The study used positron emission tomography (PET) to investigate brain regions activated during the observation of grasping movements in humans. Seven right-handed subjects were tested under three conditions: observing grasping movements, reaching and grasping objects, and simply observing objects. The results showed that observing grasping movements significantly activated the middle temporal gyrus, including the adjacent superior temporal sulcus (Brodmann's area 21), and the caudal part of the left inferior frontal gyrus (Brodmann's area 45). These areas were compared to similar regions in monkeys, suggesting functional homologies. The study also found that grasping movements activated two areas in the left hemisphere: one in the temporal lobe and the other in the caudal part of the inferior frontal gyrus. These findings support the idea of an observation/execution matching system in humans, with potential implications for understanding motor action recognition. The study used PET to measure regional blood flow changes, and statistical parametric mapping was used to analyze the data. The results indicate that observing grasping movements activates specific brain regions, which may be related to the mirror neuron system. The study also found that the left middle occipital gyrus was activated, corresponding to area V5 (MT). These findings contribute to the understanding of the neural mechanisms underlying action recognition and motor execution in humans.The study used positron emission tomography (PET) to investigate brain regions activated during the observation of grasping movements in humans. Seven right-handed subjects were tested under three conditions: observing grasping movements, reaching and grasping objects, and simply observing objects. The results showed that observing grasping movements significantly activated the middle temporal gyrus, including the adjacent superior temporal sulcus (Brodmann's area 21), and the caudal part of the left inferior frontal gyrus (Brodmann's area 45). These areas were compared to similar regions in monkeys, suggesting functional homologies. The study also found that grasping movements activated two areas in the left hemisphere: one in the temporal lobe and the other in the caudal part of the inferior frontal gyrus. These findings support the idea of an observation/execution matching system in humans, with potential implications for understanding motor action recognition. The study used PET to measure regional blood flow changes, and statistical parametric mapping was used to analyze the data. The results indicate that observing grasping movements activates specific brain regions, which may be related to the mirror neuron system. The study also found that the left middle occipital gyrus was activated, corresponding to area V5 (MT). These findings contribute to the understanding of the neural mechanisms underlying action recognition and motor execution in humans.