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Here we examine the plausibility of deep convolutional neural networks (CNNs) as a theoretical framework for understanding biological vision in the context of image classification. Recent work on object recognition in human vision has shown that both global, and local, shape information is computed, and integrated, early during perceptual processing. Our goal was to compare the similarity in how object shape information is processed by CNNs and human observers. We tested the hypothesis that, unlike the human system, CNNs do not compute representations of global and local object geometry during image classification. To do so, we trained and tested six CNNs (AlexNet, VGG-11, VGG-16, ResNet-18, ResNet-50, GoogLeNet), and human observers, to discriminate geometrically possible and impossible objects. The ability to complete this task requires computation of a representational structure of shape that encodes both global and local object geometry because the detection of impossibility derives from an incongruity between well-formed local feature conjunctions and their integration into a geometrically well-formed 3D global shape. Unlike human observers, none of the tested CNNs could reliably discriminate between possible and impossible objects. Detailed analyses using gradient-weighted class activation mapping (GradCam) of CNN image feature processing showed that network classification performance was not constrained by object geometry. In contrast, if classification could be made based solely on local feature information in line drawings the CNNs were highly accurate. We argue that these findings reflect fundamental differences between CNNs and human vision in terms of underlying image processing structure. Notably, unlike human vision, CNNs do not compute representations of object geometry. The results challenge the plausibility of CNNs as a framework for understanding image classification in biological vision systems. [ABSTRACT FROM AUTHOR]

The drift-diffusion model (DDM) is a common approach to understanding human decision making. It considers decision making as accumulation of evidence about visual stimuli until sufficient evidence is reached to make a decision (decision boundary). Recently, Smith and colleagues proposed an extension of DDM, the time-varying DDM (TV-DDM). Here, the standard simplification that evidence accumulation operates on a fully formed representation of perceptual information is replaced with a perceptual integration stage modulating evidence accumulation. They suggested that this model particularly captures decision making regarding stimuli with dynamic noise. We tested this new model in two studies by using Bayesian parameter estimation and model comparison with marginal likelihoods. The first study replicated Smith and colleagues' findings by utilizing the classical random-dot kinomatogram (RDK) task, which requires judging the motion direction of randomly moving dots (motion discrimination task). In the second study, we used a novel type of stimulus designed to be like RDKs but with randomized hue of stationary dots (color discrimination task). This study also found TV-DDM to be superior, suggesting that perceptual integration is also relevant for static noise possibly where integration over space is required. We also found support for within-trial changes in decision boundaries ("collapsing boundaries"). Interestingly, and in contrast to most studies, the boundaries increased with increasing task difficulty (amount of noise). Future studies will need to test this finding in a formal model. [ABSTRACT FROM AUTHOR]

In the last years, museums around the world began using museum guide robots as an alternative to audio guides. Thus, it is important to identify how these new museum guides can optimally interact with visitors and whether they are more efficient that conventional audio guides. In this paper, we present the results from an experimental study which compared conventional audio guides with robots with different 'personality'. These results demonstrate that people remember significantly more information when they are guided by a cheerful robot than when their guide is a serious one or a conventional audio system. Importantly, we also introduce the idea of two collaborative tour guide robots. This idea was inspired by cognitive studies showing that people remember more when they receive information from two different human speakers. Interestingly, our participants also liked more our collaborative robots, than any version of a single robot and/or audio system. [ABSTRACT FROM AUTHOR]

Humans have considerably modified their environment by making and building a number of tools, technologies, and constructions. This unique ability compared to other animals is the focus of researchers in different fields of psychology. However, there is confusion about the definitions proposed, generating difficulties in making connections between those different fields. This article presents the first unified framework (i.e., intoolligence) aiming to overcome these issues by focusing on the cognitive processes involved in the different forms taken by human tool use and technology, rather than on the overt behavior. To lay the foundation for intoolligence, we first address a series of epistemological misconceptions, which are the root cause for the current confusion. Particularly, we discuss the limitations of the widespread idea that tool use relies on specific cognitive skills, centered on the manipulative aspect of tool use. We develop, based on this analysis, details concerning our framework, which is based on the key principle that making and using are 2 independent cognitive steps. This distinction allows us to redefine tool use by breaking it down into 3 modes: assistive tool use, arbitrary tool use, and free tool use. This article opens a new chapter on the topic of human tool use and technology. [ABSTRACT FROM AUTHOR]

