Grouping does not require attention

Many theories of visual perception stipulate that Gestalt grouping occurs preattentively. Subjects' failure to report perceiving even salient grouping patterns under conditions of inattention challenges this assumption (see, e.g., Mack, Tang, Tuma, Kahn, & Rock, 1992), but Moore and Egeth (1997) showed that although subjects are indeed unable to identify grouping patterns outside the focus of attention, effects of these patterns on visual perception can be observed when they are assessed using implicit, rather than explicit, measures. However, this finding, which is the only one to date demonstrating grouping effects without attention, is open to an alternative account. In the present study, we eliminated this confound and replicated Moore and Egeth's findings, using the Müller-Lyer illusion (Experiments 1 and 2). Moreover, we found converging evidence for these findings with a variant of the flanker task (Experiment 3), when the amount of available attentional resources was varied (Experiments 4 and 5). The results reinforce the idea that, although grouping outside the focus of attention cannot be the object of overt report, grouping processes can occur without 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.     

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.     

Holding points of view does not amount to knowledge

I argue that knowing and having points of view are fundamentally different epistemic states if we assume that having justified true beliefs is necessary for knowledge. Knowers necessarily possess justified true beliefs, but persons holding points of view may, for example, lack justification, have false beliefs, or both. I examine these differences and expose other crucial differentiating patterns between the structure of knowledge and points of view that make the latter more likely to lead to disagreements. I hypothesize that these patterns remain invariant in alternative views of knowledge like contextualism as long as we preserve the classical structure. Yet there is much research to be done on the multiple and contrasting properties that emerge if we consider non-classical analyses of knowledge and points of view.     

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.     

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.     

The role of meaning in inflection: why the past tense does not require a rule

How do we produce the past tenses of verbs? For the last 20 years this question has been the focal domain for conflicting theories of language, knowledge representation, and cognitive processing. On one side of the debate have been similarity-based or single-route approaches that propose that all past tenses are formed simply through phonological analogies to existing past tenses stored in memory. On the other side of the debate are rule-based or dual-route approaches which agree that phonological analogy is important for producing irregular past tenses (e.g., think-->thought), but argue that regular past tenses (e.g., walk-->walked) are generated via a +ed rule and that a principled account of regular inflection can only be given by recourse to explicit rules. This debate has become a crucial battleground for arguments concerning the necessity and importance of abstract mental rules, embracing not only language processing, but also the of nature cognition itself. However, in centering on the roles of phonological similarity and rules, the past tense debate has largely ignored the possible role of semantics in determining inflection. This paper presents five studies that demonstrate a striking and decisive role of semantic similarity in inflection. In fact, semantic factors appear to be more important in inflection than the grammatical considerations put forward by the dual-route account. Further, these new findings provide a new way of discriminating between the claims of single-route (similarity-based) and dual-route (rule-based) approaches. It appears that inflection is carried out through analogical reminding based on semantic and phonological similarity and that a rule-based route is not necessary to account for past tense inflection.     

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.     

The semantic view of theories and higher-order languages

Synthese - Several philosophers of science construe models of scientific theories as set-theoretic structures. Some of them moreover claim that models should not be construed as structures in the...     

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.     

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.     

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.     

The rapid-chase theory does not extend to movement execution

It is assumed that the processing of a prime followed by a mask occurs sequentially in a feedforward manner when the three (initiation, takeover, and independence) criteria outlined by the rapid-chase theory are met. The purpose of the current study was to determine if the processing of the prime and mask fit the predictions of the rapid-chase theory when the prime and mask are presented during an ongoing movement. In two experiments, participants made rapid pointing movements to a target indicated by the mask. In Experiment 1, the prime was presented at movement onset and the prime-mask stimulus onset asynchrony (SOA) was manipulated. In Experiment 2, the prime-mask SOA was constant but the delay between movement and prime onset was manipulated. Although the results support the initiation and takeover criteria, the data did not support the independence criterion. Consequently, the rapid-chase theory does not appear to extend to movement execution.     

The road not taken: creative solutions require avoidance of high-frequency responses

To investigate individual differences in creativity as measured with a complex problem-solving task, we developed a computational model of the remote associates test (RAT). For 50 years, the RAT has been used to measure creativity. Each RAT question presents three cue words that are linked by a fourth word, which is the correct answer. We hypothesized that individuals perform poorly on the RAT when they are biased to consider high-frequency candidate answers. To assess this hypothesis, we tested individuals with 48 RAT questions and required speeded responding to encourage guessing. Results supported our hypothesis. We generated a norm-based model of the RAT using a high-dimensional semantic space, and this model accurately identified correct answers. A frequency-biased model that included different levels of bias for high-frequency candidate answers explained variance for both correct and incorrect responses. Providing new insight into the nature of creativity, the model explains why some RAT questions are more difficult than others, and why some people perform better than others on the RAT.