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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

Time course of abduction angle between fingers during reaching for the large target either in the absence or in the presence of an odour evoking a small object.Each trace denotes average abduction angle of a representative subject (Subject 10) for the middle-ring and the ring-little fingers when performing the ‘OL’ (black squares) and the ‘SL’ (red squares) conditions. Increase in negative values correspond to bigger abduction (i.e., increase of digits' angular distance). OL = Odourless air-Large target; SL = ‘Small’ odour-Large target.
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pone-0001795-g007: Time course of abduction angle between fingers during reaching for the large target either in the absence or in the presence of an odour evoking a small object.Each trace denotes average abduction angle of a representative subject (Subject 10) for the middle-ring and the ring-little fingers when performing the ‘OL’ (black squares) and the ‘SL’ (red squares) conditions. Increase in negative values correspond to bigger abduction (i.e., increase of digits' angular distance). OL = Odourless air-Large target; SL = ‘Small’ odour-Large target.

Mentions: For the incongruent ‘SL’ condition, the mcp joint of the index, middle, and ring fingers was more flexed than for the ‘OL’ condition (Fig. 6). In particular, the mcp joint of index, middle, and ring fingers showed an over-flexion at about half of movement duration (Table 1). However, a delayed odour ‘size’ effect was evident for the mcp joint of the index finger (Table 1). A similar pattern was also found for the pip joints of both the thumb and the index finger showing a greater flexion in the ‘SL’ than in the ‘OL’ condition at 50% and 40% of movement duration, respectively (Fig. 6 and Table 1). The middle-ring and the ring-little abduction angles were smaller for the ‘SL’ than for the ‘OL’ condition. This effect was evident within the second half of movement duration (Fig. 7 and Table 2).


The grasping side of odours.

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

Time course of abduction angle between fingers during reaching for the large target either in the absence or in the presence of an odour evoking a small object.Each trace denotes average abduction angle of a representative subject (Subject 10) for the middle-ring and the ring-little fingers when performing the ‘OL’ (black squares) and the ‘SL’ (red squares) conditions. Increase in negative values correspond to bigger abduction (i.e., increase of digits' angular distance). OL = Odourless air-Large target; SL = ‘Small’ odour-Large target.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0001795-g007: Time course of abduction angle between fingers during reaching for the large target either in the absence or in the presence of an odour evoking a small object.Each trace denotes average abduction angle of a representative subject (Subject 10) for the middle-ring and the ring-little fingers when performing the ‘OL’ (black squares) and the ‘SL’ (red squares) conditions. Increase in negative values correspond to bigger abduction (i.e., increase of digits' angular distance). OL = Odourless air-Large target; SL = ‘Small’ odour-Large target.
Mentions: For the incongruent ‘SL’ condition, the mcp joint of the index, middle, and ring fingers was more flexed than for the ‘OL’ condition (Fig. 6). In particular, the mcp joint of index, middle, and ring fingers showed an over-flexion at about half of movement duration (Table 1). However, a delayed odour ‘size’ effect was evident for the mcp joint of the index finger (Table 1). A similar pattern was also found for the pip joints of both the thumb and the index finger showing a greater flexion in the ‘SL’ than in the ‘OL’ condition at 50% and 40% of movement duration, respectively (Fig. 6 and Table 1). The middle-ring and the ring-little abduction angles were smaller for the ‘SL’ than for the ‘OL’ condition. This effect was evident within the second half of movement duration (Fig. 7 and Table 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