Motor ontology in representing gaze–object relations (original) (raw)
Related papers
Cerebral cortex, 2010
Observing other people's actions activates a network of brain regions that is also activated during the execution of these actions. Here, we used functional magnetic resonance imaging to test whether these ''mirror'' regions in frontal and parietal cortices primarily encode the spatiomotor aspects or the functional goalrelated aspects of observed tool actions. Participants viewed static depictions of actions consisting of a tool object (e.g., key) and a target object (e.g., keyhole). They judged the actions either with regard to whether the objects were oriented correctly for the action to succeed (spatiomotor task) or whether an action goal could be achieved with the objects (function task). Compared with a control condition, both tasks activated regions in left frontoparietal cortex previously implicated in action observation and execution. Of these regions, the premotor cortex and supramarginal gyrus were primarily activated during the spatiomotor task, whereas the middle frontal gyrus was primarily activated during the function task. Regions along the intraparietal sulcus were more strongly activated during the spatiomotor task but only when the spatiomotor properties of the tool object were unknown in advance. These results suggest a division of labor within the action observation network that maps onto a similar division previously proposed for action execution.
(How) observed eye-contact modulates gaze following: an fMRI study
Humans are highly sensitive to directional gaze cues and rapidly shift attention in accordance with others' gaze (i.e., gaze following). Besides providing information about the physical environment, for instance, the location of an object, gaze direction can be used to extract information about the social environment, such as whether or not two people are interacting with each other. In the present fMRI study we investigated how these two different types of information conveyed by gaze direction interact with one another. Participants saw two faces that were either looking at each other or away from each other before jointly shifting gaze toward one of two target locations. Targets either appeared at the gazed at or the non-gazed at location. Behaviorally, gaze following (faster responses to congruent versus incongruent trials) was more prominent after observing eye contact than after observing no eye contact. In line with behavioral findings, neuroimaging results revealed enhanced activation in fronto-parietal and temporal areas in congruent trials when faces had looked at each other versus away from each other. These findings demonstrate that observing an attentional relation between others augments processing of their subsequent gaze cues.
Eyes on me: an fMRI study of the effects of social gaze on action control
Social Cognitive and Affective Neuroscience, 2011
Previous evidence suggests that 'social gaze' can not only cause shifts in attention, but also can change the perception of objects located in the direction of gaze and how these objects will be manipulated by an observer. These findings implicate differences in the neural networks sub-serving action control driven by social cues as compared with nonsocial cues. Here, we sought to explore this hypothesis by using functional magnetic resonance imaging and a stimulusresponse compatibility paradigm in which participants were asked to generate spatially congruent or incongruent motor responses to both social and nonsocial stimuli. Data analysis revealed recruitment of a dorsal frontoparietal network and the locus coeruleus for the generation of incongruent motor responses, areas previously implicated in controlling attention. As a correlate for the effect of 'social gaze' on action control, an interaction effect was observed for incongruent responses to social stimuli in sub-cortical structures, anterior cingulate and inferior frontal cortex. Our results, therefore, suggest that performing actions in aalbeit minimalsocial context significantly changes the neural underpinnings of action control and recruits brain regions previously implicated in action monitoring, the reorienting of attention and social cognition.
eneuro
Humans establish joint attention with others by following the other’s gaze. Previous work has suggested that a cortical patch (gaze-following patch, GFP) close to the posterior superior temporal sulcus (pSTS) may serve as a link between the extraction of the other’s gaze direction and the resulting shifts of attention, mediated by human lateral intraparietal area (hLIP). However, it is not clear how the brain copes with situations in which information on gaze direction alone is insufficient to identify the target object because more than one may lie along the gaze vector. In this fMRI study, we tested human subjects on a paradigm that allowed the identification of a target object based on the integration of the other’s gaze direction and information provided by an auditory cue on the relevant object category. Whereas the GFP activity turned out to be fully determined by the use of gaze direction, activity in hLIP reflected the total information needed to pinpoint the target. Moreove...
Processing social aspects of human gaze: A combined fMRI-DTI study
NeuroImage, 2011
Human gaze is a critical social cue that can reveal intentions and dispositions of others. The right posterior superior temporal sulcus (pSTS) is thought to be critically involved in processing eye gaze information. We combined diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) to identify direct neural connections of right pSTS and to determine how these connections are modulated by the social significance of perceived gaze shifts. Participants saw faces with direct or averted gaze during event-related fMRI. Half of these faces remained static, and half displayed a dynamic gaze shift either towards or away from the subject. Social attention (dynamic gaze shifts towards the observer) not only increased activity in right pSTS, but also its functional connectivity with the right anterior insula (aIns) and right fusiform gyrus (FG). However, direct fiber connections from pSTS were demonstrated by DTI for the right aIns, but not the right FG. Moreover, the right FG responded to eye motion irrespective of direction and social significance; whereas the right aIns was selectively sensitive to social significance (i.e. gaze shifts towards the observer), but not generally to eye motion. We conclude that the social aspects of mutual gaze contact are processed by direct fiber pathways between right pSTS and right aIns; whereas increased connectivity with FG could reflect an enhanced perceptual analysis of changing facial features in dynamic gaze conditions and involves indirect fiber pathways with pSTS, perhaps via motion-selective regions in middle temporal (MT) gyrus that exhibited strong white-matter connections with both pSTS and FG and could thus provide inputs to these two areas.
