Perception lecture 1.4 senses.pdf

Foundations of Perception and Cognition Body Senses Dr Deanne Green  We acknowledge and pay our respects to the Kaurna people, the traditional custodians whose ancestral lands we gather on. We acknowledge the deep feelings of attachment and relationship of the Kaurna people to country and...

Foundations of Perception and Cognition Body Senses Dr Deanne Green  We acknowledge and pay our respects to the Kaurna people, the traditional custodians whose ancestral lands we gather on. We acknowledge the deep feelings of attachment and relationship of the Kaurna people to country and we respect and value their past, present and ongoing connection to the land and cultural beliefs. Perception Lectures What will you learn 1. Intro to sensation and perception 2. Methods 3. Spatial vision 4. Body senses 5. Depth perception 6. Motion perception Introduction to body senses Part 1 Proprioceptive & somatosensory systems The Vestibular system Introduction to body senses Anatomy Knowing where we are in Space The body senses Ø Proprioceptive & somatosensory systems Ø The Vestibular system Depth perception Ø Judgement of the location of objects in depth (talk about next week) Classification of the senses Sense Sensation Receptor Sensory Cortex Structure Vision Electromagnetic Photoreceptors Eyes Primary Visual energy Cortex Hearing Air pressure Mechanoreceptors Ears Auditory Cortex waves Touch Tissue distortion Mechanoreceptors Skin, Muscle Somatosensory Thermoreceptors Cortex Taste/Smell Chemical Chemoreceptors Nose/Mouth Taste and Olfactory Cortex Balance Fluid movement Mechanoreceptors Vestibular Temporal Cortex organs The body senses Somatosensory system Ø Touch & proprioception Vestibular system Ø Balance & posture control Touch receptors Sense of Touch Nerve Location Depth Sensory Function Free nerve endings All skin Superficial Pain, temperature, tickle Meissner’s corpuscles Glabrous skin Superficial Light, dynamic touch Merkel’s disks All skin Superficial Static pressure Pacinian corpuscles All skin Deep Pressure, vibration Ruffini’s corpuscles All skin Deep Stretching of skin Proprioception Nerve Location Sensory Function Muscle spindles Muscles Muscle length Golgi tendon organs Tendons Muscle tension Joint receptors Joints Joint position Nervous system pathways Part 2 3 pathways Somatosensory perception Nervous system pathways Thresholds Somatosensory Pathways Dorsal column-medial lemniscus pathway Ø Fine touch, vibration, and proprioception Spinothalamic pathway Ø Quick Ø Pain and temperature, Trigeminal pathway Ø Specific to sensations from the face, including touch, pressure, and pain. Dorsal column-medial lemniscus pathway Spinothalamic pathway Trigeminal pathway Cortical receptive fields Somatosensory perception Two point perception Ø Measured the distance between which can distinguish two points on different parts of the body Ø Sensitivity varies (tongue & lips very sensitive, back of the leg not so sensitive) Object perception Ø Object recognition possibly purely through touch Thresholds for two-point perception Vestibular system Part 3 Vestibular system Vestibular system Codes information about body position in space Important for balance and posture control Vestibular system Coded in the Vestibular Labyrinth Semicircular canals Otoliths Vestibular system Vestibular system Vestibular system In the semicircular canals & the otoliths, small area of sensory epithelium contains hair cells The displacement of these hair cells signal changes in position Vestibular system Vestibular system - ottolith Utricle organ and Saccule organ Contain hair cells, Also an otolithic membrane Respond to gravity or slow linear acceleration Movement planes Movement planes Sensory epithelia responses Semicircular canals Vestibular system Semicircular canals Right angles to each other Contains bundles of hair cells (crista) seated in a gelatinous mass (cupula) When the head moves, cause displacement of the crista Signal angular and linear acceleration of the head through space, in each of these three directions Sensory pathways in the vestibular system Body senses in action Part 4 Body senses in action Motion sickness Social and emotional touch Special system for emotional touch Ø Social bonding touch Ø Involves hormones (in the posterior insula) Touch is necessary for development Ø Humans need touch to develop psychologically Social touch is weird Social touch is weird Social touch is weird Deficiencies Touch Blindness Ø Literal inability to feel touch Ø Can even be inability to feel pain Age Ø Touch and pain receptors reduce in accuracy as we age Ø Vestibular system begins to reduce, usually resulting in falls Summary Touch and vestibular senses Nervous system pathways Vestibular system Body senses in action References Snowden, R., Thompson, P & Troscianko, T (2006): Basic Vision Oxford University Press, Oxford. Chapter 7 Mather, G (2016): Foundations of sensation and perception Psychology Press Ltd., Hove Chapters 3