Measures of angularity in digital images

In light of the growing interest in studying the affective and aesthetic attributes of curvature, the present paper describes four digital image processing techniques that can be used to objectively discriminate between angular and curvilinear stimuli. MATLAB scripts for each of the techniques accompany the paper. Three studies are then reported that evaluate the efficacy of five metrics, derived from the four techniques, at quantifying the degree of angularity depicted in an image. Images of simple polygons (Study 1), artistic drawings of everyday objects (Study 2), and real-world objects, typefaces, and abstract patterns (Study 3) were analyzed. Logistic regression models were used to determine the relative importance of the metrics at distinguishing between angular and curvilinear items. With one exception, all of the metrics were capable of distinguishing between angular and curvilinear items at a level above chance, but some metrics were better at doing so than others, and their discriminative capacity was influenced by the characteristics of the image. The strengths and limitations of the metrics are discussed, as well as some practical recommendations.

Subjective Affective Responses to Natural Scenes Require Understanding, Not Spatial Frequency Bands

It is debated whether emotional processing and response depend on semantic identification or are preferentially tied to specific information in natural scenes, such as global features or local details. The present study aimed to further examine the relationship between scene understanding and affective response while manipulating visual content. To this end, we presented affective and neutral natural scenes which were progressively band-filtered to contain global features (low spatial frequencies) or local details (high spatial frequencies) and assessed both affective response and scene understanding. We observed that, if scene content was correctly reported, subjective ratings of arousal and valence were modulated by the affective content of the scene, and this modulation was similar across spatial frequency bands. On the other hand, no affective modulation of subjective ratings was observed if picture content was not correctly reported. The present results indicate that subjective affective response requires content understanding, and it is not tied to a specific spatial frequency range.

Effects of spatially filtered fearful faces and awareness on amygdala activity in adults with autism spectrum disorder: A magnetoencephalography study

BACKGROUND

The amygdala is pivotal in emotional face processing. Spatial frequencies (SFs) of visual images are divided and processed via two visual pathways: low spatial frequency (LSF) information is conveyed by the magnocellular pathway, while the parvocellular pathway carries high spatial frequency information. We hypothesized that altered amygdala activity might underlie atypical social communication caused by changes in both conscious and non-conscious emotional face processing in the brain in individuals with autism spectrum disorder (ASD).

METHOD

Eighteen adults with ASD and 18 typically developing (TD) peers participated in this study. Spatially filtered fearful- and neutral-expression faces and object stimuli were presented under supraliminal or subliminal conditions, and neuromagnetic responses in the amygdala were measured using 306-channel whole-head magnetoencephalography.

RESULTS

The latency of the evoked responses at approximately 200 ms to unfiltered neutral face stimuli and object stimuli in the ASD group was shorter than that in the TD group in the unaware condition. Regarding emotional face processing, the evoked responses in the ASD group were larger than those in the TD group under the aware condition. The later positive shift during 200-500 ms (ARV) was larger than that in the TD group, regardless of awareness. Moreover, ARV to HSF face stimuli was larger than that to the other spatial filtered face stimuli in the aware condition.

CONCLUSION

Regardless of awareness, ARV might reflect atypical face information processing in the ASD brain.

Threat shapes visual context sensitivity selectively through low-spatial-frequency channels

Threat has long been supposed to affect human cognitive processing including visual size perception. Whether such threat-related modulation effect varies as a function of spatial frequency is largely unexplored. Here we used low- or high-pass filtered threatening animal and fearful face images as primes and measured their effects on the processing of the Ebbinghaus illusion. Results showed that threatening-animal primes relative to neutral ones significantly decreased the illusion magnitude in low-spatial-frequency rather than in high-spatial-frequency ranges. However, fearful- and neutral-face primes had a comparable effect on the illusion magnitude in both spatial frequency ranges. Notably, when inhibitory transcranial magnetic stimulation was applied to the left temporo-parietal junction (TPJ), fearful-face primes significantly decreased the illusion magnitude in low-spatial-frequency rather than in high-spatial-frequency ranges. However, the opposite pattern of results was observed with right TPJ stimulation. The findings suggest that threat shapes basic aspects of visual perception in a spatial frequency-specific manner, possibly via magnocellular projections from both subcortical and cortical fear-processing systems to early visual cortex.

