Psychology (Functional Area: Brain, Behaviour & Cognitive Sciences)
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Browsing Psychology (Functional Area: Brain, Behaviour & Cognitive Sciences) by Author "Ayala, Maria Nadine"
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Item Open Access Context-Dependent Dual Adaptation to Opposing Visuomotor Rotations(2015-12-16) Ayala, Maria Nadine; Henriques, DensieWhen reaching towards objects, the human central nervous system (CNS) can actively compensate for two different perturbations simultaneously (dual adaptation), though this does not simply occur upon presentation. Dual adaptation is made more difficult when the desired trajectories and targets are identical and hence do not cue the impending perturbation. In cases like this, the CNS requires contextual cues in order to predict the dynamics of the environment. Not all cues are effective at facilitating dual adaptation. In two experiments we investigated the efficacy of hand and body posture contextual cues that are intrinsic to the CNS. For the hand posture experiment, we also look at the role of extended training. We found that how people held the tool or oriented their body while reaching is sufficient for concurrently adapting separate visuomotor mappings such that over time, reach errors significantly decrease. Extended practice did not lead to further benefits though.Item Open Access Movement-Based Cues Aid the Formation and Retrieval of Multiple Motor Memories(2021-11-15) Ayala, Maria Nadine; Henriques, DeniseThe ability to switch between different visuomotor mapping accurately and efficiently is an invaluable feature to a flexible and adaptive human motor system. This can be examined in dual adaptation paradigms where the motor system is challenged to perform under randomly switching, opposing perturbations. Typically, dual adaptation doesnt proceed unless each mapping is trained in association with a predictive contextual cue. To investigate this, in Experiment 1 I explored whether dual adaptation occurs if cued by distinct movement types (ballistic or pursuit/tracking reaches), and how adaptation to a perturbation while tracking an object generalize to ballistic reaches. Next, motivated by Experiment 1 findings that support the idea that "intrinsic" or motor-based cues (i.e., pertaining to a distinct goal) is key to dual adaptation along with recent work that shows the critical role of motor planning in dual adaptation, in Experiment 2 I looked at whether movement skew as elicited by distinct visual obstacles can facilitate dual adaptation. Next, in Experiment 3 I look at whether intrinsic cues need to be actively produced to elicit dual adaptation. Additionally, to better understand the underlying components of dual learning, I implement a Process Dissociation Procedure borrowed from cognitive sciences literature to understand the underlying explicit and implicit processes contributing to dual adaptation. In Experiment 4 I give participants an explicit strategy to drive learning where it otherwise would not occur due to an insufficient extrinsic visual cue. Finally, to understand dual adaptation in the most ecologically valid manner, in Experiment 5 I implemented the conventional virtual reality paradigm in Head-mounted VR, while also answering how the brain attributes error in this novel setup. Together, these findings provide further insight as to how the motor system plans movements and learns to adapt to an ever-changing environment, and the underlying mechanisms that drive it.