Searching for a tactile target: the impact of set-size on the N140cc.

The time needed to find a visual target amongst distractors (search task) can increase as a function of the distractors' number (set-size) in the search-array (inefficient search). While the allocation of attention in search tasks has been extensively investigated and debated in the visual domain, little is known about these mechanisms in touch. Initial behavioral evidence shows inefficient search behavior when participants have to distinguish between target and distractors defined by their vibro-tactile frequencies. In the present study, to investigate the allocation of attention to items of the search-array we measured the N140cc during a tactile task in which the set-size was manipulated. The N140cc is a lateralized component of event-related brain potentials recently described as a psychophysiological marker of attentional allocation in tactile search tasks. Participants localized the target, a singleton frequency, while ignoring one, three or five homogeneous distractors. Results showed that error rates linearly increased as a function of set-size, while response times were not affected. Reliable N140cc components were observed for all set-sizes. Crucially, the N140cc amplitude decreased as the number of distractors increased. We argue that the presence of additional distractors hindered the preattentive analysis of the search array resulting in increased uncertainty about the target location (inefficient preattentive stage). This, in turn, increased the variability of the deployment of attention to the target, resulting in reduced N140cc amplitudes. Consistent with existing behavioral evidence, these findings highlight systematic differences between the visual and the tactile attentional systems.

Emotions in motion: affective valence can influence compatibility effects with graspable objects.

Previous studies showed that affective valence (positive, negative) influences Stimulus-Response Compatibility (SRC) effects elicited by both relevant and irrelevant spatial dimensions. We tested whether valence influences SRC effects when the irrelevant spatial dimension rather than being conveyed by the entire stimulus location is conveyed by the location of the stimulus' graspable part, i.e., the Handle-Response (H-R) compatibility effect. Participants saw objects with either a flower, a spider or nothing on their handle and categorized them as kitchen utensils or garage tools through button presses. In Experiment 1, a random presentation of valenced stimuli was used, whereas in Experiment 2 differently valenced stimuli were arranged in different blocks. Furthermore, participants in Experiment 2 could be spider-fearful or not. In Experiment 1, an H-R compatibility effect occurred for response latencies, regardless of whether stimuli presented a negative, positive or no element on their handle. In Experiment 2 the effect occurred only when a positive element was shown on the object's handle. In addition, spider-fearful individuals showed significantly slower responses when the element appearing on the object's handle had a negative valence. These results suggest that the SRC effect observed with pictures of graspable objects may be sensitive to the affective characteristics of stimuli and that approach/avoidance response tendencies may also depend on individual differences (being spider-fearful or not).

Does a look of fear prompt to act? The effects of gaze and face emotional expression on manipulable objects.

Gaze direction is an important social cue for understanding the intentions of other people. Indeed, interacting with others requires the ability to encode their current focus of attention in order to predict their future actions. Previous studies have showed that when asked to detect or identify a target, people are faster if shown a gaze oriented toward rather than away from that target. Most importantly, there is evidence that the emotion conveyed by the face with the averted gaze matters. We further tested the interplay between gaze and face emotion in the context of manipulable objects to understand whether and to what extent other people's gaze influences our own actions toward objects. Participants judged whether a target graspable object was upright or inverted after viewing a face cue with a central or averted gaze. Importantly, the target's handle could be oriented toward the gazed-at location or the opposite side such that gaze and handle were corresponding or non-corresponding in space. Furthermore, we manipulated the expression of the cue by using neutral and fearful faces. Results showed a handle-response (H-R) compatibility effect (i.e., a facilitation when the response key is on the same side as the object's handle) only with fearful cues with a central gaze.

Impact of the COVID-19 pandemic on dental hygiene students in the Italian region of Emilia-Romagna.

BACKGROUND: The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a new coronavirus detected in China at the end of 2019. Because SARS-CoV-2 is highly infectious due to contamination in the air, there is a high risk of infection in the dental environment which is represents a serious problem for professionals and students (dentistry and dental hygiene). In Italy, since February 23, 2020, the government has suspended all teaching activities of schools and universities. METHODS: An anonymous questionnaire was administered to the students of the degree courses in Dental Hygiene of the Emilia Romagna Region, one of the most affected regions in Italy. The survey was intended to highlight the practical and emotional consequences of the emergency of COVID-19 on educational activities and in the training of students. RESULTS: The survey was sent to the 150 students enrolled in the universities of Bologna, Ferrara and Modena and Reggio Emilia; 141 of them completed it (94%). Since the start of the COVID-19 pandemic, several surveys have been proposed to measure the impact of this emergency situation on dental professionals; at present, however, there are still no assessments for dental hygiene degree courses, in particular aimed at assessing the psychological impact on students. CONCLUSIONS: Students consider the dental hygienist as a risky profession, while the risk taken by patients is considered as low. Given the concern reported the students, it would be useful to address the issue of proper assessment of risk during the university training of dental hygienists.

