Psychology 1
PREVIOUS: Learning
Seeing, hearing, tasting, feeling.. Learning requires us acquire knowledge about the world. So how do we know the world?
Nativism believed that it was just in us–knowledge was given to us by God. Empiricism suggested we acquire knowledge through experience and are the reflection on our experiences. Synthesis also believed this, but also believed that our experience of the world depended on innate thought/mental structures.
Sensation: the process by which we detect an object in the event or environment. Is there something out there? How intense is it?
Perception: A mental representation of that event. What is it? Where is it? What is it doing?
Distal Stimulus: The object of perception itself (tree, rock, ocean, car)
Proximal Stimulus: Light waves, sound, that emnate from the stimulus and is recieved by our eyes, ears, nose…
Steps in Sensation
- Transduction: The conversion of proximal stimulus into a neural impulse. This is accomplished by a specific sensory receptor organ.
- Neural impulse transmitted to Cerebal Cortex
- Beginning of perception, creation of a mental perception–physical features, purpose/meaning.
How did we get from sensation to perception? Step 2.5? How many senses are there? Modern day senses are split into two categories:
- Extroception: Distance (no direct contact; vision, audition), Chemical Senses (chemical molecules gustation, olfaction), Skin Senses (touch, temperature, pain).
- Proprioception: Concern the position and motion of the body: (Kinesthesis (Pose), equilibrium (up and down))
- Interoception: Blood–hunger,thirst, but we won’t talk about these anymore.
How do we know how many there actually are (5 senses??) Transduction is done by the sensory receptors. Neural impulses are carried through the sensory tract into the brain’s sensory projection area.
Vision
Electromagnetic Radiation (380~780 nanometers) are visible to the human eyes. These pass through the cornea and pupil and focused so that it lands in the retina of the eye. This creates the retinal image.
The sensory tract takes the image and transmits it to the brain (V1/Broddman’s Area 17).
Audition
Sound waves are essentially just vibrations in the ear. The receptor organ takes in sound waves, which vibrates hair cells and go through the sensory tract and go to the thalamus. Goes to A41 (Broddman’s Area 41).
Gustation/Taste
Are just the chemical molecules in food and drink, which are dissolved in saliva. The taste buds are carried over the cranial nerve 9, 7, or 10. This is in the frontal lobe, as well as the somatosensory cortex.
Olfaction/Smell
Also just chemical molecules, but in the air. The receptor cells are in the olfactory epithelium, which are carried to the primary olfactory cortex (1). It does NOT pass through the thalamus
Touch
Sense to pressure towards the skin. Displacements to skin or hair will send neural impulses to the afferent tract through the spinal nerves/cord. Broddmann’s Area 1,2,3.
Thermal Sense
Proximal Stimulus is the temperature differential are just differences between the temperature of the skin. The +/- send the karuse end bulbs and the ruffini end-organs (cold, warm, respectively). Sent to the primary somatosensory cortex through spinal cord (1, 2 3).
Cutaneous Pain
Almost anything can be “painful.” Pain from the skin is just injury/destruction of tissue (inflammation). Fast pain is mediated by A-delta fibers and C fibers handle slow pain. These travel toward the neospinothalamic tract and the paleospinothalamic tract and into thalamus.
Kinesthesis (Movement, position)
Basically your IMU– activity in skeletal musculature tell you what your Pose is. Neuromuscular spindles, neurotendinous organs, go up the spinal nerves and to the same (1, 2, 3).
Vestibular Sense (equilibrium/Balance)
Gravitational force pull on our otoliths in our ear, which are also hair cells and go through (VIII) to our vesitbular component projection area and our cerebellum.