Alcohol dependence decreases functional activation of the caudate nucleus during model-based decision processes.

BACKGROUND: Impaired decision making, a key characteristic of alcohol dependence (AD), manifests in continuous alcohol consumption despite severe negative consequences. The neural basis of this impairment in individuals with AD and differences with known neural decision mechanisms among healthy subjects are not fully understood. In particular, it is unclear whether the choice behavior among individuals with AD is based on a general impairment of decision mechanisms or is mainly explained by altered value attribution, with an overly high subjective value attributed to alcohol-related stimuli. METHODS: Here, we use a functional magnetic resonance imaging (fMRI) monetary reward task to compare the neural processes of model-based decision making and value computation between AD individuals (n = 32) and healthy controls (n = 32). During fMRI, participants evaluated monetary offers with respect to dynamically changing constraints and different levels of uncertainty. RESULTS: Individuals with AD showed lower activation associated with model-based decision processes in the caudate nucleus than controls, but there were no group differences in value-related neural activity or task performance. CONCLUSIONS: Our findings highlight the role of the caudate nucleus in impaired model-based decisions of alcohol-dependent individuals.

Determinants of Global Color-Based Selection in Human Visual Cortex.

Feature attention operates in a spatially global way, with attended feature values being prioritized for selection outside the focus of attention. Accounts of global feature attention have emphasized feature competition as a determining factor. Here, we use magnetoencephalographic recordings in humans to test whether competition is critical for global feature selection to arise. Subjects performed a color/shape discrimination task in one visual field (VF), while irrelevant color probes were presented in the other unattended VF. Global effects of color attention were assessed by analyzing the response to the probe as a function of whether or not the probe's color was a target-defining color. We find that global color selection involves a sequence of modulations in extrastriate cortex, with an initial phase in higher tier areas (lateral occipital complex) followed by a later phase in lower tier retinotopic areas (V3/V4). Importantly, these modulations appeared with and without color competition in the focus of attention. Moreover, early parts of the modulation emerged for a task-relevant color not even present in the focus of attention. All modulations, however, were eliminated during simple onset-detection of the colored target. These results indicate that global color-based attention depends on target discrimination independent of feature competition in the focus of attention.

Neural correlates of visual motion processing without awareness in patients with striate cortex and pulvinar lesions.

Patients with striate cortex lesions experience visual perception loss in the contralateral visual field. In few patients, however, stimuli within the blind field can lead to unconscious (blindsight) or even conscious perception when the stimuli are moving (Riddoch syndrome). Using functional magnetic resonance imaging (fMRI), we investigated the neural responses elicited by motion stimulation in the sighted and blind visual fields of eight patients with lesions of the striate cortex. Importantly, repeated testing ensured that none of the patients exhibited blindsight or a Riddoch syndrome. Three patients had additional lesions in the ipsilesional pulvinar. For blind visual field stimulation, great care was given that the moving stimulus was precisely presented within the borders of the scotoma. In six of eight patients, the stimulation within the scotoma elicited hemodynamic activity in area human middle temporal (hMT) while no activity was observed within the ipsilateral lesioned area of the striate cortex. One of the two patients in whom no ipsilesional activity was observed had an extensive lesion including massive subcortical damage. The other patient had an additional focal lesion within the lateral inferior pulvinar. Fiber-tracking based on anatomical and functional markers (hMT and Pulvinar) on individual diffusion tensor imaging (DTI) data from each patient revealed the structural integrity of subcortical pathways in all but the patient with the extensive subcortical lesion. These results provide clear evidence for the robustness of direct subcortical pathways from the pulvinar to area hMT in patients with striate cortex lesions and demonstrate that ipsilesional activity in area hMT is completely independent of conscious perception.

Spatio-temporal patterns of brain activity distinguish strategies of multiple-object tracking.