Corrigendum: Exploring the Role of Action Consequences in the Handle-Response Compatibility Effect.

[This corrects the article DOI: 10.3389/fnhum.2020.00286.].

The role of the co-actor's response reachability in the joint Simon effect: remapping of working space by tool use.

The Simon effect, that is the advantage of the spatial correspondence between stimulus and response locations when stimulus location is task irrelevant, occurs even when the task is performed by two participants, each performing a go/no-go task. This effect, known as the joint Simon effect, does not emerge when participants sit outside each other's peripersonal space, thus suggesting that the presence of an active confederate in peripersonal space might provide a reference for response coding. The present study investigated whether this finding is due to the distance separating the participants and/or to the distance separating each participant and the other agent's response. In two experiments, pairs of participants performed a social detection task sitting outside each other's arm reach, with response keys located close to the participants or outside arm reach. When the response key was located outside the participant's arm reach, he/she could reach it by means of a tool. In Experiment 1, by means of a tool, participants could reach their response key only, while in Experiment 2, they could reach also their co-agent's response key. The joint Simon effect did not emerge when participants could not reach the co-actor's response, while it emerged when they could potentially reach the other participant's response using the tool, but only when turn taking was required. These results may be taken as evidence that the possibility to reach and act upon the co-actor's response key may be at the bases of compatibility effects observed in joint action contexts requiring complementary responses.

Psychological reactions to COVID-19 and epidemiological aspects of dental practitioners during lockdown in Italy.

BACKGROUND: Due to droplet production and exposure to saliva and blood, dental practitioners are at high risk of COVID-19 contagion during their routine procedures. The aim of this study was to investigate the behavior of Italian dentists and to analyze their reactions in relation to Sars-CoV-2 pandemic professional restrictive measures. METHODS: An online structured survey composed of 40 questions has been sent to dental practitioners all over Italy to investigate their behavior and to analyze their reactions in relation to Sars-CoV-2 pandemic restrictive measures introduced by the Italian national administrative order of 10 March 2020 (DM-10M20). RESULTS: 1109 dentists replied. To assess concerns and psychological responses the sample was divided into two groups based on the number of cases registered in their work area. In the first group were included all the responders working in the Italian regions that had more than 15,000 confirmed cases of COVID-19 as of April 29, 2020. The second group included responders working in the Italian regions that had less than 15,000 confirmed cases. The 45.2% of the respondents showed minimal anxiety, 34.5% showed mild anxiety, 13.9% showed moderate anxiety, while 6.4% showed a score indicative of a severe level of anxiety. CONCLUSIONS: The COVID-19-related emergency condition had a highly negative impact on dental practices in Italy. Those who completed the survey reported practice closure or reduction during the lockdown, and a high level of concern about the professional future for all dental practitioners. Concerns related to professional activity were accompanied by severe anxiety levels.

The perceived impact of the COVID-19 pandemic on dental undergraduate students in the Italian region of Emilia-Romagna.

INTRODUCTION: The outbreak and diffusion of the novel SARS-CoV2 coronavirus have caused an emergency status in the dental education system. MATERIALS AND METHODS: An anonymous survey composed of 34 questions was delivered to students of the Master Degree Programme in Dentistry and Dental Prosthodontics of the Universities of Emilia-Romagna, the fifth Italian region most affected by the pandemic. The psychological impact of COVID-19 was assessed by means of the Generalised Anxiety Disorder-7 scale (GAD-7). Numerically recoded data were analysed using the Analysis of Variance (ANOVA), whilst to investigate the association between quantitative variables, the Pearson correlation coefficient (R) was computed. RESULTS: The questionnaire was completed by 399 students (75%) out of 532. Most students experienced difficulties in working at the thesis during the COVID-19 emergency. For over half of them, online teaching could only partially replace traditional face-to-face lessons. The negative impact on the study career was judged as particularly high by sixth-year students. Clinical training activities were considered as exposing to the risk of contracting COVID-19 infection by the majority of the students. The level of concern of contracting COVID-19 infections during future university activities was positively correlated to risk perception related to clinical training. CONCLUSION: The results of this survey could be used to train students to a correct risk assessment. Students reported experiencing concern whilst thinking of COVID-19 and 6.5% of them showed symptoms related to high levels of anxiety. These data may guide Universities in trying to reduce students' anxiety by means of correct communication strategies.

