Intro to sensation and perception

What is the difference between sensation and perception?

Sensation is the process of detecting stimuli; perception is the interpretation and organization of those sensations into meaningful experiences.

What is transduction in psychology?

The process by which sensory receptors convert external stimuli (like light or sound) into neural signals that can be interpreted by the brain

What is an absolute threshold?

The minimum stimulation needed to detect a stimulus 50% of the time.

ex. the faintest sound you can detect. like a clock ticking in the room next over

What is a difference threshold (just noticeable difference, JND)?

The smallest detectable difference between two stimuli.

What does Weber’s Law state?

The JND is a constant proportion of the original stimulus.

In simpler terms, the amount of change needed to detect a difference increases as the original stimulus gets stronger.

What is signal detection theory?

A theory that detection of stimuli depends on both sensory sensitivity and decision-making processes (hits, misses, false alarms, correct rejections).

What are rods and cones?

Rods are photoreceptors sensitive to light and dark; cones are photoreceptors sensitive to color and fine detail.

Where are rods and cones located?

In the retina of the eye.

What is the fovea?

The central point in the retina where cones are concentrated, responsible for sharp vision.

What is the optic nerve?

The bundle of axons that carries visual information from the retina to the brain.

What is the blind spot?

The point where the optic nerve leaves the eye; no photoreceptors are located there.

What is top-down processing?

Perception driven by prior knowledge, expectations, and context.

What is bottom-up processing?

Perception driven by sensory input without prior knowledge.

What is the Gestalt principle of figure-ground?

The tendency to separate objects (figures) from their background.

What are Gestalt principles of organization?

Proximity, similarity, continuity, closure, and connectedness.

What is depth perception?

The ability to see objects in three dimensions and judge distance.

What are monocular cues?

Depth cues available to one eye, such as relative size, linear perspective, interposition, and texture gradient.

What are binocular cues?

Depth cues that require both eyes, such as retinal disparity and convergence.

What is the cochlea?

A spiral-shaped structure in the inner ear that contains hair cells which transduce sound vibrations into neural signals.

What is place theory of hearing?

The idea that different frequencies stimulate different places on the cochlea’s basilar membrane.

What is frequency theory of hearing?

The idea that the rate of neural impulses matches the frequency of a sound.

What is the vestibular sense?

The sense of balance, controlled by the semicircular canals and vestibular sacs in the inner ear.

What is the somatosensory system?

The system responsible for touch, pressure, temperature, and pain.

What is the gate-control theory of pain?

The theory that the spinal cord contains a neurological "gate" that can block or allow pain signals to pass to the brain.

What is sensory adaptation?

A decrease in sensitivity to a constant stimulus over time.

What is perceptual set?

A mental predisposition to perceive one thing and not another, influenced by expectations, culture, and context.