Interference from multiple affordances when selecting everyday graspable objects: Thematic relations solve it.

Object perception and action are closely interrelated: Various grasping components are evoked when perceiving visual objects ("object affordances"). Yet little is known about the impact of the evocation of multiobject affordances on object perceptual processing. This study aimed to determine whether object processing may be affected by the similarity of affordances evoked by multiple objects and whether semantic relations between objects modulate this effect. Adult students were presented with three-dimensional scenes involving pairs of graspable objects. Each object evoked grasp size affordances (precision or power grasps). Affordances of the two objects could be similar or dissimilar and objects could be thematically related (spatula-pan) or unrelated (spatula-snow globe). Participants had to judge the color of a target object by performing power and precision grasps compatible or incompatible with the target evoked grasp. Results showed slower responses on compatible targets when unrelated distractors evoked similar compared to dissimilar affordances. This cost of similar affordances disappeared when objects were thematically related. Findings corroborate predictions of recent models hypothesizing automatic inhibition of distractor affordances when selecting one object among others. We further provide novel evidence for a role of thematic relations between objects in the perception of multiple affordances. Findings have implications for object processing in naturalistic scenes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Stimulus-response compatibility effects during object semantic categorisation: Evocation of grasp affordances or abstract coding of object size?

When the size of visual objects matches the size of the response required to perform the task, a potentiation effect has been reported, with faster responses in compatible than incompatible situations. Size compatibility effects have been taken as evidence of close perception-action interrelations. However, it is still unclear whether the effect arises from abstract coding of the size of stimulus and response or from the evocation of grasp affordances from visual objects. We aimed to disentangle the two interpretations. Two groups of 40 young adults categorised small and large objects presented in standardised size as natural or artefact objects. One group categorised manipulable objects that may be associated with small or large size properties and evoke power or precision grasp affordances. The other group categorised non-manipulable objects that may only be associated with small or large size properties. Categorisation responses were made by reaching and grasping a monotonic cylindric device with a power or precision grip in a grasping condition and with large or small touch responses in a control condition. Compatibility effects were found in both grasping and control conditions, independently of the manipulability or category of objects. Participants were faster when the size of the expected response matched the size of the object than when they mismatched, especially for power grasps or whole-hand touch responses. Overall findings support the abstract coding hypothesis and suggest that compatibility between the conceptual size of the object and the size of the hand response is sufficient to facilitate semantic categorisation judgements.

Too much to handle? Interference from distractors with similar affordances on target selection for handled objects.

The existence of handle affordances has been classically demonstrated using the Stimulus-Response Compatibility paradigm, with shorter response times when the orientation of the object handle and the response hand are compatible in comparison to incompatible. Yet the activation of handle affordances from visual objects has been investigated in very simple situations involving single stimulus and motor response. As natural perceptual scenes are usually composed of multiple objects that could activate multiple affordances, the consequence of multiple affordance activation on the perception and processing of a given object of the scene requires more investigation. The aim of this study was to determine the impact of distractor affordances on the processing of a target object in situations involving several familiar graspable objects. In two online experiments, 229 participants had to select a target object (the kitchen utensil or the tool) in a visual scene displaying a pair of objects. They performed left key presses when the target was on the left and right key presses when the target was on the right. Target handle orientation and response side could be compatible or incompatible. Critically, target and distractor objects had similar or dissimilar handle affordances, with handles oriented for left- or right-hand grasps. Results from the two experiments showed slower response times when target and distractor objects had similar handle affordances in comparison to dissimilar affordances, when participants performed right hand responses and when target orientation and response were compatible. Thus, affordance similarity between objects may interfere rather than facilitate object processing and slow down target selection. These findings are in line with models of affordance and object selection assuming automatic inhibition of distractors' affordances for appropriate object interaction.

The pain hidden in your hands: Facial expression of pain reduces the influence of goal-related information in action recognition.