Exploration of Exogenous Attention to Disgust and Fear Pictures with Different Spatial Frequencies Through Event-related Potentials

The study of the effects of fear and disgust on the capture of automatic attention is gaining interest. Most findings reveal a more efficient capture of exogenous attention by disgust than by fear stimuli, although the underlying mechanisms are not completely understood. The manipulation of their spatial frequency may provide new insight that may contribute to clarify this issue. The present study aimed to explore differential processing of disgust and fear scenes containing only low spatial frequencies (LSF) or all spatial frequencies (intact) presented as distractors in an exogenous attention task. Event-related potentials (ERPs) and behavioral responses were recorded as dependent variables from forty participants (29 women). The results showed that disgust and fear distractors captured exogenous attention equally early, as indicated by the augmented amplitude of the N2p, and later disgust distractors are the ones eliciting the highest amplitude of the LPP component. While in an initial stage, both stimuli seem to have similar preferential access to further processing allowing fast responding in both cases, disgust is more deeply processed at a later stage probably facilitating its examination. These findings suggest that exploring the temporal course of processing is relevant for the understanding of the differential capture of exogenous attention by disgust and fear distractors.

Effect of the congruity of emotional contexts at encoding on source memory: Evidence from ERPs

Emotion's influence on source memory has proven more elusive and the lack of studies investigates the effect of the congruent emotional contexts on source memory. Here, we investigated these issues using event-related potentials (ERPs) to assess emotional-induced neural correlates. During encoding, congruent word-picture (a word 'shoes' - a picture described shoes) and incongruent word-picture (a word 'pepper' - a picture described shoes) with a prompt (Common? or Natural?) were presented. At retrieval, participants indicated which prompts were concomitantly presented with the word during encoding. Behavioral results revealed that source memory accuracy was enhanced in the neutral contexts compared to the negative contexts, and enhanced in the incongruent condition relative to the congruent condition, suggesting that emotional contexts impaired source memory performance, and incongruent information enhanced source memory. ERPs results showed that early P2 old/new effect (150-250 ms) and FN400 old/new effect (300-450 ms) were observed for words with correct source that had been encoded in the congruent emotional contexts, and that a larger parietal old/new effect, between 500 and 700 ms, was observed for words with correct source that had been encoded in the incongruent condition than in the congruent condition, irrespective the nature of context. The ERPs results indicate that retrieval of source details for the associated emotionally congruent information supports the idea that emotional events could attract more attentional resources, and reflects the contribution of familiarity-based process. Meanwhile, retrieval of source details for the associated incongruent information reflects a stronger contribution of recollection-based process.

Low-spatial-frequency information facilitates threat detection in a response-specific manner

The role of different spatial frequency bands in threat detection has been explored extensively. However, most studies use manual responses and the results are mixed. Here, we aimed to investigate the contribution of spatial frequency information to threat detection by using three response types, including manual responses, eye movements, and reaching movements, together with a priming paradigm. The results showed that both saccade and reaching responses were significantly faster to threatening stimuli than to nonthreatening stimuli when primed by low-spatial-frequency gratings rather than by high-spatial-frequency gratings. However, the manual response times to threatening stimuli were comparable to nonthreatening stimuli, irrespective of the spatial frequency content of the primes. The findings provide clear evidence that low-spatial-frequency information can facilitate threat detection in a response-specific manner, possibly through the subcortical magnocellular pathway dedicated to processing threat-related signals, which is automatically prioritized in the oculomotor system and biases behavior.

