Salient stimuli presented at unattended locations are not always perceived, a phenomenon termed inattentional blindness. We hypothesized that inattentional blindness may be mediated by attentional inhibition. It has been shown that attentional inhibition effects are maximal near an attended location. If our hypothesis is correct, inattentional blindness effects should similarly be maximal near an attended location. During central fixation, participants viewed rapidly presented colored digits at a peripheral location. An unexpected black circle was concurrently presented. Participants were (...) instructed to maintain central fixation and name each color/digit, requiring focused attention to that location. For each participant, the critical stimulus was presented either near to or far from the attended location . In support of our hypothesis, inattentional blindness effects were maximal near the attended location, but only at intermediate task accuracy. (shrink)

ABSTRACTPrior research on attention bias in anxious youth, often utilising a visual dot probe task, has yielded inconsistent findings, which may be due to how bias is assessed and/or variability in the phenomenon. The present study utilises eye gaze tracking to assess attention bias in socially anxious adolescents, and explores several methodological and within-subject factors that may contribute to variability in attention bias. Attention bias to threat was measured in forty-two treatment-seeking adolescents diagnosed with Social Anxiety Disorder. Bias scores toward (...) emotional stimuli and bias scores away from emotional stimuli were explored. Bias scores changed between vigilance and avoidance within individuals and over the course of stimulus presentation. These differences were not associated with participant characteristics nor with self-reported social anxiety symptoms. However, clinician rated severity of social anxiety, explained a signific... (shrink)

Optical distortions as a visual disturbance are inherent in many optical devices such as spectacles or virtual reality headsets. In such devices, distortions vary spatially across the visual field. In progressive addition lenses, for example, the left and right regions of the lens skew the peripheral parts of the wearers visual field in opposing directions. The human visual system adapts to homogeneous distortions and the respective aftereffects are transferred to non-retinotopic locations. This study investigates simultaneous adaptation to two opposing (...) distortions at different retinotopic locations. Two oppositely skewed natural image sequences were presented to 10 subjects as adaptation stimuli at two distinct locations in the visual field. To do so, subjects were instructed to keep fixation on a target. Eye tracking was used for gaze control. Change of perceived motion direction was measured in a direction identification task. The point of subjective equality, that is, the angle at which a group of coherently moving dots was perceived as moving horizontal, was determined for both retinal locations. The shift of perceived motion direction was evaluated by comparing PSE before and after adaptation. A significant shift at both retinal locations in the direction of the skew distortion of the corresponding adaptation stimulus is demonstrated. Consequently, parallel adaptation to two opposing distortions in a retinotopic reference frame was confirmed by this study. (shrink)

Peripheral vision has different functional priorities for mammals than foveal vision. One of its roles is to monitor the environment while central vision is focused on the current task. Becoming distracted too easily would be counterproductive in this perspective, so the brain should react to behaviourally relevant changes. Gist processing is good for this purpose, and it is therefore not surprising that evidence from both functional brain imaging and behavioural research suggests a tendency to generalize and blend information in (...) the periphery. This may be caused by the balance of perceptual influence in the periphery between bottom-up and top-down processing channels. Here, we investigated this interaction behaviourally using a peripheral numerosity discrimination task with top-down and bottom-up manipulations. Participants compared numerosity between the left and right peripheries of a screen. Each periphery was divided into a centre and a surrounding area, only one of which was a task relevant target region. Our top-down task modulation was the instruction which area to attend – centre or surround. We varied the signal strength by altering the stimuli durations i.e., the amount of information presented/processed. We found that numerosity perceived in target regions was affected by contextual information in neighbouring areas. This effect appeared as soon as stimulus duration allowed the task to be reliably performed and persisted even at the longest duration. We compared the pattern of results with an ideal-observer model and found a qualitative difference in the way centre and surround areas interacted perceptually in the periphery. When participants reported on the central area, the irrelevant surround would affect the response as a weighted combination – consistent with the idea of a receptive field focused in the target area to which irrelevant surround stimulation leaks in. When participants report on surround, we can best describe the response with a model in which occasionally the attention switches from task relevant surround to task irrelevant centre – consistent with a selection model of two competing streams of information. Overall our results show that the influence of spatial context in the periphery is mandatory but task dependent. (shrink)

