Processing Of Visual Stimuli Research Articles

Optimizing the algorithm for assessing the efficacy of treatment for amblyopia in astigmats through the investigation of the features of meridional acuity characteristics as vector quantities

Background: Refractive asymmetry associated with astigmatism may cause a special form of amblyopia, meridional amblyopia (MA). MA manifests itself as alterations in selective mechanisms of visual stimulus processing during recognition of contours of a certain orientation. Current routine examination of amblyopes does not include meridional acuity assessment and thus does not allow determining whether MA is present or not, as well as performing a more detailed evaluation of the efficacy of treatment for amblyopia in astigmats. Purpose: To optimize the algorithm for assessing the efficacy of stand-alone and complex methods of treatment for amblyopia in astigmats through the determination of the features of changes in visual acuities in orthogonal retinal meridians as vector quantities. Material and Methods: Twenty-four hyperopic astigmats with amblyopia (48 eyes) aged 5 to 12 years were involved in the study. Patients were treated by accommodative facility training only and, in 3 months, by complex therapy (accommodative facility training plus the use of device-based methods). Treatment course duration was 10 days. The results were assessed by changes in best-corrected visual acuity (Sivtsev Chart) and meridional separable visual acuity (MSVA) determined with the software which generates Landolt ring optotypes. Results: The study sample was found to be heterogeneous regarding the features of asymmetries in MSVA. Separable visual acuity in the horizontal meridian was equal in magnitude to that in the vertical meridian in 16.65% of patients. Asymmetries in separable visual acuity that may be considered MA were found in dominant and non-dominant (fellow) eyes in 83.35% of astigmats with amblyopia. Two different clusters were determined in the group with asymmetries in MSVA. Separable visual acuity in the horizontal meridian was higher than that in the vertical meridian in 35.45% of eyes in cluster 1, and lower than that in the vertical meridian in 47.85% of eyes in cluster 2. After treatment, mean separable visual acuity value in the vertical meridian was practically similar to that in the horizontal meridian in both groups for the dominant and fellow eyes, which allowed concluding that both methods were equally effective in treating the disease. However, the number of eyes with the same MSVA in orthogonal meridians increased by 10.41% after MA treatment with accommodative facility training only versus 18.75% after complex treatment. Conclusion: Assessing the features of changes in visual acuities in orthogonal retinal meridians as vector quantities enables obtaining principally new information on the performance of sensory functions in patients with amblyopia and assessing more reliably the efficacy of stand-alone and complex pleoptic methods as methods of treatment for MA.

Exploring cross-cultural variations in visual attention patterns inside and outside national borders using immersive virtual reality.

We examined theories of cross-cultural differences in cognitive style on a sample of 242 participants representing five cultural groups (Czechia, Ghana, eastern and western Turkey, and Taiwan). The experiment involved immersive virtual environments consisting of two salient focal objects and a complex background as stimuli, which were presented using virtual reality headsets with integrated eye-tracking devices. The oculomotor patterns confirmed previous general conclusions that Eastern cultures have a more holistic cognitive style, while Western cultures predominantly have an analytic cognitive style. The differences were particularly noticeable between Taiwan and the other samples. However, we found that the broader cultural background of each group was perhaps just as important as geographical location or national boundaries. For example, observed differences between Eastern (more holistic style) and Western Turkey (more analytic style), suggest the possible influence of varying historical and cultural characteristics on the cognitive processing of complex visual stimuli.