The involvement of the sensorimotor system in the perception of painful actions has been repeatedly demonstrated. Yet the cognitive processes corresponding to sensorimotor activations have not been identified. In particular, the respective role of higher-level and lower-level action representations such as goals and grips in the recognition of painful actions is not clear. Previous research has shown that in a neutral context, higher-level action representations (goals) are prioritized over lower-level action representations (grips) and guide action recognition. The present study evaluates to what extent the general priority given to goal-related information in the processing of visual actions can be modulated by a context of pain. We used the action violation paradigm developed by van Elk et al. (2008). In the present action tasks, participants had to judge whether the grip or the goal of object-directed actions displayed in photographs was correct or not. The actress in the photograph could show either a neutral facial expression or a facial expression of pain. In the control task, they had to judge whether the actress expressed pain. In the action tasks, goals influenced grip judgements more than grips influenced goal judgements overall, corroborating the priority given to goal-related information previously reported. Critically, the impact of irrelevant goal-related information on the identification of incorrect grips disappeared in the pain context. Moreover, judgements in the control task were similarly influenced by grip and goal-related information. Results suggest that a context of pain reduces the reliance on higher-level action for action judgments. Findings provide novel directions regarding the cognitive and brain mechanisms involved in action processing in painful situations and support pluralist views of action understanding.

Congruent action context releases Mu rhythm desynchronization when visual objects activate competing action representations.

Recent findings demonstrated that object perception is affected by the competition between action representations. Simultaneous activation of distinct structural ("grasp-to-move") and functional ("grasp-to-use") action representations slows down perceptual judgements on objects. At the brain level, competition reduces motor resonance effects during manipulable object perception, reflected by an extinction of µ rhythm desynchronization. However, how this competition is solved in the absence of object-directed action remains unclear. The present study investigates the role of context in the resolution of the competition between conflicting action representations during mere object perception. To this aim, thirty-eight volunteers were instructed to perform a reachability judgment task on 3D objects presented at different distances in a virtual environment. Objects were conflictual objects associated with distinct structural and functional action representations. Verbs were used to provide a neutral or congruent action context prior or after object presentation. Neurophysiological correlates of the competition between action representation were recorded using EEG. The main result showed a release of µ rhythm desynchronization when reachable conflictual objects were presented with a congruent action context. Context influenced µ rhythm desynchronization when the action context was provided prior or after object presentation in a time-window compatible with object-context integration (around 1000 ms after the presentation of the first stimulus). These findings revealed that action context biases competition between co-activated action representations during mere object perception and demonstrated that µ rhythm desynchronization may be an index of activation but also competition between action representations in perception.

Nonspecific Effects of Normal Aging on Taxonomic and Thematic Semantic Processing.

OBJECTIVE: This study aimed to assess the effect of normal aging on the processing of taxonomic and thematic semantic relations. METHOD: We used the Visual-World-Paradigm coupled with eye-movement recording. We compared performance of healthy younger and older adults on a word-to-picture matching task in which participants had to identify each target among semantically related (taxonomic or thematic) and unrelated distractors. RESULTS: Younger and older participants exhibited similar patterns of gaze fixations in the two semantic conditions. The effect of aging took the form of an overall reduction in sensitivity to semantic competitors, with no difference between the taxonomic and thematic conditions. Moreover, comparison of the proportions of fixations between the younger and older participants indicated that targets were identified equally quickly in both age groups. This was not the case when mouse-click reaction times were analyzed. CONCLUSIONS: Findings argue in favor of nonspecific effects of normal aging on semantic processing that similarly affect taxonomic and thematic processing. There are important clinical implications, as pathological aging has been repeatedly shown to selectively affect either taxonomic or thematic relations. Measuring eye-movements in a semantic task is also an interesting approach in the elderly, as these seem to be less impacted by aging than other motor responses.

Diagnosing homo digitalis: towards a standardized assessment for digital tool competencies.

