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We compared problem‐solving in four sets of classical insight and analytic problems in the verbal and spatial domains, and examined the impact of externalization (verbalization or sketching). In a within‐participants factorial design, we presented 24 classical insight and analytic problems, half verbal and half spatial. Participants solved these problems either while thinking aloud, while sketching, or in a baseline condition where neither was allowed. Higher solving accuracy was found in the analytic problems than in the insight ones as well as in the verbal problems than in the spatial ones. The verbal problems were also found to be solved faster than were spatial ones; in particular, verbal‐insight problems were solved faster than spatial‐insight and verbal‐analytic ones. Therefore, spatial‐insight problems stand out as particularly hard among the ones typically found in the literature. Surprisingly, no effects of externalization were found on problem‐solving speed or accuracy. We discuss the implications of our results for the theses that insight problems involve special processes. [ABSTRACT FROM AUTHOR]

Eye movement research has shown that attention shifts from the currently fixated location to the next before a saccade is executed. We investigated whether the cost of the attention shift depends on higher-order processing at the time of fixation, in particular on visual working memory load differences between fixations and refixations on task-relevant items. The attention shift is reflected in EEG activity in the saccade-related potential (SRP). In a free viewing task involving visual search and memorization of multiple targets amongst distractors, we compared the SRP in first fixations versus refixations on targets and distractors. The task-relevance of targets implies that more information will be loaded in memory (e.g. both identity and location) than for distractors (e.g. location only). First fixations will involve greater memory load than refixations, since first fixations involve loading of new items, while refixations involve rehearsal of previously visited items. The SRP in the interval preceding the saccade away from a target or distractor revealed that saccade preparation is affected by task-relevance and refixation behavior. For task-relevant items only, we found longer fixation duration and higher SRP amplitudes for first fixations than for refixations over the occipital region and the opposite effect over the frontal region. Our findings provide first neurophysiological evidence that working memory loading of task-relevant information at fixation affects saccade planning. [ABSTRACT FROM AUTHOR]

Activity-dependent plasticity refers to a range of mechanisms for adaptively reshaping neuronal connections. We model their common principle in terms of adaptive rewiring of network connectivity, while representing neural activity by diffusion on the network: Where diffusion is intensive, shortcut connections are established, while underused connections are pruned. In binary networks, this process is known to steer initially random networks robustly to high levels of structural complexity, reflecting the global characteristics of brain anatomy: modular or centralized small world topologies. We investigate whether this result extends to more realistic, weighted networks. Both normally- and lognormally-distributed weighted networks evolve either modular or centralized topologies. Which of these prevails depends on a single control parameter, representing global homeostatic or normalizing regulation mechanisms. Intermediate control parameter values exhibit the greatest levels of network complexity, incorporating both modular and centralized tendencies. The simulation results allow us to propose diffusion based adaptive rewiring as a parsimonious model for activity-dependent reshaping of brain connectivity structure. [ABSTRACT FROM AUTHOR]

Abstract: Sense of agency can be defined as the self‐awareness of bodily movement, whereas extended agency as the self‐awareness of affecting, through movement, events concomitant with movement. As a distinctive manifestation of agency, we review Spizzo's effect. This effect arises when agents coordinate their rhythmic movements with visual pulses. Once coordination is established, agents feel controlling the onset or the offset of the pulses through their movements. Spizzo's effect, therefore, constitutes a manifest case of extended agency, in which agents are aware of controlling, through movement, the pulses temporally concomitant with movement. We propose that sense of agency requires continuity of kinesthesia, which in turn requires the continuity of selfhood. The continuity of kinesthesia is necessarily deduced from the consistent kinematics observed in movements, whereas the continuity of selfhood may stem from the patterns of rhythmic coordination that humans encounter ever since intrauterine life. The primacy of these patterns in adults is in accordance with phenomena such as Spizzo's effect, which require coordination to be induced. We, therefore, propose coordination as the fundamental interaction from which selfhood, kinesthesia, and agency arise. [ABSTRACT FROM AUTHOR]

