Case 1 - The Man Who Lost His Body Flashcards
What is integration of information?
How to combine information from various sources about the body and its surroundings
Sense of ownership
Understanding what contributes to the feeling of owning and identifying with one’s body
Plasticity of Body Representation
Examining the malleability or stability of our mental representation of the body over short-term and long-term periods
Who is Ian Waterman?
A significant case in psychology, a man who lost touch and muscle sense below the neck but not on his face due to a virus, relying on vision and relearning basic movements
What does afferent mean?
Refers to sensory nerve fibres
What does efferent refer to?
Motor nerve fibres
What is somatosensation?
The perception of the body, including skin senses, proprioception, and internal organ sensations
What is proprioception?
The ability to sense the body’s position, movement and orientation
What are cutaneous mechanoreceptors?
Specialised receptors in the skin responding to different stimuli (e.g., pressure, flutter, stretching, vibration)
Psychophysics of touch
Study of the relationship between physical stimuli and sensory experiences, involving four touch channels
What are nociceptors?
Pain receptors detecting mechanical, thermal, chemical and polymodal stimuli
What are thermoreceptors?
Receptors sensitive to temperature changes, differentiating between hot and cold sensations
What are proprioceptive receptors?
Mechanosensitive receptors in muscles and joints providing information about body position and movement
Dorso Column-Medial Lemniscal System
Neural pathway for touch and proprioception
Spinothalamic System
Neural pathway for pain and temperature
Somatosensory Cortex
Brain regions processing sensory information, including muscle sense, skin receptors, pressure and joint sense.
What is a postural schema?
A dynamic mental mode of body posture and movement, constantly updated based on sensory input
What does ‘body in the brain’ mean?
Mental constructs like body schema, body image and corporeal awareness related to the dynamic organisation of one’s body
Postural Schema (Head and Holmes)
The idea that the cortex associates sensations from altered postures with a plastic schema, constantly changing based on new movements
Body Schema vs. Body Image:
Body schema is the pre-attentive representation of body and posture, influencing consciousness. Body image is the set of beliefs and attitudes about the body, treating the body as an object of perception.
Criticisms: Interchangeable use of terms, challenges in defining independence of representations
Proprioception for perceiving bodies
Inversion effects in recognising body postures, potentially influenced by proprioception. Study on Ian Waterman and controls, suggesting long-term body representation’s role in posture recognition
Forward Model of Motor Control
Movements in deafferented patients (e.g., IW and GL) lacking feedback from muscles, relying on vision for flexibility.
Finger Tapping and Sensory Feedback
Study on tapping fingers with varying sensory feedback, highlighting the importance of somatosensation for anticipatory timing.
Retained Proprioceptive Inputs
Patients with retained proprioceptive and tactile inputs from head and neck, showing more plasticity in the nervous system
C Tactile (CT) Afferents:
Unmyelinated mechnoreceptors with low thresholds, found in humans. Patient GL’s study indicating activation in the insular cortex, suggesting a slow touch system in humans.
Pleasant Touch and Emotional Aspects
Evidence for a slow touch system in humans associated with emotional aspects of tactile stimulation. The disembodied lady’s experience and the link between CT fiber firing and pleasantness
Function of Pleasant Touch
Promotion of affiliative behaviour, formation of social bonds, and nonverbal communication of emotions. Affective proprioception as a potential source of pleasure derived from precise and harmonious.
Affective Proprioception
Pleasure from movements related to the match between intentions and feedback. Consideration of how movements look and what they achieve, and the emotional binding of agency with embodied selves.