Emotional face recognition in autism and in cerebral visual impairments: In search for specificity

Autism spectrum disorder (ASD) is characterized by difficulties in the social domain, but also by hyper- and hypo-reactivity. Atypical visual behaviours and processing have often been observed. Nevertheless, several similar signs are also identified in other clinical conditions including cerebral visual impairments (CVI). In the present study, we investigated emotional face categorization in groups of children with ASD and CVI by comparing each group to typically developing individuals (TD) in two tasks. Stimuli were either non-filtered or filtered by low- and high-spatial frequencies (LSF and HSF). All participants completed the autism spectrum quotient score (AQ) and a complete neurovisual evaluation. The results show that while both clinical groups presented difficulties in the emotional face recognition tasks and atypical processing of filtered stimuli, they did not differ from one another. Additionally, autistic traits were observed in the CVI group and symmetrically, some visual disturbances were present in the ASD group as measured via the AQ score and a neurovisual evaluation, respectively. The present study suggests the relevance of comparing ASD to CVI by showing that emotional face categorization difficulties should not be solely considered as autism-specific but merit investigation for potential dysfunction of the visual processing neural network. These results are of interest in both clinical and research perspectives, indicating that systematic visual examination is warranted for individuals with ASD.

Anodal tDCS of right temporo-parietal junction promotes threat detection in low-spatial-frequency channels

Fast detection of threat is crucial for survival. Previous studies have suggested the involvement of low- and high-spatial-frequency (LSF and HSF) information in the process of threat detection. However, the specific contributions of LSF and HSF information to it are still controversial. Here we probed this issue by utilizing a prime procedure coupled with the transcranial direct current stimulation (tDCS) technique. Specifically, in a single-blind design, participants were exposed to LSF or HSF faces prior to the presentation of looming or receding spheres. Meanwhile, tDCS was applied over the right or left temporo-parietal junction (TPJ), which has been found to be preferentially associated with the processing of LSF and HSF information, respectively. The results showed significant LSF-related facilitation of threat detection when anodal tDCS was applied to the right TPJ. However, HSF-related facilitation of threat detection was not observed when anodal tDCS was applied to the left TPJ. The findings support the idea that LSF information can facilitate threat detection, and provide direct evidence that the right TPJ is vital for LSF-related facilitation of threat detection.

How do Asians perceive Caucasian eyes? Electrophysiological correlates of perceiving racial differences from the eyes region of the face

Past research has found that several brain event-related potentials (ERPs) were sensitive to the perception of ethnic differences displayed on human faces. This body of research suggests that the phenomenon of "race perception" involves a cascade of cognitive processes that includes both automatic and overt attentional mechanisms. However, most of these studies used stimuli depicting whole faces rather than stimuli depicting separate facial features. Therefore, it is still largely unknown if ERP responses to racial differences are the result of a holistic processing of the whole face, or whether they can be accounted for by the perception of single facial features. To address this issue, we examined whether a single facial feature, the eyes region, can provide sufficient information to trigger known ERP correlates of race perception such as the P2, the N400 and the Late Positive Complex (LPC). Specifically, we showed pictures depicting only the eyes region of Caucasian and Asian faces to a sample of Asian participants. We found that the P2 was larger for other-race (OR) compared to same-race (SR) eyes, and that the N400 was larger for SR compared to OR eyes. The effects on the P2 may suggest an enhanced vigilance response to OR eyes whereas the N400 effect could reflect a signal of familiarity triggered by SR eyes. These results indicate that a specific facial feature, the eyes region, can account for known effects of race perception on early brain potentials. Our findings also indicate that well-known early neural correlates of race perception can be triggered in the absence of a holistic processing of the whole face.

Spatial Frequency Thresholds for Detecting Latent Facial Signals of Threat

This study examined whether latent facial signals of threat can be detected at more extreme ranges of spatial frequencies (SFs), and thus with fewer frequencies from an optimal middle band for face identification, compared with latent nonthreatening facial signals. Using an adaptive staircase procedure and a two-interval forced-choice same-different task, SF thresholds from the lower and higher ends of the SF spectrum were obtained for nonexpressive threatening and nonthreatening faces. Threatening faces were discriminated from neutral faces more quickly and accurately, and engendered more extreme SF thresholds, compared with nonthreatening faces. The results indicate that the components of latent threatening facial signals can be detected under a greater degree of impoverished visual information for face processing compared with their nonthreatening counterparts.