Correction: Truth and lies in your eyes: Pupil dilation of White participants in truthful and deceptive responses to White and Black partners.

[This corrects the article DOI: 10.1371/journal.pone.0239512.].

Truth and lies in your eyes: Pupil dilation of White participants in truthful and deceptive responses to White and Black partners.

In the present study, we examined the pupillary response of White participants who were asked to tell the truth or lie to White or Black partners. Research on cues to deception has assumed that lying is more cognitively demanding that truth telling. In line with this assumption, previous studies have shown that lying is associated with greater pupil dilation, a behavioral cue that typically manifests itself under conditions of stress or cognitive effort. In accordance with these results, we predicted greater pupil dilation when lying than when telling the truth. Furthermore, pupil dilation was expected to be greater when responding to White than Black partners. Finally, we hypothesized that pupil dilation would be greater when lying to White than Black partners. Participants were instructed to answer a set of questions, half truthfully and half deceptively. They were led to believe that White vs. Black partners (one male and one female) would ask the questions via computer connection. Indeed, we used feminine and masculine synthetic voices. Pupil dilation was assessed with a remote eye-tracking system. Results provided support for the first two hypotheses. However, the predicted interaction between race of partners and truth status of message (lying vs. telling the truth) was nonsignificant. Our findings highlight the importance of considering race in the study of truthful and deceptive communications.

Exploring the Role of Action Consequences in the Handle-Response Compatibility Effect.

Previous research investigating handle-response compatibility effects with graspable objects used different categories of objects as stimuli, regardless of their specific, intrinsic characteristics. The current study explores whether different types of objects' characteristics may elicit different types of spatial compatibility, that is, handle-response and response-effect compatibility as well as their potential interaction. In Experiment 1, objects having a graspable handle opposite to either a visible functional component (i.e., handle-function objects: a teapot) or a latent functional component (handle-only objects: a pitcher lacking the spout) were presented separately in different blocks. Both the handle and the goal-directed functional components of these objects were located on the horizontal axis. In Experiment 2, handle-only objects had a handle located on the horizontal axis and a latent functional component located on the vertical axis (e.g., a cup). In both experiments, participants were required to judge the material (plastic and metal) the object was made of. Results showed that the handle-response compatibility effect was sensitive to whether the actions consequences of object manipulation took place on the horizontal rather than on the vertical axis.

Epidemiological Aspects and Psychological Reactions to COVID-19 of Dental Practitioners in the Northern Italy Districts of Modena and Reggio Emilia.

The outbreak and diffusion of the Severe Acute Respiratory Syndrome-Coronavirus-2 (Sars-CoV-2) and COronaVIrus Disease 19 (COVID-19) have caused an emergency status in the health system, including in the dentistry environment. Italy registered the third highest number of COVID-19 cases in the world and the second highest in Europe. An anonymous online survey composed of 40 questions has been sent to dentists practicing in the area of Modena and Reggio Emilia, one of the areas in Italy most affected by COVID-19. The survey was aimed at highlighting the practical and emotional consequences of COVID-19 emergence on daily clinical practice. Specifically, it assessed dentists' behavioral responses, emotions and concerns following the Sars-CoV-2 pandemic restrictive measures introduced by the Italian national administrative order of 10 March 2020 (DM-10M20), as well as the dentists' perception of infection likelihood for themselves and patients. Furthermore, the psychological impact of COVID-19 was assessed by means of the Generalized Anxiety Disorder-7 test (GAD-7), that measures the presence and severity of anxiety symptoms. Using local dental associations (ANDI-Associazione Nazionale Dentisti Italiani, CAO-Commissione Albo Odontoiatri) lists, the survey was sent by email to all dentists in the district of Modena and Reggio Emilia (874 practitioners) and was completed by 356 of them (40%). All dental practitioners closed or reduced their activity to urgent procedures, 38.2% prior to and 61.8% after the DM-10M20. All reported a routinely use of the most common protective personal equipment (PPE), but also admitted that the use of PPE had to be modified during COVID-19 pandemic. A high percentage of patients canceled their previous appointments after the DM-10M20. Almost 85% of the dentists reported being worried of contracting the infection during clinical activity. The results of the GAD-7 (General Anxiety Disorder-7) evaluation showed that 9% of respondents reported a severe anxiety. To conclude, the COVID-19 emergency is having a highly negative impact on the activity of dentists practicing in the area of Modena and Reggio Emilia. All respondents reported practice closure or strong activity reduction. The perception of this negative impact was accompanied by feelings of concern (70.2%), anxiety (46.4%) and fear (42.4%). The majority of them (89.6%) reported concerns about their professional future and the hope for economic measures to help dental practitioners.

