Functional magnetic resonance adaptation reveals the involvement of the dorsomedial stream in hand orientation for grasping

Abstract

Reach-to-grasp actions require coordination of different segments of the upper limbs. Previous studies have examined the neural substrates of arm transport and hand grip components of such actions; however, a third component has been largely neglected: the orientation of the wrist and hand appropriately for the object. Here we used functional magnetic resonance imaging adaptation (fMRA) to investigate human brain areas involved in processing hand orientation during grasping movements. Participants used the dominant right hand to grasp a rod with the four fingers opposing the thumb or to reach and touch the rod with the knuckles without visual feedback. In a control condition, participants passively viewed the rod. Trials in a slow event-related design consisted of two sequential stimuli in which the rod orientation changed (requiring a change in wrist posture while grasping but not reaching or looking) or remained the same. We found reduced activation, that is, adaptation, in superior parieto-occipital cortex (SPOC) when the object was repeatedly grasped with the same orientation. In contrast, there was no adaptation when reaching or looking at an object in the same orientation, suggesting that hand orientation, rather than object orientation, was the critical factor. These results agree with recent neurophysiological research showing that a parieto-occipital area of macaque (V6A) is modulated by hand orientation during reach-to-grasp movements. We suggest that the human dorsomedial stream, like that in the macaque, plays a key role in processing hand orientation in reach-to-grasp movements.

Contributions of the parietal cortex to increased efficiency of planning-based action selection

“…Previous studies reveal RS in some of the same parietal and frontal regions during repeated grasping (Króliczak, Mcadam, Quinlan & Culham, 2008; Monaco, Cavina-Pratesi, Sedda, Fattori, Galletti & Culham, 2011; Monaco, Chen, Medendorp, Crawford, Fiehler & Henriques, 2014) or hand gestures (Chouinard & Goodale, 2009; Dinstein, Hasson, Rubin & Heeger, 2007; Hamilton & Grafton, 2009). While several of these studies distinguished motor- from visually-driven RS (Chouinard & Goodale, 2009; Króliczak, et al, 2008; Monaco, et al, 2011; Monaco, et al, 2014), it has remained unclear whether motor-driven effects reflected the repetition of planning/selection, execution-related processes, or both. Our Condition * Congruency interaction with Plan RS > Rule RS revealed effects in left SMg, bilateral cSPL, as well as the left Cerebellum.…”

Functional versus effector-specific organization of the human posterior parietal cortex: revisited

“…RS paradigms are widely used in fMRI research (see, e.g., Grill-Spector et al 2006), and RS paradigms have been used successfully for the investigation of motor planning (Bernier and Grafton 2010; Hamilton and Grafton 2009; Króliczak et al 2008; Majdandžić et al 2009; Monaco et al 2011; Valyear et al 2012; Van Pelt et al 2010). RS effects have been previously reported in the regions studied here (e.g., Hamilton and Grafton 2009; Króliczak et al 2008; Van Pelt et al 2010).…”

TMS of the anterior intraparietal area selectively modulates orientation change detection during action preparation

“…For task used in the current study, where orientation is a relevant feature, one may consider the involvement of other brain areas somehow involved in aspects of orientation coding for motor planning. Of particular interest is the monkey area V6(A) (Fattori et al 2010;Galletti et al 2003) and its likely human homolog, the superior parietooccipital cortex (SPOC; Gallivan et al 2009;Monaco et al 2011), both of which have been shown to be important for wrist orientation while grasping. Further studies are necessary not only to show the exact mechanism that drives the perceptual changes due to action preparation, but also to identify these other motor areas involved in the general mechanism of action-modulated perception.…”