Smelling odors, understanding actions.

Previous evidence indicates that we understand others' actions not only by perceiving their visual features but also by their sound. This raises the possibility that brain regions responsible for action understanding respond to cues coming from different sensory modalities. Yet no studies, to date, have examined if this extends to olfaction.

Investigation of the neural correlates underlying action observation in multiple sclerosis patients.

Recent fMRI evidence indicates that both the execution and the observation of hand actions in multiple sclerosis (MS) patients increase recruitment of a portion of the so-called mirror neuron system. However, it remains unclear whether this is the expression of a compensatory mechanism for the coding of observed action or whether such a mechanism represents a rather unspecific functional adaptation process. Here we used fMRI on early relapsing remitting MS (RRMS) patients to clarify this issue.

Observing social interactions: the effect of gaze.

Our social abilities depend on specialized brain systems that allow us to perform crucial operations such as interpreting the actions of others. This functional magnetic resonance imaging (fMRI) study investigated whether human brain activity evoked by the observation of social interactions is modulated by gaze. During scanning participants observed social or individual actions performed by agents whose gaze could be either available or masked.

Neurofunctional modulation of brain regions by the observation of pointing and grasping actions.

Previous neuroimaging research on healthy humans has provided evidence for a neural system underlying the observation of another person's hand actions. However, whether the neural processes involved in this capacity are activated by the observation of other transitive hand actions such as pointing remains unknown. Therefore, using functional magnetic resonance imaging we investigated the neural mechanisms underlying the observation of static images representing the hand of a human model pointing to an object (pointing condition), grasping an object (grasping condition), or resting in proximity of an object (control condition).

Mirror neurons in humans: consisting or confounding evidence?

The widely known discovery of mirror neurons in macaques shows that premotor and parietal cortical areas are not only involved in executing one's own movement, but are also active when observing the action of others. The goal of this essay is to critically evaluate the substance of functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) studies whose aim has been to reveal the presence of a parallel system in humans. An inspection of this literature suggests that there is relatively weak evidence for the existence of a circuit with 'mirror' properties in humans, such as that described in monkeys.

Motor ontology in representing gaze-object relations.

Event-related functional magnetic resonance imaging (fMRI) was used to explore how the human brain models gaze-object relations. During scanning participants observed a human model gazing towards or away a target object presented either in isolation or flanked by a distractor object. In two further conditions the model's gaze was shifted and subsequently maintained away from the stimulus/i.

Robotic movement elicits visuomotor priming in children with autism.

The ability to understand another person's action and, if needed, to imitate that action, is a core component of human social behaviour. Imitation skills have attracted particular attention in the search for the underlying causes of the social difficulties that characterize autism. In recent years, it has been reported that people with autism can bypass some of their social deficits by interacting with robots.

The neural basis of selection-for-action.

The selection of objects in the visual environment is important in everyday life when acting in a goal-directed manner. Here we used functional magnetic resonance imaging (fMRI) to investigate brain activity while healthy subjects (N=15) selectively reached to grasp a three-dimensional (3D) target stimulus presented either in isolation or in the presence of 3D non-target stimuli. A pneumatic MRI compatible apparatus was designed to precisely control the presentation of 3D graspable stimuli within the scanner.

When gaze turns into grasp.

Previous research has provided evidence for a neural system underlying the observation of another person's hand actions. Is the neural system involved in this capacity also important in inferring another person's motor intentions toward an object from their eye gaze? In real-life situations, humans use eye movements to catch and direct the attention of others, often without any accompanying hand movements or speech. In an event-related functional magnetic resonance imaging study, subjects observed videos showing a human model either grasping a target object (grasping condition) or simply gazing (gaze condition) at the same object.

Virtual reality applications for the remapping of space in neglect patients.

Purpose: The aims of the present article were the following: (i) to provide some evidence of the potential of virtual reality (VR) for the assessment, training and recovery of hemispatial neglect; (ii) to present data from our laboratory which seem to confirm that the clinical manifestation of neglect can be improved by using VR techniques; and (iii) to ascertain the neural bases of this improvement.

Methods: We used a VR device (DataGlove) interfaced with a specially designed computer program which allowed neglect patients to reach and grasp a real object while simultaneously observing the grasping of a virtual object located within a virtual environment by a virtual hand. The virtual hand was commanded in real time by their real hand.

Transfer of interfered motor patterns to self from others.

Previous behavioural and neuroimaging data on humans demonstrated that kinematics and the level of brain activity vary according to whether participants reach towards and grasp a target object presented in isolation or flanked by a distractor object. Here we seek to explore whether a differential activation can be revealed by the mere observation of another person grasping an object in isolation or alongside a distractor. To this end we used event-related functional magnetic resonance imaging to localize neural activity related to action observation that was influenced by the presence of a distractor object.

Failure to read motor intentions from gaze in children with autism.

A core feature of autism is the abnormal use of gaze to attribute mental states to others, and thus to predict others' behaviour. An untested idea is whether this dysfunction is confined to mental states having a propositional content, such as beliefs and desire or extends to motor intentional states which allow one to make inferences about the actions of others. This study used kinematics to examine the ability to use gaze to inform one about the motor states of another in normal and autistic children.

Effects of increasing visual load on aurally and visually guided target acquisition in a virtual environment.

The aim of the present study is to investigate interactions between vision and audition during a target acquisition task performed in a virtual environment. We measured the time taken to locate a visual target (acquisition time) signalled by auditory and/or visual cues in conditions of variable visual load. Visual load was increased by introducing a secondary visual task.

Comparing effects of 2-D and 3-D visual cues during aurally aided target acquisition.

The aim of the present study was to investigate interactions between vision and audition during a visual target acquisition task performed in a virtual environment. In two experiments, participants were required to perform an acquisition task guided by auditory and/or visual cues. In both experiments the auditory cues were constructed using virtual 3-D sound techniques based on nonindividualized head-related transfer functions.