Do my hands prime your hands? The hand-to-response correspondence effect.

Previous research has shown an effect of handle-response correspondence on key-press responses when participants judged the upright or inverted orientation of photographed one-handled graspable objects. In three experiments, we explored whether this effect still holds for symmetric graspable objects that are usually grasped by two hands (i.e. two-handled objects; e.g. shears). In Experiments 1 and 2, participants were required to perform a between-hand response in order to categorize cooking or amusement objects appearing as grasped from either an allocentric (Experiment 1) or an egocentric perspective (Experiment 2). In Experiment 3, they were required to perform a within-hand response to categorize the same stimuli appearing as grasped from an egocentric perspective. Across all three experiments, results showed that categorization was more difficult when the objects were displayed as grasped on the opposite side than the response rather than on the same side. We discuss the implications of these results for theories of action potentiation and spatial coding and suggest that different mechanisms may be recruited depending on the required action (i.e. response mode).

Correspondence effect driven by salient visual asymmetries in integral object stimuli.

The handle-to-hand correspondence effect consists of faster and more accurate responses when the responding hand is aligned with the handle side of an object tool, compared to when they lay on opposite sides. This effect has been attributed to the activation of affordances. Recent studies, however, claimed that it may depend on the spatial coding of the object on the basis of its visual asymmetry (location-coding account). Affordances are namely direct and meaningful relations between recognized objects and the observers' action system. Therefore, any manipulation that disrupts the body structure of object tools could potentially affect their identification and prevent the activation of affordances. The present study investigated the nature of the handle-to-hand correspondence effects by manipulating structural asymmetry and visual salience of object tools, while preserving their integrity that is, leaving unaltered the original possibilities to activate grasping affordances. Three experiments were run. Results were consistent with the location-coding account and claim for accurate control of visual asymmetries in object stimuli during investigation of affordance effects.

Trial-by-trial modulations in the orienting of attention elicited by gaze and arrow cues.

Recent findings suggested that the orienting of attention towards gazed at locations (i.e., the gaze cueing effect) could result from the conflict emerging in incongruent trials between the spatial information conveyed by gaze direction and the target spatial position. In two experiments, we assessed this hypothesis by investigating whether this effect is influenced by the same trial-by-trial modulations that are reported in a spatial conflict task, i.e., the Simon task. In Experiment 1, we compared the trial-by-trial modulations emerging in the Simon task with those emerging in a gaze cueing task, while in Experiment 2, we compared gaze and arrows cues. Trial-by-trial modulations were evident in both tasks. In the Simon task, correspondence sequence affected both corresponding and noncorresponding responses, this resulting in a larger Simon effect when the preceding trial was corresponding and an absent effect when the preceding trial was noncorresponding. Differently, in the gaze cueing task, congruence sequence affected only congruent responses with faster responses when the preceding trial was congruent compared to when it was incongruent, resulting in a larger gaze cuing effect when the preceding trial was congruent. Same results were evident with nonpredictive arrow cues. These findings speak against a spatial conflict account.

The unimanual handle-to-hand correspondence effect: evidence for a location coding account.

The handle-to-hand correspondence effect refers to faster and more accurate responses when the responding hand is aligned with the graspable part of an object tool, compared to when they lay on opposite sides. We performed four behavioral experiments to investigate whether this effect depends on the activation of grasping affordances (affordance activation account) or is to be traced back to a Simon effect, resulting from the spatial coding of stimuli and responses and from their dimensional overlap (location coding account). We manipulated the availability of a response alternative by requiring participants to perform either a unimanual go/no-go task (absence of a response alternative) or a joint go/no-go task (available response alternative) and the type of response required (button-press or grasping response). We found no handle-to-hand correspondence effect in the individual go/no-go task either when a button-press (Experiment 1A) or a grasping (Experiment 2A) response was required, whereas a significant effect emerged in the joint go/no-go task, irrespective of response modality (Experiments1B and 2B). These results do not support the idea that complex motor affordances are activated for meaningful objects, but are rather consistent with the more parsimonious location coding account.