Introduction: In the 21st century, digital devices have become integral to our daily lives. Still, practical assessments designed to evaluate an individual's digital tool competencies are absent. The present study introduces the "Digital Tools Test" ("DIGI"), specifically designed for the evaluation of one's proficiency in handling common applications and functions of smartphones and tablets. The DIGI assessment has been primarily tailored for prospective use among older adults and neurological patients with the latter frequently suffering from so-called apraxia, which potentially also affects the handling of digital tools. Similar to traditional tool use tests that assess tool-selection and tool-action processes, the DIGI assessment evaluates an individual's ability to select an appropriate application for a given task (e.g., creating a new contact), their capacity to navigate within the chosen application and their competence in executing precise and accurate movements, such as swiping. Methods: We tested the implementation of the DIGI in a group of 16 healthy adults aged 18 to 28 years and 16 healthy adults aged 60 to 74 years. All participants were able to withstand the assessment and reported good acceptance. Results: The results revealed a significant performance disparity, with older adults displaying notably lower proficiency in the DIGI. The DIGI performance of older adults exhibited a correlation with their ability to employ a set of novel mechanical tools, but not with their ability to handle a set of familiar common tools. There was no such correlation for the younger group. Conclusion: In conclusion, this study introduces an innovative assessment tool aimed at evaluating common digital tool competencies. Our preliminary results demonstrate good acceptance and reveal expected group differences. For current cohorts of older adults, the results seem to indicate that the ability to use novel tools may aid digital tool use. In the next step, the psychometric properties of the DIGI assessment should be evaluated in larger and more diverse samples. The advancement of digital tool competency assessments and rehabilitation strategies is essential when we aim at facilitating societal inclusion and participation for individuals in affected populations.

Can the early visual processing of others' actions be related to social power and dominance?

Although goals often drive action understanding, this ability is also prone to important variability among individuals, which may have its origin in individual social characteristics. The present study aimed at evaluating the relationship between the tendency to prioritize goal information over grip information during early visual processing of action and several social dimensions. Visual processing of grip and goal information during action recognition was evaluated in 64 participants using the priming protocol developed by Decroix and Kalénine (Exp Brain Res 236(8):2411-2426, 2018). Object-directed action photographs were primed by photographs sharing the same goal and/or the same grip. The effects of goal and grip priming on action recognition were evaluated for different prime durations. The same participants further fulfilled questionnaires characterizing the way individuals deal with their social environment, namely their sense of social power, dominance, perspective taking, and construal level. At the group level, results confirmed greater goal than grip priming effects on action recognition for the shortest prime duration. Regression analyses between the pattern of response times in the action priming protocol and scores at the questionnaires further showed that the advantage of goal over grip priming was associated with higher sense of social power, and possibly to lower dominance. Overall, data confirm that observers tend to prioritize goal-related information when processing visual actions but further indicate that this tendency is sensitive to individual social characteristics. Results suggest that goal information may not always drive action understanding and point out the connection between low-level processing of observed actions and more general individual characteristics.

State-dependent TMS of inferior frontal and parietal cortices highlights integration of grip configuration and functional goals during action recognition.

Understanding the object-directed actions of conspecifics not only implies recognition of the object (e.g., a pen) and processing of the motor components (e.g., grip configuration), but also identification of the functional goal of the action (e.g., writing). Motor components and goal representations are both known to be critically involved in action recognition, but how the brain integrates these two pieces of information remains unclear. Action priming was used to tune the cognitive system to the integration of grip and goal representations. We evaluated the effect of briefly presented primes sharing grip and/or goal information with the target on recognition of action photographs. Single-pulse transcranial magnetic stimulation (TMS) was applied at target onset over the inferior frontal cortex (IFC) or the inferior parietal lobule (IPL) to evaluate their involvement in integrating grip and goal information. IFC and IPL stimulation specifically reduced integration of these two pieces of information. These results demonstrate, for the first time, the existence of specialized neuronal populations dedicated to grip/goal integration within a fronto-parietal network, supporting the importance given to this network by sensorimotor and predictive models of action recognition.

Neural dynamics of grip and goal integration during the processing of others' actions with objects: An ERP study.

