The disengagement deficit after right-hemisphere damage: Distinct roles of lateral frontal and parietal damage.

An influential model of spatial attention postulates three main attention-orienting mechanisms: disengagement, shifting, and engagement. Early research linked disengagement deficits with superior parietal damage, regardless of hemisphere or presence of spatial neglect. Subsequent studies supported the involvement of more ventral parietal regions, especially in the right hemisphere, and linked spatial neglect to deficient disengagement from ipsilateral cues. However, previous lesion studies faced serious limitations, such as small sample sizes and the lack of brain-injured controls without neglect. Additionally, some studies employed symbolic cues or used long cue-target intervals, which may fail to reveal impaired disengagement. We here used a machine-learning approach to conduct lesion-symptom mapping (LSM) on 89 patients with focal cerebral lesions to the left (LH) or right (RH) cerebral hemisphere. A group of 54 healthy participants served as controls. The paradigm used to uncover disengagement deficits employed non-predictive cues presented in the visual periphery and at short cue-target intervals, targeting exogenous attention. The main factors of interest were group (healthy participants, LH, RH), target position (left, right hemifield) and cue validity (valid, invalid). LSM-analyses were performed on two indices: the validity effect, computed as the absolute difference between reaction times (RTs) following invalid compared to valid cues, and the disengagement deficit, determined by the difference between contralesional and ipsilesional validity effects. While LH patients showed general slowing of RTs to contralesional targets, only RH patients exhibited a disengagement deficit from ipsilesional cues. LSM associated the validity effect with a right lateral frontal cluster, which additionally affected subcortical white matter of the right arcuate fasciculus, the corticothalamic pathway, and the superior longitudinal fasciculus. In contrast, the disengagement deficit was related to damage involving the right temporoparietal junction. Thus, our results support the crucial role of right inferior parietal and posterior temporal regions for attentional disengagement, but also emphasize the importance of lateral frontal regions, for the reorienting of attention.

Electrophysiological analysis of signal detection outcomes emphasizes the role of decisional factors in recognition memory.

Introduction: Event-related potential (ERP) studies have identified two time windows associated with recognition memory and interpreted them as reflecting two processes: familiarity and recollection. However, using relatively simple stimuli and achieving high recognition rates, most studies focused on hits and correct rejections. This leaves out some information (misses and false alarms) that according to Signal Detection Theory (SDT) is necessary to understand signal processing. Methods: We used a difficult visual recognition task with colored pictures of different categories to obtain enough of the four possible SDT outcomes and analyzed them with modern ERP methods. Results: Non-parametric analysis of these outcomes identified a single time window (470 to 670 ms) which reflected activity within fronto-central and posterior-left clusters of electrodes, indicating differential processing. The posterior-left cluster significantly distinguished all STD outcomes. The fronto-central cluster only distinguished ERPs according to the subject's response: yes vs. no. Additionally, only electrophysiological activity within the posterior-left cluster correlated with the discrimination index (d'). Discussion: We show that when all SDT outcomes are examined, ERPs of recognition memory reflect a single-time window that may reveal a bottom-up factor discriminating the history of items (i.e. memory strength), as well as a top-down factor indicating participants' decision.

How embodied is cognition? fMRI and behavioral evidence for common neural resources underlying motor planning and mental rotation of bodily stimuli.

Functional neuroimaging shows that dorsal frontoparietal regions exhibit conjoint activity during various motor and cognitive tasks. However, it is unclear whether these regions serve several, computationally independent functions, or underlie a motor "core process" that is reused to serve higher-order functions. We hypothesized that mental rotation capacity relies on a phylogenetically older motor process that is rooted within these areas. This hypothesis entails that neural and cognitive resources recruited during motor planning predict performance in seemingly unrelated mental rotation tasks. To test this hypothesis, we first identified brain regions associated with motor planning by measuring functional activations to internally-triggered vs externally-triggered finger presses in 30 healthy participants. Internally-triggered finger presses yielded significant activations in parietal, premotor, and occipitotemporal regions. We then asked participants to perform two mental rotation tasks outside the scanner, consisting of hands or letters as stimuli. Parietal and premotor activations were significant predictors of individual reaction times when mental rotation involved hands. We found no association between motor planning and performance in mental rotation of letters. Our results indicate that neural resources in parietal and premotor cortex recruited during motor planning also contribute to mental rotation of bodily stimuli, suggesting a common core component underlying both capacities.

