The detection of temporally defined objects does not require focused attention

Perceptual grouping is crucial to distinguish objects from their background. Recent studies have shown that observers can detect an object that does not have any unique qualities other than unique temporal properties. A crucial question is whether focused attention is needed for this type of grouping. In two visual search experiments, we show that searching for an object defined by temporal grouping can occur in parallel. These findings suggest that focused attention is not needed for temporal grouping to occur. It is proposed that temporal grouping may occur because the neurons representing the changing object elements adopt firing frequencies that cause the visual system to bind these elements together without the need for focused attention.     

The detection of temporally defined objects does not require focused attention

Perceptual grouping is crucial to distinguish objects from their background. Recent studies have shown that observers can detect an object that does not have any unique qualities other than unique temporal properties. A crucial question is whether focused attention is needed for this type of grouping. In two visual search experiments, we show that searching for an object defined by temporal grouping can occur in parallel. These findings suggest that focused attention is not needed for temporal grouping to occur. It is proposed that temporal grouping may occur because the neurons representing the changing object elements adopt firing frequencies that cause the visual system to bind these elements together without the need for focused attention.     

The word-superiority effect does not require a T-scope

Six experiments examined the possibility of obtaining a word-superiority effect (WSE) without the use of brief stimulus exposures or a poststimulus mask. In each experiment, subjects were presented a stimulus string and two alternative strings that differed by a single letter (Reicher, 1969). The alternatives and stimulus remained in view until subjects responded, and subjects were under no pressure to respond quickly. In Experiments 1–3, the stimuli were presented in very small type so that they were difficult to see. Subjects were significantly more accurate with words than with nonwords, letters embedded among digits, or letters embedded among number signs (#s). In Experiments 4 and 5, the stimuli were embedded in a simultaneously present pattern mask. Subjects were significantly more accurate with words than with single letters by themselves. In the final experiment, the stimuli were presented in a mask with specific spatial frequency characteristics, and performance was significantly better with words than with nonwords. The WSE is a more general phenomenon than previously supposed; it is not limited to a tachistoscopic exposure.     

The word-superiority effect does not require a T-scope.

Six experiments examined the possibility of obtaining a word-superiority effect (WSE) without the use of brief stimulus exposures or a poststimulus mask. In each experiment, subjects were presented a stimulus string and two alternative strings that differed by a single letter (Reicher, 1969). The alternatives and stimulus remained in view until subjects responded, and subjects were under no pressure to respond quickly. In Experiments 1-3, the stimuli were presented in very small type so that they were difficult to see. Subjects were significantly more accurate with words than with nonwords, letters embedded among digits, or letters embedded among number signs (#s). In Experiments 4 and 5, the stimuli were embedded in a simultaneously present pattern mask. Subjects were significantly more accurate with words than with single letters by themselves. In the final experiment, the stimuli were presented in a mask with specific spatial frequency characteristics, and performance was significantly better with words than with nonwords. The WSE is a more general phenomenon than previously supposed; it is not limited to a tachistoscopic exposure.     

Spatial localization does not require the presence of local cues

The purpose of this paper is to demonstrate that rats can rapidly learn to locate an object that they can never see, hear, or smell provided it remains in a fixed spatial location relative to distal room cues. Four groups of rats were permitted to escape from opaque water onto a platform which was either just above or just below the water surface, and in either a fixed or varied location. Learning occurred rapidly except for the group for whom the escape platform was below the water surface and moved about from place to place. Transfer tests revealed that a spatial location search strategy was employed by the group for whom the platform was below water but in a fixed location. A second experiment investigated this learning further, revealing instantaneous transfer when the rats were required to approach the platform from a novel starting position. The data of both studies are discussed in relation to recent work on spatial memory in the rat. The concept of the “acuity” of spatial memory is introduced and the procedures used may provide a new approach to comparing spatial memory with classical and instrumental conditioning.     