Microsaccades, small saccadic eye movements occurring during fixation, have been suggested to be modulated by various sensory, cognitive, and affective processes relating to arousal. Although the modulation of fatigue-related arousal on microsaccade behavior has previously been characterized, the influence of other aspects of arousal, such as emotional arousal, is less understood. Moreover, microsaccades are modulated by cognitive processes that could also be linked to arousal. To investigate the influence of emotional arousal, saccade preparation, and global luminance levels on microsaccade (...) behavior, emotional auditory stimuli were presented prior to the onset of a fixation cue whose color indicated to look either at the peripheral stimulus or in the opposite direction of the stimulus. Microsaccade behavior was found to be significantly modulated by saccade preparation and global luminance level, but not emotional arousal. In the pro- and anti-saccade task, microsaccade rate was lower during anti-saccade preparation as compared to pro-saccade preparation, though microsaccade dynamics were comparable during both trial types. Our results reveal a differential role of arousal linked to emotion, fatigue, saccade preparation, and global luminance level on microsaccade behavior. (shrink)

Previous experiments have shown a serial-position effect (SPE) in paired-associate (PA) learning where the pairs contained stimuli pre- viously learned in serial order. The present experiment extended the number of pairs from 10 to 14. Pairs containing stimuli from terminal serial positions were learned with significantly fewer errors than pairs whose stimuli derived from central positions. The latter produced a dip in the PA error distribution suggesting the presence of sequential associations in SL between items occupying central (...) positions. (shrink)

Bart Streumer thinks that we cannot believe the global normative error theory. Streumer's argument presupposes a Cartesian theory of belief fixation. The Cartesian theory entails that we can understand a proposition without believing it. But the Cartesian theory of belief fixation is false, and the Spinozan theory is true. The Spinozan theory of belief fixation entails that we cannot understand a proposition without believing it. The present paper argues that Streumer's claim is false, and we can believe (...) the global normative error theory because the Spinozan theory is correct. The paper then applies the Spinozan theory of belief fixation to the “Now what?” problem for global normative error theory and responds to objections. (shrink)

Language is more than a source of information for accessing higher-order conceptual knowledge. Indeed, language may determine how people perceive and interpret visual stimuli. Visual processing in linguistic contexts, for instance, mirrors language processing and happens incrementally, rather than through variously-oriented fixations over a particular scene. The consequences of this atypical visual processing are yet to be determined. Here, we investigated the integration of visual and linguistic input during a reasoning task. Participants listened to sentences containing conjunctions or disjunctions (...) and looked at visual scenes containing two pictures that either matched or mismatched the nouns. Degree of match between nouns and pictures and between their expected and actual spatial positions affected fixations as well as judgments. We conclude that language induces incremental processing of visual scenes, which in turn becomes susceptible to reasoning errors during the language-meaning verification process. (shrink)

Inattentional blindness is the failure to perceive salient stimuli presented at unattended locations. Whereas the behavioral manifestation of inattentional blindness has been investigated, the neural basis of this phenomenon has remained elusive. In the current study, event-related fMRI was used to identify the neural substrates associated with inattentional blindness. During central fixation, participants named colored digits presented at a peripheral location. On a subset of trials, an unexpected checkerboard circle was presented at the same eccentricity along with (...) the colored digits . Neural activity during inattentional blindness was observed in the prefrontal cortex. Together with previous findings, these results call into question the widespread view that activity in the prefrontal cortex reflects conscious processing. (shrink)

Inappropriate saccades are prevented by fixation and by voluntary attention. The fixation system inhibits the saccade system. Like monkeys without a fixation system, humans with a weak fixation system produce many express saccades and cannot suppress prosaccades in an antisaccade task. With permanent attention to a peripheral location only a few express saccades to a stimulus at this location can be elicited: the sustained component of attention acts like fixation. When attention is captured by (...) a precue, more express saccades are obtained: the stimulus-driven component of attention facilitates saccade generation. If the cue correctly indicates the direction for an antisaccade error rate and latencies are increased. (shrink)