Adaptive rewiring provides a basic principle of self-organizing connectivity in evolving neural network topology. By selectively adding connections to regions with intense signal flow and deleting underutilized connections, adaptive rewiring generates optimized brain-like, i.e. modular, small-world, and rich club connectivity structures. Besides topology, neural self-organization also follows spatial optimization principles, such as minimizing the neural wiring distance and topographic alignment of neural pathways. We simulated the interplay of these spatial principles and adaptive rewiring in evolving neural networks with weighted and directed connections. The neural traffic flow within the network is represented by the equivalent of diffusion dynamics for directed edges: consensus and advection. We observe a constructive synergy between adaptive and spatial rewiring, which contributes to network connectedness. In particular, wiring distance minimization facilitates adaptive rewiring in creating convergent-divergent units. These units support the flow of neural information and enable context-sensitive information processing in the sensory cortex and elsewhere. Convergent-divergent units consist of convergent hub nodes, which collect inputs from pools of nodes and project these signals via a densely interconnected set of intermediate nodes onto divergent hub nodes, which broadcast their output back to the network. Convergent-divergent units vary in the degree to which their intermediate nodes are isolated from the rest of the network. This degree, and hence the context-sensitivity of the network's processing style, is parametrically determined in the evolving network model by the relative prominence of spatial versus adaptive rewiring. Author summary: Context-sensitivity plays an important role in neural signal processing. A type of network structure supporting context-sensitive processing is known as a convergent-divergent unit. Convergent-divergent units can give rise to sensory neurons that respond to local features but are also modulated, in their activities, by long-range contextual information. These units can arise through self-organization in neural networks according to adaptive rewiring, a principle used to optimize network structure for information processing. Two spatial rewiring principles, distance minimization and topographic alignment, are also considered important in shaping network connectivity structure, but their role in the formation of context sensitivity is unknown. We asked whether these spatial rewiring principles can facilitate adaptive rewiring in the formation of convergent-divergent units. Using weighted digraphs, we found that the proportion of rewiring based on distance minimization improves context-sensitivity, as shown by the increased robustness of the convergent-divergent units, while the subtler effects of the alignment principle depend on the shape of the topographic map that network connections align with. [ABSTRACT FROM AUTHOR]

In the course of perceptual organization, incomplete optical stimulation can evoke the experience of complete objects with distinct perceptual identities. According to a well-known principle of perceptual organization, stimulus parts separated by shorter spatial distances are more likely to appear as parts of the same perceptual identity. Whereas this principle of proximity has been confirmed in many studies of perceptual grouping in static displays, we show that it does not generalize to perception of object identity in dynamic displays, where the parts are separated by spatial and temporal distances. We use ambiguous displays which contain multiple moving parts and which can be perceived two ways: as two large objects that gradually change their size or as multiple smaller objects that rotate independent of one another. Grouping over long and short distances corresponds to the perception of the respectively large and small objects. We find that grouping over long distances is often preferred to grouping over short distances, against predictions of the proximity principle. Even though these effects are observed at high luminance contrast, we show that they are consistent with results obtained at the threshold of luminance contrast, in agreement with predictions of a theory of efficient motion measurement. This is evidence that the perception of object identity can be explained by a computational principle of neural economy rather than by the empirical principle of proximity. [ABSTRACT FROM AUTHOR]

In compound, hierarchical stimuli (also known as Navon figures), a Global Precedence Effect (GPE) can reliably be observed for both letters and non-letters. However, when presentation conditions sufficiently resemble those of reading, the GPE for letters has occasionally been found to disappear. We corroborate this effect in a study with a large group of participants. In addition, in-between two sessions, participants were trained in associating the non-letters with either phonological or non-phonological sounds. We reasoned that learning distinctive phonological associations might be akin to the acquisition of letter knowledge. This might eliminate the GPE also for the non-letters. However, the GPE persisted for the trained non-letters in both conditions. The large number of participants in this study revealed additional effects in the letter condition, which enabled further insights in the processing dissociation between letters and non-letter shapes. [ABSTRACT FROM AUTHOR]

We propose a novel framework for processing a continuous speech stream that contains a varying number of words, as well as non-speech periods. Speech samples are segmented into word-tokens and non-speech periods. An augmented version of an earlier-proposed, cascaded neuro-computational model is used for recognising individual words within the stream. Simulation studies using both a multi-speaker-dependent and speaker-independent digit string database show that the proposed method yields a recognition performance comparable to that obtained by a benchmark approach using hidden Markov models with embedded training. [ABSTRACT FROM PUBLISHER]

