAE). Participants performed an alignment task after adaptation involving various manipulations of spatial attention. In 1 condition, participants counted how often numbers occurred in an alphanumeric sequence presented during adaptation. (The sequence also appeared in a comparison condition, but no attention was required.) The FAE was reduced when the alphanumeric sequence attended to was in the center of the display while the adaptation figure was 3 degrees eccentric but not when the pattern was superimposed on the adaptation figure. Forced attention to 1 feature of the adaptation figure, its orientation, did not reduce the FAE (Experiment 3). To obtain a maximum FAE, the span of attention must cover the adaptation figure.     

The retinotopy of visual spatial attention

We used high-field (3T) functional magnetic resonance imaging (fMRI) to label cortical activity due to visual spatial attention, relative to flattened cortical maps of the retinotopy and visual areas from the same human subjects. In the main task, the visual stimulus remained constant, but covert visual spatial attention was varied in both location and load. In each of the extrastriate retinotopic areas, we found MR increases at the representations of the attended target. Similar but smaller increases were found in V1. Decreased MR levels were found in the same cortical locations when attention was directed at retinotopically different locations. In and surrounding area MT+, MR increases were lateralized but not otherwise retinotopic. At the representation of eccentricities central to that of the attended targets, prominent MR decreases occurred during spatial attention.     

Effects of lorazepam on film-induced differentiated emotions in healthy volunteers

We studied the effects of lorazepam, a benzodiazepine, on differentiated emotions in healthy volunteers. In order to induce differentiated emotions, film excerpts were selected on the basis of the type of emotion they induced (fear, anger and for affective tone neutral film). For 6 days (D1 to D6), ten healthy volunteers received lorazepam (1 mg bid) or placebo in a randomized cross-over double-blind trial. During each treatment period, emotional induction occurred on D4, D5 and D6. One film excerpt (fear, anger or neutral) was presented each morning after relaxation. Evaluation was performed before and after each emotional induction and included questionnaires (Differential Emotions Scale and physical activation visual analog scales), and neurophysiological parameters (systolic and diastolic blood pressure, heart rate and norepinephrine levels). Globally, the film excerpts induced the predicted emotions. An analysis of variance was undertaken and revealed a significant effect of lorazepam versus placebo. On the Differential Emotions Scale and during fear induction, lorazepam induced a significantly higher increase in fear, anxiety and disgust emotions than placebo, whereas no effect was observed after anger induction. Lorazepam also induced a significantly higher increase in diastolic and systolic blood pressure with no change in heart rate, and physical activation items ("tears" and "faster breathing") without no significant change in norepinephrine. In conclusion, our results are consistent with an overall increase in emotional reactivity with lorazepam (1 mg bid) as compared to placebo. The pertinence of film-induced differentiated emotions has to be confirmed for clinical pharmacological use.     

The effect of spatial attention on memory scanning.

Examined the influence of spatial attention on the retrieval of items from short term memory. 48 participants (aged 18–40 yrs) responded to probe letters after sets of 2, 4, and 6 letters were memorized (S. Sternberg, 1966, 1969). Spatial attention was controlled by central arrow cues and stimuli were presented in a clear or a visually degraded form. Overall RT was shorter for attended than for unattended locations, and shorter for clear than for degraded stimuli. Even though the function relating RT to memory-set size for stimuli in attended locations had a significantly smaller zero-intercept than the function for unattended locations, the slope was unchanged, which suggests that attention did not influence the memory-scanning stage. Visual quality interacted with attention, which suggests that they influenced the same stage of processing, presumably the early visual-encoding stage of processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ERP effects of intermodal attention and cross-modal links in spatial attention

The function of articular cartilage as a weight-bearing tissue depends on the specific arrangement of collagen types II and IX into a three-dimensional organized collagen network that can balance the swelling pressure of the proteoglycan/water gel. To determine whether cartilage engineered in vitro contains a functional collagen network, chondrocyte-polymer constructs were cultured for up to 6 weeks and analyzed with respect to the composition and ultrastructure of collagen by using biochemical and immunochemical methods and scanning electron microscopy. Total collagen content and the concentration of pyridinium crosslinks were significantly (57% and 70%, respectively) lower in tissue-engineered cartilage that in bovine calf articular cartilage. However, the fractions of collagen types II, IX, and X and the collagen network organization, density, and fibril diameter in engineered cartilage were not significantly different from those in natural articular cartilage. The implications of these findings for the field of tissue engineering are that differentiated chondrocytes are capable of forming a complex structure of collagen matrix in vitro, producing a tissue similar to natural articular cartilage on an ultrastructural scale.     