An important question about eye-movement behavior is when the decision is made to terminate a fixation and program the following saccade. Different approaches have found converging evidence in favor of a mixed-control account, in which there is some overlap between processing information at fixation and planning the following saccade. We examined one interesting instance of mixed control in visual search: lag-2 revisits, during which observers fixate a stimulus, move to a different stimulus, and then revisit the first stimulus (...) on the next fixation. Results show that the probability of lag-2 revisits occurring increased with the number of target-similar stimuli, and revisits were preceded by a brief fixation on the intervening distractor stimulus. We developed the Efficient Visual Sampling computational model to simulate our findings and to provide insight into mixed control of fixations and the perceptual, cognitive, and motor processes that produce lag-2 revisits. (shrink)

If two stimuli need different times to be processed, this difference should in principle be reflected both by response times (RT) and by judgments of their temporal order (TOJ). However, several dissociations have been reported between RT and TOJ, e.g., RT is more affected than TOJ when stimulus intensity decreases. One account for these dissociations is to assume differences in the allocation of attention induced by the two tasks. To test this hypothesis, different distributions of attention were induced in (...) the present study between two stimulus positions (above and below fixation). Only bright stimuli appeared in one position and either bright or dim stimuli in the other. In the two RT experiments, participants had to respond to every stimulus appearing in one of the two positions. Reaction times to bright stimuli were faster when they appeared in the position where dim stimuli were likely to occur. This finding suggests that the allocation of attention was adapted to the asymmetrical arrangement of stimuli, not suggested by explicit instruction. In the two TOJ experiments, the temporal order of stimuli appearing in the two positions had to be judged. Although bright stimuli appearing at the bright-and-dim location were judged to be earlier, this effect was small and insignificant. Further, the intensity dissociation between RT and TOJ was insensitive to random vs blockwise presentations of intensities, therefore was not modified by attentional preferences. Thus, asymmetrical arrangement of stimuli has an impact on the allocation of attention, but only in the RT task. Therefore dissociations between TOJ and response times cannot be accounted for by an attentional bias in the TOJ task but probably by different use of temporal information in the two tasks. (shrink)

Defects in man in four steps of 4‐aminobutyric acid (GABA) metabolism may interefere with the function of this major inhibitory neurotransmitter. Glutamic acid decarboxylase, 4‐aminobutyric acid aminotransferase, succinic semialdehyde dehydrogenase, and homocarnosinase are closely identified with the brain, but two of these enzymes are expressed in cultured peripheral cells, which may permit novel approaches to the study of the metabolism and regulation of GABA.

Prospective memory (PM) enables people to remember to complete important tasks in the future. Failing to do so can result in consequences of varying severity. Here, we investigated how PM error-consequence severity impacts the neural processing of relevant cues for triggering PM and the ramification of that processing on the associated prospective task performance. Participants role-played a cafeteria worker serving lunches to fictitious students and had to remember to deliver an alternative lunch to students (as PM cues) who would otherwise (...) experience a moderate or severe aversive reaction. Scalp-recorded, event-related potential (ERP) measures showed that the early-latency frontal positivity, reflecting the perception-based neural responses to previously learned stimuli, did not differ between the severe versus moderate PM cues. In contrast, the longer-latency parietal positivity, thought to reflect full PM cue recognition and post retrieval processes, was elicited earlier by the severe than the moderate PM cues. This faster instantiation of the parietal positivity to the severe-consequence PM cues was then followed by faster and more accurate behavioral responses. These findings indicate how the relative importance of a PM can be neurally instantiated in the form of enhanced and faster PM cue recognition and processing and culminate into better PM. (shrink)

It is well-documented that emotional stimuli impact both the cognitive and motor aspects of “goal-directed” behavior. However, how emotional distractors impact motor performance remains unclear. This study aimed to characterize how movement quality was impacted during emotional distractors. We used a modified oddball paradigm and documented the performance of pure movement. Participants were designated to draw a triangle or a polygon, while an emotional stimulus was presented. Speed was assessed using reaction time and movement time. The quality and precision (...) of movement were assessed by calculating the accuracy and root-mean-square error. Compared to drawings of triangles, polygons had higher accuracy under negative stimuli, but lower RMSE under positive stimuli. The results indicate that distracting emotional stimuli impact different aspects of movement quality, with movement complexity influencing accuracy under negative distractors and precision under positive distractors. This study provides further evidence that movement precision is an important feature of emotional embodiment that should be incorporated in future studies. (shrink)

