Reward history modulates visual attention in an avian model

Animal Cognition - Attention can be biased towards previously reward-associated stimuli even when they are task-irrelevant and physically non-salient, although studies of reward-modulated attention...     

初级视觉皮层在注意振荡中的作用

注意离散性是注意间歇性地采集外界信息的特性, 这种特性在行为中的表现被称为注意振荡。尽管有研究使用经典的线索靶子范式和视觉搜索范式发现行为数据中存在注意振荡, 证明了注意是离散的, 但其相应的神经机制, 即注意离散性与哪些脑区有关, 尚不明确。研究采用高时间分辨率的线索靶子范式和双眼分视技术, 基于人眼视觉通路的解剖学特性, 比较了线索靶子出现在双眼(实验1)、同眼和异眼(实验2)条件下的注意振荡, 考察初级视觉皮层对注意振荡的影响。结果发现：1)双眼分视会对注意振荡发生的频段产生影响, 非双眼分视条件下, 注意振荡出现在低频(2 Hz和8 Hz)。而双眼分视条件下, 注意振荡则出现在更高的频段(12.5 Hz)。2)无论线索靶子出现在同眼还是异眼, 注意振荡的频段无显著差异。结果表明V1区双眼视觉通路或者更高级的视觉区可能参与注意振荡, 为探明注意振荡的神经机制提供了重要的行为学证据。     

Self-construal priming modulates the scope of visual attention

Although it is well documented that cultures influence basic cognitive processes such as attention, the underlying mechanisms remain unclear. We tested the hypothesis that self-concepts that characterize people from different cultures mediate the variation of visual attention. After being primed with self-construals that emphasize the Eastern interdependent self or the Western independent self, Chinese participants were asked to discriminate a central target letter flanked by compatible or incompatible stimuli (Experiment 1) or global/local letters in a compound stimulus (Experiment 2). Experiment 1 showed that, while responses were slower to the incompatible than to the compatible stimuli, this flanker compatibility effect was increased by the interdependent relative to the independent self-construal priming. Experiment 2 showed that the interdependent-self priming resulted in faster responses to the global than to the local targets in compound letters whereas a reverse pattern was observed in the independent-self priming condition. The results provide evidence for dynamics of the scope of visual attention as a function of self-construal priming that switches self-concept toward the interdependent or independent styles in Chinese.     

Voluntary attention modulates processing of eye-specific visual information

Visual attention functions to select relevant information from a vast amount of visual input that is available for further processing. Information from the two eyes is processed separately in early stages before converging and giving rise to a coherent percept. Observers normally cannot access eye-of-origin information. In the research reported here, we demonstrated that voluntary attention can be eye-specific, modulating visual processing within a specific monocular channel. Using a modified binocular-rivalry paradigm, we found that attending to a monocular cue while remaining oblivious to its eye of origin significantly enhanced the competition strength of a stimulus presented to the cued eye, even when the stimulus was suppressed from consciousness. Furthermore, this eye-specific attentional effect was insensitive to low-level properties of the cue (e.g., size and contrast) but sensitive to the attentional load. Together, these findings suggest that top-down attention can have a significant modulation effect at the eye-specific stage of visual information processing.     

Self-construal priming modulates the scope of visual attention

Although it is well documented that cultures influence basic cognitive processes such as attention, the underlying mechanisms remain unclear. We tested the hypothesis that self-concepts that characterize people from different cultures mediate the variation of visual attention. After being primed with self-construals that emphasize the Eastern interdependent self or the Western independent self, Chinese participants were asked to discriminate a central target letter flanked by compatible or incompatible stimuli (Experiment 1) or global/local letters in a compound stimulus (Experiment 2). Experiment 1 showed that, while responses were slower to the incompatible than to the compatible stimuli, this flanker compatibility effect was increased by the interdependent relative to the independent self-construal priming. Experiment 2 showed that the interdependent-self priming resulted in faster responses to the global than to the local targets in compound letters whereas a reverse pattern was observed in the independent-self priming condition. The results provide evidence for dynamics of the scope of visual attention as a function of self-construal priming that switches self-concept toward the interdependent or independent styles in Chinese.     

Selective visual attention modulates the direct tilt aftereffect

One's being able to allocate attention to particular regions or properties of the visual field is fundamental to visual information processing. Visual attention determines what input is carefully analyzed and what input is more or less ignored. But at what stage of the visual system is this process evident? We describe three experiments that demonstrate an effect of voluntary spatial attention and voluntary object-based attention on an orientation illusion (the tilt aftereffect) that is believed to take place in primary visual cortex. This finding, in which selective visual attention influences adaptation to visual orientation information, contributes to mounting evidence for a view of visual perception in which mutual interaction takes place between high-level and low-level subsystems.     

