Tubaldi Federico, Ansuini Caterina, Tirindelli Roberto, Castiello Umberto
Department of General Psychology, University of Padua, Padua, Italy.
PLoS One. 2008 Mar 19;3(3):e1795. doi: 10.1371/journal.pone.0001795.
Research on multisensory integration during natural tasks such as reach-to-grasp is still in its infancy. Crossmodal links between vision, proprioception and audition have been identified, but how olfaction contributes to plan and control reach-to-grasp movements has not been decisively shown. We used kinematics to explicitly test the influence of olfactory stimuli on reach-to-grasp movements.
METHODOLOGY/PRINCIPAL FINDINGS: Subjects were requested to reach towards and grasp a small or a large visual target (i.e., precision grip, involving the opposition of index finger and thumb for a small size target and a power grip, involving the flexion of all digits around the object for a large target) in the absence or in the presence of an odour evoking either a small or a large object that if grasped would require a precision grip and a whole hand grasp, respectively. When the type of grasp evoked by the odour did not coincide with that for the visual target, interference effects were evident on the kinematics of hand shaping and the level of synergies amongst fingers decreased. When the visual target and the object evoked by the odour required the same type of grasp, facilitation emerged and the intrinsic relations amongst individual fingers were maintained.
CONCLUSIONS/SIGNIFICANCE: This study demonstrates that olfactory information contains highly detailed information able to elicit the planning for a reach-to-grasp movement suited to interact with the evoked object. The findings offer a substantial contribution to the current debate about the multisensory nature of the sensorimotor transformations underlying grasping.
在诸如伸手抓握等自然任务中的多感官整合研究仍处于起步阶段。视觉、本体感觉和听觉之间的跨模态联系已被确定，但嗅觉如何有助于计划和控制伸手抓握动作尚未得到明确证实。我们使用运动学来明确测试嗅觉刺激对伸手抓握动作的影响。
方法/主要发现：要求受试者在不存在或存在气味的情况下伸手去抓一个小的或大的视觉目标（即精确抓握，对于小尺寸目标涉及食指和拇指相对，对于大目标涉及所有手指围绕物体弯曲的强力抓握），该气味分别唤起一个如果被抓握则需要精确抓握和全手抓握的小物体或大物体。当气味唤起的抓握类型与视觉目标的抓握类型不一致时，对手部塑形的运动学有明显的干扰作用，手指间的协同水平降低。当视觉目标和气味唤起的物体需要相同类型的抓握时，促进作用出现，单个手指之间的内在关系得以维持。
结论/意义：本研究表明嗅觉信息包含高度详细的信息，能够引发适合与所唤起物体相互作用的伸手抓握动作的计划。这些发现为当前关于抓握背后感觉运动转换的多感官性质的争论做出了重大贡献。