3 The Aesthetics of Empathy in Agenesis of the Corpus Callosum

Objective:Previous research suggests that individuals with isolated Agenesis of the Corpus Callosum (AgCC) have cognitive and psychosocial deficiencies that include impaired recognition of the emotions of others (Symington et al., 2010) and a diminished ability to infer and describe the emotions of others (Paul et al., 2021; Turk et al., 2010). In addition, galvanic skin responses effectively discriminated between emotional images despite atypical emotion ratings (Paul et al, 2006), supporting a dissociation between cognitive and affective empathy in AgCC. Likewise, atypical patterns of visual attention to faces corresponded with impaired emotion recognition in AgCC (Bridgman et al, 2014), suggesting that atypical visual attention in AgCC negatively impacts the ability to identify others’ emotions. This study used the Multifaceted Empathy Test [MET] (Foell et al., 2018) to examine the impact of visual aesthetics (photo composition) on empathetic feelings (affective empathy) and situational emotion recognition (cognitive empathy) in persons with AgCC. Both cognitive and affective empathy scores are typically higher on MET stimuli composed according to the “Golden Spiral” (Callaway, 2022).Participants and Methods:Results from 50 control participants recruited from Cloud Research were compared to responses from 19 participants with AgCC and normal-range FSIQ (>80). Data was gathered through an online version of the MET, which uses a series of photographs of individuals displaying an emotion, half of which adhere to the compositional technique known as “The Golden Spiral.” To measure cognitive empathy, the participants are asked to pick the correct emotion being displayed with three distractors for each item. To measure affective empathy, they are then asked on a sliding scale, “how much do you empathize with the person shown” (1 = Not at all, 7 = Very much).Results:Repeated measures mixed ANOVAs revealed no difference between AgCC and control groups on affective empathy, and as expected on the MET, both groups had significantly higher ratings for photos composed according to the Golden Spiral (AgCC, np2 = .071; control, np2 = .136). In contrast, the AgCC group scored significantly lower than controls overall on cognitive empathy, np2 =.065. Exploratory post-hoc found a significant group difference in cognitive empathy only on photos composed according to the Golden Spiral, np2 = .090, with the scores in the AgCC group unimpacted by composition type while the control group exhibiting significantly higher scores Golden Spiral images, np2 = .254.Conclusions:Empathic deficits in AgCC were restricted to the cognitive component, while affective empathy was not impaired. Visual aesthetics of photo composition influenced affective empathy ratings in both AgCC and control groups. However, adults with AgCC had diminished ability to give cognitive labels to the emotional states of others, which was not enhanced by the formal aesthetics of stimuli. Thus the corpus callosum seems to facilitate the ability to cognitively label emotions by facilitating visual attention. It also suggests that the corpus callosum does not facilitate affective empathy, in part because it does not appear to determine whether formal aesthetics influences the processing of visual stimuli in AgCC or neurotypical controls.

Brief Visual Deprivation Effects on Brain Oscillations During Kinesthetic and Visual-motor Imagery.

It is widely recognized that opening and closing the eyes can direct attention to external or internal stimuli processing. This has been confirmed by studies showing the effects of changes in visual stimulation changes on cerebral activity during different tasks, e.g., motor imagery and execution. However, an essential aspect of creating a mental representation of motion, such as imagery perspective, has not yet been investigated in the present context. Our study aimed to verify the effect of brief visual deprivation (under eyes open [EO] and eyes closed [EC] conditions) on brain wave oscillations and behavioral performance during kinesthetic imagery (KMI) and visual-motor imagery (VMI) tasks. We focused on the alpha and beta rhythms from visual- and motor-related EEG activity sources. Additionally, we used machine learning algorithms to establish whether the registered differences in brain oscillations might affect motor imagery brain-computer interface (MI-BCI) performance. The results showed that the occipital areas in the EC condition presented significantly stronger desynchronization during VMI tasks, which is typical for enhanced visual stimuli processing. Furthermore, the stronger desynchronization of alpha rhythms from motor areas in the EO, than EC condition confirmed previous effects obtained during real movements. It was also found that simulating movement under EC/EO conditions affected signal classification accuracy, which has practical implications for MI-BCI effectiveness. These findings suggest that shifting processing toward external or internal stimuli modulates brain rhythm oscillations associated with different perspectives on the mental representation of movement.

Perception of masculinized or feminized men’s faces and its relation to the menstrual cycle phase of women: Electrophysiological evidence

ABSTRACT Facial perception involves several brain areas: occipital to process visual stimuli, temporal to regulate emotions, and frontal and parietal to activate attention. Emotional processing relates to theta and delta bands in the temporal and frontal areas. We used a longitudinal design with twelve women to investigate whether the absolute power (AP) of areas involved in face perception changed in response to masculinized and feminized men’s faces during the LFP and LP. Results show that the perception of masculinized faces, when compared with feminized faces, modified the AP of delta in the occipital area; the AP of delta, theta, and alpha in the temporal area; and the AP of delta, alpha, and beta in the frontal and parietal areas during the LFP, but not the LP. Furthermore, AP was greater for masculinized faces during the LFP than during the LP. These findings provide new insights into the cortical activity underlying facial masculinity perception during the LFP and LP.