How visual spatial attention alters perception

Visual attention is essential for visual perception. Spatial attention allows us to grant priority in processing and selectively process information at a given location. In this paper, I explain how two kinds of spatial attention: covert (allocated to the target location, without accompanying eye movements) and presaccadic (allocated to the location of the upcoming saccade’s target) affect performance and alter appearance. First, I highlight some behavioral and neuroimaging research on covert attention, which alters performance and appearance in many basic visual tasks. Second, I review studies showing that presaccadic attention improves performance and alters appearance at the saccade target location. Further, these modulations change the processing of feature information automatically, even when it is detrimental to the task at hand. We propose that saccade preparation may support transsaccadic integration. Systematically investigating the common and differential characteristics of covert attention and presaccadic attention will continue to further our understanding of the pervasive selective processing of information, which enables us to make sense of our complex visual world.     

Spatial attention modulates feature crosstalk in visual word processing

One major idea about spatial attention is that it serves to modulate crosstalk between features during reading. Two reading aloud experiments are reported in which a cue-validity manipulation was combined with manipulations that are thought to increase the likelihood of feature-level crosstalk: interletter spacing and the presence or absence of irrelevant features. Both experiments yielded an interaction between the effects of spatial cuing and each of these factors. These results are taken to support the hypothesis that when spatial attention is focused on the word, it provides protection against crosstalk among features in the context of reading aloud.     

How arousal modulates memory: Disentangling the effects of attention and retention

Emotion may influence memory both by altering attention and perception during encoding and by affecting memory retention. To date, studies have focused on the enhancement of memory consolidation by arousal. However, they have failed to rule out a role for attention. To specifically link memory enhancement of arousing material to modulation of memory retention, we examined recognition of neutral and arousing words at two time points and under conditions that manipulate attention during encoding. Participants were briefly presented with an arousing or neutral word at the periphery, while fixating on a central word. Recognition of peripheral words was assessed either immediately or after 24 h. Whereas recognition of neutral words became worse over time, recognition of arousing words remained the same and was better than neutral word recognition at delay. The results indicate that arousal supports slower forgetting even when the difference in attentional resources allocated to stimuli is minimized.     

Flexible attention allocation to visual and auditory working memory tasks: manipulating reward induces a trade-off

Prominent roles for general attention resources are posited in many models of working memory, but the manner in which these can be allocated differs between models or is not sufficiently specified. We varied the payoffs for correct responses in two temporally-overlapping recognition tasks, a visual array comparison task and a tone sequence comparison task. In the critical conditions, an increase in reward for one task corresponded to a decrease in reward for the concurrent task, but memory load remained constant. Our results show patterns of interference consistent with a trade-off between the tasks, suggesting that a shared resource can be flexibly divided, rather than only fully allotted to either of the tasks. Our findings support a role for a domain-general resource in models of working memory, and furthermore suggest that this resource is flexibly divisible.     

The modulatory impact of reward and attention on global feature selection in human visual cortex

Reward powerfully influences human behaviour and perception, with reward effects being observed already on the level of basic sensory processing. Although reward-related modulations generally resemble those related to attentional selection, it is debated whether these effects indeed reflect the same selection operations. Here we focus on neuromagnetic indices of global colour-based attention in visual cortex, and ask whether reward elicits the same or separable underlying modulation effects. Observers performed a colour/orientation selection task where colour served to define the target as well as reward prospect. On each trial a target containing the target colour and one other colour was presented in the left visual field (VF) together with a bicoloured distractor in the right VF. Reward was delivered on correctly performed trials when the reward colour appeared in the target but not when it appeared in the distractor. The effect of global colour selection was assessed by comparing the brain response to the distractor depending on whether it contained the target colour, the reward colour, both, or neither. We observed that both the reward and target colour led to similar increases of the neuromagnetic response between ~200–260 ms originating from the same ventral extrastriate visual cortex areas, albeit slightly temporally lagged. Importantly, the response to the target and reward colour alone always added up to match the response size of their combined presentation. These results suggest that while reward and attention recruit the same global feature selection effects in extrastriate visual cortex, they are likely controlled by independent top-down influences.     

Endogenous attention modulates early selective attention in psychopathy: An ERP investigation

Psychopathic individuals are prone to act on urges without adequate consideration of future consequences or the rights of other individuals. One interpretation of this behavior is that it reflects abnormal selective attention (i.e., a failure to process information that is incongruent with their primary focus of attention; Hiatt, Schmitt, & Newman, Neuropsychology, 18, 50-59, 2004). Unfortunately, it is unclear whether this selective attention abnormality reflects top-down endogenous influences, such as the strength or specificity of attention focus (i.e., top-down set) apart from other, more exogenous (bottom-up), effects on attention. To explore this question, we used an early visual event-related potential (N2pc) in combination with a modified visual search task designed to assess the effect of early endogenous (i.e., top-down) attention on the processing of set-congruent information. The task was administered to a sample of 70 incarcerated adult males, who were assigned to high, intermediate, and low psychopathy groups using Hare’s Psychopathy Checklist-Revised (Hare, 2003). Based on the assumption that their failure to process set-incongruent information reflects the exaggerated effects of endogenous attention, we predicted that participants with high psychopathy scores would show an exaggerated N2pc response to set-congruent information. The results supported the hypothesis and provide novel electrophysiological evidence that psychopathy is associated with exaggerated endogenous attention effects during early stages of processing. Further research is needed to examine the implications of this finding for the well-established failure of psychopathic individuals to process set-incongruent information and inhibit inappropriate responses.     