Potential interactions between objects affect response selection in action-related object pairs. The present paper aimed to examine whether this effect is conditional on the knowledge about object functionality, or whether action-related structures such as handles are sufficient. This issue was investigated by utilizing a paradigm established previously. They presented imperative central targets which overlapped with task-irrelevant object pairs and required speeded left/right responses to the targets. With this paradigm, two stable effects of implied actions between objects on response selection have been identified: an inhibitory effect on responses aligned with the passive object (e.g., a bowl in a bowl–spoon pair) and an advantage associated with responses aligned with the active objects (e.g., a spoon). The present paper utilized these two effects as the indexes of response selection in paired-object scenarios, and found that active–passive object pairs without established functionality (e.g., a saw and a bowl, Experiment 1) generated the same effects, suggesting that response selection does not rely on functionality knowledge of given object pairs. Further, the two effects were also observed in passive–passive object pairs with handles (e.g., a cup–nail pair), but not in those without a handle (e.g., a bowl–nail pair, Experiment 2), and remained when the active objects were replaced by novel objects with handle but no known functionality (Experiment 3), suggesting that the action-related structures of objects are sufficient to affect response selection. The present study empirically illustrated the automaticity and directness of the extraction of potential interaction between objects, probably based on the relative location of action-related structure of objects. [ABSTRACT FROM AUTHOR]

Psychopathy and metacognitive difficulties have been associated with the occurrence of violence in schizophrenia. However, evidence suggests that nonschizophrenic psychopaths match or even outperform healthy controls on tests of metacognition. We hypothesize that the metacognitive difficulties associated with schizophrenia may be ameliorated by comorbid psychopathy. To this end, metacognition (using the Metacognition Assessment Scale-Abbreviated [MAS-A]) and psychopathy (using the Hare Psychopathy Checklist-Revised [PCL-R]) are assessed in 79 patients with schizophrenia with a history of criminal offending. Piecewise regression reveals that the association between metacognition and psychopathy changes from a negative to a positive association at a breakpoint corresponding to a score of 24 on the PCL-R. This score is within the range of the cut-off point used for the diagnosis of psychopathy in Europe, which corresponds to a score of 26 on the PCL-R. The patients scoring above 24 on the PCL-R demonstrated better overall metacognitive abilities, suggesting that these patients constitute a specific group in which schizophrenia has an attenuated impairing effect on metacognition. However, this effect was absent for the Mastery subscale of the MAS-A, which refers to the ability to use one's own mental states to solve social and psychological dilemmas. Our results suggest that the relative preservation of metacognitive abilities in schizophrenic patients with extreme levels of psychopathy may contribute to their offending behavior as it may enable them to understand how to manipulate and extort their victims. However, enhancing the Mastery domain of metacognition in these patients may attenuate this offending behavior. [ABSTRACT FROM AUTHOR]

Everyday perception-action interaction often requires selection of a single goal from multiple possibilities. According to a recent framework of attentional control, object selection is guided not only by the well-established factors of perceptual salience and current goals but also by selection history. Yet, underlying mechanisms linking selection history and visually-guided actions are poorly understood. To examine such interplay and disentangle the impact of target and distractor history on action selection, we employed a priming-of-popout (PoP) paradigm combined with continuous tracking of reaching movements and computational modeling. Participants reached an odd-colored target among homogeneous distractors while we systematically manipulated the sequence of target and distractor colors from one trial to the next. We observed that current reach movements were significantly influenced by the interaction between attraction by the prior target feature and repulsion by the prior distractor feature. With principal component regression, we found that inhibition led by prior distractors influenced reach target selection earlier than facilitation led by the prior target. In parallel, our newly developed computational model validated that current reach target selection can be explained best by the mechanism postulating the preceded impact of previous distractors followed by a previous target. Such converging empirical and computational evidence suggests that the prior selection history triggers a dynamic interplay between target facilitation and distractor inhibition to guide goal-directed action successfully. This, in turn, highlights the necessity of an explicitly integrated approach to determine how visual attentional selection links with adaptive actions in a complex environment. Author summary: Most real-world visual scenes are complex and crowded, where multiple objects compete for attention and goal-directed action. The interactions between mechanisms of attentional selection and action selection are at the root of many complex behaviors. However, their link has been understudied. To examine this interplay and disentangle the impact of target and distractor history on action selection, we employed a priming-of-popout (PoP) paradigm combined with continuous tracking of reaching movements and computational modeling. This integrated approach constitutes a significant departure from existing practice, where attention and action selection mechanisms are typically investigated separately. Our converging evidence supports the notion that prior selection history triggers a dynamic interplay between target facilitation and distractor inhibition to guide goal-directed action successfully. This finding highlights the necessity of an explicitly integrated approach to determine how visual attentional selection links with adaptive actions in complex environments. Taken together, our study provides valuable insights into the mechanisms underlying attentional selection and action selection, and has important implications for future research in this field. [ABSTRACT FROM AUTHOR]

