Sensation and Perception

Sensation

The process of using our sensory systems to detect stimuli in our environment.

Perception

How we consciously recognize, organize, and identify sensory stimuli, involving bottom-up and top-down processing.

Absolute Threshold

The smallest amount of stimulation necessary for a stimulus to be detected 50% of the time.

Difference Threshold

The minimal difference needed to notice a difference between two stimuli.

Signal Detection Theory

A theory stating that the response to a signal depends on an individual's ability to differentiate between the signal and noise.

Inattentional Blindness

The failure to perceive an unexpected stimulus in plain sight due to a lack of attention.

Olfactory Receptor Neurons

Sensory receptor cells that convert chemical signals from odorants into neural impulses.

Ageusia

The inability to taste.

Anosmia

The inability to detect odors.

Hyposmia

Reduced ability to smell.

Tactile Senses

The combination of skin senses including pressure, touch, temperature, vibration, and pain.

Meissner’s Corpuscles

Sensory receptors located in the fingertips, lips, and palm that detect sensitive touch.

Phantom Pain

Hallucinations of touch, pressure, or pain in a body part that is no longer present.

Gate Control Theory of Pain

Theory suggesting that the spinal cord has a mechanism that either allows or blocks pain signals to the brain.

Frequency (in Hearing)

The number of cycles per second in a sound wave.

Auditory Deafness

Loss of hearing that may be genetic or caused by infection.

Rods

Photoreceptors in the retina that detect light for peripheral and night vision.

Cones

Photoreceptors in the retina used for central and color vision.

Visual Agnosia

Damage to the 'what' pathway, preventing visual recognition of objects.

Gestalt Theory

The theory that the brain organizes visual information into meaningful wholes rather than individual elements.

Cataracts

Clouding of the lens of the eye, affecting acuity and color vision.

Synesthesia

A neurological condition causing the simultaneous activation of two senses, leading to experiences such as associating sounds with colors.