Automatizing of visual attention

Perceptual automatizing was argued to occur as a consequence of repeated experience with a stimulus. Automatizing was hypothesized to entail a stereotyping in sampling of sensory information together with an attendant decrease in the rate of sampling of that information. An experiment was performed in which human Ss observed stimulus pictures for several trials, during which records were made of their visual fixations. It was found that fixation rate habituated and that this habituation was accompanied by a reduction in the uncertainty (entropy) of the spatial distributions of fixations. These results were interpreted as evidence for automatizing of visual fixation processes. Analysis of eye-movement distances suggested a possible mechanism for the reported loss of vividness of a stimulus which is perceived habitually.     

Multiple influences of reward on perception and attention

Visual processing is influenced by stimulus-driven and goal-driven factors. Recent interest has centred on understanding how reward might provide additional contributions to visual perception and unravelling the underlying neural mechanisms. In this review, I suggest that the impact of reward on vision is not unitary and depends on the type of experimental manipulation. With this in mind, I outline a possible classification of the main paradigms employed in the literature and discuss potential brain processes that operate during some of the experimental manipulations described.     

The interplay of attention and emotion: top-down attention modulates amygdala activation in psychopathy

Psychopathic behavior has long been attributed to a fundamental deficit in fear that arises from impaired amygdala function. Growing evidence has demonstrated that fear-potentiated startle (FPS) and other psychopathy-related deficits are moderated by focus of attention, but to date, no work on adult psychopathy has examined attentional modulation of the amygdala or concomitant recruitment of relevant attention-related circuitry. Consistent with previous FPS findings, here we report that psychopathy-related differences in amygdala activation appear and disappear as a function of goal-directed attention. Specifically, decreased amygdala activity was observed in psychopathic offenders only when attention was engaged in an alternative goal-relevant task prior to presenting threat-relevant information. Under this condition, psychopaths also exhibited greater activation in selective-attention regions of the lateral prefrontal cortex (LPFC) than did nonpsychopaths, and this increased LPFC activation mediated psychopathy’s association with decreased amygdala activation. In contrast, when explicitly attending to threat, amygdala activation did not differ in psychopaths and nonpsychopaths. This pattern of amygdala activation highlights the potential role of LPFC in mediating the failure of psychopathic individuals to process fear and other important information when it is peripheral to the primary focus of goal-directed attention.     

Effects of reward and nonreward on frustration and attention in attention deficit disorder

The effects of reward schedule (100%, 50%, and 30%) and termination of rewards (extinction) on 30 attention deficit disorder with hyperactivity (ADD-H) and 30 normal children were studied using measures of frustration (speed/strength of lever pulling) and attention (reaction time to a light signal). ADD-Hs pulled harder on the lever than controls during extinction and on the lowest (30%) partial schedule, providing empirical evidence that they respond with greater frustration than normals when expected rewards fail to appear. The groups did not differ on the attentional measure on 100% reward. However, the partial schedules appeared to have an alerting or motivating effect on the controls, so that they responded more quickly and consistently than ADD-Hs on the partial schedules. Findings are discussed with reference to opposing theories regarding the nature of the abnormal response of ADD-Hs to reward.This research was supported by grant MA 11252 from the Medical Research Council of Canada.     

Dimension-based visual attention modulates dual-judgment accuracy in Duncan's (1984) one- versus two-object report paradigm

Four experiments, adapting the object-judgment paradigm developed by J. Duncan (1984), examined the relationship between object-based and domain-based mechanisms of visual attention. The experiments demonstrated a cross-domain cost, in terms of accuracy, when observers made dual color-form judgments to one or two overlapping objects presented briefly, relative to within-domain, dual-color and dual-form judgments. This domain-based selection effect was additive to an object-based effect, a cost of making dual judgments to separate objects, as reported by J. Duncan (1984). The pattern of object- and domain-based effects points to a capacity limitation in how multidimensional features are bound into a coherent object representation, consistent with the dimension-weighting account of H. J. Miller, D. Heller, and J. Ziegler (1995), which postulates that there is a limit to the total selection weight available to be allocated to an object's dimensions.