Recent behavioural evidence suggests that when processing others' actions, motor acts and goal-related information both contribute to action recognition. Yet the neuronal mechanisms underlying the dynamic integration of the two action dimensions remain unclear. This study aims to elucidate the ERP components underlying the processing and integration of grip and goal-related information. The electrophysiological activity of 28 adults was recorded during the processing of object-directed action photographs (e.g., writing with pencil) containing either grip violations (e.g. upright pencil grasped with atypical-grip), goal violations (e.g., upside-down pencil grasped with typical-grip), both grip and goal violations (e.g., upside-down pencil grasped with atypical-grip), or no violations. Participants judged whether actions were overall typical or not according to object typical use. Brain activity was sensitive to the congruency between grip and goal information on the N400, reflecting the semantic integration between the two dimensions. On earlier components, brain activity was affected by grip and goal typicality independently. Critically, goal typicality but not grip typicality affected brain activity on the N300, supporting an earlier role of goal-related representations in action recognition. Findings provide new insights on the neural temporal dynamics of the integration of motor acts and goal-related information during the processing of others' actions.

Overreliance on thematic knowledge in semantic dementia: Evidence from an eye-tracking paradigm.

OBJECTIVE: The present study explored two types of semantic relationships in semantic dementia (SD), that rely on functionally and neuroanatomically distinct semantic systems (taxonomic vs. thematic). METHOD: We used the visual world paradigm coupled with eye-movement recordings, to gain an implicit, fine-grained and dynamic measure of semantic processing. Nine patients with SD and 15 healthy controls performed a simple word-to-picture matching task in which they had to identify each target among semantically related (taxonomic or thematic) competitors and unrelated distractors. RESULTS: We demonstrated different patterns of gaze fixations between patients with SD and controls: while patients with SD and controls were similarly sensitive to competition from taxonomically related pictures, patients with SD were far more sensitive than controls to thematically related competitors before identifying the targets. Moreover, most of the confusion errors made by patients with SD involved taxonomic distractors rather than thematic ones. CONCLUSIONS: We interpreted these findings as reflecting a semantic disequilibrium in SD, with increasing overreliance on thematic knowledge as taxonomic knowledge gradually deteriorates. We concluded that thematic relationships constitute a set of residual semantic knowledge and that their exaggerated activation in SD might certainly deserve further explorations to determine their specific role in this disease and notably, their influence on patients' abilities to deal with daily living activities. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Activation of manipulation and function knowledge during visual search for objects.

This study aimed at comparing the time course of the activation of function and manipulation knowledge during object identification. The influence of visual similarity and context information was also assessed. In 3 eye-tracking experiments, conducted with the Visual-World-Paradigm, participants heard the name of an object and had to identify it among four pictures. The target object (e.g., shopping cart) could be presented along with objects related by (a) function (e.g., basket), (b) manipulation (e.g., lawnmower), (c) context (e.g., cash register), (d) visual similarity (e.g., toaster), and (e) completely unrelated objects. Growth curve analyses were used to assess competition effects among semantically (a, b, and c), visually related (d), and unrelated competitors (e). Results showed that manipulation- and function-related, but not context-related objects received more fixations than the unrelated ones, with a temporal advantage for the manipulation-related objects (Experiment 1). However, the visually similar objects faded the semantic competition effects, especially for function-related objects (Experiment 2). Finally, no temporal differences appeared when manipulation- and function-related objects were shown within the same visual array (Experiment 3). These results support the idea that both function and manipulation are relevant features of object semantic representations, but in the absence of other semantic competitors the activation of manipulation features appears prioritized during object identification. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

What first drives visual attention during the recognition of object-directed actions? The role of kinematics and goal information.

The recognition of others' object-directed actions is known to involve the decoding of both the visual kinematics of the action and the action goal. Yet whether action recognition is first guided by the processing of visual kinematics or by a prediction about the goal of the actor remains debated. In order to provide experimental evidence to this issue, the present study aimed at investigating whether visual attention would be preferentially captured by visual kinematics or by action goal information when processing others' actions. In a visual search task, participants were asked to find correct actions (e.g., drinking from glass) among distractor actions. Distractors actions contained grip and/or goal violations and could therefore share the correct goal and/or the correct grip with the target. The time course of fixation proportion on each distractor action has been taken as an indicator of visual attention allocation. Results show that visual attention is first captured by the distractor action with similar goal. Then the withdrawal of visual attention from the action distractor with similar goal suggests a later attentional capture by the action distractor with similar grip. Overall, results are in line with predictive approaches of action understanding, which assume that observers first make a prediction about the actor's goal before verifying this prediction using the visual kinematics of the action.