There are some conspicuous differences between the sensibilities of cutaneous and visceral tissues: (1) Direct trauma, which readily produces pain when applied to the skin, is mostly without effect in healthy visceral tissue. (2) Pain that arises from visceral tissues is initially often poorly localised and diffuse. (3) With time, visceral pains are often referred to more superficial structures. (4) The site of referred pain may also show hyperalgesia. (5) In disease states, the afflicted viscera may also become hyperalgesic. In (...) this target article, I consider to what extent differences in the physiology, anatomy, and chemistry of peripheral processing systems explain these different sensibilities. In almost every aspect, there are subtle differences in the properties of the processing mechanisms for cutaneous and visceral information. These may arise because of distinct developmental cues operating in the two domains. Many of the differences between visceral and cutaneous afferents are quantitative rather than qualitative. The quantitative differences, for example in the density of afferent innervation, can be large. The quantitative differences in the numbers of afferents alone may be a sufficient explanation for some aspects of the differential sensibility, for example, the poor localisation of sensation and the apparent insensitivity to focal yet tissue- damaging stimuli. In addition, the few clear qualitative differences apparent in the innervations of the two tissue types may be of special importance. That the encoding of visceral nociceptive events may occur by an intensity mechanism rather than a specificity mechanism could be the key difference in viscerosensory and somatosensory processing. (shrink)

This study examined self-recognition processing in both the auditory and visual modalities by determining how comparable hearing a recording of one’s own voice was to seeing photograph of one’s own face. We also investigated whether the simultaneous presentation of auditory and visual self-stimuli would either facilitate or inhibit self-identification. Ninety-one participants completed reaction-time tasks of self-recognition when presented with their own faces, own voices, and combinations of the two. Reaction time and errors made when responding with both the right (...) and left hand were recorded to determine if there were lateralization effects on these tasks. Our findings showed that visual self-recognition for facial photographs appears to be superior to auditory self-recognition for voice recordings. Furthermore, a combined presentation of one’s own face and voice appeared to inhibit rather than facilitate self-recognition and there was a left-hand advantage for reaction time on the combined-presentation tasks. (shrink)

Evidence from various subtypes of Specific Language Impairment and developmental peripheral dyslexias is presented to support the idea that even developmental disorders can be modular. However, in developmental letter position dyslexia and neglect dyslexia we show that additional errors can occur because of insufficient orthographic-lexical knowledge.

ABSTRACTIt is known that people covertly attend to threatening stimuli even when it is not beneficial for the task. In the current study we examined whether overt selection is affected by the presence of an object that signals threat. We demonstrate that stimuli that signal the possibility of receiving an electric shock capture the eyes more often than stimuli signalling no shock. Capture occurred even though the threat-signalling stimulus was neither physically salient nor task relevant at any (...) point during the experiment. Crucially, even though fixating the threat-related stimulus made it more likely to receive a shock, results indicate that participants could not help but doing it. Our findings indicate that the presence of a stimulus merely signalling the possibility of receiving a shock is prioritised in selection, and exogenously captures the eyes even when this ultimately results in the execution of the threat. Oculomotor capture was particularly pronounced for the fastest saccades which is consistent with the idea that threat influences visual selection at an early stage of processing, when selection is mainly involuntarily. (shrink)