Avoidance behaviour generalizes to eye processing in posttraumatic stress disorder.

Background: Avoidance describes any action designed to prevent an uncomfortable situation or emotion from occurring. Although it is a common reaction to trauma, avoidance becomes problematic when it is the primary coping strategy, and plays a major role in the development and maintenance of posttraumatic stress disorder (PTSD). Avoidance in PTSD may generalize to non-harmful environmental cues that are perceived to be unsafe. Objective: We tested whether avoidance extends to social cues (i.e. emotional gazes) that are unrelated to trauma. Method: A total of 159 participants (103 who had been exposed to the 2015 Paris terrorist attacks and 56 who had not) performed a gaze-cueing task featuring sad, happy and neutral faces. Attention to the eye area was recorded using an eyetracker. Of the exposed participants, 52 had been diagnosed with PTSD (PTSD+) and 51 had not developed PTSD (PTSD-). As a result of the preprocessing stages, 52 PTSD+ (29 women), 50 PTSD- (20 women) and 53 nonexposed (31 women) participants were included in the final analyses. Results: PTSD+ participants looked at sad eyes for significantly less time than PTSD- and nonexposed individuals. This effect was negatively correlated with the intensity of avoidance symptoms. No difference was found for neutral and happy faces. Conclusions: These findings suggest that maladaptive avoidance in PTSD extends to social processing, in terms of eye contact and others' emotions that are unrelated to trauma. New therapeutic directions could include targeting sociocognitive deficits. Our findings open up new and indirect avenues for overcoming maladaptive avoidance behaviours by remediating eye processing.Trial registration: ClinicalTrials.gov identifier: NCT02810197. HIGHLIGHTS: Avoidance is a key symptom of posttraumatic stress disorder (PTSD).Avoidance is often viewed as limited to reminders linked to the trauma.Results show that attention to the eyes of sad faces is also affected by PTSD. This effect is correlated with avoidance symptoms in PTSD.

Antecedentes: La evitación describe cualquier acción diseñada para prevenir una situación o emoción desagradable. Aunque es una reacción común al trauma, la evitación se vuelve problemática cuando es la principal estrategia de afrontamiento, y desempeña un papel importante en el desarrollo y mantenimiento del trastorno de estrés postraumático (TEPT). La evitación en el TEPT puede generalizarse a señales ambientales no dañinas que se perciben como inseguras. Objetivo: Probamos si la evitación se extiende a las señales sociales (es decir, las miradas emocionales) que no están relacionadas con el trauma. Método: Un total de 159 participantes (103 que habían estado expuestos a los atentados terroristas de París del 2015 y 56 que no lo habían estado) realizaron una tarea de captación de miradas con rostros tristes, felices y neutros. La atención a la zona de los ojos se registró mediante un rastreador ocular. De los participantes expuestos, 52 habían sido diagnosticados con TEPT (TEPT+) y 51 no habían desarrollado TEPT (TEPT-). Resultados: Los participantes con TEPT+ miraron los ojos tristes durante un tiempo significativamente menor que los individuos con TEPT- y los no expuestos. Este efecto se correlacionó negativamente con la intensidad de los síntomas de evitación. No se encontraron diferencias para las caras neutras y felices Conclusiones: Estos hallazgos sugieren que la evitación desadaptativa en el TEPT se extiende al procesamiento social, en cuanto al contacto visual y las emociones de los demás que no están relacionadas con el trauma. Las nuevas direcciones terapéuticas podrían incluir centrarse en los déficits sociocognitivos. Nuestros hallazgos abren vías nuevas e indirectas para superar las conductas de evitación desadaptativas mediante la remediación del procesamiento ocular.

Language is the missing link in action-perception coupling: an EEG study.