In this study, we applied Bayesian-based distributional analyses to examine the shapes of response time (RT) distributions in three visual search paradigms, which varied in task difficulty. In further analyses we investigated two common observations in visual search-the effects of display size and of variations in search efficiency across different task conditions-following a design that had been used in previous studies (Palmer, Horowitz, Torralba, & Wolfe, Journal of Experimental Psychology: Human Perception and Performance, 37, 58-71, ; Wolfe, Palmer, & Horowitz, Vision Research, 50, 1304-1311, ) in which parameters of the response distributions were measured. Our study showed that the distributional parameters in an experimental condition can be reliably estimated by moderate sample sizes when Monte Carlo simulation techniques are applied. More importantly, by analyzing trial RTs, we were able to extract paradigm-dependent shape changes in the RT distributions that could be accounted for by using the EZ2 diffusion model. The study showed that Bayesian-based RT distribution analyses can provide an important means to investigate the underlying cognitive processes in search, including stimulus grouping and the bottom-up guidance of attention. [ABSTRACT FROM AUTHOR]

Inhibition of return (IOR) refers to the performance disadvantage when detecting a target presented at a previously cued location. The current paper contributes to the long-standing debate whether IOR is caused by attentional processing or perceptual processing. We present a series of four experiments which varied the cue luminance in mixed and blocked conditions. We hypothesised that if inhibition was initialized by an attentional process the size of IOR should not vary in the blocked condition as participants should be able to adapt to the level of cue luminance. However, if a perceptual process triggers inhibition both experimental manipulations should lead to varying levels of IOR. Indeed, we found evidence for the latter hypothesis. In addition, we also varied the target luminance in blocked and mixed condition. Both manipulations, cue luminance and target luminance, affected IOR in an additive fashion suggesting that the two stimuli affect human behaviour on different processing stages. [ABSTRACT FROM AUTHOR]

Abstract: We provide novel evidence for a two-stage model of visual search applied to the selection based on top-down cues to stimulus colour and orientation. The model supposes that visual displays are first parsed into colour based groups, a process that is modulated by the presence of an initial cue to the target’s colour. Subsequently search is directed to other featural properties represented within the colour-based groups. Cues to the orientation of the target are only effective at this second stage. The results provide strong evidence that colour and orientation cues operate in different ways to guide search. [Copyright &y& Elsevier]

Abstract: Previous studies have demonstrated that observers can search through a subset of items carrying a minority feature to find a conjunction target (). We examined whether subset search takes place when participants have less specific foreknowledge of the target (when the target is one of two possible items), measuring eye movements as well as reaction times. When there were unequal ratios of distractors, fixations were initially directed to the small subset. These initial eye movements were often directed between items with the same feature, suggesting guidance from pooled feature values. There was stronger guidance within color- than orientation-defined groups, although the features were balanced for salience. The results suggest that grouping of items by color operates more globally than grouping in orientation. [Copyright &y& Elsevier]

Inhibition of return (IOR) occurs when reaction times (RTs) are slowed to respond to a target that appears at a previously attended location. We used the speed-accuracy trade-off (SAT) procedure to obtain conjoint measures of IOR on sensitivity and processing speed by presenting targets at cued and uncued locations. The results showed that IOR is associated with both delays in processing speed and shifts in response criterion. When the target was briefly presented, the results supported a criterion shift account of IOR. However, when the target was presented until response, the evidence indicated that, in addition to a response bias effect, there was an increase in the minimal time required for information about the target to accumulate above chance level. A hybrid account of IOR is suggested that describes effects on both response bias and perceptual processing. [ABSTRACT FROM AUTHOR]

