Behavioral Sciences Ch 2. Sensation and Perception Flashcards
Sensation
The conversion, or transduction, a physical, electromagnetic, auditory, and other information from the internal and external environment into electrical signals in the nervous system, performed by receptors in the PNS
Perception
The processing of sensory information to make sense of its significance, includes both external sensory experience and the internal actives of the brain and spinal cord
Sensory receptors
Nerves that respond to stimuli and trigger electrical signals, stimuli transmitted to projection areas in the brain
Sensory ganglia
Collections of cell bodies outside the central nervous system that are associated with sensory neurons
Projection areas
Areas in the brain that further analyze sensory input
Common sensory receptors
Photo receptors, hair cells, nociceptors, thermoreceptors, osmoreceptors, olfactory receptors, and taste receptors
Threshold
The minimum stimulus that causes a change in signal transduction, aka limina
Absolute threshold
The minimum of stimulus energy that is needed to activate a sensory system, may not be significant enough to be converted to an action potential through transduction
Threshold of conscious perception
The minimum of stimulus energy that will create a signal large enough in size and long enough and duration to be brought into awareness, can be tested with discrimination testing
Difference threshold
aka just noticeable difference, the minimum difference in magnitude between two stimuli before one can perceive the difference
Just-noticeable difference
jnd - aka difference threshold, the minimum difference in magnitude between two stimuli before one can perceive the difference
Weber’s Law
States that the just noticeable difference for stimulus is proportional to the magnitude of the stimulus, and that this proportion is constant or most of the range of possible stimuli
Signal detection theory
Refers to the effects of non-sensory factors, such as experiences, motives, and expectations, and perception of stimuli, experiences allow us to look at response bias
Response bias
The tendency of subjects to systematically respond to a stimulus in a particular way due to non-sensory factors
Adaption
A decrease in response to a stimulus over time, one way the mind and body try to focus attention on only the most relevant stimuli
Eye
An organ specialized to detect light in the form of photons
Cornea
Gathers and filters incoming light, clear, domelike window in the front of the eye
Iris
Divides the front of the eye into the anterior and posterior chambers, it contains two muscles, the dilator and the constrictor pupillae, which open and close the pupil
Anterior chamber of the eye
Lies in front of the iris
Posterior chamber of the eye
Lies between the iris and the lens
Dilator pupillae
Muscle in the iris that is responsible for dilating the pupil during sympathetic stimulation
Constrictor pupillae
Muscle in the iris that is responsible for constricting the pupil during parasympathetic stimulation
Pupil
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Lens
Refracts incoming light to focus it on the retina and is held in place by suspensory ligaments connected to the ciliary muscle, right behind the iris