The importance of recurrent top-down synaptic connections for the anticipation of dynamic emotions

Different studies have shown the efficiency of a feed-forward neural network in categorizing basic emotional facial expressions. However, recent findings in psychology and cognitive neuroscience suggest that visual recognition is not a pure bottom-up process but likely involves top-down recurrent connectivity. In the present computational study, we compared the performances of a pure bottom-up neural network (a standard multi-layer perceptron, MLP) with a neural network involving recurrent top-down connections (a simple recurrent network, SRN) in the anticipation of emotional expressions. In two complementary simulations, results revealed that the SRN outperformed the MLP for ambiguous intensities in the temporal sequence, when the emotions were not fully depicted but when sufficient contextual information (related to previous time frames) was provided. Taken together, these results suggest that, despite the cost of recurrent connections in terms of energy and processing time for biological organisms, they can provide a substantial advantage for the fast recognition of uncertain visual signals.

Introduction and validation of the Natural Disasters Picture System (NDPS)

Given the growing demand for studies dealing with natural disasters, the research fields of emotion and social cognition require validated picture stimuli of natural hazards. Such material is essential for studying perceptual processes and behaviors of exposed individuals, and it could find practical applications, such as the improvement of communication strategies during crises. We present the Natural Disasters Picture System (NDPS), a database of pictures of natural hazards, with an emphasis on volcanic threats, and their impact on the environment and humans. We first describe in detail the picture selection and database creation. We then report the validation procedure. One hundred twenty participants rated the pictures on the basis of four dimensions: valence, arousal, dominance and certainty. For each picture, we ultimately determined the best-fitting emotion on the basis of its dimensional pattern. The Hierarchical Ascendant Classification, which yielded 4 clusters subdivided into 9 classes, indicated a highly consistent and distinctive classification of the pictures. Overall, 90% of the pictures elicited negative emotions (fear or sadness), and the other 10% induced neutral to positive emotions (e.g., aesthetic emotions). The NDPS offers a new tool for studying natural events and disasters in the field of affective and cognitive sciences, which will benefit from scientific research and its practical applications. The NDPS is unrestrictedly accessible for researchers.

The Saliency of Angular Shapes in Threatening and Nonthreatening Faces

Several lines of evidence suggest that angularity and curvilinearity are relied upon to infer the presence or absence of threat. This study examines whether angular shapes are more salient in threatening compared with nonthreatening emotionally neutral faces. The saliency of angular shapes was measured by the amount of local maxima in S(θ), a function that characterizes how the Fourier magnitude spectrum varies along specific orientations. The validity of this metric was tested and supported with images of threatening and nonthreatening real-world objects and abstract patterns that have predominantly angular or curvilinear features (Experiment 1). This metric was then applied to computer-generated faces that maximally correlate with threat (Experiment 2a) and to real faces that have been rated according to threat (Experiment 3). For computer-generated faces, angular shapes became increasingly salient as the threat level of the faces increased. For real faces, the saliency of angular shapes was not predictive of threat ratings after controlling for other well-established threat cues, however, other facial features related to angularity (e.g., brow steepness) and curvilinearity (e.g., round eyes) were significant predictors. The results offer preliminary support for angularity as a threat cue for emotionally neutral faces.

Evidence of Rapid Modulation by Social Information of Subjective, Physiological, and Neural Responses to Emotional Expressions

Recent research suggests that conceptual or emotional factors could influence the perceptual processing of stimuli. In this article, we aimed to evaluate the effect of social information (positive, negative, or no information related to the character of the target) on subjective (perceived and felt valence and arousal), physiological (facial mimicry) as well as on neural (P100 and N170) responses to dynamic emotional facial expressions (EFE) that varied from neutral to one of the six basic emotions. Across three studies, the results showed reduced ratings of valence and arousal of EFE associated with incongruent social information (Study 1), increased electromyographical responses (Study 2), and significant modulation of P100 and N170 components (Study 3) when EFE were associated with social (positive and negative) information (vs. no information). These studies revealed that positive or negative social information reduces subjective responses to incongruent EFE and produces a similar neural and physiological boost of the early perceptual processing of EFE irrespective of their congruency. In conclusion, the article suggests that the presence of positive or negative social context modulates early physiological and neural activity preceding subsequent behavior.