Using a cued conjunction search task, Anderson, Heinke, and Humphreys (2010) demonstrated larger effects from cueing target colour than from cueing target orientation. In this study, we separated the implicit (nonexpectation-dependent) and explicit (expectation-dependent) effects of orientation and colour visual cues. In Experiment 1, we replicated the original findings for short cue durations (100-200 ms), demonstrating that cues matching the physical property of the target on 80% of trials exert a rapid effect on search. These early cueing effects on reaction times were supported by evidence of guidance from cues on early eye movements. Experiment 2 introduced a feature to the cue that randomly matched the colour or orientation of the target. When cue orientation was predictive, there were strong implicit effects based on whether the colour of the cue and target matched. When cue colour was predictive, there were only weak effects from the cue's orientation. Implicit effects from cue colour remained when orientation-predictive cues were used and colour was unlikely to predict the target (Experiment 3). The data suggest that strong effects of colour cueing result from a combination of implicit and explicit processes, whereas effects from orientation cues are largely limited to the explicit guidance of visual search. [ABSTRACT FROM AUTHOR]

We present the case for a role of biologically plausible neural network modeling in bridging the gap between physiology and behavior. We argue that spiking-level networks can allow "vertical" translation between physiological properties of neural systems and emergent `whole-system" performance- enabling psychological results to be simulated from implemented networks and also inferences to be made from simulations concerning processing at a neural level. These models also emphasize particular factors (e.g. the dynamics of performance in relation to real-time neuronal processing) that are not highlighted in other approaches and that can be tested empirically. We illustrate our argument from neural-level models that select stimuli by biased competition. We show that a model with biased competition dynamics can simulate data ranging from physiological studies of single-cell activity (Study 1) to whole-system behavior in human visual search (Study 2), while also capturing effects at an intermediate level, including performance breakdown after neural lesion (Study 3) and data from brain imaging (Study 4). We also show that, at each level of analysis, novel predictions can be derived from the biologically plausible parameters adopted, which we proceed to test (Study 5). We argue that, at least for studying the dynamics of visual attention, the approach productively links single-cell to psychological data. [ABSTRACT FROM AUTHOR]

The search over time and space (sSoTS) model attempts to simulate both the spatial and the temporal aspects of human visual search using spiking level neurons, which incorporate some biologically plausible aspects of neuronal firing. The model contains pools of units that (a) code basic features of objects, presumed to reside in the ventral visual stream, and (b) respond in a feature-independent way to stimulation at their location, presumed to operate in the posterior parietal cortex. We examined the effects of selective lesioning neurons responding to one side of the location map. Unilateral damage introduced spatial biases into selection that affected conjunction more than single-feature search. In addition, there was an impaired ability to segment stimuli over time as well as space (e.g., in preview search). These results match previously reported data on patients with posterior parietal lesions. In addition we show that spatial biases in selection increase under conditions in which there is decreased activity from excitatory neurotransmitters, mimicking effects of reduced arousal. Further simulations explored the effects of time and of visual grouping on extinction, generating predictions that were then tested empirically. The model provides a framework for linking behavioural data from patients with neural-level determinants of visual attention. [ABSTRACT FROM AUTHOR]

In the real world, visual information is selected over time as well as space, when we prioritise new stimuli for attention. Watson and Humphreys [Visual marking: prioritising selection for new objects by top-down attentional inhibition of old objects. Psychol. Rev. 104 (1997) 90–122] presented evidence that the prioritisation of new information in search tasks depends, at least in part, on the active ignoring of old items–a process they termed visual marking. In the present paper we present for the first time an explicit computational model of visual marking using a biologically plausible neural network. The model incorporates different synaptic components and a frequency adaptation mechanism, which acts to suppress the previously attended items. We show that, when coupled with a process of active inhibition to the old items, the pattern of preview search can be captured, as well as both efficient and inefficient search patterns in baseline conditions. The simulations point to the involvement of both active and passive inhibitory mechanisms in the preview effect in human search. [Copyright &y& Elsevier]

Our aim has been to study visual search in hierarchical patterns through a computational neuroscience perspective. In this way we were able to analyse the relationship between the global precedence effect and attention. The theoretical part of our investigations extended a model built upon the biased-competition hypothesis. An important feature of this extension is that different spatial frequencies are processed with different time constants. Simulations with this model resulted in specific predictions that were confirmed with a novel visual-search experiment utilising hierarchical patterns. Both experiment and simulations suggest that the global-precedence effect prevails under the condition of visual search. [ABSTRACT FROM AUTHOR]

We present a revised version of the Selective Attention for Identification Model (SAIM), using an initial feature detection process to code edge orientations. We show that the revised SAIM can simulate both efficient and inefficient human search, that it shows search asymmetries, and that top-down expectancies for targets play a major role in the model's selection. Predictions of the model for top-down effects are tested with human participants, and important similarities and dissimilarities are discussed. [ABSTRACT FROM AUTHOR]

