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Perception for movement - Y2 - Coggle Diagram
Perception for movement - Y2
Scope of multimodal perception
Perception is multimodal -
Sensory perception - the ability to detect, organise and interpret external stimulus properties (Miller et al, 2012)
Inputs from different sensory modalities not processed independently
Multi-modal perception - information collected by various individual sensory systems is integrated and coordinated to make sense of environmental stimuli
-> information is combined and treated as a unitary representation of the world
Ability to integrate different sources of information (available at different times), is an ability of vital importance in building perceptions of the world around us (Murray and Wallace, 2011)
Cue the memory by using multiple senses - associative networks; learning by using contextual cues
Speech is a classic example of multi-modal perception -
When an individual speaks, they generate sound waves carrying meaningful information
If the perceiver is looking at speaker; also have access to visual patterns that carry meaningful information
Observations of how a speaker's mouth moves helps us understand what the speaker says (Ross et al, 2007) - McGurk Effect
Multisensory processing confers many social and cognitive advantages -
The ability to detect and react to targets enhanced by multisensory information (Brandwein et al, 2013; Juan et al, 2017)
Interpretations of facial expressions affected by simultaneous emotional vocal cues (Campanella and Balin, 2007; de Gelder and Vroomen, 2000)
In addition to the perceptual and recognition advantages, multisensory information contributes to learning (Shams and Seitz, 2008)
-> Auditory information facilitates visual learning (Seitz et al, 2006)
Where do we look when we move?
Gibson's ecological theory was specific to pilots - needed more explanation for general movement
Studies investigating eye movements across a range of tasks -
-> Driving (Land and Lee, 1994)
-> Tea-making (Land and Hayhoe, 2002)
-> Simple walking tasks (Hollands et al, 2002; Patla and Vickers, 1997; 2003)
-> Crossing at an intersection (Geruschat et al, 2003)
In addition to information received from optic flow (bottom-up) people look at areas within a scene which have a high proportion of relevant information (top-down)
Allport (1989) claims that we pay attention only to features in the environment that are relevant toward an intended action, thus vision and action are inextricably linked
Time-to-Contact - Behaviours regulated using TTC:
If you know the size of an object you can estimate its distance
If you note the change in size during approach you can estimate speed (the change in the distance)
If you know the distance and speed, you can estimate the time until you reach the object (TTC)
You can prepare behaviour if you know the TTC
TTC calculation - if you mistake size, distance or speed you fail
Ecological approach to TTC -
Lee (2009) argues that TTC can be calculated using a single variable
-> Rate of expansion of the objects retinal image
-> Objects travelling towards us grow in size, those moving away shrink in size
-> The faster an image is expanding, the less time there is too contact
-> Inverse rate of expansion of retinal image - Tau; this is seen as innate traits, as calculation would take too much cognitive effort
--> Also, would mean TTC would be effected by intelligence, but this is not the cause of issues with TTC
Evidence - Fishing Gannets (Lee and Reddish):
Dive from a height of 30cm
Reach speed of 24 m/sec
Wings are streamlined just before reaching the water
-> Too soon and they would not have enough speed
-> Too late and they would break their wings
-> Predictions based on Tau fit the data
Biological motion
Perception of motion -
Estimate the direction in which you are heading
Compute the 3D shape of object
Monocular depth cues -
-> Segmentation of foreground and background
--> Motion parallax - as we move, objects that are closer slide across our FOV - further objects slide slower, and we use Tau to compute distance to them
Binocular depth cues -