Human observers can readily track up to four independently moving items simultaneously, even in the presence of moving distractors. Here we combined EEG and magnetoencephalography recordings to investigate the neural processes underlying this remarkable capability. Participants were instructed to track four of eight independently moving items for 3 sec. When the movement ceased a probe stimulus consisting of four items with a higher luminance was presented. The location of the probe items could correspond fully, partly, or not at all with the tracked items. Participants reported whether the probe items fully matched the tracked items or not. About half of the participants showed slower RTs and higher error rates with increasing correspondence between tracked items and the probe. The other half, however, showed faster RTs and lower error rates when the probe fully matched the tracked items. This latter behavioral pattern was associated with enhanced probe-evoked neural activity that was localized to the lateral occipital cortex in the time range 170-210 msec. This enhanced response in the object-selective lateral occipital cortex suggested that these participants performed the tracking task by visualizing the overall shape configuration defined by the vertices of the tracked items, thereby producing a behavioral advantage on full-match trials. In a later time range (270-310 msec) probe-evoked neural activity increased monotonically as a function of decreasing target-probe correspondence in all participants. This later modulation, localized to superior parietal cortex, was proposed to reflect the degree of mismatch between the probe and the automatically formed visual STM representation of the tracked items.

Reward- and attention-related biasing of sensory selection in visual cortex.

Attention to task-relevant features leads to a biasing of sensory selection in extrastriate cortex. Features signaling reward seem to produce a similar bias, but how modulatory effects due to reward and attention relate to each other is largely unexplored. To address this issue, it is critical to separate top-down settings defining reward relevance from those defining attention. To this end, we used a visual search paradigm in which the target's definition (attention to color) was dissociated from reward relevance by delivering monetary reward on search frames where a certain task-irrelevant color was combined with the target-defining color to form the target object. We assessed the state of neural biasing for the attended and reward-relevant color by analyzing the neuromagnetic brain response to asynchronously presented irrelevant distractor probes drawn in the target-defining color, the reward-relevant color, and a completely irrelevant color as a reference. We observed that for the prospect of moderate rewards, the target-defining color but not the reward-relevant color produced a selective enhancement of the neuromagnetic response between 180 and 280 msec in ventral extrastriate visual cortex. Increasing reward prospect caused a delayed attenuation (220-250 msec) of the response to reward probes, which followed a prior (160-180 msec) response enhancement in dorsal ACC. Notably, shorter latency responses in dorsal ACC were associated with stronger attenuation in extrastriate visual cortex. Finally, an analysis of the brain response to the search frames revealed that the presence of the reward-relevant color in search distractors elicited an enhanced response that was abolished after increasing reward size. The present data together indicate that when top-down definitions of reward relevance and attention are separated, the behavioral significance of reward-associated features is still rapidly coded in higher-level cortex areas, thereby commanding effective top-down inhibitory control to counter a selection bias for those features in extrastriate visual cortex.

Reward prospect rapidly speeds up response inhibition via reactive control.

Response inhibition is an important cognitive-control function that allows for already-initiated or habitual behavioral responses to be promptly withheld when needed. A typical paradigm to study this function is the stop-signal task. From this task, the stop-signal response time (SSRT) can be derived, which indexes how rapidly an already-initiated response can be canceled. Typically, SSRTs range around 200 ms, identifying response inhibition as a particularly rapid cognitive-control process. Even so, it has recently been shown that SSRTs can be further accelerated if successful response inhibition is rewarded. Since this earlier study effectively ruled out differential preparatory (proactive) control adjustments, the reward benefits likely relied on boosted reactive control. Yet, given how rapidly such control processes would need to be enhanced, alternative explanations circumventing reactive control are important to consider. We addressed this question with an fMRI study by gauging the overlap of the brain networks associated with reward-related and response-inhibition-related processes in a reward-modulated stop-signal task. In line with the view that reactive control can indeed be boosted swiftly by reward availability, we found that the activity in key brain areas related to response inhibition was enhanced for reward-related stop trials. Furthermore, we observed that this beneficial reward effect was triggered by enhanced connectivity between task-unspecific (reward-related) and task-specific (inhibition-related) areas in the medial prefrontal cortex (mPFC). The present data hence suggest that reward information can be translated very rapidly into behavioral benefits (here, within ~200 ms) through enhanced reactive control, underscoring the immediate responsiveness of such control processes to reward availability in general.

Fast construction of voxel-level functional connectivity graphs.