Abstract: According to Garner, visual patterns are mentally represented as categories rather than by their physical identity. On the other hand, physical and categorical identification tasks engender their own specific processing strategies. Nevertheless, categorical strategies should be more generic than physical ones. We tested this prediction using Garner patterns in a same–different task: one version involved categorical, the other physical identification. Both tasks showed effects of categorical representation but also contrasting categorical and physical processing strategies in their response time profiles. When trials from categorical and physical identification tasks were randomly intermixed, mixing costs were additive for categorical trials but not for physical trials, indicating a shift in processing strategy for the latter. For these trials, the physical response time profile was found to be displaced by a categorical profile. We concluded that the more generic processing strategy is the one that maximizes the role of categorical representation. [Copyright &y& Elsevier]

In human speech recognition, words are analysed at both pre-lexical (i.e., sub-word) and lexical (word) levels. The aim of this paper is to propose a constructive neuro-computational model that incorporates both these levels as cascaded layers of pre-lexical and lexical units. The layered structure enables the system to handle the variability of real speech input. Within the model, receptive fields of the pre-lexical layer consist of radial basis functions; the lexical layer is composed of units that perform pattern matching between their internal template and a series of labels, corresponding to the winning receptive fields in the pre-lexical layer. The model adapts through self-tuning of all units, in combination with the formation of a connectivity structure through unsupervised (first layer) and supervised (higher layers) network growth. Simulation studies show that the model can achieve a level of performance in spoken word recognition similar to that of a benchmark approach using hidden Markov models, while enabling parallel access to word candidates in lexical decision making. [ABSTRACT FROM AUTHOR]

Activity in neural circuits is spatiotemporally organized. Its spatial organization consists of multiple, localized coherent patterns, or patchy clusters. These patterns propagate across the circuits over time. This type of collective behavior has ubiquitously been observed, both in spontaneous activity and evoked responses; its function, however, has remained unclear. We construct a spatially extended, spiking neural circuit that generates emergent spatiotemporal activity patterns, thereby capturing some of the complexities of the patterns observed empirically. We elucidate what kind of fundamental function these patterns can serve by showing how they process information. As self-sustained objects, localized coherent patterns can signal information by propagating across the neural circuit. Computational operations occur when these emergent patterns interact, or collide with each other. The ongoing behaviors of these patterns naturally embody both distributed, parallel computation and cascaded logical operations. Such distributed computations enable the system to work in an inherently flexible and efficient way. Our work leads us to propose that propagating coherent activity patterns are the underlying primitives with which neural circuits carry out distributed dynamical computation. [ABSTRACT FROM AUTHOR]

We adopted the psychological refractoriness paradigm to study whether visual pattern goodness affects central processing load in a same-different task. In a dual-task experiment, a two-alternative forced choice auditory classification was followed by a same-different task in which Garner's classical five-dot patterns were presented. Goodness of these patterns and stimulus-onset asynchrony (SOA) between the first and second task were varied between trials. Participants used a physical sameness criterion; only patterns of the same shape and orientation were responded to as same. Strong effects of pattern goodness and SOA were found, and both factors had additive effects on response latencies. This result was taken as evidence that pattern goodness determines central processing load in the physical sameness task. The result is consistent with Lachmann and van Leeuwen (2007a ), in which a categorical sameness task was used. Comparing both studies it was concluded that goodness reduces the central processing load of visual stimulus information independently of task variation. [ABSTRACT FROM AUTHOR]

Abstract: Pairs of letters, pseudo-letters, and basic geometrical shapes were presented in a sequential same–different task, in which the time between the first and second items was varied. The second item was either presented in isolation or surrounded by an irrelevant geometrical shape that could be congruent or incongruent to the target. Congruence effects were obtained for shapes and pseudo-letters, but not for letters if the interval between the first and second items was short. Absence of congruence effects was interpreted, in accordance with earlier findings, as categorical influence on early visual integration processes; letters are processed less holistically than non-letter shapes. The present result indicates that categorical influence of letters depends on the time course of stimulus processing. As a highly automatized process, it is effective for stimuli appearing at a relatively fast rate, whereas, a slower rate of stimulus presentation eliminates task-irrelevant categorical influences. [Copyright &y& Elsevier]