A large-scale fMRI dataset for the visual processing of naturalistic scenes

One ultimate goal of visual neuroscience is to understand how the brain processes visual stimuli encountered in the natural environment. Achieving this goal requires records of brain responses under massive amounts of naturalistic stimuli. Although the scientific community has put a lot of effort into collecting large-scale functional magnetic resonance imaging (fMRI) data under naturalistic stimuli, more naturalistic fMRI datasets are still urgently needed. We present here the Natural Object Dataset (NOD), a large-scale fMRI dataset containing responses to 57,120 naturalistic images from 30 participants. NOD strives for a balance between sampling variation between individuals and sampling variation between stimuli. This enables NOD to be utilized not only for determining whether an observation is generalizable across many individuals, but also for testing whether a response pattern is generalized to a variety of naturalistic stimuli. We anticipate that the NOD together with existing naturalistic neuroimaging datasets will serve as a new impetus for our understanding of the visual processing of naturalistic stimuli.

Different Mechanisms for Visual Attention at the Hand-movement Goal and Endogenous Visual Attention.

Visual perception is closely related to body movements and action, and it is known that processing visual stimuli is facilitated at the hand or at the hand-movement goal. Such facilitation suggests that there may be an attentional process associated with the hands or hand movements. To investigate the underlying mechanisms of visual attention at a hand-movement goal, we conducted two experiments to examine whether attention at the hand-movement goal is a process independent from endogenous attention. Endogenous attention is attention that is intentionally focused on a location, feature, or object. We controlled the hand-movement goal and endogenous attention separately to investigate the spatial profiles of the two types of attention. A visual target was presented either at the goal of hand movement (same condition) or at its opposite side (opposite condition) while steady-state visual-evoked potential (SSVEP) was used to estimate the spatial distributions of the facilitation effect from the 2 types of attention around the hand-movement goal and around the visual target through EEG. We estimated the spatial profile of attentional modulation for the hand-movement goal by taking the difference in SSVEP amplitude between conditions with and without hand movement, thereby obtaining the effect of visual endogenous attention alone. The results showed a peak at the hand-movement goal, independent of the location of the visual target where participants intentionally focused their attention (endogenous attention). We also found differences in the spatial extent of attentional modulation. Spatial tuning was narrow around the hand-movement goal (i.e., attentional facilitation only at the goal location) but was broadly tuned around the focus of endogenous attention (i.e., attentional facilitation spreading over adjacent stimulus locations), which was obtained from the condition without hand movement. These results suggest the existence of two separate mechanisms, one underlying the attention at the hand-movement goal and another underlying endogenous attention.

Mapping the time-varying functional brain networks in response to naturalistic movie stimuli.

One of human brain's remarkable traits lies in its capacity to dynamically coordinate the activities of multiple brain regions or networks, adapting to an externally changing environment. Studying the dynamic functional brain networks (DFNs) and their role in perception, assessment, and action can significantly advance our comprehension of how the brain responds to patterns of sensory input. Movies provide a valuable tool for studying DFNs, as they offer a naturalistic paradigm that can evoke complex cognitive and emotional experiences through rich multimodal and dynamic stimuli. However, most previous research on DFNs have predominantly concentrated on the resting-state paradigm, investigating the topological structure of temporal dynamic brain networks generated via chosen templates. The dynamic spatial configurations of the functional networks elicited by naturalistic stimuli demand further exploration. In this study, we employed an unsupervised dictionary learning and sparse coding method combing with a sliding window strategy to map and quantify the dynamic spatial patterns of functional brain networks (FBNs) present in naturalistic functional magnetic resonance imaging (NfMRI) data, and further evaluated whether the temporal dynamics of distinct FBNs are aligned to the sensory, cognitive, and affective processes involved in the subjective perception of the movie. The results revealed that movie viewing can evoke complex FBNs, and these FBNs were time-varying with the movie storylines and were correlated with the movie annotations and the subjective ratings of viewing experience. The reliability of DFNs was also validated by assessing the Intra-class coefficient (ICC) among two scanning sessions under the same naturalistic paradigm with a three-month interval. Our findings offer novel insight into comprehending the dynamic properties of FBNs in response to naturalistic stimuli, which could potentially deepen our understanding of the neural mechanisms underlying the brain's dynamic changes during the processing of visual and auditory stimuli.

Robust and efficient representations of dynamic stimuli in hierarchical neural networks via temporal smoothing.

