AP Psych 1.6-Sensation

What is sensation?

The process by which sensory receptors and the nervous system receive and represent stimuli from the environment.

How is sensation related to behavior and mental processes?

Sensation provides the raw sensory input that influences perception, decision-making, emotional responses, and behavior.

What is stimulus detection?

The process by which sensory receptors detect physical energy (light, sound waves, chemicals) from the environment.

What is the absolute threshold?

The minimum intensity of a stimulus that can be detected 50% of the time.

What is the difference threshold (JND)?

The smallest detectable change in a stimulus.

What is Weber’s Law?

The principle that the JND is proportional to the intensity of the original stimulus, not a constant amount.

How does Weber’s Law apply to real life?

Adding sugar to unsweet tea is noticeable, but the same amount added to very sweet tea is not.

What is sensory adaptation?

A decrease in sensitivity due to constant stimulation over time.

Why does sensory adaptation occur?

It allows us to focus on changes in the environment rather than constant, unimportant stimuli.

What is sensory interaction?

When one sense influences another, such as smell affecting taste.

What is synesthesia?

A rare condition where stimulation of one sensory pathway causes automatic experiences in another (e.g., hearing colors).

What is priming?

Exposure to one stimulus influences the response to a later stimulus.

What is the cornea?

The clear outer layer that helps focus incoming light.

What is the pupil?

The opening that controls how much light enters the eye.

What is the iris?

The colored muscle that controls pupil size.

What is the lens?

A flexible structure that changes shape to focus light on the retina.

What is lens accommodation?

The process by which the lens changes shape to focus light clearly.

What is the retina?

The light-sensitive layer containing rods and cones that transduce light into neural signals.

What is the fovea?

The center of the retina with the sharpest vision, packed with cones.

What is the optic nerve?

The nerve that carries visual information from the eye to the brain.

What are rods?

Photoreceptors that detect light intensity and work best in low light.

What are cones?

Photoreceptors that detect color and fine detail, concentrated in the fovea.

What is nearsightedness (myopia)?

Light focuses in front of the retina, causing distant objects to appear blurry.

What is farsightedness (hyperopia)?

Light focuses behind the retina, causing near objects to appear blurry.

What causes afterimages?

Fatigue of cones and opponent-process mechanisms in ganglion cells.

What are color vision deficiencies?

Inability to distinguish certain colors due to missing or malfunctioning cones.

What is the cochlea?

A fluid-filled structure that converts vibrations into electrical signals.

What is the basilar membrane?

A membrane inside the cochlea lined with hair cells that respond to sound frequencies.

What is the auditory (cochlear) nerve?

Carries sound signals from the cochlea to the brain.

What is place theory?

High-pitched sounds activate specific locations on the basilar membrane.

What is frequency theory?

Low-pitched sounds are encoded by the rate of neural firing matching the sound frequency.

What is volley theory?

Groups of neurons take turns firing to encode medium-to-high frequencies (1,000–4,000 Hz).

How do we locate sound?

By comparing timing and intensity differences between both ears.

How does smell work?

Airborne molecules dissolve in mucus and stimulate olfactory receptors.

Where do smell signals go in the brain?

Directly to the olfactory bulb and limbic system, bypassing the thalamus.

Why are smells strongly linked to memory?

Because olfaction connects directly to emotion and memory centers.

What are taste buds?

Structures on the tongue containing taste receptors.

What do taste receptors do?

Detect chemicals dissolved in saliva and send signals to the brain.

Who are supertasters?

People with many taste buds who are highly sensitive, especially to bitterness.

Who are nontasters?

People with fewer taste buds and reduced taste sensitivity.

How do smell and taste interact?

Flavor perception depends on both systems working together.

What are mechanoreceptors?

Receptors that detect pressure and texture.

What are thermoreceptors?

Receptors that detect temperature.

What are nociceptors?

Receptors that detect pain.

What is the somatosensory cortex?

The parietal lobe area that processes touch, with more space for sensitive body parts.

What is the thalamus’ role in touch?

It relays sensory information to the cortex.

What is pain’s purpose?

To signal potential harm and encourage protective behavior.

What is gate control theory?

The idea that non-painful input can close the spinal gate, reducing pain perception.

What is phantom limb sensation?

Feeling sensations in an amputated limb due to the brain’s sensory map remaining active.

What does the vestibular system do?

Maintains balance, posture, and spatial orientation.

What are the semicircular canals?

Three fluid-filled canals that detect head movement.

Why does dizziness occur after spinning?

Fluid continues moving after the body stops.

What is vertigo?

A spinning sensation caused by conflicting sensory signals.

What is kinesthesis?

The sense of body position and movement without visual input.

Why is kinesthesia important?

It allows coordinated movement and precise action.