Do already grasped objects activate motor affordances?

This study investigated whether in a stimulus-response compatibility (SRC) task affordance effects in response to picture of graspable objects emerge when these objects appear as already grasped. It also assessed whether the observed effects could be explained as due to spatial compatibility between the most salient part in the object/display and the hand of response rather than to action potentiation. To this aim, we conducted three behavioural experiments in which participants were required to discriminate the vertical orientation (upright vs. inverted) of an object presented in the centre of the screen, while ignoring the right-left orientation of its handle. The object could be presented alone, as already grasped, as partially masked (Experiment 1) or with a human hand close to its graspable side (Experiment 2). In addition, to assess the role of perceptual salience, the object could be presented with a human hand or a non-biological (a geometrical shape) distractor located opposite to the object's graspable side. Results showed faster responses when the object's handle was located on the same side of the responding hand with a larger effect when upright objects were shown as already grasped (Experiment 1) or when a hand was displayed close to its handle (Experiment 2), and a smaller reversed effect when the hand or the geometrical shape was located opposite to the handled side (Experiment 3). We interpreted these findings as indicating that handle orientation effects emerging in SRC tasks may result from the interplay between motor affordance and spatial compatibility mechanisms.

The role of perspective in discriminating between social and non-social intentions from reach-to-grasp kinematics.

Making correct inferences regarding social and individual intentions may be crucial for successful interactions, especially when we are required to discriminate between cooperative and competitive behaviors. The results of previous studies indicate that reach-to-grasp kinematic parameters may be used to infer the social or individual outcome of a movement. However, the majority of the studies investigated this ability by presenting reach-to-grasp movements from a third-person perspective only. The aim of the present study was to assess whether the ability to recognize the intent associated to a reach-to-grasp movement varies as a function of perspective by manipulating the perspective of observation (second- and third-perspective) within participants. To this end, we presented participants with video clips of models performing a reach-to-grasp movement with different intents. The video clips were recorded both from a lateral view (third-person perspective) and from a frontal view (second-person perspective). After viewing the clips, in two subsequent tasks participants were asked to distinguish between social and non-social intentions by observing the initial phase of the same action recorded from the two different views. Results showed that, when a fast-speed movement was presented from a lateral view, participants were able to predict its social intention. In contrast, when the same movement was observed from a frontal view, performance was impaired. These results indicate that the ability to detect social intentions from motor cues can be biased by the visual perspective of the observer, specifically for fast-speed movements.

Visual versus auditory Simon effect: A behavioural and physiological investigation.

This study investigated whether the visual and auditory Simon effects could be accounted for by the same mechanism. In a single experiment, we performed a detailed comparison of the visual and the auditory Simon effects arising in behavioural responses and in pupil dilation, a psychophysiological measure considered as a marker of the cognitive effort induced by conflict processing. To address our question, we performed sequential and distributional analyses on both reaction times and pupil dilation. Results confirmed that the mechanisms underlying the visual and auditory Simon effects are functionally equivalent in terms of the interaction between unconditional and conditional response processes. The two modalities, however, differ with respect to the strength of their activation and inhibition. Importantly, pupillary data mirrored the pattern observed in behavioural data for both tasks, adding physiological evidence to the current literature on the processing of visual and auditory information in a conflict task.

Practice-induced and sequential modulations in the Simon task: evidence from pupil dilation.

Recent evidence showed that pupil dilation (PD) reflects modulations in the magnitude of the Simon interference effect due to correspondence sequence. In the present study we used this measure to assess whether these modulations, thought to result from cognitive control mechanisms, are influenced by prior practice with an incompatible stimulus-response (S-R) mapping. To this end, PD and reaction times (RTs) were recorded while participants performed a Simon task before and after executing a spatially incompatible practice. The sequential analysis revealed that PD mirrored the conflict-adaptation pattern observed in RTs. Crucially, sequential modulations were not affected by prior practice. These findings support the view that the modulations of the Simon effect due to prior practice and those due to correspondence sequence result from two different mechanisms, and suggest that PD can help to better understand the mechanisms underlying response selection and cognitive control in the Simon task.