Ettore Ambrosini

Where does an object trigger an action? An investigation about affordances in space

A series of experiments provide evidence that affordances rely not only on the mutual appropriateness of the features of an object and the abilities of an individual, but also on the fact that those features fall within her own reachable space, thus being really ready-to-her-own-hand. We used a spatial alignment effect paradigm and systematically examined this effect when the visually presented object was located either within or outside the peripersonal space of the participants, both from a metric (Experiment 1) and from a functional point of view (Experiment 2). We found that objectual features evoke actions only when the object is presented within the portion of the peripersonal space that is effectively reachable by the participants. Experiments 3 and 4 ruled out that our results could be merely accounted for by differences in the visual salience of the presented objects. Our data suggest that the power of an object to automatically trigger an action is strictly linked to the effective possibility that an individual has to interact with it.

When objects are close to me: Affordances in the peripersonal space

In the present study, we investigated, using language, which motor information is automatically activated by observing 3-D objects (i.e., manipulation vs. function) and whether this information is modulated by the objects’ location in space. Participants were shown 3-D pictures of objects located in peripersonal versus extrapersonal space. Immediately after, they were presented with function, manipulation, or observation verbs (e.g., “to drink,” “to grasp,” “to look at”) and were required to judge whether the verb was compatible with the presented object. We found that participants were slower with observation verbs than with manipulation and function verbs. With both function and manipulation verbs, participants were faster when objects were presented in reachable space. Interestingly, the fastest response times were recorded when participants read function verbs while objects were presented in the accessible space. Results suggest that artifacts are first conceived in terms of affordances linked to manipulation and use, and that affordances are differently activated, depending on context.

The adaptation of the Affective Norms for English Words (ANEW) for Italian

We developed affective norms for 1,121 Italian words in order to provide researchers with a highly controlled tool for the study of verbal processing. This database was developed from translations of the 1,034 English words present in the Affective Norms for English Words (ANEW; Bradley & Lang, 1999) and from words taken from Italian semantic norms (Montefinese, Ambrosini, Fairfield, & Mammarella, Behavior Research Methods, 45, 440–461, 2013). Participants evaluated valence, arousal, and dominance using the Self-Assessment Manikin (SAM) in a Web survey procedure. Participants also provided evaluations of three subjective psycholinguistic indexes (familiarity, imageability, and concreteness), and five objective psycholinguistic indexes (e.g., word frequency) were also included in the resulting database in order to further characterize the Italian words. We obtained a typical quadratic relation between valence and arousal, in line with previous findings. We also tested the reliability of the present ANEW adaptation for Italian by comparing it to previous affective databases and performing split-half correlations for each variable. We found high split-half correlations within our sample and high correlations between our ratings and those of previous studies, confirming the validity of the adaptation of ANEW for Italian. This database of affective norms provides a tool for future research about the effects of emotion on human cognition.

Looking Ahead: Anticipatory Gaze and Motor Ability in Infancy

The present study asks when infants are able to selectively anticipate the goals of observed actions, and how this ability relates to infants’ own abilities to produce those specific actions. Using eye-tracking technology to measure on-line anticipation, 6-, 8- and 10-month-old infants and a control group of adults were tested while observing an adult reach with a whole hand grasp, a precision grasp or a closed fist towards one of two different sized objects. The same infants were also given a comparable action production task. All infants showed proactive gaze to the whole hand grasps, with increased degrees of proactivity in the older groups. Gaze proactivity to the precision grasps, however, was present from 8 months of age. Moreover, the infants’ ability in performing precision grasping strongly predicted their ability in using the actor’s hand shape cues to differentially anticipate the goal of the observed action, even when age was partialled out. The results are discussed in terms of the specificity of action anticipation, and the fine-grained relationship between action production and action perception.

Rtms of medial parieto-occipital cortex interferes with attentional reorienting during attention and reaching tasks

Unexpected changes in the location of a target for an upcoming action require both attentional reorienting and motor planning update. In both macaque and human brain, the medial posterior parietal cortex is involved in both phenomena but its causal role is still unclear. Here we used on-line rTMS over the putative human V6A (pV6A), a reach-related region in the dorsal part of the anterior bank of the parieto-occipital sulcus, during an attention and a reaching task requiring covert shifts of attention and planning of reaching movements toward cued targets in space. We found that rTMS increased RTs to invalidly cued but not to validly cued targets during both the attention and reaching task. Furthermore, we found that rTMS induced a deviation of reaching endpoints toward visual fixation and that this deviation was larger for invalidly cued targets. The results suggest that reorienting signals are used by human pV6A area to rapidly update the current motor plan or the ongoing action when a behaviorally relevant object unexpectedly occurs in an unattended location. The current findings suggest a direct involvement of the action-related dorso-medial visual stream in attentional reorienting and a more specific role of pV6A area in the dynamic, on-line control of reaching actions.