A Rapid Subcortical Amygdala Route for Faces Irrespective of Spatial Frequency and Emotion

There is significant controversy over the existence and function of a direct subcortical visual pathway to the amygdala. It is thought that this pathway rapidly transmits low spatial frequency information to the amygdala independently of the cortex, and yet the directionality of this function has never been determined. We used magnetoencephalography to measure neural activity while human participants discriminated the gender of neutral and fearful faces filtered for low or high spatial frequencies. We applied dynamic causal modeling to demonstrate that the most likely underlying neural network consisted of a pulvinar-amygdala connection that was uninfluenced by spatial frequency or emotion, and a cortical-amygdala connection that conveyed high spatial frequencies. Crucially, data-driven neural simulations revealed a clear temporal advantage of the subcortical connection over the cortical connection in influencing amygdala activity. Thus, our findings support the existence of a rapid subcortical pathway that is nonselective in terms of the spatial frequency or emotional content of faces. We propose that that the "coarseness" of the subcortical route may be better reframed as "generalized."SIGNIFICANCE STATEMENT The human amygdala coordinates how we respond to biologically relevant stimuli, such as threat or reward. It has been postulated that the amygdala first receives visual input via a rapid subcortical route that conveys "coarse" information, namely, low spatial frequencies. For the first time, the present paper provides direction-specific evidence from computational modeling that the subcortical route plays a generalized role in visual processing by rapidly transmitting raw, unfiltered information directly to the amygdala. This calls into question a widely held assumption across human and animal research that fear responses are produced faster by low spatial frequencies. Our proposed mechanism suggests organisms quickly generate fear responses to a wide range of visual properties, heavily implicating future research on anxiety-prevention strategies.

Cerebral Correlates of Emotional and Action Appraisals During Visual Processing of Emotional Scenes Depending on Spatial Frequency: A Pilot Study

Visual processing of emotional stimuli critically depends on the type of cognitive appraisal involved. The present fMRI pilot study aimed to investigate the cerebral correlates involved in the visual processing of emotional scenes in two tasks, one emotional, based on the appraisal of personal emotional experience, and the other motivational, based on the appraisal of the tendency to action. Given that the use of spatial frequency information is relatively flexible during the visual processing of emotional stimuli depending on the task’s demands, we also explored the effect of the type of spatial frequency in visual stimuli in each task by using emotional scenes filtered in low spatial frequency (LSF) and high spatial frequencies (HSF). Activation was observed in the visual areas of the fusiform gyrus for all emotional scenes in both tasks, and in the amygdala for unpleasant scenes only. The motivational task induced additional activation in frontal motor-related areas (e.g. premotor cortex, SMA) and parietal regions (e.g. superior and inferior parietal lobules). Parietal regions were recruited particularly during the motivational appraisal of approach in response to pleasant scenes. These frontal and parietal activations, respectively, suggest that motor and navigation processes play a specific role in the identification of the tendency to action in the motivational task. Furthermore, activity observed in the motivational task, in response to both pleasant and unpleasant scenes, was significantly greater for HSF than for LSF scenes, suggesting that the tendency to action is driven mainly by the detailed information contained in scenes. Results for the emotional task suggest that spatial frequencies play only a small role in the evaluation of unpleasant and pleasant emotions. Our preliminary study revealed a partial distinction between visual processing of emotional scenes during identification of the tendency to action, and during identification of personal emotional experiences. It also illustrates flexible use of the spatial frequencies contained in scenes depending on their emotional valence and on task demands.