Normally reading adults (N = 15) and primary school children (N = 24) and two diagnostic subgroups of children with developmental dyslexia (N = 21)—all native German speakers—performed a successive same-different task with pairs of letters and nonletters (pseudoletters or geometrical shapes). The first item of a pair was always presented on its own, and the second either on its own or surrounded by a congruent or incongruent nontarget shape. Adults showed congruence effects with nonletters but not with letters, and children with both types of stimuli. Frequent-word reading-impaired dyslexics (N = 11) in addition showed dramatically slower overall reaction times. Nonword reading-impaired dyslexics (N = 10) showed congruence effects with nonletters but negative congruence effects with letters. The results support the notion that normal readers have established a special visual processing strategy for letters. Processing speed rather than reading expertise seems crucial for this strategy to emerge. The contrasting effects between subgroups of dyslexics reveal specific underlying deficits. [ABSTRACT FROM AUTHOR]

LaRock provides a rather perplexing critique of the binding problem. He argues that neural synchrony, the proposed solution to the binding problem, is not sufficient to explain the unity of objects in visual consciousness. Did anyone claim it was? Neural synchrony can at best be necessary for consciousness, not sufficient. The binding problem originally has nothing to do with the conscious content of our perception. Misidentification of binding and consciousness may lead to tunnel vision with respect to other roles that neural synchrony could play in conscious experience. A different perspective is offered on how neural synchrony relates to visual consciousness. [ABSTRACT FROM AUTHOR]

In three experiments, participants determined the orientation of a global triangle formed by three Gabor patches of a target spatial frequency in a field of distracters. The orientation of the target patches and their proximity were varied between conditions. When all the target patches had the same orientation this facilitated the response compared to random orientations. This effect occurred only when the patches were in close proximity. When the orientations of the target patches were different but aligned to the global triangle, facilitation occurred regardless of proximity. These contrasting types of facilitation were attributed to different early perceptual integration mechanisms that enable the perception of holistic structure. [ABSTRACT FROM AUTHOR]

We adopted the Psychological Refractoriness Paradigm to study whether perceptual Goodness affects the load of central processing resources. In three dual-task experiments, 2-Alternative Forced Choice auditory classification was followed by a same–different task in which Garner’s classical five-dot patterns were presented. Goodness of these patterns and stimulus-onset asynchrony (SOA) between the first and second task were varied between trials. These factors had additive effects on response latencies and accuracy, indicating that pattern Goodness determines central processing load in performing the same–different task. In a fourth experiment, same–different judgment with Garner patterns was the single task. SOA between the first and second pattern was varied. Over-additive effects of Goodness with decreasing SOA were obtained, indicating sharing of central resources between consolidation of the first Garner pattern and performing the same–different task. Whereas, the resources needed for the latter, again, depend on Goodness, those needed for consolidation are independent of it. [ABSTRACT FROM AUTHOR]

In a number of studies, children diagnosed with developmental dyslexia reached normal scores in standard visual processing tasks, and some researchers concluded that visual processing deficits are not involved in the syndrome. The tasks used, however, may be insensitive to anomalous visual information processing strategies used to compensate for an underlying deficit. To determine whether children with dyslexia use anomalous visual processing strategies, a same�different task was applied, in which 2 items identical under rotation and reflection were judged as same. Pairs of letters or dot patterns were used, which were either symmetric or asymmetric in shape. Children with dyslexia performed faster than normal-reading children�in particular, remarkably, with letters. Symmetry of dot patterns facilitated performance in both children with dyslexia and normal-reading children; symmetry of letters facilitated performance in children with dyslexia but not in normal-reading children. Children with dyslexia, therefore, fail to adequately differentiate visual processing of linguistic and nonlinguistic materials; they process symmetry in letters similarly to that in shapes, which leads in this particular task to the paradoxical observation of children with dyslexia outperforming normal readers with letters. [ABSTRACT FROM AUTHOR]

Perceptual experience cast be explained by contextualized brain dynamics. An inner loop of ongoing activity within the brain produces dynamic patterns of synchronization and de-synchronization that are necessary, but not sufficient, for visual experience. This inner loop is controlled by evolution, development, socialization, learning, task and perception-action contingencies, which constitute an outer loop. This outer loop is sufficient, but not necessary, for visual experience. Jointly, the inner and outer loop may offer sufficient and necessary conditions for the emergence of visual experience. This hypothesis has methodological, empirical, theoretical, and philosophical implications. [ABSTRACT FROM AUTHOR]

