06. Important information Flashcards
Why have sensory systems evolved in animals?
In order to guide their behaviour and provide specific kind of information the animal needs to survive and reproduce
Define sensation
The psychological experience associated with sound, light, or other simple stimuli and the initial information-processing steps by which sense organs and neural pathways take in stimulus information from the environment.
Define perception
The recognition, organisation, and meaningful interpretation of sensory stimuli.
What are the steps in the process of sensation
physical stimulus- physiological response- sensory experience
True or false: each sense has distinct sensory receptors and neural pathways to and within the brain?
true
What are sensory receptors?
Specialised biological structures—which in some cases are separate cells and in other cases are the sensitive tips of sensory neurons—that respond to physical stimuli by producing electrical changes that can initiate neural impulses (action potentials) in sensory neurons.
What are sensory areas?
Areas of the brain’s cerebral cortex that receive and analyse input from the body’s senses. Separate sensory areas exist for each distinct sense.
What is sensory coding?
The process by which information about the quality and quantity of a stimulus is preserved in the pattern of action potentials sent through sensory neurons to the central nervous system
What is transduction?
The process by which a receptor cell produces an electrical change in response to physical stimulation.
What are receptor potentials?
Electrical changes in neurons that can trigger action potentials in sensory neurons
How does the coding of stimulus quality occur?
Qualitatively different stimuli optimally activate different sets of neurons
What is sensory adaptation?
The temporary decrease in sensitivity to sensory stimulation that occurs when a sensory system is stimulated for a period of time, and the temporary increase in sensitivity that occurs when a sensory system is not stimulated for a period of time.
What is pyschophysics?
The scientific study of the relationship between physical characteristics of stimuli and the psychological (sensory) experiences that the stimuli produce.
What is the absolute threshold?
In psychophysics, the faintest (lowest-intensity) stimulus of a given sensation (such as sound or light) that an individual can detect.
What is the difference threshold?
In psychophysics, the minimal difference that must exist between two otherwise similar stimuli for an individual to detect them as different; also called the just-noticeable difference (jnd).
What is Weber’s law?
The idea that, within a given sensory modality (such as vision), the difference threshold (amount that the stimulus must be changed in magnitude to be perceived as different) is a constant proportion of the magnitude of the original stimulus.
What is signal detection theory?
Proposes that the detection of a sensory stimulus is dependent upon both the physical intensity of the stimulus and the psychological state (including expectations, motivation, and alertness) of the perceiver.
Why are smell and tase called chemical senses?
Because the stimuli for them are chemical molecules
Define olfaction
Sense of smell
How many different types of sensory neurons are contained in the olfactory nerve and where are their terminals located?
roughly 400 different types, the olfactory epithelium
Where do the glomeruli in the olfactory bulb send most of their output and what effect might this account for
Most output goes to structures in the limbic system and the hypothalamus which are involved in basic drives and emotions. These connections account for the strong and often unconscious effects that smell can have on our motivational and emotional states
Where are the primary and secondary olfactory areas located?
Primary- underside of the temporal lobe
Secondary- orbitofrontal cortex located at the underside of the frontal lobe
Areas are crucial for the conscious understanding of and identifying of odors
Odourants can reach the olfactory epithelium via two different routes which are…
The nostrils and an opening in the mouth called the nasal pharynx
Where does flavour come from?
Taste and smell triggered through the nasal pharynx
Which gender is more sensitive to odor?
Women
When does the sense of smell decline?
With age
What is one finding that helps to substantiate the theory that olfaction serves one or more special functions related to reproduction?
Women of child bearing age have smell sensitivity which is not present in prepubescent girls or post-menopausal women
Odour figures into the complex stimuli that are involved in attachment between human infants and their mothers. True or false
True
Why would mice choose mates that have the most different smell from them?
- This indicates that the are not likely to be close relatives
- This will add new genetic variation to the mix of disease-fighting cells that develop in offspring
(their smell is associated with genes that determine some cells in the immune system)