Identification of taxonomic and thematic relationships: Do the two semantic systems have the same status in semantic dementia?

Introduction: Disequilibrium between the taxonomic and thematic semantic systems was previously hypothesized in participants with semantic dementia (SD), without rigorously assessing their ability to identify the two types of semantic relationships. Therefore, the aim of the present study was to directly compare the ability of 10 participants with SD, 10 participants with Alzheimer's disease (AD), and 20 controls to identify thematic versus taxonomic relationships. Methods: Participants performed an explicit forced-choice picture-matching task in which they had to determine which of two pictures of choice was semantically related to the target picture. Target pictures could display natural or artifact objects. Each target was presented once with a taxonomically related picture and once with a thematically related picture. Results: Analyses of correct thematic and taxonomic matches as a function of target domain showed that the performance of the two groups of patients differed in the taxonomic conditions but not in the thematic conditions, demonstrating a relative preservation of thematic knowledge in SD. Additional correlation analyses further indicated that the particular status of thematic relationships in SD was even stronger for artifact concepts. Conclusions: Results provide evidence of the heterogeneous nature of semantic knowledge disruption in SD, and could be regarded as being consistent with the existence of two neuroanatomically and functionally distinct semantic systems. Results further stress the relevance of performing a more detailed and complete assessment of semantic performance in participants with SD, in order to capture the impaired but also preserved aspects of their knowledge.

Do manufactured and natural objects evoke similar motor information? The case of action priming.

There is considerable evidence that visually presented manipulable objects evoke motor information, supporting the existence of affordance effects during object perception. However, most arguments come from stimulus-response compatibility paradigms, raising the issue of the automaticity of affordance effects. Action priming paradigms overcome this issue but show less reliable results, possibly because affordance effects are moderated by additional factors. The present study aimed to assess whether affordance effects highlighted in action priming paradigms could be affected by object category (manufactured or natural). A total of 24 young adults performed a semantic categorisation task on natural and manufactured target objects presented after neutral (non-grasping hand postures) or action (congruent power or precision grips) primes. Results revealed a modulation of action priming effects as a function of object category. Object semantic categorisation was faster after action than neutral primes, but only for manufactured objects. Results suggest that natural and manufactured objects evoke distinct types of affordances and that action priming paradigms favour the evocation of functional affordances during object semantic categorisation. This finding fuels the debate on the nature of the motor information evoked by visual objects.

Timing of grip and goal activation during action perception: a priming study.

Several models of action recognition acknowledge the involvement of distinct grip and goal representations in the processing of others' actions. Yet, their functional role and temporal organization are still debated. The present priming study aimed at evaluating the relative timing of grip and goal activation during the processing of photographs of object-directed actions. Action could be correct or incorrect owing to grip and/or goal violations. Twenty-eight (Experiment 1) and 25 (Experiment 2) healthy adults judged the correctness of target actions according to object typical use. Target pictures were primed by action pictures sharing the same grip or same goal, both the same grip and same goal or none. Primes were presented for 66 or 300 ms in Experiment 1 and for 120 or 220 ms in Experiment 2. In Experiment 1, facilitative priming effects were observed for goal and grip similarity after 300 ms primes but only for goal after 66 ms primes. In Experiment 2, facilitative priming effects were found for both goal and grip similarity from 120 ms of prime processing. In addition, results from a control condition in Experiment 2 indicated that mere object priming could partially account for goal similarity priming effects, suggesting that object identity may help the observer to make predictions about possible action goals. Findings demonstrate an early and first activation of goal representations, as compared to grip representations, in action decoding, consistent with predictive accounts of action understanding. Future studies should determine to what extent the timing of grip and goal activation is context-sensitive.

Dorsal and ventral stream contribution to the paired-object affordance effect.