Distinct effects of contrast and color on subjective rating of fearfulness

Natural scenes provide important affective cues for observers to avoid danger. From an adaptationist perspective, such cues affect the behavior of the observer and shape the evolution of the observer’s response. It is evolutionarily significant for individuals to extract affective information from the environment as quickly and as efficiently as possible. However, the nearly endless variations in physical appearance of natural scenes present a fundamental challenge for perceiving significant visual information. How image-level properties, such as contrast and color, influence the extraction of affective information leading to subjective emotional perception is unclear. On the one hand, studies have shown that visual perception and emotional perception seem to interact with each other at the earliest stages in cortical processing. On the other hand, it is important for high-level subjective ratings to be invariant to low-level visual properties. Using a psychophysical approach and signal detection theory (SDT), we tested how contrast and color influenced fearfulness ratings of a set of natural scene pictures that varied in contents and in levels of fearfulness. Image contrast influenced perceptual sensitivity but not the decision criterion of fearfulness rating, whereas color affected the decision criterion but not perceptual sensitivity. These results show that different low-level visual features contribute independently to sensitivity or decision criterion in affective perception, suggesting distinct interactions between visual cognition and affective processing. Specifically, our naturalistic approach using a novel stimulus set, combined with SDT, has demonstrated two dissociable types of cognitive mechanisms underlying how image-level properties leverage the extraction of affective information in natural vision.

The effects of a distracting N-back task on recognition memory are reduced by negative emotional intensity

Memory performance is usually impaired when participants have to encode information while performing a concurrent task. Recent studies using recall tasks have found that emotional items are more resistant to such cognitive depletion effects than non-emotional items. However, when recognition tasks are used, the same effect is more elusive as recent recognition studies have obtained contradictory results. In two experiments, we provide evidence that negative emotional content can reliably reduce the effects of cognitive depletion on recognition memory only if stimuli with high levels of emotional intensity are used. In particular, we found that recognition performance for realistic pictures was impaired by a secondary 3-back working memory task during encoding if stimuli were emotionally neutral or had moderate levels of negative emotionality. In contrast, when negative pictures with high levels of emotional intensity were used, the detrimental effects of the secondary task were significantly attenuated.

Recollecting positive and negative autobiographical memories disrupts working memory

The present article reports two experiments examining the impact of recollecting emotionally valenced autobiographical memories on subsequent working memory (WM) task performance. Experiment 1 found that negatively valenced recollection significantly disrupted performance on a supra-span spatial WM task. Experiment 2 replicated and extended these findings to a verbal WM task (digit recall), and found that both negative and positive autobiographical recollections had a detrimental effect on verbal WM. In addition, we observed that these disruptive effects were more apparent on early trials, immediately following autobiographical recollection. Overall, these findings show that both positive and negative affect can disrupt WM when the mood-eliciting context is based on autobiographical memories. Furthermore, these results indicate that the emotional disruption of WM can take place across different modalities of WM (verbal and visuo-spatial).

The visual detection of threat: a cautionary tale

The fear response hypothesis and the associated claim that humans have an evolutionary propensity to detect threats automatically in their immediate visual environment are critically appraised. This review focuses on reports of visual search experiments in which participants were tested with speeded oddball tasks in which the search displays contained photographic images of naturally occurring entities. In such tasks, participants have to judge whether all the images are from one category or whether the display contains a distinctive image. The evidence, which has been used to support the fear response hypothesis, is assessed against a series of concerns that relate to stimulus factors and stimulus selection. It is shown that when careful consideration is given to such methodological details, it becomes very difficult to defend the fear response hypothesis. It is concluded that, at present, the fear response hypothesis has no convincing empirical support, and it is urged that, in the future, researchers who wish to study visual threat detection take stimulus selection much more seriously.