We studied the relationship between perceptual switching in the Necker cube and long-distance transient phase synchronization in EEG. Transient periods of response related synchrony between parietal and frontal areas were observed. They start 800–600, ms prior to the switch response and occur in pairs. Four types of pairs could be distinguished, two of which are accompanied by transient alpha band activity in the occipital area. The results indicate that perceptual switching processes involve parietal and frontal areas; these are the ones that are normally associated with various cognitive processes. Sensory information in the visual areas is involved in some, but not in all, of switching processes. The intrinsic variability, as well as the participating areas, points to the role of strategic cognitive processes in perceptual switching. [ABSTRACT FROM AUTHOR]

Phase plots of coupled maps have shown turbulent, semi-ordered, intermittent and ordered behaviour as a function of control parameters for networks of uniform scale. We investigate the dependence of coupled map dynamics on scale, i.e . number of neurons. We compare results for globally coupled maps (GCMs) and ones with minor lesions, employing a new chaotic function that we propose. The behaviours are described in terms of phase transformations involving emergence, disappearance, migration, or engulfment of phases. [ABSTRACT FROM AUTHOR]

We studied context dependency of the representations underlying perceptual “goodness”. Three experiments used a same – different task with classical Garner 5-dot patterns presented with an interstimulus interval (ISI) of 500  ms. Same patterns were allowed to be rotated or reflected versions of each other. Pattern goodness was varied according to rotation and reflection equivalence, using GarneR&Rsquo;s equivalence set size (ESS) measure. The ESS of both first and second patterns affected reaction time and accuracy. A model based on assumptions that GarneR&Rsquo;s equivalence sets constitute the generic representation of these patterns and that items within these sets are accessed serially was fitted to the data. Excellent fits were obtained, which were robust against frequency-induced bias at the level of the individual pattern, but sensitive to such bias at the level of the equivalence set. It was concluded that individual pattern representations are context independent, whereas their collective representations are context dependent. Simplicity and likelihood principles, therefore, seem to apply to different levels of a representation hierarchy. [ABSTRACT FROM AUTHOR]

In two experiments, pairs of Garner’s classical 5-dot patterns were presented with an interstimulus interval of 500 ms in a same–different task in which a physical sameness criterion was used: Rotated or reflected versions of the same pattern were rated as different . Patterns varied in “goodness” according to Garner’s equivalence set size measure. Both first and second pattern goodness affected reaction time and accuracy. This result and fits of models to reaction time data indicate that equivalence set representations are used in the task, as in a related categorical matching task in previous studies. Two effects were observed that contrast with the categorical matching task: One is a conflict between the need to respond different to patterns that are categorically equivalent under the equivalence set representation; the other is that extra time is needed for rechecking of the representation if pattern structures are hard to distinguish. In combination with previous studies, the present results show that even though the processes differ, the same representational mechanism is used across tasks. [ABSTRACT FROM AUTHOR]

Abstract: Early perceptual grouping was studied using 256-channels event-related potentials in a choice response task. The task involved the detection of a triangle configuration of Gabor patches among patches of different spatial frequencies. The influence of two task-irrelevant factors was compared. One was the spatial proximity relation between the target patches and the other their relative orientation, a non-spatial relationship. Non-spatial effects were predominant in early peaks N64 and P100 in the occipital areas, and were reduced in size for later peaks. Spatial effects started from N180 in the occipital areas and continued in P250 and P430 in the central areas, increasing in size with time. These findings constitute a case of reversal of the usual order of spatial and non-spatial feature processing, illustrating that the flexibility in the early visual system may be greater than previously assumed. [Copyright &y& Elsevier]

High-density, 256-channel, event-related potentials (ERP) were recorded in 12 subjects, who had to find a triangle of which only the corners were marked in an array of distracters. The orientation of the corner markers to each other and their proximity varied across trials. An early, pre-attentional, nonspatial effect of marker orientation was found at 64 and 100 ms after stimulus presentation in the right occipital areas. A spatial effect of marker proximity (triangle size) was reflected in a negative peak of 180 ms in the occipital areas and in P250 and P430 in the central areas. This result is contrary to the usual precedence of spatial over nonspatial grouping and suggests a greater flexibility in precedence based on task demands. [Copyright &y& Elsevier]