Abstract: In the real world, visual information is selected over time as well as space, when we prioritise new stimuli for attention. Watson and Humphreys [Watson, D., Humphreys, G.W., 1997. Visual marking: prioritizing selection for new objects by top–down attentional inhibition of old objects. Psychological Review 104, 90–122] presented evidence that new information in search tasks is prioritised by (amongst other processes) active ignoring of old items – a process they termed visual marking. In this paper we present, for the first time, an explicit computational model of visual marking using biologically plausible activation functions. The “spiking search over time and space” model (sSoTS) incorporates different synaptic components (NMDA, AMPA, GABA) and a frequency adaptation mechanism based on [Ca2+] sensitive K+ current. This frequency adaptation current can act as a mechanism that suppresses the previously attended items. We show that, when coupled with a process of active inhibition applied to old items, frequency adaptation leads to old items being de-prioritised (and new items prioritised) across time in search. Furthermore, the time course of these processes mimics the time course of the preview effect in human search. The results indicate that the sSoTS model can provide a biologically plausible account of human search over time as well as space. [Copyright &y& Elsevier]

Four experiments explored the interrelations between working memory, attention, and eye movements. Observers had to identify a tilted line amongst vertical distractors. Each line was surrounded by a colored shape that could be precued by a matching item held in memory. Relative to a neutral baseline, in which no shapes matched the memory item, search was more efficient when the memory cue matched the shape containing the target, and it was less efficient when the cued stimulus contained a distractor. Cuing affected the shortest reaction times and the first saccade in search. The effect occurred even when the memory cue was always invalid but not when the cue did not have to be held in memory. There was also no evidence for priming effects between consecutive trials. The results suggest that there can be early, involuntary top-down directing of attention to a stimulus matching the contents of working memory. [ABSTRACT FROM AUTHOR]

The selective attention for identification model (SAIM) is presented. This uses a spatial window to select visual information for recognition, binding parts to objects and generating translation-invariant recognition. The model provides a qualitative account of both normal and disordered attention. Simulations of normal attention demonstrate 2-object costs and effects of object familiarity on selection, global precedence, spatial cueing, and inhibition of return. When lesioned. SAIM demonstrated either view- or object-centered neglect or spatial extinction, depending on the type and extent of lesion. The model provides a framework to unify (a) object- and space-based theories of normal selection, (b) dissociations within the syndrome of unilateral neglect, and (c) attentional and representational accounts of neglect. [ABSTRACT FROM AUTHOR]

On the basis of a computational and neurodynamical model, we investigate a cognitive impairment in stroke patients termed visual neglect. The model is based on the “biased competition hypothesis” and is structured in several network modules which are related to the dorsal and ventral pathway in the visual cortex. By damaging the model, visual neglect can be simulated and explained as an unbalanced neurodynamical competition. We predict that acquiring knowledge of objects can increase the frequency of saccades to previously ignored object parts. This prediction is confirmed in a single case study by monitoring eye movements of a neglect patient. [Copyright &y& Elsevier]

We have presented a computational model called selective attention for identification model (SAIM), that can account for a broad range of psychological and neuropsychological phenomena on attention [1]. In this paper we report on work that extends SAIM to model data from visual search tasks. The results show that SAIM can capture important aspects of findings in visual search experiments, including variations of search slopes with the similarity between targets and distractors. SAIM is also capable of simulating experimental findings for redundant targets, including the violation of the Miller inequality. SAIM explains these experimental findings as the consequence of competitive processes involved in object identification. [Copyright &y& Elsevier]

There is increasing experimental and neuropsychological evidence that action selection is directly constrained by perceptual information from objects as well as by more abstract semantic knowledge. To capture this evidence, we develop a new connectionist model of action and name selection from objects - NAM (Naming and Action Model), based on the idea that action selection is determined by convergent input from both visual structural descriptions and abstract semantic knowledge. We show that NAM is able to simulate evidence for a direct route to action selection from both normal subjects (Experiments 1 and 2) and neuropsychological patients (Experiments 3-6). The model provides a useful framework for understanding how perceptual knowledge influences action selection. [ABSTRACT FROM AUTHOR]

Presents information on a study which used multilayer perception (MLP) on real-world data, in an effort to compare the performance of neural networks. Identification of the networks; Indication that the real-world datasets consist of four different datasets; Performance of the networks on the datasets; Application of statistical evaluations of the study.