Visual extinction, a parietal syndrome in which patients exhibit perceptual impairments when two objects are simultaneously presented in the visual field, is reduced when objects are correctly positioned for action, indicating that action helps patients' visual attention. Similarly, healthy individuals make faster action decisions on object pairs that appear in left/right standard co-location for actions in comparison to object pairs that appear in a mirror location, a phenomenon called the paired-object affordance effect. However, the neural locus of such effect remains debated and may be related to the activity of ventral or dorsal brain regions. The present fMRI study aims at determining the neural substrates of the paired-object affordance effect. Fourteen right-handed participants made decisions about semantically related (i.e. thematically related and co-manipulated) and unrelated object pairs. Pairs were either positioned in a standard location for a right-handed action (with the active object - lid - in the right visual hemifield, and the passive object - pan - in the left visual hemifield), or in the reverse location. Behavioral results showed a suppression of the observed cost of correctly positioning related pairs for action when performing action decisions (deciding if the two objects are usually used together), but not when performing contextual decisions (deciding if the two objects are typically found in the kitchen). Anterior regions of the dorsal stream (e.g. supplementary motor area) responded to inadequate object co-positioning for action, but only when the perceptual task required action decisions. In the ventral cortex, the left lateral occipital complex showed increased activation for objects correctly positioned for action in all conditions except when neither task demands nor object relatedness was relevant for action. Thus, fMRI results demonstrated a joint contribution of ventral and dorsal cortical streams to the paired-affordance effect. They further suggest that this contribution may depend on contextual situations and task demands, in line with flexible views of affordance evocation.

Conflict between gesture representations extinguishes µ rhythm desynchronization during manipulable object perception: An EEG study.

Recent findings showed that competition between object structural ("grasp-to-move") and functional ("grasp-to-use") gestures slows down the initiation of object-directed actions but also object visual processing. The present study investigates the neurophysiological correlates of the competition between gesture representations during object perception. 3D conflictual objects (distinct structural and functional gestures) and non-conflictual objects (similar structural and functional gestures) were presented in three spaces (peripersonal, boundary of peripersonal, and extrapersonal) in a virtual environment. Participants performed reach-to-grasp and semantic judgments on objects while EEG was recorded. Results revealed that the conflict between evoked gestures impacts 8-12 Hz desynchronization at both central (µ rhythm) and posterior (α rhythm) sites. Critically, µ rhythm desynchronization was suppressed when conflictual objects were presented in peripersonal space. Findings indicate that µ rhythm desynchronization is reduced by the competition between evoked gestures and suggest that neural motor resonance may also reflect action selection processes during object perception.

The Development of Object Function and Manipulation Knowledge: Evidence from a Semantic Priming Study.

Object semantics include object function and manipulation knowledge. Function knowledge refers to the goal attainable by using an object (e.g., the function of a key is to open or close a door) while manipulation knowledge refers to gestures one has to execute to use an object appropriately (e.g., a key is held between the thumb and the index, inserted into the door lock and then turned). To date, several studies have assessed function and manipulation knowledge in brain lesion patients as well as in healthy adult populations. In patients with left brain damage, a double dissociation between these two types of knowledge has been reported; on the other hand, behavioral studies in healthy adults show that function knowledge is processed faster than manipulation knowledge. Empirical evidence has shown that object interaction in children differs from that in adults, suggesting that the access to function and manipulation knowledge in children might also differ. To investigate the development of object function and manipulation knowledge, 51 typically developing 8-9-10 year-old children and 17 healthy young adults were tested on a naming task associated with a semantic priming paradigm (190-ms SOA; prime duration: 90 ms) in which a series of line drawings of manipulable objects were used. Target objects could be preceded by three priming contexts: related (e.g., knife-scissors for function; key-screwdriver for manipulation), unrelated but visually similar (e.g., glasses-scissors; baseball bat-screwdriver), and purely unrelated (e.g., die-scissors; tissue-screwdriver). Results showed a different developmental pattern of function and manipulation priming effects. Function priming effects were not present in children and emerged only in adults, with faster naming responses for targets preceded by objects sharing the same function. In contrast, manipulation priming effects were already present in 8-year-olds with faster naming responses for targets preceded by objects sharing the same manipulation and these decreased linearly between 8 and 10 years of age, 10-year-olds not differing from adults. Overall, results show that the access to object function and manipulation knowledge changes during development by favoring manipulation knowledge in childhood and function knowledge in adulthood.