Representing visual recursion does not require verbal or motor resources

The ability to form and use recursive representations while processing hierarchical structures has been hypothesized to rely on language abilities. If so, linguistic resources should inevitably be activated while representing recursion in non-linguistic domains. In this study we use a dual-task paradigm to assess whether verbal resources are required to perform a visual recursion task. We tested participants across 4 conditions: (1) Visual recursion only, (2) Visual recursion with motor interference (sequential finger tapping), (3) Visual recursion with verbal interference – low load, and (4) Visual recursion with verbal interference – high load. Our results show that the ability to acquire and use visual recursive representations is not affected by the presence of verbal and motor interference tasks. Our finding that visual recursion can be represented without access to verbal resources suggests that recursion is available independently of language processing abilities.     

Categorical perception of emotional facial expressions does not require lexical categories

Does our perception of others' emotional signals depend on the language we speak or is our perception the same regardless of language and culture? It is well established that human emotional facial expressions are perceived categorically by viewers, but whether this is driven by perceptual or linguistic mechanisms is debated. We report an investigation into the perception of emotional facial expressions, comparing German speakers to native speakers of Yucatec Maya, a language with no lexical labels that distinguish disgust from anger. In a free naming task, speakers of German, but not Yucatec Maya, made lexical distinctions between disgust and anger. However, in a delayed match-to-sample task, both groups perceived emotional facial expressions of these and other emotions categorically. The magnitude of this effect was equivalent across the language groups, as well as across emotion continua with and without lexical distinctions. Our results show that the perception of affective signals is not driven by lexical labels, instead lending support to accounts of emotions as a set of biologically evolved mechanisms.     

Grouping with and without attention

The effects of perceptual grouping on a line discrimination task were investigated using Moore and Egeth's (1997) paradigm. Observers judged which of two lines, presented one above the other over a matrix of spots, was longer. On some trials, larger spots at both ends of the lines formed arrowheads, thereby making possible the Müller-Lyer illusion. When observers attended only to the lines, they were not aware of the arrowheads. Yet their line judgment performance showed that they had succumbed to the illusion. When the observers' attention was directed to the arrowheads but they nevertheless failed to discern the arrowheads' orientation, their line judgments were still influenced by the illusion.     

Automatic attention does not equal automatic fear: preferential attention without implicit valence

Theories of nonassociative fear acquisition hold that humans have an innate predisposition for some fears, such as fear of snakes and spiders. This predisposition may be mediated by an evolved fear module (Ohman & Mineka, 2001) that responds to basic perceptual features of threat stimuli by directing attention preferentially and generating an automatic fear response. Visual search and affective priming tasks were used to examine attentional processing and implicit evaluation of snake and spider pictures in participants with different explicit attitudes; controls (n = 25) and snake and spider experts (n = 23). Attentional processing and explicit evaluation were found to diverge; snakes and spiders were preferentially attended to by all participants; however, they were negative only for controls. Implicit evaluations of dangerous and nondangerous snakes and spiders, which have similar perceptual features, differed for expert participants, but not for controls. The authors suggest that although snakes and spiders are preferentially attended to, negative evaluations are not automatically elicited during this processing.     

Functional specialization does not require a one-to-one mapping between brain regions and emotions

Lindquist et al. have assumed that functional specialization requires a one-to-one mapping between brain regions and discrete emotions. This assumption is in tension with the fact that regions can have multiple functions in the context of different, possibly distributed, networks. Once we open the door to other forms of functional specialization, neuroimaging data no longer favor constructionist models over natural kind models.     

Cued visual attention does not distinguish between occluded and occluding objects

Does visual attention spread from the cued end of an occluded object to locations occupied by inferred portions of that object? We investigated this question by using a probe detection paradigm with two-dimensional (2-D) displays of occluded objects. Probes could appear in occluded or nonoccluded locations on either a cued or noncued object. Participants responded faster to probes appearing within the region of space occupied by the cued object. This was true not only when the probe appeared in positions separated from the cued location by an occluder (as demonstrated by Moore, Yantis, & Vaughan, 1998), but also when it appeared in positions on the occluder itself. Thus, results suggest that cued facilitation spreads to regions of noncued occluding objects that overlap cued occluded objects in 2-D space.     