Superposition of sigmoid function over a finite time interval is shown to be equivalent to the linear combination of the solutions of a linearly parameterized system of logistic differential equations. Due to the linearity with respect to the parameters of the system, it is possible to design an effective procedure for parameter adjustment. Stability properties of this procedure are analyzed. [ABSTRACT FROM AUTHOR]

To study the evolution of complex network with dynamical units, in this paper we consider the development of the network with chaotic units. By the addition of new nodes continuously and the adaptive rewiring of the connections according to the dynamic coherence of the activity patterns in the network, we can obtain that the growing network self-organizes into a complex network of which the connectivity distribution reveals a power law, at the same time, the network has a high clustering coefficient and small average shortest path length. The importance of chaos in the emergence of this type of scale-free network is investigated through comparing it to systems of periodic and stochastic units. The functional advantage of the self-organized network with dynamical units is revealed by showing the robustness of the spatiotemporal dynamics of the complex network. [Copyright &y& Elsevier]

The robustness and consistency of dynamic clustering behaviour in standard and adaptive coupled maps was investigated. For illustration purposes, a particular subset of dynamic clustering behaviour was chosen to represent information processing. This behaviour consists of the formation and annihilation of a limited number of synchronization clusters within an episode, which show quasi-periodic activity patterns. Metastable quasi-periodicity and dynamic clustering detection algorithms allow this behaviour to be observed in short segments of a system's orbit. Robustness and consistency of this behaviour were confirmed in compact support regions of the control parameter spaces of standard and extended coupled map systems. [ABSTRACT FROM AUTHOR]

Connectionist models based on activation spreading and attractor dynamics are functionally limited by representational and processing flexibility constraints, the 'feature binding problem' and the need to balance accurately activation and inhibition. We suggest an alternative approach, in which network units are characterized by two variables: activation and phase. Whereas activation evolves according to a 'classical' connectionist rule, the phase variable is characterized by a chaotic evolution. We present a model of memory retrieval with reference to the paradigmatic McClelland's 1981 'Jets and Sharks' model. The model solves the 'multiple reinstantiation problem', i.e. the problem of retrieval of multiple items with overlapping features, implied by its classical predecessor. In our network, multiple pattern reinstantiation in terms of activation spreading is disambiguate through selective and differential coherence patterns. The system flexibly represents pattern similarity and feature relationships by means of graded and intermittent synchrony. The domain-general implications of this approach for connectionist 'interactive activation models' and its neurophysiological plausibility are discussed. [ABSTRACT FROM AUTHOR]

Coupled map lattices (CMLs) offer a new framework for modelling visual information processes. The framework involves computing with non-stationary patterns of synchronized activity. In this framework structural features of the visual field emerge through the lateral interaction of locally coupled non-linear maps. Invariant representations develop independent of top-down, or re-entrant, feedback. These representations distort certain features of the pattern, giving rise to visual field illusions. Boundary contours, among others, are emphasized, which suggests that special cases of boundary contour problem could be solved by the system. Simulation studies were performed to test the hypothesis that the system represents visual patterns in a solid/outline invariant manner. A standard back-propagation neural network trained with a CML-filtered set of solid images and tested with CML-filtered outline versions of the same set of images (or vice versa) showed perfect generalization. Generalization failed to occur for unfiltered or contour-filtered images. The CML representations, therefore, were concluded to be solid/outline invariant. [ABSTRACT FROM AUTHOR]

In each of two experiments 992 novel compounds of associatively unrelated Dutch nouns were rated for 'plausibility' or meaningfulness of the compound. The independent variables of interest in Experiment 1 were associate-availability (high or low) and associate dominance (high or low). High availability and low dominance were found to lead to significantly higher plausibility ratings. Experiment 2 included a replication of Experiment 1 and extended its findings with a 'distractor' task condition and with a 'variable-scale' task condition. Whereas the effect of availability is expectable, the effect of dominance is not readily predictable on a priori grounds. This latter result was interpreted as favoring a network theory of retrieval over a rival decision theory. [ABSTRACT FROM AUTHOR]

Examines the plausibility of novel compounds. Plausibility through associate-availability and associate-dominance; Analysis of plausibility ratings in a four-factor variance; Multiple correlation.

Presents an experiment in pattern perception. Memory reproduction task performed by subjects; Study of puzzle pieces for 60 seconds; Implications on perceptual organization.