Agrees with the thinking of John Findlay, professor of psychology and Robin Walker, psychology lecturer that detailed accounts of visually guided behavior will need to explain selection over time and selection over space. How the coupled `When' and `Where' systems operate in practice; Discussion on temporal preparation and cognitive control of saccade timing parameters; Argument on the proposal that saccades to a target are disrupted by remote distractors.

Humans can point fairly accurately to memorized states when closing their eyes despite slow or even missing sensory feedback. It is also common that the arm dynamics changes during development or from injuries. We propose a biologically motivated implementation of an arm controller that includes an adaptive observer. Our implementation is based on the neural field framework, and we show how a path integration mechanism can be trained from few examples. Our results illustrate successful generalization of path integration with a dynamic neural field by which the robotic arm can move in arbitrary directions and velocities. Also, by adapting the strength of the motor effect the observer implicitly learns to compensate an image acquisition delay in the sensory system. Our dynamic implementation of an observer successfully guides the arm toward the target in the dark, and the model produces movements with a bell-shaped velocity profile, consistent with human behavior data. [ABSTRACT FROM AUTHOR]

In this paper we consider recent advances in the use of deep convolutional neural networks to understanding biological vision. We focus on claims about the plausibility of feedforward deep convolutional neural networks (fDCNNs) as models of image classification in the biological system. Despite the putative similarity of these networks to some properties of the biological vision system, and the remarkable levels of performance accuracy of some fDCNNs, we argue that their plausibility as a framework for understanding image classification remains unclear. We highlight two key issues that we suggest are relevant to the evaluation of any form of DNN used to examine biological vision: (1) Network transparency under analysis - that is, the challenge of understanding what networks do, and how they do it. (2) Identifying appropriate benchmarks for comparing network performance and the biological system using both quantitative and qualitative performance measures. We show that there are important divergences between fDCNNs and biological vision that reflect fundamental differences in computational architectures, and representational structures, supporting image classification in these networks and the biological system. [ABSTRACT FROM AUTHOR]

Evidence from experiments with single objects indicates that perceiving objects leads to automatic extraction of affordances. Here we examined the influence of implied between-object actions on affordance processing. Images of task-irrelevant object pairs (e.g., a spoon and a bowl) were followed by imperative central targets. Participants made speeded left/right responses to targets, and the responses randomly aligned with the affordance of one of the objects. The orientation of one object was manipulated across trials, leaving the colocation between objects correct or incorrect for potential interaction. Four experiments demonstrated that positioning the objects correctly for between-object actions led to a prioritization of the object active in the action (e.g., the spoon) over the passive (e.g., the bowl) object. Moreover, there was an inhibitory effect on responses to the passive object: responses congruent with the passive object were slower when pairs of objects were shown as if in interaction, compared with when they were not. The effects did not change in the single-hand response task but disappeared when the passive objects were absent--though an affordance should still have been presented by the active object. These results present evidence for affordance selection in action-related object pairs, and suggest inhibition of the action afforded by the passive objects under conditions of affordance competition. [ABSTRACT FROM AUTHOR]

We examined the effects of cue luminance on visual orienting. Experiment 1 established that the commonly-found early facilitation and late inhibition of return (IOR) effects were independent of cue luminance with single cues in terms of their amplitude, although IOR was delayed in the low compared to the high luminance cue condition. In contrast, Experiment 2 revealed that, with dual cues of mixed luminance, both facilitation and IOR effects were found only with bright cues. When cues had equal luminance, however, there were cueing effects for two cued locations but only when the cues were bright. The data were accommodated in a neural network model of biased competition in which cueing effects emerge at more than one location provided input activation is sufficient to overcome competitive damping of the selection system. [ABSTRACT FROM PUBLISHER]

Abstract: Working memory plays a crucial role in the control of visual selection. Previous research has shown that attentional deployment can be biased to objects in an array matching the contents of working memory. Here, we examined the role of the frontal cortex in determining the interaction between working memory and attention. At the start of each trial, participants memorized an object cue that could contain either the target or a distracter, when the object reappeared in the subsequent search array. Relative to age-matched controls, patients suffering from damage to the frontal lobes showed a stronger effect of the memory stimulus on search. Interestingly, there was an effect of frontal damage on the mean latencies to fixate targets but the effect of memory validity on the number of first saccades to the target, and their time of initiation, was similar across the groups. The results suggest that, following the earliest deployment of attention, frontal lobe structures are involved in separating relevant target from irrelevant (object cue) information, when both are held in memory. [Copyright &y& Elsevier]