-> Retinal disparity - each of our eyes sees the world from a slightly different angle
Biological motion detection -
Point-light walker stimulus - Johanasson (1975) attached lights to actors joints so that only the lights were visible in the dark
-> observers could make good judgements about movement and posture
-> biological motion could be perceived when a point-light display was shown for just 0.2s (Johansson et al, 1980)
Humans are able to perceive human motion and infer a person's intentions from it (Blake and Shiffrar, 2007)
Motion smoothness - important component related to understanding the intention of a target from body actions (Miura et al, 2010)
-> Smoothness of movement often perceived to signal an attractive, trustworthy or competent person
Gentle et al, 2020 - Perceptions of coordinated movement -
Two sets of participants -
Four models - 2 adult males with DCD, 2 adult male controls
Audience - 266 typically developed adults (207 female, mean age of 20 years)
TD audience observed recording of model's movements from motion capture system
Sociometric questionnaire (Lewisohn et al, 1980)
-> 17 positive characteristics (friendly, popular, sociable, confident, trusting, assertive, attractive, warm and humour) rated on 7-pt Likert Scale
Models with DCD rated overall significantly lower (3.39) on sociometric scales compared to TD models (3.58); t (1075) = -2.939, p = .003
Our ability to perceive biological motion may be based on imitation
Gallese et al, 2004, demonstrated the existence of mirror neurons in area F5 of the premotor cortex
-> Diminished response if an object is grasped by a tool such as pliers
Expertise/mirror neurons in humans -
-> Calvino-Merion et al, 2024 - brain activity recorded using fMRI
-> Results - significant difference in brain activity between dancers and controls
--> Stronger activation in premotor, parietal cortices and STS when expert dancers viewed movements that they had been trained to perform compared to movements they had not
-> Discussion - motor expertise has an influence on action observation
--> If you are skilled at a physical activity like ballet, the part of your brain that controls movement activates differently than the same part in the brain of someone who's not skilled in that activity
Mirror neurons -
To help imitate an observed action
Once the brain has learned a skill, it may simulate the skill without even moving, through simple observation
To help understand another animal's actions and react to them appropriately
Link sensory perceptions and other motor actions
May be associated with empathy - Autism, DCD, CP
Impact -
-> Injured athletes continue to train without moving a muscle, and perhaps could help stroke victims regain lost movement
-> Rehabilitate people whose motor skills were damaged by stroke through imitation to relearn them
Perception for motion
Perception for locomotion - Environment is complex:
Rich visual information - processed to safely negotiate a path to our destination
Different group terrains and obstacles - maintain balance whilst also propelling the body forward
Dynamic information - environmental information is not static
Sensory integration for movement -
Vision provides information about the surrounding environment, both near and distant
-> Movement regulated based on feedback control, and feed-forward information to plan and adapt movement strategies (Patla, 1998)
The vestibular system likened to a gyroscope, assist with orientation, sensing changes in linear and angular speed together with the directional pull of gravity
Proprioceptive information is used to identify the positions of the body segments in relation to each other and is important to understand where we are in space
These systems integrate to form a complete mental picture
Typical locomotion -
Three requirements for successful walking (Patla et al)
Support the body against gravitational forces
Keep the body balanced
Adapt to changing environmental demands
To walk around the environment, perceptual information must be integrated with the motor demands required to move the body forward and keep it balanced
What happens when the perceptual systems are atypical?