Efficient coding that minimizes informational redundancy of neural representations is a widely accepted neural coding principle. Despite the benefit, maximizing efficiency in neural coding can make neural representation vulnerable to random noise. One way to achieve robustness against random noise is smoothening neural responses. However, it is not clear whether the smoothness of neural responses can hold robust neural representations when dynamic stimuli are processed through a hierarchical brain structure, in which not only random noise but also systematic error due to temporal lag can be induced. In the present study, we showed that smoothness via spatio-temporally efficient coding can achieve both efficiency and robustness by effectively dealing with noise and neural delay in the visual hierarchy when processing dynamic visual stimuli. The simulation results demonstrated that a hierarchical neural network whose bidirectional synaptic connections were learned through spatio-temporally efficient coding with natural scenes could elicit neural responses to visual moving bars similar to those to static bars with the identical position and orientation, indicating robust neural responses against erroneous neural information. It implies that spatio-temporally efficient coding preserves the structure of visual environments locally in the neural responses of hierarchical structures. The present results suggest the importance of a balance between efficiency and robustness in neural coding for visual processing of dynamic stimuli across hierarchical brain structures.

Allocation of cognitive resources in cognitive processing of rhythmic visual stimuli before gait-related motor initiation.

Rhythmic visual cues can affect the allocation of cognitive resources during gait initiation (GI) and motor preparation. However, it is unclear how the input of rhythmic visual information modulates the allocation of cognitive resources and affects GI. The purpose of this study was to explore the effect of rhythmic visual cues on the dynamic allocation of cognitive resources by recording electroencephalographic (EEG) activity during exposure to visual stimuli. This study assessed event-related potentials (ERPs), event-related synchronization/desynchronization (ERS/ERD), and EEG microstates at 32 electrodes during presentation of non-rhythmic and rhythmic visual stimuli in 20 healthy participants. The ERP results showed that the amplitude of the C1 component was positive under exposure to rhythmic visual stimuli, while the amplitude of the N1 component was higher under exposure to rhythmic visual stimuli compared to their non-rhythmic counterparts. Within the first 200 ms of the onset of rhythmic visual stimuli, ERS in the theta band was highly pronounced in all brain regions analyzed. The results of microstate analysis showed that rhythmic visual stimuli were associated with an increase in cognitive processing over time, while non-rhythmic visual stimuli were associated with a decrease. Overall, these findings indicated that, under exposure to rhythmic visual stimuli, consumption of cognitive resources is lower during the first 200 ms of visual cognitive processing, but the consumption of cognitive resources gradually increases over time. After approximately 300 ms, cognitive processing of rhythmic visual stimuli consumes more cognitive resources than processing of stimuli in the non-rhythmic condition. This indicates that the former is more conducive to the completion of gait-related motor preparation activities, based on processing of rhythmic visual information during the later stages. This finding indicates that the dynamic allocation of cognitive resources is the key to improving gait-related movement based on rhythmic visual cues.

Can neural correlates of encoding explain the context dependence of reward-enhanced memory?

Selective encoding can be studied by manipulating how valuable it is for participants to remember specific stimuli, for instance, by varying the monetary reward participants receive for recalling a particular stimulus in a subsequent memory test. It would be reasonable for participants to strategically attend more to high-reward items compared to low-reward items in mixed list contexts, but to attend both types of items equally in pure list contexts, where all items are of equal value. Reward-enhanced memory may be driven by automatic dopaminergic interactions between reward circuitry and the hippocampus and thus be insensitive to list context; or it may be driven by meta-cognitive strategies, and thus context-dependent. We contrasted these alternatives by manipulating list composition and tracked selective encoding through multiple EEG measures of attention and rehearsal. Behavioral results were context-dependent, such that recall of high-reward items was increased only in mixed lists. This result and aspects of the recall dynamics confirm predictions of the eCMR (emotional Context Maintenance and Retrieval) model. The power of ssVEPs was lower for high-reward items regardless of list composition, suggesting decreased visual processing of high-reward stimuli and that ssVEPs may index the modulation of context-to-item associations predicted by eCMR. By contrast, reward modulated the amplitude of Late Positive Potential and Frontal Slow Wave only in mixed lists. Taken together, the results provide evidence that reward-enhanced memory is caused by an interplay between strategic processes applied when high- and low-reward items compete for cognitive resources during encoding and context-dependent mechanisms operating during recall.

