Perception 1 Flashcards
Auditory, Gustatory, Olfactory, and Somatosensory Senses
What is perception?
Our interpretation of the senses
What are the steps of sensory processing that all senses go through?
- External sense organ (eye, ear, skin, etc.)
- Receives physical/chemical input (stimulus)
- Transformed into neural signal
- Transmitted through relay stations (mainly thalamus)
- Processed in primary cortical area (A1 V1, S1, etc.)
- Refined in secondary sensory areas
- Modified/regulated in association and frontal areas
What are the steps in the auditory pathway?
Stimulus = sound wave
1. Outer ear (air) - change in pressure
2. Middle ear (bones) - vibrate
3. Inner ear (fluid) - waves
4. Cochlea (hair cells) - mechanoreceptors
5. Travels to auditory nerve
6. Brainstem/midbrain relays
7. Thalamus
8. Primary Auditory Cortex
9. Secondary Auditory Cortex
How are Cochlea organized?
Organized by frequency (tonotopic map)
What is another name for the Primary Auditory Cortex?
A1 or Heschl’s Gyrus
Where is the Primary Auditory Cortex located?
Superior Temporal Cortex
What is another name for the Secondary Auditory Cortex?
A2
Where is the Secondary Auditory Cortex located?
Surrounds the primary auditory cortex in the superior temporal cortex
What is interaural time difference?
When sound reaches the ear first and it finds the horizontal position of sound
What is the interaural intensity difference?
When the sound is louder in the closer ear and you compare neuron firing rates from both ears
What are some of the auditory cognitive functions?
Sound localization (what the sound is and where its coming from), detection/discrimination, speech, music
What are the steps in the gustatory pathway?
Stimulus = food molecules/tastants (chemical sense)
1. Mouth - tongue (taste buds)
2. Tastant binds to taste cell
3. Chemical transduction - depolarizes cell
4. Action potential
5. Gustatory nerves (then processed by the cortex)
6. Brainstem relays
7. Thalamus
8. Primary gustatory cortex
9. Orbitofrontal cortex
Is gustation a chemical, mechanical or physical sense?
Chemical
What are the 5 different kinds of taste cells?
Salty, Sweet, Sour, Bitter, and Umami
All have different chemical transduction
Where is the primary gustatory cortex located?
Insula and operculum in the Frontal Lobe
What is another name for the orbitofrontal cortex?
Secondary Gustatory Cortex
What is a function of the Secondary Gustatory Cortex?
Involved in how rewarding you find food (enjoyment and preference)
What are some of the gustatory cognitive functions?
Nutrition, enjoyment/reward/preference, discrimination/detection
What are the steps in the olfactory pathway?
Stimulus = odor molecules (odorants)
1. Nose - nasal cavity (odor receptors)
2. Odorant binds to receptor
3. Signaling cascade –> action potential
4. Signal sent to olfactory bulb
5. Olfactory nerve
6. Primary olfactory cortex
7. Orbitofrontal cortex
Is olfaction a chemical, mechanical or physical sense?
Chemical Sense
Where is the primary olfactory cortex located?
Frontal Lobe (orbitofrontal cortex)
What is another function of the primary olfactory cortex?
Involved in habituation (more they smell –> lower signal) and presence or change of an odor
What is another function of the secondary olfactory cortex?
Identifying what the odor was
What sense isn’t transmitted through the thalamus as a relay station?
Olfaction (sense of smell)
What are some of the olfactory cognitive functions?
Detection/discrimination, sniffing, memory/emotional links, pheromones
What are the steps in the somatosensory pathway?
Stimulus = touch/pressure, temperature, pain, position
1. Skin (different types of receptors)
2. Mechanical change to receptor
3. Transduce to neural signal
4. Spinal nerve
5. Spinal cord
6. Brainstem/midbrain relays (cross to contralateral side)
7. Thalamus
8. Primary somatosensory Cortex (S1)
9. Secondary somatosensory cortex (S2)
10. Also cerebellum, etc.
What is Somatotopic Organization?
Somatosensory hommunculus
Areas are big due to importance not size (cortical magnification)
Located in Parietal Lobe
Where is the primary somatosensory cortex located?
Anterior Parietal Lobe (post central gyrus)
What is Somatotopic (Re)Organization
Cortical plasticity explains how things can reorganize depending on how you use your digits (Phantom Limb)
What are some of the somatosensory cognitive functions?
Object recognition (texture, shape), pleasure/pain, avoidance/learning, posture/motor control