BACKGROUND: Graph-based analysis of fMRI data has recently emerged as a promising approach to study brain networks. Based on the assessment of synchronous fMRI activity at separate brain sites, functional connectivity graphs are constructed and analyzed using graph-theoretical concepts. Most previous studies investigated region-level graphs, which are computationally inexpensive, but bring along the problem of choosing sensible regions and involve blurring of more detailed information. In contrast, voxel-level graphs provide the finest granularity attainable from the data, enabling analyses at superior spatial resolution. They are, however, associated with considerable computational demands, which can render high-resolution analyses infeasible. In response, many existing studies investigating functional connectivity at the voxel-level reduced the computational burden by sacrificing spatial resolution. METHODS: Here, a novel, time-efficient method for graph construction is presented that retains the original spatial resolution. Performance gains are instead achieved through data reduction in the temporal domain based on dichotomization of voxel time series combined with tetrachoric correlation estimation and efficient implementation. RESULTS: By comparison with graph construction based on Pearson's r, the technique used by the majority of previous studies, we find that the novel approach produces highly similar results an order of magnitude faster. CONCLUSIONS: Its demonstrated performance makes the proposed approach a sensible and efficient alternative to customary practice. An open source software package containing the created programs is freely available for download.

Distinct representations of attentional control during voluntary and stimulus-driven shifts across objects and locations.

Efficient interaction with the sensory environment requires the rapid reallocation of attentional resources between spatial locations, perceptual features, and objects. It is still a matter of debate whether one single domain-general network or multiple independent domain-specific networks mediate control during shifts of attention across features, locations, and objects. Here, we employed functional magnetic resonance imaging to directly compare the neural mechanisms controlling attention during voluntary and stimulus-driven shifts across objects and locations. Subjects either maintained or switched voluntarily and involuntarily their attention to objects located at the same or at a different visual location. Our data demonstrate shift-related activity in multiple frontoparietal, extrastriate visual, and default-mode network regions, several of which were commonly recruited by voluntary and stimulus-driven shifts between objects and locations. However, our results also revealed object- and location-selective activations, which, moreover, differed substantially between voluntary and stimulus-driven attention. These results suggest that voluntary and stimulus-driven shifts between objects and locations recruit partially overlapping, but also separable, cortical regions, implicating the parallel existence of domain-independent and domain-specific reconfiguration signals that initiate attention shifts in dependence of particular demands.

Separable mechanisms underlying global feature-based attention.

Feature-based attention is known to operate in a spatially global manner, in that the selection of attended features is not bound to the spatial focus of attention. Here we used electromagnetic recordings in human observers to characterize the spatiotemporal signature of such global selection of an orientation feature. Observers performed a simple orientation-discrimination task while ignoring task-irrelevant orientation probes outside the focus of attention. We observed that global feature-based selection, indexed by the brain response to unattended orientation probes, is composed of separable functional components. One such component reflects global selection based on the similarity of the probe with task-relevant orientation values ("template matching"), which is followed by a component reflecting selection based on the similarity of the probe with the orientation value under discrimination in the focus of attention ("discrimination matching"). Importantly, template matching occurs at ∼150 ms after stimulus onset, ∼80 ms before the onset of discrimination matching. Moreover, source activity underlying template matching and discrimination matching was found to originate from ventral extrastriate cortex, with the former being generated in more anterolateral and the latter in more posteromedial parts, suggesting template matching to occur in visual cortex higher up in the visual processing hierarchy than discrimination matching. We take these observations to indicate that the population-level signature of global feature-based selection reflects a sequence of hierarchically ordered operations in extrastriate visual cortex, in which the selection based on task relevance has temporal priority over the selection based on the sensory similarity between input representations.

Spatiotemporal dynamics of feature-based attention spread: evidence from combined electroencephalographic and magnetoencephalographic recordings.

Attentional selection on the basis of nonspatial stimulus features induces a sensory gain enhancement by increasing the firing-rate of individual neurons tuned to the attended feature, while responses of neurons tuned to opposite feature-values are suppressed. Here we recorded event-related potentials (ERPs) and magnetic fields (ERMFs) in human observers to investigate the underlying neural correlates of feature-based attention at the population level. During the task subjects attended to a moving transparent surface presented in the left visual field, while task-irrelevant probe stimuli executing brief movements into varying directions were presented in the opposite visual field. ERP and ERMF amplitudes elicited by the unattended task-irrelevant probes were modulated as a function of the similarity between their movement direction and the task-relevant movement direction in the attended visual field. These activity modulations reflecting globally enhanced processing of the attended feature were observed to start not before 200 ms poststimulus and were localized to the motion-sensitive area hMT. The current results indicate that feature-based attention operates in a global manner but needs time to spread and provide strong support for the feature-similarity gain model.

