Human Information Processing Flashcards
What do sensory systems have?
- Sense organs and receptors that detect info from the environment.
What are sensory receptors?
- Specialized structures that adopt different shapes depending on their function.
- Nerve ending, once activated, sends signal to CNS
Transduction?
- Refers to the conversion of physical/chemical stimuli into electrical signals (action potentials)
How is a stimulus converted into a neural signal?
- The stimulus opens ion channels in the receptor membrane. In most cases, channel opening results in the influx of Na+ into the receptor, causing a depolarization of the membrane.
4 different ways our sensory perception can be changed?
- Modality: way we perceive stimuli
- Intensity: stimuli intensity
- Duration: Stimuli time-course
- Location: Where you perceive stimuli.
Sensory receptors (modality)
- Specific neuronal pathways sending info to specific cortical areas.
Sensory receptors (Intensity)
- Proportional to intensity of the stimulus.
- How much we are depolarizing
a. Frequency code
b. Receptors population code.
Population Coding
- Related to intensity
- Number of receptors activated.
- 1 finger vs 5 fingers touching you.
Sensory Receptors (Duration)
- Depends on the firing pattern of sensory receptors.
- Rapidly adapting: Sitting in a chair for a long time, (forgetting its there)
- slowly adapting
Frequency Code
- More activation over a long period of time creates greater intensity.
Cones
- Gives our vision color
- Red, Blue, Green
Sensory Receptors (Location)
- Provides info about spatial location and spatial resolution of the stimulus.
- Resolution represents touch detail
Retina
- Contains sensory receptors (photoreceptors) and other types of neurons organized in different cellular layers.
- Receive light, convert light into neural signals, send signals to brain for visual recognition.
What are rods and cones?
- Contains pigments that can be stimulated by light (different wave lengths)
Sensory Receptor Field
- Each sensory receptor is most sensitive to stimulation of a specific area.
- What action potential are released from a sensory neuron, the neuron receptive field codes the stimulus location.
Rods
- Vision in low light
3 types of sensory systems
- Somatosensory
- Auditory
- Visual
Visual Pathways
- Through thalamus transmit (and process) visual info to visual cortex.
Spatial Perception
- Dorsal visual stream; determines “where is it”
- Parietal Lobe
Object recognition
- Ventral visual stream; determines “what is it?”
- Temporal Lobe
Somatosensory System
- Provides info from our body that is essential to make movements.
- Touch, body temp, pain, body position
Touch Receptors
- Located on skin and muscles (sense external stimuli.)
- Mediated by four types of mechanoreceptors in the human hand.
Meissner’s Corpuscle
- Initial contact of the body with objects
- Adapt quickly
- RA: Rapidly adapting
- Initial contact with chair
- Neural spike at beginning and end of touch sensation.
Merkel’s complex
- SA: Slowly adapting
- Merkle’s disc/nerve endings
- reading braille
- Picks up ridges and edges (typing)
Pacinian Corpuscles
- Detecting deep pressure
- Detecting Vibration
Rapid adapting
Ruffini Corpuscle
- Slow adapting
- Detecting stretch
- Minor stretching relating to object manipulation (squeezing a cup to keep it from slipping.)
Proprioceptors
- Located on muscles and joints and sense muscle position and movement of our body.
The 4 mechanoreceptors
- Meissner corpuscle
- Merkel cells
- Pacinian corpuscle
- Ruffini endings
Muscle Spindle
- Velocity of stretch and length of muscle stretch
Golgi Tendon organ
- Located between muscle and tendon.
- Detects amount of force generating with muscle.
Vestibular System
- In the inner ear
- Contributes to balance and controlling eye movement.
- Upright standing and walking
Semicircular canals
- Head rotation
Utricle and saccule
- Linear motion
- Inner ear