Abstract: Top-down feedback from working memory (WM) can exert an early and involuntary influence on visual selection for targets that are relatively difficult to discriminate [Soto, D., Heinke, D., Humphreys, G. W., & Blanco, M. J. (2005) Journal of Experimental Psychology: Human Perception and Performance, 31, 248]. Here, we demonstrate similar effects even on search for a pop-out target. At the beginning of each trial, participants memorized a prime that could contain either the search target or a distracter in the subsequent search array. Targets and distractors were easily discriminable. Despite this, the prime in WM affected responses latencies and the direction of the first saccade. Top-down search, guided by the contents of WM, can modulate selection even when salient bottom-up cues are present. [Copyright &y& Elsevier]

Top-down feedback from working memory (WM) can exert an early and involuntary influence on visual selection for targets that are relatively difficult to discriminate [Soto, D., Heinke, D., Humphreys, G. W., & Blanco, M. J. (2005) Journal of Experimental Psychology: Human Perception and Performance, 31, 248]. Here, we demonstrate similar effects even on search for a pop-out target. At the beginning of each trial, participants memorized a prime that could contain either the search target or a distracter in the subsequent search array. Targets and distractors were easily discriminable. Despite this, the prime in WM affected responses latencies and the direction of the first saccade. Top-down search, guided by the contents of WM, can modulate selection even when salient bottom-up cues are present. [ABSTRACT FROM AUTHOR]

Spontaneous Trait Inference (STI) is a psychological phenomenon that allows people to infer personality traits from others' behaviors without any intention or awareness. This phenomenon helps us organize our complex social world and ultimately it shapes our interaction with others. The goal of this manuscript is 1) to conduct a systematic analysis of the different types of measures that are currently used to detect inferences, 2) to identify their main limitations and 3) to propose a new paradigm that overcomes most of these limitations. The new paradigm is based on the modified free association task that Hourihan and MacLeod (2007) proposed as a pure conceptual implicit memory measure. This new paradigm simultaneously overcomes the contamination problem of memory measures and the dependency on data-driven processing of the activation measures. In the presented experiments we use the modified free association paradigm to detect STIs and also to compare its results to the naming task and the modified Stroop task. We show that this measure is able to reliably detect STI and discuss why it is more appropriate to study inferences. Additionally, we show that it can be used to investigate the underlying processes responsible for STI and to distinguish it from similar but different phenomena like Spontaneous Trait Transference. This manuscript focuses on STIs, but the arguments presented here apply to any research field that investigates spontaneous inference making. [ABSTRACT FROM AUTHOR]

Perceiving and selecting the action possibilities (affordances) provided by objects is an important challenge to human vision, and is not limited to single-object scenarios. Xu et al. (2015) identified two effects of implied actions between paired objects on response selection: an inhibitory effect on responses aligned with the passive object in the pair (e.g. a bowl) and an advantage associated with responses aligned with the active objects (e.g. a spoon). The present study investigated the neurocognitive mechanisms behind these effects by examining the involvement of the ventral (vision for perception) and the dorsal (vision for action) visual streams, as defined in Goodale and Milner's (1992) two visual stream theory. Online repetitive transcranial magnetic stimulation (rTMS) applied to the left anterior intraparietal sulcus (aIPS) reduced both the inhibitory effect of implied actions on responses aligned with the passive objects and the advantage of those aligned with the active objects, but only when the active objects were contralateral to the stimulation. rTMS to the left lateral occipital areas (LO) did not significantly alter the influence of implied actions. The results reveal that the dorsal visual stream is crucial not only in single-object affordance processing, but also in responding to implied actions between objects. [ABSTRACT FROM AUTHOR]

We present an extension of a neurobiologically inspired robotics model, termed CoRLEGO (Choice reaching with a LEGO arm robot). CoRLEGO models experimental evidence from choice reaching tasks (CRT). In a CRT participants are asked to rapidly reach and touch an item presented on the screen. These experiments show that non-target items can divert the reaching movement away from the ideal trajectory to the target item. This is seen as evidence attentional selection of reaching targets can leak into the motor system. Using competitive target selection and topological representations of motor parameters (dynamic neural fields) CoRLEGO is able to mimic this leakage effect. Furthermore if the reaching target is determined by its colour oddity (i.e. a green square among red squares or vice versa), the reaching trajectories become straighter with repetitions of the target colour (colour streaks). This colour priming effect can also be modelled with CoRLEGO. The paper also presents an extension of CoRLEGO. This extension mimics findings that transcranial direct current stimulation (tDCS) over the motor cortex modulates the colour priming effect (Woodgate et al., 2015). The results with the new CoRLEGO suggest that feedback connections from the motor system to the brain’s attentional system (parietal cortex) guide visual attention to extract movement-relevant information (i.e. colour) from visual stimuli. This paper adds to growing evidence that there is a close interaction between the motor system and the attention system. This evidence contradicts the traditional conceptualization of the motor system as the endpoint of a serial chain of processing stages. At the end of the paper we discuss CoRLEGO’s predictions and also lessons for neurobiologically inspired robotics emerging from this work. [ABSTRACT FROM AUTHOR]