Rhythmic Information Sampling in the Brain during Visual Recognition.

When we fixate an object, visual information is continuously received on the retina. Several studies observed behavioral oscillations in perceptual sensitivity across such stimulus time, and these fluctuations have been linked to brain oscillations. However, whether specific brain areas show oscillations across stimulus time (i.e., different time points of the stimulus being more or less processed, in a rhythmic fashion) has not been investigated. Here, we revealed random areas of face images at random moments across time and recorded the brain activity of male and female human participants using MEG while they performed two recognition tasks. This allowed us to quantify how each snapshot of visual information coming from the stimulus is processed across time and across the brain. Oscillations across stimulus time (rhythmic sampling) were mostly visible in early visual areas, at theta, alpha, and low beta frequencies. We also found that they contributed to brain activity more than previously investigated rhythmic processing (oscillations in the processing of a single snapshot of visual information). Nonrhythmic sampling was also visible at later latencies across the visual cortex, either in the form of a transient processing of early stimulus time points or of a sustained processing of the whole stimulus. Our results suggest that successive cycles of ongoing brain oscillations process stimulus information incoming at successive moments. Together, these results advance our understanding of the oscillatory neural dynamics associated with visual processing and show the importance of considering the temporal dimension of stimuli when studying visual recognition.SIGNIFICANCE STATEMENT Several behavioral studies have observed oscillations in perceptual sensitivity over the duration of stimulus presentation, and these fluctuations have been linked to brain oscillations. However, oscillations across stimulus time in the brain have not been studied. Here, we developed an MEG paradigm to quantify how visual information received at each moment during fixation is processed through time and across the brain. We showed that different snapshots of a stimulus are distinctly processed in many brain areas and that these fluctuations are oscillatory in early visual areas. Oscillations across stimulus time were more prevalent than previously studied oscillations across processing time. These results increase our understanding of how neural oscillations interact with the visual processing of temporal stimuli.

Tuberculose pulmonaire sur maladie de Takayasu compliquée de dissection de l’artère carotide commune

Previous studies have observed lower visual cortex activation for visual processing in cochlear implant (CI) users compared to normal hearing controls, while others reported enhanced visual speechreading abilities in CI users. The present work investigated whether lower visual cortical activation for visual processing can be explained by a more efficient visual sensory encoding in CI users. Specifically, we investigated whether CI users show enhanced stimulus-specific adaptation for visual stimuli compared to controls. Auditory sensory adaptation was also investigated to explore the sensory specificity of the predicted effect. Twenty post-lingually deafened adult CI users and twenty age-matched controls were presented with repeated visual and auditory stimuli during simultaneous acquisition of electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). By integrating EEG and fNIRS signals we found significantly enhanced visual adaptation and lower visual cortex activation in CI users compared to controls. That is, responses to repeated visual stimuli decreased more prominently in CI users than in controls. The results suggest that CI users process visual stimuli more efficiently than controls.

Visual perceptual load and processing of somatosensory stimuli in primary and secondary somatosensory cortices

Load theory assumes that neural activation to distractors in early sensory cortices is modulated by the perceptual load of a main task, regardless of whether task and distractor share the same sensory modality or not. While several studies have investigated the question of load effects on distractor processing in early sensory areas, there is no functional magnetic resonance imaging (fMRI) study regarding load effects on somatosensory stimuli. Here, we used fMRI to investigate effects of visual perceptual load on neural responses to somatosensory stimuli applied to the wrist in a study with 44 participants. Perceptual load was manipulated by an established sustained visual detection task, which avoided simultaneous target and distractor presentations. Load was operationalized by detection difficulty of subtle or clear color changes of one of 12 rotating dots. While all somatosensory stimuli led to activation in somatosensory areas SI and SII, we found no statistically significant difference in brain activation to these stimuli under high compared to low sustained visual load. Moreover, exploratory Bayesian analyses supported the absence of differences. Thus, our findings suggest a resistance of somatosensory processing to at least some forms of visual perceptual load, possibly due to behavioural relevance of discrete somatosensory stimuli and separable attentional resources for the somatosensory and visual modality.

Neural Indicators of Visual Andauditory Recognition of Imitative Words on Different De-Iconization Stages.