Goal-oriented gaze strategies afforded by object interaction
Vision Research, 2015
Task influence has long been known to play a major role in the way our eyes scan a scene. Yet most studies focus either on visual search or on sequences of active tasks in complex real world scenarios. Few studies have contrasted the distribution of eye fixations during viewing and grasping objects. Here we address how attention is deployed when different actions are planned on objects, in contrast to when the same objects are categorized. In this respect, we are particularly interested in the role every fixation plays in the unfolding dynamics of action control. We conducted an eye-tracking experiment in which participants were shown images of real-world objects. Subjects were either to assign the displayed objects to one of two classes (categorization task), to mimic lifting (lifting task), or to mimic opening the object (opening task). Results suggest that even on simplified, two dimensional displays the eyes reveal the participant's intentions in an anticipatory fashion. For the active tasks, already the second saccade after stimulus onset was directed towards the central region between the two locations where the thumb and the rest of the fingers would be placed. An analysis of saliency at fixation locations showed that fixations in active tasks have higher correspondence with salient features than fixations in the passive task. We suggest that attention flexibly coordinates visual selection for information retrieval and motor planning, working as a gateway between three components, linking the task (action), the object (target), and the effector (hand) in an effective way.
The motor cortex is causally related to predictive eye movements during action observation.
2013
We examined the hypothesis that predictive gaze during observation of other people's actions depends on the activation of corresponding action plans in the observer. Using transcranial magnetic stimulation and eye-tracking technology we found that stimulation of the motor hand area, but not of the leg area, slowed gaze predictive behavior (compared to no TMS). This result shows that predictive eye movements to others' action goals depend on a somatotopical recruitment of the observer's motor system. The study provides direct support for the view that a direct matching process implemented in the mirror-neuron system plays a functional role for real-time goal prediction.
Action observation activates premotor and parietal areas in a somatotopic manner: an fMRI study
European Journal of …, 2001
Functional magnetic resonance imaging (fMRI) was used to localize brain areas that were active during the observation of actions made by another individual. Object-and non-object-related actions made with different effectors (mouth, hand and foot) were presented. Observation of both object-and non-object-related actions determined a somatotopically organized activation of premotor cortex. The somatotopic pattern was similar to that of the classical motor cortex homunculus. During the observation of object-related actions, an activation, also somatotopically organized, was additionally found in the posterior parietal lobe. Thus, when individuals observe an action, an internal replica of that action is automatically generated in their premotor cortex. In the case of object-related actions, a further object-related analysis is performed in the parietal lobe, as if the subjects were indeed using those objects. These results bring the previous concept of an action observation/execution matching system (mirror system) into a broader perspective: this system is not restricted to the ventral premotor cortex, but involves several somatotopically organized motor circuits.
Predicting others' actions via grasp and gaze: evidence for distinct brain networks
Psychological Research, 2011
During social interactions, how do we predict what other people are going to do next? One view is that we use our own motor experience to simulate and predict other people’s actions. For example, when we see Sally look at a coffee cup or grasp a hammer, our own motor system provides a signal that anticipates her next action. Previous research has typically examined such gaze and grasp-based simulation processes separately, and it is not known whether similar cognitive and brain systems underpin the perception of object-directed gaze and grasp. Here we use functional magnetic resonance imaging to examine to what extent gaze- and grasp-perception rely on common or distinct brain networks. Using a ‘peeping window’ protocol, we controlled what an observed actor could see and grasp. The actor could peep through one window to see if an object was present and reach through a different window to grasp the object. However, the actor could not peep and grasp at the same time. We compared gaze and grasp conditions where an object was present with matched conditions where the object was absent. When participants observed another person gaze at an object, left anterior inferior parietal lobule (aIPL) adjacent to secondary somatosensory cortex showed a greater response than when the object was absent. In contrast, when participants observed the actor grasp an object, premotor, posterior parietal, fusiform and middle occipital brain regions showed a greater response than when the object was absent. These results point towards a division in the neural substrates for different types of motor simulation. We suggest that left aIPL is involved in a predictive process that signals a future hand interaction with an object based on another person’s eye gaze, whereas a broader set of brain areas, including parts of the action observation network, are engaged during observation of an ongoing object-directed hand action.