Sensation and Perception: Key Concepts

Sensation and Perception

• Transduction is the conversion of physical energy into neural signals.
• Absolute threshold refers to the minimum amount of stimulation needed for detection 50% of the time.
• Synesthesia is a phenomenon where a person can taste shapes or see sounds.
• Just-noticeable difference (JND) is the smallest detectable difference between two stimuli.
• Weber's Law states that the JND is proportional to the original stimulus intensity.
• Sensory adaptation involves decreased sensitivity to constant stimulation.
• Bottom-up processing refers to processing that begins with the smallest sensory details.
• The cocktail party effect demonstrates the ability to selectively attend to one conversation in a noisy environment.
• Change blindness occurs when people fail to notice significant visual changes.
• Top-down processing involves using expectations and prior knowledge to interpret sensory input.
• Perceptual set refers to the way past experiences influence current perception.
• Sensory interaction is when senses work together to enhance perception.
• Selective attention is demonstrated by focusing on specific stimuli while ignoring others.
• The absolute threshold for hearing is the faintest sound that can be detected 50% of the time.
• Absolute threshold does not influence perceptual set.
• Sensory adaptation serves to prevent sensory overload.
• The cocktail party effect is an example of selective attention.
• Change blindness demonstrates that attention is necessary for conscious perception.
• Weber's Law is most relevant to difference threshold calculations.
• Transduction converts environmental energy to neural signals.

Vision

• The primary function of the retina is to convert light energy into electrical signals.
• The blind spot occurs where the optic nerve exits the retina.
• Rod cells are responsible for vision in low light conditions.
• Dark adaptation refers to the process of eyes adjusting to see in dim light.
• According to the trichromatic theory, human color vision is based on three types of cone cells.
• Accommodation in the eye refers to the process of changing lens shape to focus.
• Nearsightedness (myopia) is characterized by difficulty seeing distant objects clearly.
• The opponent process theory explains how humans perceive contrasting colors.
• Afterimages occur due to fatigue of photoreceptors.
• Ganglion cells transmit information to the brain via the optic nerve.
• Dichromatism is having reduced color vision with two cone types.
• The visual (optic) nerve carries visual information to the brain.
• Monochromatism is characterized by complete color blindness.
• Prosopagnosia is a condition where individuals cannot recognize faces.
• Farsightedness (hyperopia) occurs when the eyeball is too short.
• Blindsight refers to the ability to detect motion despite cortical blindness.
• The lens of the eye focuses light onto the retina.
• Rods are more sensitive than cones.
• The trichromatic theory explains how humans see different colors.
• Ganglion cells contribute to vision by processing initial visual information and detecting edges and contrast.

Hearing and Other Senses

• Place theory dictates that the location of hair cell stimulation on the basilar membrane determines the perception of pitch.
• Frequency theory explains how low frequency sounds are perceived (below 100 Hz).
• Sound localization primarily relies on interaural time and intensity differences.
• Conduction deafness has problems with the mechanical transmission of sound waves.
• The thalamus serves as the major relay center for sensory information before it reaches the cortex.
• Supertasters can taste certain substances more intensely due to a higher concentration of fungiform papillae.
• The vestibular sense is primarily responsible for balance and spatial orientation.
• There are three semicircular canals present in each inner ear.
• Kinesthesis refers to the sense of body position and movement.
• Sensorineural deafness involves damage to the cochlea or auditory nerve.
• Gate control theory explains how pain signals are modulated.
• Phantom limb sensation is explained by cortical reorganization.
• Pheromones in humans are for chemical communication.
• The semicircular canals contain endolymph fluid.
• Volley theory explains the perception of mid-range frequency sounds.
• Sensorineural deafness treatment typically involves hearing aids or cochlear implants.
• The perception of body movement and position (kinesthesis) involves multiple sensory receptors throughout the body.
• The thalamus’ primary role in sensory processing is initial relay and filtering of sensory information.
• Suptetasters are more sensitive to bitter tastes.
• The vestibular system's primary sensory organs include the semicircular canals and otolith organs.

Perception

• Closure is the Gestalt principle that explains how incomplete figures are perceived as complete.
• The "figure" in the figure-ground relationship is the object that stands out from its surroundings.
• The Gestalt principle of proximity suggests that objects close to each other appear to form groups.
• Retinal disparity is the binocular depth cue that involves the slight difference between the images received by each eye.
• Convergence is when one's eyes turn inward to focus on a nearby object.
• The principle of similarity states that objects with similar characteristics tend to be grouped together.
• Relative clarity is the monocular depth cue that involves objects appearing less detailed and hazier when far away.
• Linear perspective is when parallel lines appear to converge in the distance
• Perceptual constancy is the perception that an object maintains its shape regardless of the angle from which it is viewed.
• Interposition is when one object partially blocks another from view (monocular depth cue).
• Apparent movement occurs when static images are presented in rapid succession.
• The Gestalt principle of closure is demonstrated when the mind completes incomplete figures.
• Convergence is a depth cue that relies on both eyes working together.
• In figure-ground perception, the "ground" is the background or surrounding area.
• Texture gradient is the gradual change in detail of a surface as it extends into the distance.
• Perceptual constancy helps recognize objects despite changing conditions.
• Proximity is what explains why we tend to see stars in constellations as connected patterns.
• Retinal disparity is most effective for judging depth at short distances.
• Similarity is the Gestalt principle most related to how we group similar colors together.
• When viewing a painting, the main subject is typically perceived as the figure.