The research aims to reveal neural indicators of recognition for iconic words and the possible cross-modal multisensory integration behind this process. The goals of this research are twofold: (1) to register event-related potentials (ERP) in the brain in the process of visual and auditory recognition of Russian imitative words on different de-iconization stages; and (2) to establish whether differences in the brain activity arise while processing visual and auditory stimuli of different nature. Sound imitative (onomatopoeic, mimetic, and ideophonic) words are words with iconic correlation between form and meaning (iconicity being a relationship of resemblance). Russian adult participants (n = 110) were presented with 15 stimuli both visually and auditorily. The stimuli material was equally distributed into three groups according to the criterion of (historical) iconicity loss: five explicit sound imitative (SI) words, five implicit SI words and five non-SI words. It was established that there was no statistically significant difference between visually presented explicit or implicit SI words and non-SI words respectively. However, statistically significant differences were registered for auditorily presented explicit SI words in contrast to implicit SI words in the N400 ERP component, as well as implicit SI words in contrast to non-SI words in the P300 ERP component. We thoroughly analyzed the integrative brain activity in response to explicit IS words and compared it to that in response to implicit SI and non-SI words presented auditorily. The data yielded by this analysis showed the N400 ERP component was more prominent during the recognition process of the explicit SI words received from the central channels (specifically Cz). We assume that these results indicate a specific brain response associated with directed attention in the process of performing cognitive decision making tasks regarding explicit and implicit SI words presented auditorily. This may reflect a higher level of cognitive complexity in identifying this type of stimuli considering the experimental task challenges that may involve cross-modal integration process.

Early visual perceptual processing is altered in obsessive–compulsive disorder

ObjectiveExisting studies have shown changes in attention and emotion processing of disorder-relevant visual stimuli in those with obsessive compulsive disorder (OCD). However, early visual processing in OCD has not been assessed, as previous studies did not examine the entire time course of visual processing but instead assessed potential differences in pre-determined visual evoked potentials (VEPs). This study investigates the entire visual processing stream in OCD compared to healthy age-matched controls (HC) using emotionally-neutral visual stimuli and a data-driven rather than hypothesis-driven approach. Methods35 HC and 26 participants with OCD underwent EEG recording while completing a modified Eriksen flanker task. Permutation-controlled t-tests were used to identify group differences in the data’s full time course of visual evoked potentials. Baseline-corrected amplitudes at time points where the groups were significantly different were analyzed using ANCOVAs with BDI, BAI, and SNAP-inattentiveness scores included as covariates. ResultsThis analysis identified enhanced P1 amplitudes to two visual stimuli (the initial flanker and the stimulus), corresponding to time windows of 65–93 ms and 157–187 ms post-flanker presentation in the OCD group compared to controls. Group (OCD vs. HC) was the strongest predictor of VEP amplitude during both time windows, with no significant influences of any covariates. ConclusionsThis study showed an enhanced P1 component in people with OCD to neutral visual stimuli, potentially reflecting either inefficient or excessive early visual processing in this population. Additional inquiry is necessary to determine whether altered visual processing is associated with the sensory hypervigilance observed in those with OCD. SignificanceThis work identifies early visual processing alterations in OCD using neutral stimuli and a data-driven approach.

Brain Correlates of Eating Disorders in Response to Food Visual Stimuli: A Systematic Narrative Review of FMRI Studies.

This article summarizes the results of studies in which functional magnetic resonance imaging (fMRI) was performed to investigate the neurofunctional activations involved in processing visual stimuli from food in individuals with anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorder (BED). A systematic review approach based on the PRISMA guidelines was used. Three databases-Scopus, PubMed and Web of Science (WoS)-were searched for brain correlates of each eating disorder. From an original pool of 688 articles, 30 articles were included and discussed. The selected studies did not always overlap in terms of research design and observed outcomes, but it was possible to identify some regularities that characterized each eating disorder. As if there were two complementary regulatory strategies, AN seems to be associated with general hyperactivity in brain regions involved in top-down control and emotional areas, such as the amygdala, insula and hypothalamus. The insula and striatum are hyperactive in BN patients and likely involved in abnormalities of impulsivity and emotion regulation. Finally, the temporal cortex and striatum appear to be involved in the neural correlates of BED, linking this condition to use of dissociative strategies and addictive aspects. Although further studies are needed, this review shows that there are specific activation pathways. Therefore, it is necessary to pay special attention to triggers, targets and maintenance processes in order to plan effective therapeutic interventions. Clinical implications are discussed.

