Acquisition and contextual switching of multiple internal models for different viscous force fields

Wada, Yasuhiro; Kawabata, Yasuhiro; Kotosaka, Shinya; Yamamoto, Kenji; Kitazawa, Shigeru; Kawato, Mitsuo

doi:10.1016/s0168-0102(03)00094-4

Cited by 78 publications

(94 citation statements)

References 26 publications

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“…Also, during associative learning, there were reports of firing rate changes in this area (although not representing the task parameters) (Mitz et al, 1991). Furthermore, there is agreement with psychophysical studies showing that the motor system can use contextual information (for example, for rapid task switching) (Krouchev and Kalaska, 2003;Wada et al, 2003;Mistry and Contreras-Vidal, 2004).…”

Section: Learning-related Responsessupporting

confidence: 53%

Emergence of Novel Representations in Primary Motor Cortex and Premotor Neurons during Associative Learning

Zach

Inbar²,

Grinvald³

et al. 2008

J. Neurosci.

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Neurons in the motor areas of cortex play a key role in associating sensory instructions with movements. However, their ability to acquire and maintain representations of novel stimulus features, especially when these features are behaviorally relevant, remains unknown. We investigated neuronal changes in these areas during and after associative learning, by training monkeys on a novel reaching task that required associating target colors with movement directions. Before and after learning, the monkeys performed a well known center-out task. We found that during learning, up to 48% of the neurons developed learning-related responses, differentiating between the associative task and the center-out task, although movement kinematics were the same. After learning, on returning to the center-out task in which color was irrelevant, many of these neurons maintained their response to the associative task; they displayed novel sensitivity to the color of the target that was relevant during learning. These neuronal responses prevailed in both the primary motor cortex and the ventral and dorsal premotor cortices, without degrading the information that the neurons firing carried about movement direction. Our results show that motor cortical neurons can rapidly develop and maintain sensitivities to novel arbitrary sensory features such as color, when such features are behaviorally relevant.

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Section: Learning-related Responsessupporting

confidence: 53%

Emergence of Novel Representations in Primary Motor Cortex and Premotor Neurons during Associative Learning

Zach

Inbar²,

Grinvald³

et al. 2008

J. Neurosci.

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“…Our paradigm bears resemblance to those used by Wada et al (2003) and Osu et al (2004), who alternated two oppositely directed velocity-dependent fields within epochs. These studies found participants could recall each field when the fields were presented with distinct sensory cues.…”

Section: Discussionmentioning

confidence: 99%

Intermittent Practice Facilitates Stable Motor Memories

Overduin¹,

Richardson²,

Lane³

et al. 2006

J. Neurosci.

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Humans adaptively control reaching movements to maintain good performance in the presence of novel forces acting on the arm. A recent study suggested that motor memories of different force conditions are not transformed from fragile to stable states, but rather are always vulnerable to interference from newly learned conditions (Caithness et al., 2004). This is contrary to the results of previous studies (Brashers-Krug et al., 1996; Shadmehr and Brashers-Krug, 1997), although all of these studies followed similar methods. Here, we show that a seemingly insignificant and inconsistently applied methodological detail may reconcile this discrepancy. Catch trials, in which the novel forces are removed, may be randomly interspersed among the more frequent force trials to assess how a subject is learning to predict the pattern of forces. In the absence of an interfering condition, subjects retained their learning until retest a day later regardless of whether they experienced catch trials. But in the presence of an interfering condition, only the subjects who had experienced forces intermittently retained their learning and thereby showed resistance to the interference. Thus, intermittent rather than constant practice conditions appear to be critical for dynamic motor memory stabilization.

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“…Although spatially relevant visual cues for movement planning are more effective for contextual adaptation, extensive training of feature-based cues has led to contextual learning in arm movement adaptation (Krouchev and Kalaska 2003;Wada et al 2003). Low prior probabilities of a context being utilized may simply require more exposure to evoke significant contextual adaptation.…”

Section: Can Feature-based Contextual Cues Be Trained?mentioning

confidence: 99%