Discusses the ecologist realist concept of information as environmental specification. Notion of Gestalt quality; Objective information; Ecological formalism; Property of intentionality; Information as relational; Levels of theory in ecological realism; Multiple specification; Reconciliation; Intentionality in perception-action couplings.

An introduction to this issue is presented in which the editor discusses topics including the retirement of Bill Bechtel as an editor of the periodical, developments in philosophical and scientific thinking about the mind, and psychology of perception, cognition, and consciousness.

When freely viewing a scene, the eyes often return to previously visited locations. By tracking eye movements and coregistering eye movements and EEG, such refixations are shown to have multiple roles: repairing insufficient encoding from precursor fixations, supporting ongoing viewing by resampling relevant locations prioritized by precursor fixations, and aiding the construction of memory representations. All these functions of refixation behavior are understood to be underpinned by three oculomotor and cognitive systems and their associated brain structures. First, immediate saccade planning prior to refixations involves attentional selection of candidate locations to revisit. This process is likely supported by the dorsal attentional network. Second, visual working memory, involved in maintaining task-related information, is likely supported by the visual cortex. Third, higher-order relevance of scene locations, which depends on general knowledge and understanding of scene meaning, is likely supported by the hippocampal memory system. Working together, these structures bring about viewing behavior that balances exploring previously unvisited areas of a scene with exploiting visited areas through refixations. [ABSTRACT FROM AUTHOR]

We investigated visual working memory encoding across saccadic eye movements, focusing our analysis on refixation behavior. Over 10-s periods, participants performed a visual search for three, four, or five targets and remembered their orientations for a subsequent change-detection task. In 50% of the trials, one of the targets had its orientation changed. From the visual search period, we scored three types of refixations and applied measures for quantifying eye-fixation recurrence patterns. Repeated fixations on the same regions as well as repeated fixation patterns increased with memory load. Correct change detection was associated with more refixations on targets and less on distractors, with increased frequency of recurrence, and with longer intervals between refixations. The results are in accordance with the view that patterns of eye movement are an integral part of visual working memory representation. [ABSTRACT FROM AUTHOR]

Highlights • Spizzo's effect is a manifestation of extended agency in sensorimotor coordination. • Tapping along with a metronome induces agentive control on metronome pulses. • Fractal classification of tapping asynchronies and reaction times series. • Agentive control depends on fractal class of the series. • Tapping mode (anticipatory, reactive) reflects the type of agentive control. Abstract When we synchronize finger tapping with a visual metronome, we experience a strikingly robust phenomenon of extended agency known as Spizzo's effect. This effect is the compelling sense that we are controlling the metronome. The effect arises even though the agent knows that the metronome operates autonomously. We propose that the extended agency here established over metronome pulses results from sensorimotor coordination. To test this hypothesis, we operationalize sensorimotor coordination in terms of the correlation structures in series of asynchronies or reaction times from two finger-tapping tasks. Analyses reveal that, whereas correlation structures vary across individuals and show a systematic drift towards nonstationarity with increasing metronome frequency conditions, the presence of correlation structure is co-extensive with Spizzo's effect. We interpret this result as supporting the view that extended agency relies on sensorimotor coordination. Sensorimotor coordination, we suggest, may induce the effect by integrating the perception of visual pulses and the agency over tapping into a synesthetic experience. [ABSTRACT FROM AUTHOR]

Abstract Human connectome studies suggest that the brain has a modular small world network structure with rich-club effect. Such structure emerges spontaneously in simple model neural networks, (e.g. coupled maps), through adaptive rewiring according to the dynamic functional connectivity. The utility of adaptive rewiring has so far exclusively been demonstrated for unweighted networks; it is anything but guaranteed to work as well for weighted networks. We investigate adaptive rewiring in weighted networks, comparing various right-skewed, symmetrical, and left-skewed fixed weight distributions. We examine how network clustering, path length, modularity, and rich club coefficients develop for weakly, intermediate and strongly coupled networks. At low coupling strength, the weight distribution, as well as episodes of functional synchrony, have a significant effect on network evolution. With increased coupling strengths, all weighted networks robustly develop architectures similar to the unweighted ones. Adaptive rewiring appears relatively ineffective in networks with (biologically implausibly) extreme right-skewed weight distributions but performed most economically in biologically plausible log-normal distributions. [ABSTRACT FROM AUTHOR]