This study investigates the procedural learning, retention, and reactivation of temporal sensorimotor sequences in children with and without developmental coordination disorder. Twenty typically-developing children and 12 children with DCD took part in this study. The children were required to tap on a keyboard, synchronizing with auditory or visual stimuli presented as an isochronous temporal sequence, and practice non-isochronous temporal sequences to memorize them. Immediate and delayed retention of the audio-motor and visuo-motor non-isochronous sequences were tested by removing auditory or (...) visual stimuli immediately after practice and after a delay of 2 h. A reactivation test involved reintroducing the auditory and visual stimuli after the delayed recall. Data were computed via circular analyses to obtain asynchrony, the stability of synchronization and errors. Firstly, an overall deficit in synchronization with both auditory and visual isochronous stimuli was observed in DCD children compared to TD children. During practice, further improvements were found for the audio-motor non-isochronous sequence compared to the visuo-motor non-isochronous sequence in both TD children and children with DCD. However, a drastic increase in errors occurred in children with DCD during immediate retention as soon as the auditory stimuli were removed. Reintroducing auditory stimuli decreased errors in the audio-motor sequence for children with DCD. Such changes were not seen for the visuo-motor non-isochronous sequence, which was equally learned, retained and reactivated in DCD and TD children. All these results suggest that TD children benefit from both auditory and visual stimuli to memorize the sequence, whereas children with DCD seem to present a deficit in integrating an audio-motor sequence in their memory. The immediate effect of reactivation suggests a specific dependency on auditory information in DCD. Contrary to the audio-motor sequence, the visuo-motor sequence was both learned and retained in children with DCD. This suggests that visual stimuli could be the best information for memorizing a temporal sequence in DCD. All these results are discussed in terms of a specific audio-motor coupling deficit in DCD. (shrink)

We demonstrate “economies of experience” in eye-movement patterns—that is, optimization of eye-movement patterns aimed at more efficient and less costly visual processing, similar to the priming-induced formation of sparser cortical representations or reduced reaction times. Participants looked at Mooney-type, degraded stimuli that were difficult to recognize without prior experience, but easily recognizable after exposure to their undegraded versions. As predicted, eye-movement dispersion, velocity, and the number of fixations decreased with each stimulus presentation. Further analyses showed that this effect was (...) contingent on recognition, and the selection of information from the stimulus could be informed by the identity of the presented object. Finally, our study demonstrates that after exposure to the undegraded version of the stimulus, eye-movement patterns associated with its degraded and undegraded versions become more similar. This suggests that eye-movement patterns can evolve to facilitate the optimal processing of a given stimulus via experience-driven perceptual learning. (shrink)

ABSTRACTIndividual differences in fear generalisation have been proposed to play a role in the aetiology and/or maintenance of anxiety disorders, but few data are available to directly support that claim. The research that is available has focused mostly on generalisation of peripheral and central physiological fear responses. Far less is known about the generalisation of avoidance, the behavioural component of fear. In two experiments, we evaluated how neuroticism, a known vulnerability factor for anxiety, modulates an array of fear responses, (...) including avoidance tendencies, towards generalisation stimuli. Participants underwent differential fear conditioning, in which one conditioned stimulus was repeatedly paired with an aversive outcome, whereas another was not. Fear generalisation was observed across measures in Experiment 1 and Experiment 2, with overall highest responding to the CS+, lowest to the CS− and intermediate responding to the GSs. Neuroticism had very little impact on fear generalisation, in line with the idea that fear generalisation is largely an adaptive process. (shrink)

Among the studies on the perception of gaze vs. non-gaze stimuli, some have shown that the two types of stimuli trigger different patterns of attentional effects, while others have reported no such differences. In three experiments, we investigated the role of stimulus perceivability in spatial interference effects when the targets were gaze vs. non-gaze stimuli. We used a spatial Stroop task that required participants to make a speeded response to the direction indicated by the targets located on (...) the left or right side of fixation. In different experiments, the targets consisted of eyes, symbols, and/or arrows. The results showed that the magnitude of the spatial congruency effect differed between the types of targets when stimulus perceivability was not controlled. However, when the perceivability of the task relevant parts was comparable between the different types of targets, similar congruency effects were found regardless of target type. These results underscore the importance of controlling for stimulus perceivability, which is closely linked to the attentional zoom required to perform a task, when making inferences about the attentional mechanisms in the processing of gaze vs. non-gaze stimuli. (shrink)