How your hand drives my eyes

When viewing object-related hand actions people make proactive eye movements of the same kind as those made when performing such actions. Why is this so? It has been suggested that proactive gaze when viewing a given hand action depends on the recruitment of motor areas such as the ventral premotor (PMv) cortex that would be involved in the execution of that action. However, direct evidence for a distinctive role of the PMv cortex in driving gaze behavior is still lacking. We recorded eye moments while viewing hand actions before and immediately after delivering repetitive transcranial magnetic stimulation (rTMS) over the left PMv and the posterior part of the left superior temporal sulcus, which is known to be involved in high-order visual action processing. Our results showed that rTMS-induced effects were selective with respect to the viewed actions following the virtual lesion of the left PMv only. This, for the first time, provides direct evidence that the PMv cortex might selectively contribute to driving the viewers gaze to the actions target. When people view anothers action, their eyes may be driven by motor processes similar to those they would need to perform the action themselves.

Out of your hand's reach, out of my eyes' reach.

When witnessing anothers action, people recruit the same motor resources that enable them to efficiently perform that action, thus gazing at its target well before the agents hand. But just to what extent does this recruitment help people in grabbing anothers action target? If the latter seems to be out of the agents reach, will this impact on peoples gaze behaviour? We recorded proactive eye movements while participants witnessed someone else trying to reach for and grasp objects located either within or outside his reach. Proactivity of gaze was impaired when the targets were just out of the agents reach. This effect is likely to be due to an interpersonal bodily space representation that allows one to map anothers reaching space, thus prompting proactive eye movements towards the target just in case the agent is in the position to act upon it.

Which body for embodied cognition? Affordance and language within actual and perceived reaching space

The mental representation of ones own body does not necessarily correspond to the physical body. For instance, a dissociation between perceived and actual reach-ability has been shown, that is, individuals perceive that they can reach objects that are out of grasp. We presented participants with 3D pictures of objects located at four different distances, namely near-reaching space, actual-reaching space, perceived-reaching space and non-reaching space. Immediately after they were presented with function, manipulation, observation or pointing verbs and were required to judge if the verb was compatible with the object. Participants were faster with function and manipulation verbs than with observation and pointing verbs. Strikingly, with both function and manipulation verbs participants were faster when objects were presented in actual than the perceived reaching space. These findings suggest that our knowledge of the world is implicitly built online through behaviour, and is not necessarily reflected in explicit estimates or conscious representations.

Investigating the relationship between interoceptive accuracy, interoceptive awareness, and emotional susceptibility.

Interoception, the sense of the physiological condition of the body, provides a basis for subjective feelings and emotions. Anterior insular cortex activity represents the state of the body and varies according to personality traits, such as emotional susceptibility (ES)—the tendency to experience feelings of discomfort and vulnerability when facing emotionally-laden stimuli. The accuracy of perceiving ones own bodily signals, or interoceptive accuracy (IAc), can be assessed with the heartbeat perception task (HPT), which is the experimental measure used by most of the existing research on interoception. However, IAc is only one facet of interoception. Interoceptive awareness (IAw) is the conscious perception of sensations from inside the body, such as heart beat, respiration, satiety, and the autonomic nervous system sensations related to emotions, which create the sense of the physiological condition of the body. We developed an Italian version of the recent self-report Multidimensional Assessment of Interoceptive Awareness (MAIA), tested its psychometric properties (reliability, dimensionality, and construct validity), and examined its relationship to ES, as assessed using the Emotional Susceptibility Scale, in a sample (n = 321) of healthy Italian psychology students (293 females, mean age: 20.5 years). In a subgroup of females (n = 135), we measured IAc with the HPT. We used a series of correlation/regression analyses to examine the complex interplay between the three constructs. We provide further evidence for a substantial independence of the IAc and IAw measures, confirming previous reports and current theoretical models that differentiate between IAc and IAw. Our analyses elucidate the complex relationship between distinct dimensions of IAw and ES, highlighting the need for continued efforts to shed more light on this topic.

Action perception as hypothesis testing

We present a novel computational model that describes action perception as an active inferential process that combines motor prediction (the reuse of our own motor system to predict perceived movements) and hypothesis testing (the use of eye movements to disambiguate amongst hypotheses). The system uses a generative model of how (arm and hand) actions are performed to generate hypothesis-specific visual predictions, and directs saccades to the most informative places of the visual scene to test these predictions – and underlying hypotheses. We test the model using eye movement data from a human action observation study. In both the human study and our model, saccades are proactive whenever context affords accurate action prediction; but uncertainty induces a more reactive gaze strategy, via tracking the observed movements. Our model offers a novel perspective on action observation that highlights its active nature based on prediction dynamics and hypothesis testing.