We expect that the general strategy described holds true for situations using more than two objects, but this is something for a follow-up experiment. Looking forward to sharing more on this area over the coming months!.

In sum, we show how people can use their hand in an incredibly flexible manner to cumulatively grasp and transport objects. This common motor skill shows how we can use a range of grips, other than finger-thumb opposition, for efficient object transport.

More broadly, we observed that the grip choices for holding the first object in place were highly variable and linked to specific object combinations.

Notably, we found that objects which were smaller were more likely to be grasped first, likely due to the ease with which they could be held whilst keeping the thumb and adjacent fingers free for grasping the second object (Part A in above figure).

This overarching strategy (using finger-thumb opposition to grasp each object, and atypical grips to secure a prior object) appeared to be facilitated by object selection order.

These included finger-finger (FF) and finger-palm (FP) opposition, as well as a range of Other (O) grips that were highly unusual (e.g., fingers opposing themselves, objects placed within a palmar crease).

We observed that whilst finger-thumb opposition (FT) was typically preferred for grasping and lifting the objects, a range of atypical grips were used to hold the first object in place prior to grasping the second (Part B in below figure).

We then coded the grip types used for lifting object 1, holding object 1, and lifting object 2. We also examined which objects were preferentially grasped first. This allowed us to capture what we believe is an overarching strategy used for multiple object handling.

In this project we presented participants with pairs of everyday objects. They were asked to grasp one of the objects and then, with the first still in hand, grasp the second and transport both.

What’s particularly interesting are the range of atypical grips (i.e., not finger-thumb opposition) we use in these cases – consider the times where you hold a second glass between two fingers after picking up a first.

It’s a skill you’ll all be familiar with. You use it to transport objects more efficiently, such as when you’re clearing the dining table after a meal or selecting fruit at the supermarket.

Happy to share a new preprint! Me and my excellent RA co-authors provide insight into how humans use a single hand to cumulatively grasp and then transport multiple objects. We’ve decided to refer to this behaviour as ‘multiple object handling’

RT @catrionascriv: Looking forward to presenting our concurrent TMS-fMRI work on the role of the IPS in prioritising task-relevant visual i….

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Do you have a congenital upper limb difference? Do you rarely use a functional prosthesis/assistive device? Please RT and get in touch if you would like to to help us better understand the experiences and needs of those with a limb difference!

I'm very much riding on the coattails of Nick and others who have put such hard work into this extensive project, but I'm glad to have been able to provide a (very minor) contribution - mainly ongoing discussion and picky manuscript feedback!.

'The focality of TMS is not fixed, but varies according to coil position and orientation, the shape of the participant’s brain and the context in which the brain is stimulated'.

Essential reading for TMS users! TMS can potentially stimulate brain areas >5cm away from the target, depending on context (shown here by stimulating regions around M1 during movement). Brings 1cm focality into question. .

RT @UCU_Stirling: Day 4 of our strike. During the summer MAB, mgmt said it was a national dispute about which they could do nothing, and re….

RT @UCU_Stirling: Tomorrow marks the start of 10 days local strike action for our branch @StirUni . We desperately do not want to strike no….