The paper reports an electrophysiological (EEG) study investigating how language is involved in perception-action relations in musically trained and untrained participants. Using an original backward priming paradigm, participants were exposed to muted point-light videos of violinists performing piano or forte nuances followed by a congruent vs. incongruent word. After the video presentation, participants were asked to decide whether the musician was playing a piano or forte musical nuance. EEG results showed a greater P200 event-related potential for trained participants at the occipital site, and a greater N400 effect for untrained participants at the central site. Musically untrained participants were more accurate when the word was semantically congruent with the gesture than when it was incongruent. Overall, language seems to influence the performance of untrained participants, for which perception-action couplings are less automatized.

Electrical Neuroimaging of Music Processing in Pianists With and Without True Absolute Pitch.

True absolute pitch (AP), labeling of pitches with semitone precision without a reference, is classically studied using isolated tones. However, AP is acquired and has its function within complex dynamic musical contexts. Here we examined event-related brain responses and underlying cerebral sources to endings of short expressive string quartets, investigating a homogeneous population of young highly trained pianists with half of them possessing true-AP. The pieces ended regularly or contained harmonic transgressions at closure that participants appraised. Given the millisecond precision of ERP analyses, this experimental plan allowed examining whether AP alters music processing at an early perceptual, or later cognitive level, or both, and which cerebral sources underlie differences with non-AP musicians. We also investigated the impact of AP on general auditory cognition. Remarkably, harmonic transgression sensitivity did not differ between AP and non-AP participants, and differences for auditory cognition were only marginal. The key finding of this study is the involvement of a microstate peaking around 60 ms after musical closure, characterizing AP participants. Concurring sources were estimated in secondary auditory areas, comprising the planum temporale, all transgression conditions collapsed. These results suggest that AP is not a panacea to become a proficient musician, but a rare perceptual feature.

Audiomotor integration of angry and happy prosodies.

Different parts of our brain code the perceptual features and actions related to an object, causing a binding problem: how does the brain discriminate the information of a particular event from the features of other events? Hommel (1998) suggested the event file concept: an episodic memory trace binding perceptual and motor information pertaining to an object. By adapting Hommel's paradigm to emotional faces in a previous study (Coll & Grandjean, 2016), we demonstrated that emotion could take part in an event file with motor responses. We also postulate such binding to occur with emotional prosodies, due to an equal importance of automatic reactions to such events. However, contrary to static emotional expressions, prosodies develop through time and temporal dynamics may influence the integration of these stimuli. To investigate this effect, we developed three studies with task-relevant and -irrelevant emotional prosodies. Our results showed that emotion could interact with motor responses when it was task relevant. When it was task irrelevant, this integration was also observed, but only when participants were led to focus on the details of the voices, that is, in a loudness task. No such binding was observed when participants performed a location task, in which emotion could be ignored. These results indicate that emotional binding is not restricted to visual information but is a general phenomenon allowing organisms to integrate emotion and action in an efficient and adaptive way. We discuss the influence of temporal dynamics in the emotion-action binding and the implication of Hommel's paradigm.

Timing is crucial for the integration of angry facial expressions with motor responses: Investigation of subliminal and supraliminal emotion-action bindings.

Our brain codes perceptual features and actions in a distributed fashion, causing a binding problem: How does the brain recognize that information pertains to a specific object and not to other concurrently processed objects? Hommel (1998) suggested the event file concept: An episodic memory trace binding perceptual features and actions related to an event. By adapting Hommel's paradigm to emotional faces in a previous series of studies (Coll & Grandjean, 2016), we revealed that emotion could take part in an event file with motor responses when emotion is task relevant and in specific situations when emotion is task irrelevant. In the latter case, we supposed that such integration occurs because of the importance of emotion-action coupling for our survival, even when the task is not specifically related to emotion. To date, emotion-action binding has been studied only with faces presented for 500 ms. In continuation with the hypothesis that humans developed adaptive mechanisms to allow fast responses to emotions, we designed 2 experiments to investigate the influence of the duration of angry and neutral face presentation on binding with motor responses. Results showed that emotion-action integration was possible in a 100-, 250-, and 500-ms presentation, but not when the faces were subliminally (14 ms) or supraliminally (28 ms) displayed. Timing is crucial in emotion-action binding, and although reaction to emotional stimuli might take place rapidly, its integration, as shown by the present studies, seems to require at least 100 ms. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The behavioral and neural binding phenomena during visuomotor integration of angry facial expressions.