The role of the pulvinar in distractor processing and visual search.

The pulvinar nuclei of the thalamus are hypothesized to coordinate attentional selection in the visual cortex. Different models have, however, been proposed for the precise role of the pulvinar in attention. One proposal is that the pulvinar mediates shifts of spatial attention; a different proposal is that it serves the filtering of distractor information. At present, the relation between these possible operations and their relative importance in the pulvinar remains unresolved. We address this issue by contrasting these proposals in two fMRI experiments. We used a visual search paradigm that permitted us to dissociate neural activity reflecting shifts of attention from activity underlying distractor filtering. We find that distractor filtering, but not the operation of shifting attention, is associated with strong activity enhancements in dorsal and ventral regions of the pulvinar as well as in early visual cortex areas including the primary visual cortex. Our observations indicate that distractor filtering is the preponderant attentional operation subserved by the pulvinar, presumably mediated by a modulation of processing in visual areas where spatial resolution is sufficiently high to separate target from distractor input.

Task-load-dependent activation of dopaminergic midbrain areas in the absence of reward.

Dopamine release in cortical and subcortical structures plays a central role in reward-related neural processes. Within this context, dopaminergic inputs are commonly assumed to play an activating role, facilitating behavioral and cognitive operations necessary to obtain a prospective reward. Here, we provide evidence from human fMRI that this activating role can also be mediated by task-demand-related processes and thus extends beyond situations that only entail extrinsic motivating factors. Using a visual discrimination task in which varying levels of task demands were precued, we found enhanced hemodynamic activity in the substantia nigra (SN) for high task demands in the absence of reward or similar extrinsic motivating factors. This observation thus indicates that the SN can also be activated in an endogenous fashion. In parallel to its role in reward-related processes, reward-independent activation likely serves to recruit the processing resources needed to meet enhanced task demands. Simultaneously, activity in a wide network of cortical and subcortical control regions was enhanced in response to high task demands, whereas areas of the default-mode network were deactivated more strongly. The present observations suggest that the SN represents a core node within a broader neural network that adjusts the amount of available neural and behavioral resources to changing situational opportunities and task requirements, which is often driven by extrinsic factors but can also be controlled endogenously.

Assessment of cortical hemodynamics by multichannel near-infrared spectroscopy in steno-occlusive disease of the middle cerebral artery.

BACKGROUND AND PURPOSE: In a pilot study we evaluated near-infrared spectroscopy as to its potential benefit in monitoring patients with steno-occlusive disease of a major cerebral artery for alterations in cortical hemodynamics. METHODS: Cortical maps of time-to-peak (TTP) in 10 patients unilaterally affected by severe stenosis or occlusion of the middle cerebral artery were acquired by multichannel near-infrared spectroscopy after bolus application of indocyanine green. Hemodynamic manifestations were assessed by comparison between affected and unaffected hemisphere and evaluated for common constituents by principal component analysis. In one patient, TTP values were compared with those obtained by dynamic susceptibility contrast imaging. RESULTS: TTP was increased on the affected hemisphere in 9 patients. Mean difference in TTP between hemispheres was 0.44 second (P<0.05) as compared with a mean lateral difference of 0.12 second found in a control group of 10 individuals. In group analysis a significant rise in TTP was found in the distribution of the affected middle cerebral artery, whereas principal component analysis suggests augmentation of hemodynamic effects toward the border zones as a dominant pattern. A linear correlation of 0.61 between TTP values determined by dynamic susceptibility contrast MRI and near-infrared spectroscopy was found to be statistically significant (P<0.001). CONCLUSIONS: Multichannel near-infrared spectroscopy might facilitate detection of disease-related hemodynamic changes as yet only accessible by tomographic imaging modalities. Being indicative for hypoperfusion and collateral flow increased values of TTP, as found to a varying extent in the present patient group, might be of clinical relevance.

Dynamic computation of value signals via a common neural network in multi-attribute decision-making.