Episodic theory of the dynamics of spatial attention.

Previous measurements of visual attention in simple reaction time, choice reaction time and complex discrimination experiments in which attention was purported to move continuously across space are reanalyzed. These data and data from attention gating experiments are quantitatively predicted by an episodic (quantal) theory of spatial attention that proposes instead: (1) visual attention can be resolved into a sequence of discrete attentional acts (episodes), (2) each attentional episode i is defined by its spatial attention function fi(x,y), (3) the smooth transition at time t? between episodes is described by a temporal transition function G(t–t?), and (4) f and G are space-time separable. In new experiments, which use a concurrent motor reaction time task to control for nonattentional factors, the duration of an attention transition is shown to be independent of the distance traversed and of the presence of interposed visual obstacles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An effect of noise on the distribution of attention.

A paced search of a visual display was made in auditory conditions containing bursts of noise at either 68 or 105 db. Each selected visual item required 2 types of response, crossing out and counting. The preferred activity in the quieter condition was counting. When the test instructions emphasized this aspect of the task, attention shifted further toward the preferred activity during loud noise. When the instructions emphasized searching, there were no significant differences between noise and quiet. It appears that although noise will not always induce a redistribution of the attention needed to respond equally often in 2 paced activities, when it does so, the preferred activity gains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivation sharpens exogenous spatial attention.

[Correction Notice: An erratum for this article was reported in Vol 7(4) of Emotion (see record 2007-17748-024). The supplemental materials link is as follows: http://dx.doi.org/10.1037/1528-3542.7.3.668.supp.] Although both attention and motivation affect behavior, how these 2 systems interact is currently unknown. To address this question, 2 experiments were conducted in which participants performed a spatially cued forced-choice localization task under varying levels of motivation. Participants were asked to indicate the location of a peripherally cued target while ignoring a distracter. Motivation was manipulated by varying magnitude and valence (reward and punishment) of an incentive linked to task performance. Attention was manipulated via a peripheral cue, which correctly predicted the presence of a target stimulus on 70% of the trials. Taken together, our findings revealed that the signal detection measure, reflecting perceptual sensitivity, increased as a function of incentive value during both valid and invalid trials. In addition, trend analyses revealed a linear increase in detection sensitivity as a function of incentive magnitude for both reward and punishment conditions. Our results suggest that elevated motivation leads to improved efficiency in orienting and reorienting of exogenous spatial attention and that one mechanism by which attention and motivation interact involves the sharpening of attention during motivationally salient conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When cross-modal spatial attention fails.

There is now convincing evidence that an involuntary shift of spatial attention to a stimulus in one modality can affect the processing of stimuli in other modalities, but inconsistent findings across different paradigms have led to controversy. Such inconsistencies have important implications for theories of cross-modal attention. The authors investigated why orienting attention to a visual event sometimes influences responses to subsequent sounds and why it sometimes fails to do so. They examined visual-cue-on-auditory-target effects in two paradigms--implicit spatial discrimination (ISD) and orthogonal cuing (OC)--that have yielded conflicting findings in the past. Consistent with previous research, visual cues facilitated responses to same-side auditory targets in the ISD paradigm but not in the OC paradigm. Furthermore, in the ISD paradigm, visual cues facilitated responses to auditory targets only when the targets were presented directly at the cued location, not when they appeared above or below the cued location. This pattern of results confirms recent claims that visual cues fail to influence responses to auditory targets in the OC paradigm because the targets fall outside the focus of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial attention and the apprehension of spatial relations.

Seven experiments examined the role of spatial attention in apprehending spatial relations above, below, left, and right. In Exp 1, visual search was difficult when targets differed from distractors only in the spatial relation between their elements. Reaction time (RT) increased linearly with display size with a slope greater than 60 msec/item. In Exp 2, search was easy (the slope was flat) when targets differed from distractors in the identity of their elements. In Exps 3 and 4, target position was cued with a discrepant color, and performance was better when attention was pulled toward spatial-relation targets than away from them. Exps 5–7 generalized the results over different displays and extended practice. The results suggest that apprehending spatial relations requires spatial attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric asymmetries of near-far spatial attention.