Subliminal access to abstract face representations does not rely on attention

The present study used masked repetition priming to examine whether face representations can be accessed without attention. Two experiments using a face recognition task (fame judgement) presented masked repetition and control primes in spatially unattended locations prior to target onset. Experiment 1 (n=20) used the same images as primes and as targets and Experiment 2 (n=17) used different images of the same individual as primes and targets. Repetition priming was observed across both experiments regardless of whether spatial attention was cued to the location of the prime. Priming occurred for both famous and non-famous targets in Experiment 1 but was only reliable for famous targets in Experiment 2, suggesting that priming in Experiment 1 indexed access to view-specific representations whereas priming in Experiment 2 indexed access to view-invariant, abstract representations. Overall, the results indicate that subliminal access to abstract face representations does not rely on attention.     

Threat captures attention but does not affect learning of contextual regularities

Some of the stimulus features that guide visual attention are abstract properties of objects such as potential threat to one's survival, whereas others are complex configurations such as visual contexts that are learned through past experiences. The present study investigated the two functions that guide visual attention, threat detection and learning of contextual regularities, in visual search. Search arrays contained images of threat and non-threat objects, and their locations were fixed on some trials but random on other trials. Although they were irrelevant to the visual search task, threat objects facilitated attention capture and impaired attention disengagement. Search time improved for fixed configurations more than for random configurations, reflecting learning of visual contexts. Nevertheless, threat detection had little influence on learning of the contextual regularities. The results suggest that factors guiding visual attention are different from factors that influence learning to guide visual attention.     

Grouping by proximity: Selective attention measures

Attention, Perception, & Psychophysics - The role of element proximity in perceptual grouping was examined in tasks requiring speeded discrimination of two-element visual patterns. Grouping of...     

Circadian modulation of conditioned place avoidance in hamsters does not require the suprachiasmatic nucleus

Animals possess the ability to remember both the time of day as well as the location that noxious and potentially dangerous conditions occur. A behavioral expression of this learning is demonstrated in conditioned place avoidance (CPA). CPA is strongest when the time of testing matches the time of day that the prior training had occurred, suggesting the involvement of a circadian oscillator that modulates either memory retrieval or reactivity to the conditioned environment. In these experiments we show that time of day learning persists in the absence of the central circadian clock in the suprachiasmatic nucleus (SCN), demonstrating that memory for time of day is implicit in context conditioning and may involve a circadian oscillator that is distinct from the SCN.     

Incidental encoding of enclosure geometry does not require visual input: evidence from blindfolded adults

Although spatial orientation with respect to the geometric properties of an environment appears to be an ability shared across various species, debate remains concerning potential similarities and differences with respect to the underlying mechanism(s). One prominent theoretical account of orientation with respect to the environment suggests that participants match visual memories to their current visual perception and navigate to reduce the discrepancy between the two. We tested whether visual input was necessary to incidentally encode the geometric properties of an environment, by training disoriented and blindfolded adult participants to search by touch for a target object hidden in one of four locations, marked by distinctive textural cues, located in the corners of a rectangular enclosure. Following training, we removed the distinctive textural cues and probed the extent to which the participants had learned the geometry of the enclosure. Even in the absence of vision and unique textural cues, search behavior was consistent with evidence for the encoding of enclosure geometry. A follow-up experiment in which participants were trained in a rectangular enclosure but were tested in a square enclosure provided converging evidence that search behavior was influenced by the geometric properties of the enclosure. Collectively, these results suggest that even in the absence of vision, participants incidentally encoded the geometric properties of the enclosure, indicating that visual input is not required to encode the geometric properties of an environment.     

他向你所要的是什么呢？

经文:弥6:8先知弥迦是在主前739-687年,在南国犹大作先知。他出身农村田舍,生活简朴,思想单纯,议论直率,信心热切。这时的南国犹大虽然繁荣昌盛,但由于物质生活上的糜烂,带来难数的罪恶。虽然希西家作王后确有改革决心,清除圣殿中的异教敬拜,烧毁柱像和拜偶像的邱坛,颇有中兴气象。但政治上和宗教上的改革与真正的悔改,中间还有一大段距离,人民在内心上并没有彻底革新,农民因亚述军队的掳掠而处于水深火热之中。富人和官吏可在城堡里安居,而农民生活却全无保障,朝夕生活在恐惧当中。面对当前的形势,弥迦先知勇敢地指出,假先知的信息,富人的贪得无厌,投机取巧的商贾,贪污的官吏,欺诈的祭司和枉法的司法人员,要求他们和整个以色列民行公义、好怜悯、存谦卑的心与神同行。才能得拯救。