Visual perception -
Object identity and location in space, intimately connected with action systems (Jeannerod, 2006)
-> Dorsal streams radiates from occipital cortex to posterior parietal cortex; object localisation and action planning
-> Ventral stream - radiating towards superior temporal cortex; object identity
-> The two streams interact to inform action planning in 3D space
The visual perceptual system is the dominant modality for controlling goal-directed actions (Hudgins, 1977; Jeannerod, 2006)
Deficits in processing visual signals at various points along this network can lead to problems in movement planning, on-line movement correction and feedback control (Wilson and McKenzie, 1998)
Developmental Coordination Disorder -
Idiopathic movement disorder affecting development of motor control and coordination
Movement skills below what would be expected given the person's age and opportunity to practice, significantly interfering with activities of daily living, academic productivity and employment (APA, 2013)
Prevalence 5-6% of children 5-11 years (APA, 2013) but one of least recognised neurodevelopmental disorders (Hyde, Rigoli and Piek, 2017)
Motor impairments continue to negatively impact everyday activities into adulthood (Purcell et al, 2015)
Difficulties with handwriting, riding a bike, learning to drive, negotiating the environment
-> Difficulty integrating sensory information (Wilmut et al, 2016)
-> An over-reliance on visual information (Smits-Englesman et al, 2003; Wann et al, 1998)
Walking with DCD -
On level ground -
Children with DCD walk with a shorter step length, spend longer in double support than TD peers (Deconinck et al, 2006)
Pitch the trunk further forward than their peers (Deconinck et al, 2006)
Adults and children with DCD are more variable in their walking patterns than TD peers (Wilmut et al, 2017)
On uneven ground -
Children and adults with DCD < walking speed, shortened and widened their step to greater extent than TD peers (Gentle et al, 2016)
The DCD group inclined their head and trunk more towards the ground than their TD peers (Gentle et al, 2016)
Summary -
Perception is multimodal
Perception / action link - TTC, ecological approach, Tau
Perception of motion
Biological motion detection - mirror neurons
Perception for motion - locomotion, typical v atypical
Synaesthesia - an uncommon condition where stimulation of one perceptual modality results in experiencing a percept in a typically unrelated modality
Article - Role of visual-perceptual skills (non-motor) in children with developmental coordination disorder (Tsai, Wilson and Wu, 2008)
Children with DCD performed significantly poorer compared to typically developing children on the visual perceptual test, but the deficits were not common to all children to DCD
Heterogeneous approach is important
Coupling perception to action through incidental sensory consequences of motor behaviour (Rolfs and Schweitzer, 2022):
Incidental consequences of actions are generally considered a nuisance to perception that needs to be attenuated or suppressed during movement execution - however, incidental sensory consequences of actions could shape perceptual processes through action-perception couplings
Intrinsic consequences exert their effects on perceptual processes, through automated, internal processes accompanying movement preparation and intended consequences of actions
-> This impacts the relation between the sensory system and the outside world, and incidental consequences are the unavoidable effects of moving through the sensory surface itself
These consequences interact with one another, such as intrinsic consequences such as pre-saccadic attention shifts might adapt to anticipate intended and incidental consequences of movements
-> Intrinsic consequences - changes in internal state of perceptual system that accompany a movement
-> Intended consequences - actions that are the primary motivation to move
-> Incidental consequences - sensory consequences from moving intentionally
Higher level mechanisms -
Sensorimotor contingencies - associations between motor and visual information allow omission of saccade-contingent stimulation
Attentional distraction - post-saccadic stimulus onsets draw attention away from peri-saccadic visual input
Sensory downweighting - reduction of sensory weight in response to visual and motor noise
Visual mechanisms -
Metacontrast and paracontrast masking - attenuation of smear due to prolonged stimulus presence without spatial or temporal overlap
Masking by structure - static, high-intensity, pre-saccadic and post saccadic retinal images - forward and backward masking
Smearing - induction of unresolvable temporal frequencies, decreased efficiency of temporal integration
Extra-retinal mechanisms -
Suppression along the SC-pulvinar-cortex pathway - pre-emptive inhibition of neuronal activity in cortical motion-selective areas
Suppression of the magnocellular pathway - early attenuation to low spatial frequencies and motion information
Early retinal mechanisms -
Shearing forces - reduced efficiency of photoreceptors due to inertial forces acting upon retinal layers
Global image motion - decrease of signal-to-noise ratio caused by visual responses to large-field image translations
Navigation abilities and spatial anxiety in individuals with and without DCD (Gentle et al, 2024):
Compared to those with typical development, individuals with DCD have similar navigational performance but lower navigation and orientation scores and distance estimation (TTC)
Movement coordination difficulties were only a significant predictor of landmark recognition and egocentric path route knowledge, and played no role for other aspects of navigation performance
For wayfinding, the DCD group tended to use orientation strategies less, but route strategies were the same
DCD group had high spatial anxiety
Spatial navigation anxiety was a significant predictor of navigational skill in navigation & orientation, distance estimation and spatial anxiety