Studies in decision neuroscience have identified robust neural representations for the value of choice options. However, overall values often depend on multiple attributes, and it is not well understood how the brain evaluates different attributes and integrates them to combined values. In particular, it is not clear whether attribute values are computed in distinct attribute-specific regions or within the general valuation network known to process overall values. Here, we used a functional magnetic resonance imaging choice task in which abstract stimuli had to be evaluated based on variations of the attributes color and motion. The behavioral data showed that participants responded faster when overall values were high and attribute value differences were low. On the neural level, we did not find that attribute values were systematically represented in areas V4 and V5, even though these regions are associated with attribute-specific processing of color and motion, respectively. Instead, attribute values were associated with activity in the posterior cingulate cortex, ventral striatum and posterior inferior temporal gyrus. Furthermore, overall values were represented in dorsolateral and ventromedial prefrontal cortex, and attribute value differences in dorsomedial prefrontal cortex, which suggests that these regions play a key role for the neural integration of attribute values.

Feature-based attention modulates direction-selective hemodynamic activity within human MT.

Attending to the spatial location or to nonspatial features of a stimulus modulates neural activity in cortical areas that process its perceptual attributes. The feature-based attentional selection of the direction of a moving stimulus is associated with increased firing of individual neurons tuned to the direction of the movement in area V5/MT, while responses of neurons tuned to opposite directions are suppressed. However, it is not known how these multiplicatively scaled responses of individual neurons tuned to different motion-directions are integrated at the population level, in order to facilitate the processing of stimuli that match the perceptual goals. Using functional magnetic resonance imaging (fMRI) the present study revealed that attending to the movement direction of a dot field enhances the response in a number of areas including the human MT region (hMT) as a function of the coherence of the stimulus. Attending the opposite direction, however, lead to a suppressed response in hMT that was inversely correlated with stimulus-coherence. These findings demonstrate that the multiplicative scaling of single-neuron responses by feature-based attention results in an enhanced direction-selective population response within those cortical modules that processes the physical attributes of the attended stimuli. Our results provide strong support for the validity of the "feature similarity gain model" on the integrated population response as quantified by parametric fMRI in humans.

Structural alterations in lateral prefrontal, parietal and posterior midline regions of men with chronic posttraumatic stress disorder.

BACKGROUND: So far, the neural network associated with posttraumatic stress disorder (PTSD) has been suggested to mainly involve the amygdala, hippocampus and medial prefrontal cortex. However, increasing evidence indicates that cortical regions extending beyond this network might also be implicated in the pathophysiology of PTSD. We aimed to investigate PTSD-related structural alterations in some of these regions. METHODS: We enrolled highly traumatized refugees with and without (traumatized controls) PTSD and nontraumatized controls in the study. To increase the validity of our results, we combined an automatic cortical parcellation technique and voxel-based morphometry. RESULTS: In all, 39 refugees (20 with and 19 without PTSD) and 13 controls participated in the study. Participants were middle-aged men who were free of psychoactive substances and consumed little to no alcohol. Patients with PTSD (and to a lesser extent traumatized controls) showed reduced volumes in the right inferior parietal cortex, the left rostral middle frontal cortex, the bilateral lateral orbitofrontal cortex and the bilateral isthmus of the cingulate. An influence of cumulative traumatic stress on the isthmus of the cingulate and the lateral orbitofrontal cortex indicated that, at least in these regions, structural alterations might be associated with repeated stress experiences. Voxel-based morphometry analyses produced largely consistent results, but because of a poorer signal-to-noise ratio, conventional statistics did not reach significance. LIMITATIONS: Although we controlled for several important confounding variables (e.g., sex, alcohol abuse) with our particular sample, this might limit the generalizibility of our data. Moreover, high comorbidity of PTSD and major depression hinders a definite separation of these conditions in our findings. Finally, the results concerning the lateral orbito frontal cortex should be interpreted with caution, as magnetic resonance imaging acquisition in this region is affected by a general signal loss. CONCLUSION: Our results indicate that lateral prefrontal, parietal and posterior midline structures are implicated in the pathophysiology of PTSD. As these regions are particularly involved in episodic memory, emotional processing and executive control, this might have important implications for the understanding of PTSD symptoms.

Faster speed of onset of the depressive episode is associated with lower cytokine serum levels (IL-2, -4, -6, -10, TNF-α and IFN-γ) in patients with major depression.