Different parts of our brain code the perceptual features and actions related to an object, causing a binding problem, in which the brain has to integrate information related to an event without any interference regarding the features and actions involved in other concurrently processed events. Using a paradigm similar to Hommel, who revealed perception-action bindings, we showed that emotion could bind with motor actions when relevant, and in specific conditions, irrelevant for the task. By adapting our protocol to a functional Magnetic Resonance Imaging paradigm we investigated, in the present study, the neural bases of the emotion-action binding with task-relevant angry faces. Our results showed that emotion bound with motor responses. This integration revealed increased activity in distributed brain areas involved in: (i) memory, including the hippocampi; (ii) motor actions with the precentral gyri; (iii) and emotion processing with the insula. Interestingly, increased activations in the cingulate gyri and putamen, highlighted their potential key role in the emotion-action binding, due to their involvement in emotion processing, motor actions, and memory. The present study confirmed our previous results and point out for the first time the functional brain activity related to the emotion-action association.

Electrophysiological evidence for attentional capture by irrelevant angry facial expressions: Naturalistic faces.

Recently, research on lateralized event related potentials (ERPs) in response to irrelevant distractors has revealed that angry but not happy schematic distractors capture spatial attention. Whether this effect occurs in the context of the natural expression of emotions is unknown. To fill this gap, observers were asked to judge the gender of a natural face surrounded by a color singleton among five other face identities. In contrast to previous studies, the similarity between the task-relevant feature (color) and the distractor features was low. On some trials, the target was displayed concurrently with an irrelevant angry or happy face. The lateralized ERPs to these distractors were measured as a marker of spatial attention. Our results revealed that angry face distractors, but not happy face distractors, triggered a PD, which is a marker of distractor suppression. Subsequent to the PD, angry distractors elicited a larger N450 component, which is associated with conflict detection. We conclude that threatening expressions have a high attentional priority because of their emotional value, resulting in early suppression and late conflict detection.

Visuomotor integration of relevant and irrelevant angry and fearful facial expressions.

Our brain codes the features of perceptual events in a distributed fashion, raising the question of how information belonging to one event is processed without any interference of features from other events. Hommel (1998) suggested the "event file" concept to elucidate these mechanisms: an episodic memory trace "binding" together perceptual features and actions related to an object. Using a similar paradigm, we designed a pilot experiment and four additional experiments to investigate whether emotion, similarly than perceptual features, could bind with a motor response when the emotion was relevant and irrelevant for the task. Few studies have revealed this to be the case. We investigated how angry and fearful faces expressed by avatars and humans might be subject to a binding phenomenon. Our results show that at least three degrees of visuomotor binding seem to coexist: one implicating the relevant feature of the task with a strong effect on behavior, another implicating the location with a smaller behavioral effect (even if not task related), and a third implicating non-task-related features with behavioral effects only under specific conditions in which emotion could play a role. Our adaptation of Hommel's paradigm showed that emotional percepts can be subject to visuomotor binding effects even if the emotion is not task related confirming the important role of emotional information for the central nervous system. These findings offer new perspective in the investigation of the emotion-action binding at the neuronal level.

Electrophysiological evidence for attentional capture by irrelevant angry facial expressions.

Attention is believed to be biased toward threatening objects or faces. Therefore, we tested whether angry face stimuli would capture attention even when they are irrelevant to the task. Observers searched for a neutral face with a tilted nose. On some trials, the target was shown together with an irrelevant angry or happy face and we measured the N2pc (an electrophysiological marker of attentional selectivity) to the distractor expression. We found that angry distractors triggered an N2pc, whereas happy distractors did not. Follow-up experiments explored the reliability of the N2pc to angry distractors using upright or inverted angry faces, the eye or mouth region of angry faces and face-like stimuli. We conclude that a threatening expression has a high attentional priority due to its emotional content and captures attention despite being irrelevant for the task.