Although most of the visual cognitive activities performed by the left hemisphere take place close to the body (peripersonal space), most visual cognitive activities mediated by the right hemisphere take place in extrapersonal space. The left hemisphere, therefore, may have a propensity to direct attention toward the body and the right hemisphere away from the body. Because attentional bias influences judgments of spatial magnitude, the authors tested this hypothesis. Normal participants were asked to compare the size of horizontal lines presented in the sagittal plane in either right or left hemispace. When participants looked leftward, lines appeared shorter than when participants looked rightward. These results are consistent with the hypothesis that the right hemisphere directs attention toward visual extrapersonal space and the left hemisphere directs attention toward visual peripersonal space. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Luminance and spatial attention effects on early visual processing

Event-related potentials (ERPs) were recorded from healthy subjects in response to unilaterally flashed high and low luminance bar stimuli presented randomly to left and right field locations. Their task was to covertly and selectively attend to either the left or right stimulus locations (separate blocks) in order to detect infrequent shorter target bars of either luminance. Independent of attention, higher stimulus luminance resulted in higher ERP amplitudes for the posterior N95 (80-110 ms), occipital P1 (110-140 ms), and parietal N1 (130-180 ms). Brighter stimuli also resulted in shorter peak latency for the occipital N1 component (135-220 ms); this effect was not observed for the N1 components over parietal, central or frontal regions. Significant attention-related amplitude modulations were obtained for the occipital P1, occipital, parietal and central N1, the occipital and parietal P2, and the parietal N2 components; these components were larger to stimuli at the attended location. In contrast to the relatively short latencies of both spatial attention and luminance effects, the first interaction between luminance and spatial attention effects was observed for the P3 component to the target stimuli (350-750 ms). This suggests that interactions of spatial attention and stimulus luminance previously reported for reaction time measures may not reflect the earliest stages of sensory/perceptual processing. Differences in the way in which luminance and attention affected the occipital P1, occipital N1 and parietal N1 components suggest dissociations among these ERPs in the mechanisms of visual and attentional processing they reflect.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of object onset on the distribution of visual attention.

There now exists considerable evidence to suggest that the appearance of a new object in the visual field captures visual attention. One of the consequences of this attentional capture is that the object initiates a redistribution of attentional resources across visual space. This is classically observed in the precuing paradigm in which the onset of an abrupt cue influences the processing of a subsequently presented target. The present research describes a new phenomenon that occurs as a result of a new object appearing in the visual field. A stimulus presented in a region of space adjacent to a comer of an onsetting object receives an enhancement of processing relative to a stimulus presented adjacent to one of the object's straight edges. With the use of 2 converging methods, evidence is presented that suggests that the effect is a higher order attentional phenomenon whereby greater resources become directed to the comers of objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measuring and modeling the trajectory of visual spatial attention.

In a novel choice attention-gating paradigm, observers monitor a stream of 3x3 letter arrays until a tonal cue directs them to report 1 row. Analyses of the particular arrays from which reported letters are chosen and of the joint probabilities of reporting pairs of letters are used to derive a theory of attention dynamics. An attention window opens 0.15 s following a cue to attend to a location, remains open (minimally) 0.2 s, and admits information simultaneously from all the newly attended locations. The window dynamics are independent of the distance moved. The theory accounts for about 90% of the variance from the over 400 data points obtained from each of the observers in the 3 experiments reported here. With minor elaborations, it applies to all the principal paradigms used to study the dynamics of visual spatial attention. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

No-onset looming motion guides spatial attention.

These 6 experiments explored the ability of moving random dot patterns to attract attention, as measured by a simple probe-detection task. Each trial began with random motion (i.e., dots linearly moved in random directions). After 1 s motion in 1 hemifield became gradually coherent (i.e., all dots moved up-, down-, left-, or rightwards, or either towards or away from a vanishing point). The results show that only looming motion attracted attention, even when the task became a more demanding discrimination task. This effect is not due to an apparent magnification of stimuli presented in the focus of expansion. When the coherent motion started abruptly, all types of motion attracted attention at a short stimulus onset asynchrony. The looming motion effect only disappeared when attention was drawn to the target location by an arrow. These results suggest that looming motion plays a unique role in guiding spatial attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)