Opposing influences of global and local stimulus-hand proximity on crosstalk interference in dual tasks.

In contrast to traditional dualistic views of cognition, visual stimulus processing appears not independent of bodily factors such as hand positioning. For example, reduced crosstalk between two temporally overlapping tasks has been observed when the hands are moved into the attentional window alongside their respective stimuli (i.e., establishing global stimulus-hand proximity). This result indicates that hand-specific attentional processing enhancements support a more serial rather than parallel processing of the two tasks. To further elucidate the nature of these processing modulations and their effect on multitasking performance, the present study consisted of three interrelated crosstalk experiments. Experiment 1 manipulated global stimulus-hand proximity and stimulus-effect proximity orthogonally, with results demonstrating that hand proximity rather than effect proximity drives the crosstalk reduction. Experiment 2 manipulated the physical distance between both hands (i.e., varying local stimulus-hand proximity), with results showing weak evidence of increased crosstalk when both hands are close to each other. Experiment 3 tested opposing influences of global and local stimulus-hand proximity as observed in Experiment 1 and 2 rigorously within one experiment, by employing an orthogonal manipulation of these two proximity measures. Again, we observed slightly increased crosstalk for hands close to each other (replicating Experiment 2); however, in contrast to Experiment 1, the effect of global stimulus-hand proximity on the observed crosstalk was not significant this time. Taken together, the experiments support the notion of hand-specific modulations of perception-action coupling, which can either lead to more or less interference in multitasking, depending on the exact arrangement of hands and stimuli.

Visual processing of food stimuli: The impact of working memory load and color.

Our environment is surrounded by appetizing food stimuli that contribute to an increase in health problems such as obesity and overweight. Understanding the cognitive factors underlying the processing of food stimuli can play an important role in health interventions. Recent studies showed that high-calorie food stimuli impair working memory (WM) task performance, and some individuals, such as restrained eaters, are more susceptible to this WM performance decrement. The present study investigated the effect of low and high WM load on the processing of food stimuli in restrained and unrestrained eaters. Using an n-back task, identical food (low and high calorie) and non-food (object) stimuli were presented in colored (Experiment 1A) or in grayscale (Experiment 1B) versions. Performance was assessed by reaction time (RT), d-prime, and response bias C variables. Results revealed differences in the different WM load conditions. While no effects were observed in the low load, higher WM load impaired task performance. Processing the food stimuli, compared to objects, led to longer RTs and decreased task performance, indicated by d prime and response bias, only when the stimuli were presented in color but not in grayscale. Though no difference was observed in restrained and unrestrained eaters, the role of WM load on the visual processing of the food stimuli remains to be further examined.

DISTORTED FACE PERCEPTION:AN ERP STUDY OF EMOTIONAL EXPRESSION PROCESSING

Background. Reading the emotional cues from the faces of people around us is considered to be the crucial element of successful social interaction. However, at the moment there is no single point of view on the basic principles of the organization of neuromechanisms corresponding to face perception, which determines the relevance of this work. Therefore, we focused primarily on the effective neuronal networks formed during the processing of emotional visual stimuli – human faces, in their natural form and under the conditions of configurational changes‘ introduction. Current study aimed at highlighting more subtle elements of face perception and decoding mechanisms. Methods. For the purpose of the study, blurred facial expressions were presented amongst the natural face images of different emotional valence. During the exposition, the electroencephalogram was recorded, which then formed the basis for eventrelated potentials' grand average calculation. Further analysis involved comparing the grand average ERP curves recorded from the precentral cortical regions in two gender-based groups. The findings showed that female participants were more engaged in detecting and deciphering emotional expressions even from the minute hints included in the blurred photos. On the other hand, the male group also showed more significant decoding and recall processes, when presented with blurred neutral stimuli. Results. The findings showed that female participants were more engaged in detecting and deciphering emotional expressions even from the minute hints included in the blurred photos. On the other hand, the male group also showed more significant decoding and recall processes, when presented with blurred neutral stimuli. Conclusions. These results are consistent with current evidence on the emotional sensitivity hypothesis and genderspecific variations in face perception strategies, which reveal that men and women appear to perceive neutral faces with varying degrees of accuracy, and women are more likely to perform better when processing emotional expressions.