Abstract We studied the global precedence effect in primary school children with and without developmental dyslexia, using a compound figures task with familiar (Latin) or unfamiliar (Hebrew) letters. The two components of the global precedence effect were considered separately: global advantage (faster processing of global than local letters) and asymmetric interference (global distracters interfere with local targets but not vice versa). Both groups of children showed a global advantage with familiar as well as with unfamiliar letters. Children without developmental dyslexia showed asymmetric interference on familiar letters, but not on unfamiliar ones. Children with developmental dyslexia showed no asymmetric interference, neither for familiar letters nor for unfamiliar ones. The results distinguish between alternative hypothesis regarding the roles of familiarity and visual processing strategies in the compound figures task. Consequences for understanding literacy acquisition and developmental dyslexia are discussed. [ABSTRACT FROM AUTHOR]

In free viewing, the eyes return to previously visited locations rather frequently, even though the attentional and memory-related processes controlling eyemovement show a strong antirefixation bias. To overcome this bias, a special refixation triggering mechanism may have to be recruited. We probed the neural evidence for such a mechanism by combining eye tracking with EEG recording. A distinctive signal associated with refixation planning was observed in the EEG during the presaccadic interval: the presaccadic potential was reduced in amplitude before a refixation compared with normal fixations. The result offers direct evidence for a special refixation mechanism that operates in the saccade planning stage of eye movement control. Once the eyes have landed on the revisited location, acquisition of visual information proceeds indistinguishably from ordinary fixations. [ABSTRACT FROM AUTHOR]

Presents comments on an article by Ichiro Tsuda regarding interpretation of dynamic neural activity in terms of chaotic dynamical systems. Opinion on the brain processing theory; Result of studies on dynamic interplay of local and global processes in visual perception; Role of neural chaos.

Presents an attempt to provide a faithful mapping from distal shape space to proximal state space in terms of a higher order relationship defined over proximal similarity space stumbles on the context sensitivity of higher order relationships. What involves the mathematical properties of isomorphism; Relevance of surplus structural information.

Culture-related differences in visual creativity were investigated, comparing Italian and Japanese participants in terms of divergent (figural completion task) and product-oriented thinking (figural combination task). Visual restructuring ability was measured as the ability to reinterpret ambiguous figures and was included as a covariate. Results showed that in divergent thinking, Italians only outperformed Japanese participants in elaboration and in product-oriented thinking in terms of originality of products. Visual restructuring ability was found to play a key role both in originality and practicality of products. Both groups scored the same in terms of fluency, originality, and flexibility of visual divergent thinking, as well as in term of practicality of creative products. These findings are consistent with the idea that Italians and Japanese have the same creative potential, although from the early stages of the design Japanese seem to show a greater tendency to take practicality constraints into account when creating in the visual domain. [ABSTRACT FROM AUTHOR]

Co-registration of EEG and eye movement has promise for investigating perceptual processes in free viewing conditions, provided certain methodological challenges can be addressed. Most of these arise from the self-paced character of eye movements in free viewing conditions. Successive eye movements occur within short time intervals. Their evoked activity is likely to distort the EEG signal during fixation. Due to the non-uniform distribution of fixation durations, these distortions are systematic, survive across-trials averaging, and can become a source of confounding. We illustrate this problem with effects of sequential eye movements on the evoked potentials and time-frequency components of EEG and propose a solution based on matching of eye movement characteristics between experimental conditions. The proposal leads to a discussion of which eye movement characteristics are to be matched, depending on the EEG activity of interest. We also compare segmentation of EEG into saccade-related epochs relative to saccade and fixation onsets and discuss the problem of baseline selection and its solution. Further recommendations are given for implementing EEG-eye movement co-registration in free viewing conditions. By resolving some of the methodological problems involved, we aim to facilitate the transition from the traditional stimulus-response paradigm to the study of visual perception in more naturalistic conditions. [ABSTRACT FROM AUTHOR]

The article discusses a study that investigates the high storage capacity of synfire chains. The authors demonstrate stable dynamics of synchronous pulse packet propagation and global asynchronous irregular (AI) activity in a sparse network of spiking neurons. It shows that synfire waves are initiated by ongoing, intermittent delivery of external input pulses.