INTRODUCTION: Cytokines might play a key role in the pathophysiology of major depressive disorder (MDD). The speed of onset of depressive episodes has been discussed as an important clinical parameter in MDD. The aim of this study was to investigate a potential influence of the speed of onset of the depressive episode on cytokine serum levels. METHOD: Serum level of the cytokines interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNF-α), interferon-gamma (IFN-γ) granulocyte and monocyte colony stimulating factor (GM-CSF) were measured in a total of 92 patients with MDD that did not respond to at least one previous antidepressant treatment. Patients were retrospectively divided in two groups: Faster (≤4 weeks) and slower (>4 weeks) onset of the depressive episode defined as the time passing from the first depressive symptoms to a full-blown depressive episode by using information from a clinical interview. RESULTS: We found significantly lower serum levels of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ in patients with a faster onset compared to patients with a slower onset of the depressive episodes. Furthermore, lower cytokine serum levels of IL-2, IL-8, IL-10 and IFN-γ were found in patients with a shorter duration (less than 6 months) compared to a longer duration (6-24 months) of the current depressive episode. This effect on cytokines was independent from the effect of the speed of onset of the depressive episode. CONCLUSIONS: Patients with faster onset of the depressive episode might represent a biological subtype of MDD with lower serum levels of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ.

Neural correlates of exemplar novelty processing under different spatial attention conditions.

The detection of novel events and their identification is a basic prerequisite in a rapidly changing environment. Recently, the processing of novelty has been shown to rely on the hippocampus and to be associated with activity in reward-related areas. The present study investigated the influence of spatial attention on neural processing of novel relative to frequently presented standard and target stimuli. Never-before-seen Mandelbrot-fractals absent of semantic content were employed as stimulus material. Consistent with current theories, novelty activated a widespread network of brain areas including the hippocampus. No activity, however, could be observed in reward-related areas with the novel stimuli absent of a semantic meaning employed here. In the perceptual part of the novelty-processing network a region in the lingual gyrus was found to specifically process novel events when they occurred outside the focus of spatial attention. These findings indicate that the initial detection of unexpected novel events generally occurs in specialized perceptual areas within the ventral visual stream, whereas activation of reward-related areas appears to be restricted to events that do possess a semantic content indicative of the biological relevance of the stimulus.

Role of the somatostatin system in contextual fear memory and hippocampal synaptic plasticity.

Somatostatin has been implicated in various cognitive and emotional functions, but its precise role is still poorly understood. Here, we have made use of mice with somatostatin deficiency, based upon genetic invalidation or pharmacologically induced depletion, and Pavlovian fear conditioning in order to address the contribution of the somatostatin system to associative fear memory. The results demonstrate an impairment of foreground and background contextual but not tone fear conditioning in mice with targeted ablation of the somatostatin gene. These deficits were associated with a decrease in long-term potentiation in the CA1 area of the hippocampus. Both the behavioral and the electrophysiological phenotypes were mimicked in wild-type mice through application of the somatostatin-depleting substance cysteamine prior to fear training, whereas no further deficits were observed upon application in the somatostatin null mutants. These results suggest that the somatostatin system plays a critical role in the acquisition of contextual fear memory, but not tone fear learning, and further highlights the role of hippocampal synaptic plasticity for information processing concerning contextual information.

Neural mechanisms of spatial- and feature-based attention: a quantitative analysis.

Attentional selection can be based on spatial locations, non-spatial stimulus features, or entire objects as integrated feature ensembles. Several studies reported attentional modulations in those regions that process the constituent features of the presented stimuli. Here we employed functional magnetic resonance imaging (fMRI) to directly compare the magnitude of space- and/or feature-based attentional modulations while subjects directed their attention to a particular color (red or green) of a transparent surface and at the same time to a spatial location (left or right visual field). The experimental design made it possible to disentangle and quantify the hemodynamic activity elicited by identical physical stimuli when attention was directed to spatial locations and/or stimulus features. The highest modulations were observed when the attentional selection was based on spatial location. Attended features also elicited a response increase relative to unattended features when their spatial location was attended. Importantly, at unattended locations, a response increase upon feature-based selection was observed in motion-sensitive but not in color-related areas. This suggests that compared to color, motion stimuli are more effective in capturing attention at unattended locations leading to a competitive advantage. These results support the idea of a high biological relevance of the feature motion in the visual world.