So... Imagery = top-down, imposed without external stimulus, conscious Observation = bottom-up, in the presence of the actual signal, subconscious
Questions: Do these two share similar neural processes? (and are these similar to the to be learned movement?) How, and how much, do they influence (movement) behavior? How can they be used most effectively? We’ll see that they (potentially) share several mechanisms, and that the key point is that they are perhaps complimentary to each other, but that perhaps observation is the superior route to learning
Questions: And also...to what extent does the similarity of neural processing matter when considering the merits of each? We’ll see that they (potentially) share several mechanisms, and that the key point is that they are perhaps complimentary to each other, but that perhaps observation is the superior route to learning
1. The imagery process How does this typically start? “close your eyes” When eyes are closed, alpha band activity is different to when they are not (Andreassi, 2000) Neural circuits used for imagery are already different to those used for action
1. The imagery process To continue... Imagery is comprised of (De Beni, Pazzaglia, & Gardinin, 2007) Image generation Image transformation Image maintenance Image scanning Do you do any of this when you actually perform a movement? Neural similarity compromised? One seems to be necessary to manage the other Implies that the timing of the imaged act and the actual act are not likely to be very similar (imagery generally has a script, which is read, which enforces different timing than the target movement) Contrast with observation?
1. The imagery process Spatial perspective, agency, modality Spatial perspective: are you imaging from the first or third person perspective? Agency: are you imaging yourself perform the image or someone else Modality: in what sense are you imaging? Visually? Kinesthetically? Contrast with observation?
1. The imagery process Spatial perspective, agency, modality Problems: Can’t you see yourself from a 3 rd person viewpoint? (perspective and agency conflated) What of relative motion? If you don’t move while imaging a movement, will you experience the kinesthetic consequences of the movement? The point is, one must consider instructions to image very carefully in order to maintain the most similarity between the imaged and the actual movement Contrast with observation?
1. The imagery process Spatial perspective, agency, modality Agency: Imaging self versus others Imaging self movement can result in different neural activation patterns than imaging others’ Instructions should emphasize self-imaged movement Allows for full range of self-memories to be activated See Jeannerod (2006) Contrast with observation?
1. The imagery process Spatial perspective, agency, modality Perspective and viewing angle Sometimes, an external visual spatial perspective can be useful (increased consideration of certain nuances of the action, such as in gymnastics – White & Hardy 1995, see also Callow & Roberts 2010) Then perhaps multiple viewing angles should be encouraged, to explore these nuances maximally? Form-dependent (external?) vs. form independent skills (internal?) Contrast with observation?
1. The imagery process Spatial perspective, agency, modality Imagery modality How does one get the strongest cross modality imagery? (Kinesthetic, proprioceptive, visual, sound, gustatory, tactile, etc...) First or third person can generate it. Some claim 1 st person strongest (Collins et al. 1998) But…3 rd person works too…when self-agency is used, and only for skilled performers (Callow and Hardy 2004) » Such imagery “may have spatial and/or visual components” » Links with perception-action coupling – these things are experienced, and learned, together Contrast with observation?
1. The imagery process Neural associations: Imagined & real m’ment Does imagery activate primary motor cortex? Yes, but in different areas Selection and preparation are similar initiation/execution differ Results vary Methodological concerns – duration; perspective, etc... Remember the alteration of consciousness here – what if those aspects that are imagined are just the part of the movement we’re consciously aware of? Contrast with observation?
1. The imagery process Neural associations: Imagined & real m’ment Cerebellar contributions Similar to Primary Motor Cortex Cerebellum coordinates aspects of movement and handles feedforward and feedback loops But again different areas are active – seem to be inhibitory rather than excitatory…perhaps associated w activated yet suppressed movement Explicit relation to imagined movements still to be established Contrast with observation?
1. The imagery process Neural associations: Imagined & real m’ment What about the role of expertise? Skilled pianists experience neural activation in areas related to spatial and temporal aspects of skill (Lotze and colleagues, 2003, 2006) not in areas related to actual motor control of skill rehearsing feel and other abstract components Perhaps imagery for skilled movers is less about rehearsing the motor components? Experts seem to have more “efficient” & temporally accurate neural activation when imaging (Lotze et al. 2003) Contrast with observation?
1. The imagery process Conclusions There are physiological associations between imagery and real movements But the differences are as enlightening - The difference in the activities may be as important as the similarity Contrast with observation?
2. Observation Processes The supporting mechanism The mirror neuron (MN) system ( Di Pellegrino et al., 1992; Rizzolatti & Craighero, 2004 ) AKA “motor resonance” system Some quirks: MN fires more watching humans than watching “models” MN fires v. little when the action is not “plausible”, or is not known (unlearned)
2. Observation Processes Observation and neural activity Note differences to imagery here No generation, maintenance, or transformation necessary
2. Observation Processes Observation and neural activity Perspective Same possible conflation of perspective, agency, and modality Perspective alters neural patterning in ways similar to imagery Specular (mirror-like) imitation Children imitate as though performing the mirror image of the action Emphasizes spatial and temporal characteristics of skill best communicated – not total matching Maybe face the same way as the model (think aerobics instruction)??
2. Observation Processes Observation and neural activity Agency Some evidence that self- observation better than other Hand position (Urgesi et al. 06); dart throwing (Knoblich 01) Might be explained through functional similarity of the underlying neural activity
2. Observation Processes Observation and neural activity Motor Cortex and Observation Cortico-spinal system impressively active (contrast with imagery) during observation Present also when listening to action-related sounds (music, hands clapping, etc.) – may be related to imagery script effectiveness Anticipatory activation also present (not so in imagery – self-generated) – may be important for motor priming (i.e. activity in motor system prior to the actual observation) Part of the non-declarative memory set associated with moving
2. Observation Processes Observation and neural activity Role of instructions (observe to “imitate”, or observe to “recognize” or no goal at all) These alter the neural activation that occurs during observation Intent to imitate seems to be important
2. Observation Processes Observation based characteristics Imagery is fraught with construct validity concerns – observation can avoid these
3. A preference Observation based characteristics Observation is more veridical with the task being observed Still photos can be used as they imply motion (has to be less powerful though – no relative motion is perceived) All the outcomes desired of imagery can probably be better achieved using observation (see next image)
3. A preference - summary Control of internal activity (linked to real external movement)