Immediate emotion-enhanced memory dependent on arousal and valence: the role of automatic and controlled processing

The phenomenon that emotional stimuli are better remembered than neutral ones is called emotion-enhanced memory (EEM). Previous studies have shown that both valence and arousal of stimuli contributed to EEM. Kensinger and Corkin (2004) proposed that the EEM dependent on arousal was associated with automatic encoding processes, whereas the EEM dependent on valence was associated with controlled encoding processes. Their experiment with negative words provided some evidence for this associative pattern. However, it is unclear whether the observed association that occurred with negative emotional stimuli could be replicated with positive emotional stimuli. To further examine this issue, two experiments were conducted to investigate the immediate EEM of emotional words in three different attention conditions using a divided attention (DA) paradigm. Results indicated that the immediate EEM dependent on valence was associated with controlled processing, while the immediate EEM dependent on arousal was not always associated with automatic processing. The immediate EEM dependent on arousal for negative stimuli was associated with automatic processing, whereas the immediate EEM dependent on arousal for positive stimuli was associated with controlled processing. Therefore, the immediate EEM dependent on arousal, whether it is associated with automatic or controlled processing, is moderated by the valence of stimuli.

Affective and contextual values modulate spatial frequency use in object recognition

Visual object recognition is of fundamental importance in our everyday interaction with the environment. Recent models of visual perception emphasize the role of top-down predictions facilitating object recognition via initial guesses that limit the number of object representations that need to be considered. Several results suggest that this rapid and efficient object processing relies on the early extraction and processing of low spatial frequencies (LSF). The present study aimed to investigate the SF content of visual object representations and its modulation by contextual and affective values of the perceived object during a picture-name verification task. Stimuli consisted of pictures of objects equalized in SF content and categorized as having low or high affective and contextual values. To access the SF content of stored visual representations of objects, SFs of each image were then randomly sampled on a trial-by-trial basis. Results reveal that intermediate SFs between 14 and 24 cycles per object (2.3-4 cycles per degree) are correlated with fast and accurate identification for all categories of objects. Moreover, there was a significant interaction between affective and contextual values over the SFs correlating with fast recognition. These results suggest that affective and contextual values of a visual object modulate the SF content of its internal representation, thus highlighting the flexibility of the visual recognition system.

The neural fate of neutral information in emotion-enhanced memory

In this study, we report evidence that neural activity reflecting the encoding of emotionally neutral information in memory is reduced when neutral and emotional stimuli are intermixed during encoding. Specifically, participants studied emotional and neutral pictures organized in mixed lists (in which emotional and neutral pictures were intermixed) or in pure lists (only-neutral or only-emotional pictures) and performed a recall test. To estimate encoding efficiency, we used the Dm effect, measured with event-related potentials. Recall for neutral items was lower in mixed compared to pure lists and posterior Dm activity for neutral items was reduced in mixed lists, whereas it remained robust in pure lists. These findings might be caused by an asymmetrical competition for attentional and working memory resources between emotional and neutral information, which could be a major determinant of emotional memory effects.

Behavioral assessment of emotional and motivational appraisal during visual processing of emotional scenes depending on spatial frequencies

Previous studies performed on visual processing of emotional stimuli have revealed preference for a specific type of visual spatial frequencies (high spatial frequency, HSF; low spatial frequency, LSF) according to task demands. The majority of studies used a face and focused on the appraisal of the emotional state of others. The present behavioral study investigates the relative role of spatial frequencies on processing emotional natural scenes during two explicit cognitive appraisal tasks, one emotional, based on the self-emotional experience and one motivational, based on the tendency to action. Our results suggest that HSF information was the most relevant to rapidly identify the self-emotional experience (unpleasant, pleasant, and neutral) while LSF was required to rapidly identify the tendency to action (avoidance, approach, and no action). The tendency to action based on LSF analysis showed a priority for unpleasant stimuli whereas the identification of emotional experience based on HSF analysis showed a priority for pleasant stimuli. The present study confirms the interest of considering both emotional and motivational characteristics of visual stimuli.