Mismatch brain responses to unpredicted rare stimuli are suggested to be a neural indicator of prediction error, but this has rarely been studied in the somatosensory modality. Here, we investigated how the brain responds to unpredictable and predictable rare events. Magnetoencephalography responses were measured in adults frequently presented with somatosensory stimuli that were occasionally replaced by two consecutively presented rare stimuli [unpredictable rare stimulus and predictable rare stimulus ; p = 0.1 for each]. The FRE and PR (...) were electrical stimulations administered to either the little finger or the forefinger in a counterbalanced manner between the two conditions. The UR was a simultaneous electrical stimulation to both the forefinger and the little finger. The grand-averaged responses were characterized by two main components: one at 30–100 ms and the other at 130–230 ms latency. Source-level analysis was conducted for the primary somatosensory cortex and the secondary somatosensory cortex. The M55 responses were larger for the UR and PR than for the FRE in both the SI and the SII areas and were larger for the UR than for the PR. For M150, both investigated areas showed increased activity for the UR and the PR compared to the FRE. Interestingly, although the UR was larger in stimulus energy and had a larger prediction error potential than the PR, the M150 responses to these two rare stimuli did not differ in source strength in either the SI or the SII area. The results suggest that M55, but not M150, can possibly be associated with prediction error signals. These findings highlight the need for disentangling prediction error and rareness-related effects in future studies investigating prediction error signals. (shrink)

In "Does the Basic Color Terms discussion suffer from the Stimulus Error?" Rolf Kuehni describes a research stumbling block known as the "stimulus error," and hints at the difficulties it causes for mainstream color naming research. Among the issues intrinsic to Kuehni's "stimulus error" description is the important question of what can generally be inferred from color naming behaviors based on bounded samples of empirical stimuli. Here we examine some specifics of the color naming research issues that Kuehni raises. (...) While we share Kuehni's view regarding potential problems caused by the "stimulus error" and his concern regarding its prevalence, Kuehni's commentary seems primarily aimed at stimulating a general discussion of color naming research implications, because the articles he critiques do not actually commit the "stimulus error" in any serious sense. Based on Kuehni's comments, we further examine some of the relevant empirical and theoretical implications for cross-cultural color naming research. (shrink)

In this paper, I discuss the relationship between bodily experiences in dreams and the sleeping, physical body. I question the popular view that dreaming is a naturally and frequently occurring real-world example of cranial envatment. This view states that dreams are functionally disembodied states: in a majority of dreams, phenomenal experience, including the phenomenology of embodied selfhood, unfolds completely independently of external and peripheral stimuli and outward movement. I advance an alternative and more empirically plausible view of dreams (...) as weakly phenomenally-functionally embodied states. The view predicts that bodily experiences in dreams can be placed on a continuum with bodily illusions in wakefulness. It also acknowledges that there is a high degree of variation across dreams and different sleep stages in the degree of causal coupling between dream imagery, sensory input, and outward motor activity. Furthermore, I use the example of movement sensations in dreams and their relation to outward muscular activity to develop a predictive processing account. I propose that movement sensations in dreams are associated with a basic and developmentally early kind of bodily self-sampling. This account, which affords a central role to active inference, can then be broadened to explain other aspects of self- and world-simulation in dreams. Dreams are world-simulations centered on the self, and important aspects of both self- and world-simulation in dreams are closely linked to bodily self-sampling, including muscular activity, illusory own-body perception, and vestibular orienting in sleep. This is consistent with cognitive accounts of dream generation, in which long-term beliefs and expectations, as well as waking concerns and memories play an important role. What I add to this picture is an emphasis on the real-body basis of dream imagery. This offers a novel perspective on the formation of dream imagery and suggests new lines of research. (shrink)

An extended examination of Libet's works led to a comprehensive reinterpretation of his results. According to this reinterpretation, the Minimum Train Duration of electrical brain stimulation should be considered as the time needed to create a brain stimulus efficient for producing conscious sensation and not as a basis for inferring the latency for conscious sensation of peripheral origin. Latency for conscious sensation with brain stimulation may occurafterthe Minimum Train Duration. Backward masking with cortical stimuli suggests a 125-300 ms (...) minimum value for the latency for conscious sensation of threshold skin stimuli. Backward enhancement is not suitable for inferring this latency. For determining temporal relations between stimuli that correspond to subjects' reports, theendof cerebral Minimum Train Duration should be used as reference, rather than its onset. Results of coupling peripheral and cortical stimuli are explained by a latency after the cortical Minimum Train Duration, having roughly the same duration as the latency for supraliminal skin stimuli. Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency. This interpretation suggests a 230 ms minimum value for the latency for conscious sensation of somatosensory near-threshold stimuli. The backward referral hypothesis, as formulated by Libet, should not be retained. Long readiness potentials preceding spontaneous conscious or nonconscious movements suggest that both kinds of movement are nonconsciously initiated. The validity of Libet's measures of W and M moments (Libet et al., 1983a) is questionable due to problems involving latencies, training, and introspective distinction of W and M. Veto of intended actions may be initially nonconscious but dependent on conscious awareness. (shrink)