The present paper asks whether the motor cortex contributes to prediction-based guidance of target selection. This question was inspired by recent evidence that suggests (i) recurrent connections from the motor system into the attentional system may extract movement-relevant perceptual information and (ii) that the motor cortex cannot only generate predictions of the sensory consequences of movements but may also operate as predictor of perceptual events in general. To test this idea we employed a choice reaching task requiring participants to rapidly reach and touch a predictable or unpredictable colour target. Motor cortex activity was modulated via transcranial direct current stimulation (tDCS). In Experiment 1 target colour repetitions were predictable. Under such conditions anodal tDCS facilitated selection versus sham and cathodal tDCS. This improvement was apparent for trajectory curvature but not movement initiation. Conversely, where no predictability of colour was embedded reach performance was unaffected by tDCS. Finally, the results of a key-press experiment suggested that motor cortex involvement is restricted to tasks where the predictable target colour is movement-relevant. The outcomes are interpreted as evidence that the motor system contributes to the top-down guidance of selective attention to movement targets. [ABSTRACT FROM AUTHOR]

Anti-extinction occurs when there is poor report of a single stimulus presented on the contralesional side of space, but better report of the same item when it occurs concurrently with a stimulus on the ipsilesional side (Goodrich & Ward, 1997). We report a series of experiments that examine the factors that lead to anti-extinction in a patient GK, who has bilateral parietal lesions but more impaired identification of left-side stimuli. We show a pattern of anti-extinction when stimuli are briefly presented, which is followed by an extinction effect when stimuli are left for longer in the visual field. In Experiments 1 and 2 we present evidence that the anti-extinction effects are determined by stimuli onsetting together, and it is not apparent when stimuli are defined by offsets. In Experiments 3 and 4 we report that performance is not strongly affected by whether the same or different tasks are performed on the ipsi- and contralesional stimuli, and the anti-extinction effect also survives trials where eye movements are made to right-side stimuli. Experiment 5 provides evidence that anti-extinction is due to temporal grouping between stimuli, rather than to increased arousal or cueing attention to the contralesional side. Experiment 6 demonstrates that anti-extinction dissociates from GK's conscious perception of when contra- and ipsilesional stimuli occur together. We interpret the data as indicating that there is unconscious and transient temporal binding in vision. [ABSTRACT FROM AUTHOR]

Background: A considerable amount of research has discussed whether autism and psychiatric/neurodevelopmental conditions in general are best described categorically or dimensionally. In recent years, finite mixture models have been increasingly applied to mixed populations of autistic and non-autistic individuals to answer this question. However, the use of such methods with mixed populations may not be appropriate for two reasons: First, subgroups within mixed populations are often skewed and thus violate mixture models assumptions, which are based on weighted sum of Gaussian distributions. Second, these analyses have, to our knowledge, been solely applied to enriched samples, where the prevalence of the clinical condition within the study sample far exceeds epidemiological estimates. Method: We employed a dual Weibull mixture model to examine the distribution of the Autism Spectrum Quotient scores of a mixed sample of autistic and non-autistic adults (N = 4717; autism = 811), as well as of a derived sample (from the enriched sample; N = 3973; autism = 67) that reflects the current prevalence of autism within the general population. Results: In a mixed autistic and non-autistic population, our model provided a better description of the underlying structure of autistic traits than traditional finite Gaussian mixture models and performed well when applied to a sample that reflected the prevalence of autism in the general population. The model yielded results, which are consistent with predictions of current theories advocating for the co-existence of a mixed categorical and dimensional architecture within the autism spectrum. Conclusion: The results provide insight into the continuum nature of the distribution of autistic traits, support the complementary role of both categorical and dimensional approaches to autism spectrum condition, and underscore the importance of analyzing samples that reflect the epidemiological prevalence of the condition. Owing to its flexibility to represent a wide variety of distributions, the Weibull distribution might be better suited for latent structure studies, within enriched and prevalence-true samples. [ABSTRACT FROM AUTHOR]