Rapid Presentation of Emotional Expressions Reveals New Emotional Impairments in Tourette's Syndrome

OBJECTIVE

Based on a variety of empirical evidence obtained within the theoretical framework of embodiment theory, we considered it likely that motor disorders in Tourette's syndrome (TS) would have emotional consequences for TS patients. However, previous research using emotional facial categorization tasks suggests that these consequences are limited to TS patients with obsessive-compulsive behaviors (OCB).

METHOD

These studies used long stimulus presentations which allowed the participants to categorize the different emotional facial expressions (EFEs) on the basis of a perceptual analysis that might potentially hide a lack of emotional feeling for certain emotions. In order to reduce this perceptual bias, we used a rapid visual presentation procedure.

RESULTS

Using this new experimental method, we revealed different and surprising impairments on several EFEs in TS patients compared to matched healthy control participants. Moreover, a spatial frequency analysis of the visual signal processed by the patients suggests that these impairments may be located at a cortical level.

CONCLUSION

The current study indicates that the rapid visual presentation paradigm makes it possible to identify various potential emotional disorders that were not revealed by the standard visual presentation procedures previously reported in the literature. Moreover, the spatial frequency analysis performed in our study suggests that emotional deficit in TS might lie at the level of temporal cortical areas dedicated to the processing of HSF visual information.

Temporal memory of emotional experience

The few studies that have investigated judgments of time have suggested that the memory of duration is distorted more for emotional events than for neutral events, while in contrast there is abundant evidence that other aspects of memories of emotional events are more accurate. To reconcile this apparent discrepancy, we used a procedure in which the participants learned a standard duration over several trials under three emotional conditions: a threatening, a nonthreatening, and a neutral control condition. They were then tested either immediately or 24 h after learning. In this test phase, they had to indicate whether presented comparison durations were or were not the same as the previously learned standard duration. We found that durations were recalled better in the emotional than in the neutral condition, and that this occurred to a greater extent in the threatening than in the nonthreatening condition. Arousing emotions thus enhanced temporal memory, just as they enhance memory for other aspects of emotional events.

Brain mechanisms for emotional influences on perception and attention: what is magic and what is not

The rapid and efficient selection of emotionally salient or goal-relevant stimuli in the environment is crucial for flexible and adaptive behaviors. Converging data from neuroscience and psychology have accrued during the last decade to identify brain systems involved in emotion processing, selective attention, and their interaction, which together act to extract the emotional or motivational value of sensory events and respond appropriately. An important hub in these systems is the amygdala, which may not only monitor the emotional value of stimuli, but also readily project to several other areas and send feedback to sensory pathways (including striate and extrastriate visual cortex). This system generates saliency signals that modulate perceptual, motor, as well as memory processes, and thus in turn regulate behavior appropriately. Here, we review our current views on the function and properties of these brain systems, with an emphasis on their involvement in the rapid and/or preferential processing of threat-relevant stimuli. We suggest that emotion signals may enhance processing efficiency and competitive strength of emotionally significant events through gain control mechanisms similar to those of other (e.g. endogenous) attentional systems, but mediated by distinct neural mechanisms in amygdala and interconnected prefrontal areas. Alterations in these brain mechanisms might be associated with psychopathological conditions, such as anxiety or phobia. We conclude that attention selection and awareness are determined by multiple attention gain control systems that may operate in parallel and use different sensory cues but act on a common perceptual pathway.

The vividness of happiness in dynamic facial displays of emotion

Rapid identification of facial expressions can profoundly affect social interactions, yet most research to date has focused on static rather than dynamic expressions. In four experiments, we show that when a non-expressive face becomes expressive, happiness is detected more rapidly anger. When the change occurs peripheral to the focus of attention, however, dynamic anger is better detected when it appears in the left visual field (LVF), whereas dynamic happiness is better detected in the right visual field (RVF), consistent with hemispheric differences in the processing of approach- and avoidance-relevant stimuli. The central advantage for happiness is nevertheless the more robust effect, persisting even when information of either high or low spatial frequency is eliminated. Indeed, a survey of past research on the visual search for emotional expressions finds better support for a happiness detection advantage, and the explanation may lie in the coevolution of the signal and the receiver.