Visual attentional processes have been an important topic in psychological research for years. Over the last few decades, new methods have been developed, aiming to explore the characteristics of the focus of attention in more detail. Studies that applied the “Attention-Window Task” quantified the maximum extent of the “Attention Window” along its horizontal, vertical, and diagonal meridians, when subjects were required to perceive two peripheral stimuli simultaneously. In three experiments using the AWT, we investigated the effects of cue (...) validity, stimulus-onset asynchrony, and target stimuli complexity on the size and shape of the AW. Results showed that the AW was greater under valid cue conditions compared to invalid conditions, when the locations of cue and target stimuli differed. Furthermore, the AW decreased when the SOA between the cue and targets was reduced and also when the task complexity was higher and more objects within the target stimuli had to be classified. Overall, it can be stated that the AWT with its possible task changes and adjustments can be considered as a potential standard tool to measure the maximum spread and shape of the spatial AW. (shrink)

Dynamic, interactive sports require athletes to identify, pick-up and process relevant information in a very limited time, in order to then make an appropriate response. Perceptual-cognitive skills are, therefore, a key determinant of elite sporting performance. Recently, sport scientists have investigated ways to assess and train perceptual-cognitive skills, with one such method involving the use of blurred stimuli. Here, we describe the two main methods used to generate blur and then review the current findings in a sports context. Overall, (...) it has been shown the use of blur can enhance performance and learning of sporting tasks in novice participants, especially when the blur is applied to peripheral stimuli. However, while intermediate and expert level participants are relatively impervious to the presence of blur, it remains to be determined if they are positive effects on learning. In a final section, we describe some of the methodological issues that limit the application of blur and then discuss the potential use of virtual reality to extend the current research base in sporting contexts. (shrink)

Abstract“Sign stimuli” elicit specific patterns of behavior when an organism's motivation is appropriate. In the toad, visually released prey-catching involves orienting toward the prey, approaching, fixating, and snapping. For these action patterns to be selected and released, the prey must be recognized and localized in space. Toads discriminate prey from nonprey by certain spatiotemporal stimulus features. The stimulus-response relations are mediated by innate releasing mechanisms (RMs) with recognition properties partly modifiable by experience. Striato-pretecto-tectal connectivity determines the RM's recognition and (...) localization properties, whereas medialpallio-thalamo-tectal circuitry makes the system sensitive to changes in internal state and to prior history of exposure to stimuli. RMs encode the diverse stimulus conditions referring to the same prey object through different combinations of “specialized” tectal neurons, involving cells selectively tuned to prey features. The prey-selective neurons express the outcome of information processing in functional units consisting of interconnected cells. Excitatory and inhibitory interactions among feature-sensitive tectal and pretectal neurons specify the perceptual operations involved in distinguishing the prey from its background, selecting its features, and discriminating it from predators. Other connections indicate stimulus location. The results of these analyses are transmitted by specialized neurons projecting from the tectum to bulbar/spinal motor systems, providing a sensorimotor interface. Specific combinations of such projective neurons – mediating feature- and space-related messages – form “command releasing systems” that activate corresponding motor pattern generators for appropriate prey-catching action patterns. (shrink)

Predictive processing models of perception take issue with standard models of perception as hierarchical bottom-up processing modulated by memory and attention. The predictive framework posits that the brain generates predictions about stimuli, which are matched to the incoming signal. Mismatches between predictions and the incoming signal – so-called prediction errors – are then used to generate new and better predictions until the prediction errors have been minimized, at which point a perception arises. Predictive models hold that all bottom-up processes (...) are signals conveying prediction errors to higher areas, which respond by updating their predictions. We take issue with this claim and argue that object recognition requires bottom-up processing that cannot be understood in terms of prediction errors. Along the way, we expand on previous work casting doubt on the framework's ability to account for attention. Specifically, we argue that the type of attention that allows us to rapidly extract the gist of an object or scene presents an additional challenge to the predictive approach. We conclude by considering how the framework may be augmented to avoid these problems. (shrink)