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The grasping side of odours.

Tubaldi F, Ansuini C, Tirindelli R, Castiello U - PLoS ONE (2008)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of General Psychology, University of Padua, Padua, Italy.

ABSTRACT

Background: 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.

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Related in: MedlinePlus

Odour-target combination for each experimental condition.From left to right columns report the number of trials for each odour/target combination, the type of odour, the type of target, and the experimental conditions.
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pone-0001795-g002: Odour-target combination for each experimental condition.From left to right columns report the number of trials for each odour/target combination, the type of odour, the type of target, and the experimental conditions.

Mentions: With this in mind, we set out to investigate detailed hand kinematics along the entire time course of a reach-to-grasp movement towards visual targets of different size eliciting different types of grasp (Fig. 1A) in the absence or in the presence of preceding olfactory information. Specifically, we recorded angular excursion at the metacarpal phalangeal (mcp) and proximal interphalangeal (pip) joints for all five digits, and abduction angles between digits by means of a CyberGlove (Fig. 1B). For the odourless conditions, subjects reached towards and grasped either a small or a large visual target in the absence of preceding olfactory information by using a precision grip and a power grip, respectively. These conditions were termed respectively ‘OS’ and ‘OL’ (Fig. 2). For the congruent conditions, before movement initiation an odour evoking an object that if grasped would require the same type of grasp as the visual target was delivered. These conditions were named ‘SS’ and ‘LL’, respectively (Fig. 2). For the incongruent conditions, before movement initiation an odour evoking an object that if grasped would require a different type of grasp as the visual target was delivered. For the ‘SL’ condition, an odour associated with an object requiring a precise grasp was presented with a visual target requiring a whole hand grasp (Fig. 2). For the ‘LS’ condition, an odour associated with an object requiring a whole hand grasp was presented with a target requiring a precision grip (Fig. 2).


The grasping side of odours.

Tubaldi F, Ansuini C, Tirindelli R, Castiello U - PLoS ONE (2008)

Odour-target combination for each experimental condition.From left to right columns report the number of trials for each odour/target combination, the type of odour, the type of target, and the experimental conditions.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2266792&req=5

pone-0001795-g002: Odour-target combination for each experimental condition.From left to right columns report the number of trials for each odour/target combination, the type of odour, the type of target, and the experimental conditions.
Mentions: With this in mind, we set out to investigate detailed hand kinematics along the entire time course of a reach-to-grasp movement towards visual targets of different size eliciting different types of grasp (Fig. 1A) in the absence or in the presence of preceding olfactory information. Specifically, we recorded angular excursion at the metacarpal phalangeal (mcp) and proximal interphalangeal (pip) joints for all five digits, and abduction angles between digits by means of a CyberGlove (Fig. 1B). For the odourless conditions, subjects reached towards and grasped either a small or a large visual target in the absence of preceding olfactory information by using a precision grip and a power grip, respectively. These conditions were termed respectively ‘OS’ and ‘OL’ (Fig. 2). For the congruent conditions, before movement initiation an odour evoking an object that if grasped would require the same type of grasp as the visual target was delivered. These conditions were named ‘SS’ and ‘LL’, respectively (Fig. 2). For the incongruent conditions, before movement initiation an odour evoking an object that if grasped would require a different type of grasp as the visual target was delivered. For the ‘SL’ condition, an odour associated with an object requiring a precise grasp was presented with a visual target requiring a whole hand grasp (Fig. 2). For the ‘LS’ condition, an odour associated with an object requiring a whole hand grasp was presented with a target requiring a precision grip (Fig. 2).

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of General Psychology, University of Padua, Padua, Italy.

ABSTRACT

Background: 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.

Show MeSH
Related in: MedlinePlus