Unit 1 Part 2 Biological Bases of Behavior (Sensation and States of Consciousness)

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Vision

Perception of light and color through eyes.

Hearing

Perception of sound waves through ears.

Smell (olfaction)

Perception of odors through the nose.

Taste (gustation)

Perception of flavors through the tongue.

Touch (tactile)

Perception of pressure, temperature, and texture through skin.

Perception

The process of organizing and interpreting sensory information to make sense of the world around us.

Transduction

The conversion of sensory stimuli into neural impulses that can be understood by the brain.

Absolute Threshold

The minimum amount of stimulation required for a stimulus to be detected by a sensory system.

Just-Noticeable Difference (JND)

The smallest change in a stimulus that can be detected by an individual.

Weber's Law

The perceived difference in a stimulus must be proportional to the original intensity of the stimulus.

Sensory Adaptation

The process by which sensory receptors become less responsive to constant stimuli over time.

Synesthesia

A condition in which stimulation of one sensory pathway leads to automatic, involuntary experiences in another sensory pathway.

Retina

The light-sensitive inner surface of the eye containing photoreceptor cells that convert light into neural signals.

Rods

Photoreceptor cells in the retina responsible for vision in low light conditions and detecting motion.

Cones

Photoreceptor cells in the retina responsible for color vision and detail in bright light.

Fovea

Central area of the retina responsible for sharp central vision.

Blind Spot

Area on the retina where the optic nerve exits the eye, lacking photoreceptor cells.

Ganglion Cells

Neurons in the retina that receive visual information from bipolar cells and transmit it to the brain via the optic nerve.

Lens

Transparent structure in the eye that focuses light onto the retina.

Accommodation

The process by which the lens of the eye changes its shape to focus on objects at different distances.

Nearsightedness

A common vision condition where close objects appear clear, but distant objects appear blurry.

Trichromatic Theory

A theory proposing that color vision is based on three types of cone receptors, each sensitive to different wavelengths of light (red, green, and blue).

Opponent-Process Theory

A theory proposing that color vision is based on pairs of opposing color processes (red-green, blue-yellow, and black-white).

Afterimages

Visual sensations that persist after a stimulus is removed.

Dichromatism

A type of color vision deficiency where an individual has only two types of functioning cone cells instead of the normal three.

Blindsight

A phenomenon where individuals with damage to their visual cortex can respond to visual stimuli without consciously perceiving them.

Prosopagnosia

A neurological condition characterized by the inability to recognize familiar faces, including one's own face, despite intact vision and intellect.

Wavelength

The distance between sound wave peaks.

Amplitude

The measure of the intensity or loudness of a sound wave, represented by the height of its peaks.

Pitch Perception

The brain's interpretation of the frequency of sound waves, determining whether a sound is high or low in tone.

Place Theory

Idea that different parts of the inner ear detect different sound frequencies.

Frequency Theory

A theory of pitch perception proposing that the frequency of a sound wave directly corresponds to the rate at which auditory nerve fibers fire.

Volley Theory

A theory of pitch perception proposing that groups of auditory neurons fire in rapid succession, or 'volleys', to encode the frequency of sounds above 1000 Hz.

Sound Localization

The brain's ability to determine the location of a sound source in space. It relies on cues such as differences in arrival time and intensity between the ears, as well as spectral cues, to accurately locate sounds.

Conduction Deafness

Hearing impairment caused by problems with the outer or middle ear, such as damage to the ear canal, eardrum, or middle ear bones. It typically results in difficulty hearing soft sounds and can often be treated medically or surgically (temporary).

Sensorineural Deafness

Hearing loss caused by damage to the inner ear or auditory nerve. It results in difficulty hearing soft sounds and understanding speech, and is often permanent. Common causes include aging, exposure to loud noise, and certain medical conditions.

Sensory Interaction

The principle that one sense can influence another, such as when smell affects taste. It demonstrates how our senses work together to create our overall perception of the world.

Olfactory Systems

Responsible for smell. Special receptors in the nose detect smells and send signals to the brain via the olfactory nerve. The thalamus helps process this information, allowing us to identify different odors.

Pheromones

Chemical substances released by animals, including humans, that trigger social or behavioral responses in others of the same species. They play a role in communication, mating, and territorial marking.

Gustation

The sense of taste, involving receptors on the tongue that detect different flavors.

Taste Receptors

Specialized cells located on the tongue and in the mouth that detect different tastes.

Supertasters

Highly sensitive to taste, experiencing flavors more intensely, especially bitterness. Individuals with varying levels of sensitivity to taste stimuli.

Warm/Cold Receptors

Specialized sensory neurons in the skin that detect changes in temperature. Warm receptors respond to increases in temperature, while cold receptors respond to decreases.

Pain

Is a more difficult concept than others. It is in fact not a sensation but an emotional response to stimuli.

Gate Control Theory

A theory proposing that the experience of pain is modulated by a neural 'gate' in the spinal cord. This gate can open to allow pain signals to be transmitted to the brain or close to block them.

Phantom Limb

Sensation of pain or other feelings in a missing limb. It occurs due to the brain's continued perception of the limb, even though it's no longer there.

Vestibular Sense

The sense of body orientation and movement, including balance and spatial awareness. It relies on receptors in the inner ear that detect changes in head position and movement, helping to maintain stability and coordinate bodily movements.

Semicircular Canals

Fluid-filled structures in the inner ear that detect rotational movements of the head. They play a crucial role in the vestibular sense, helping to maintain balance and coordination by sending signals to the brain about changes in head position and movement.

Kinesthesis

The sense of body movement and position, including the awareness of muscle and joint sensations. It allows us to perceive and control our body's movements, providing feedback to the brain about the position and orientation of body parts.