The Thalamus and LGN Quiz

Sensory Systems

• The sensory system that detects energy or chemicals in the surrounding environment in humans is the chemosensory system.
• The sensory system that uses pressure and temperature on the skin is the somatosensory system.
• The sensory system that detects sound energy passed through the movement of molecules in a medium is the auditory system.
• The sensory system that detects light in humans is the visual system.

Visual System

• The cells in the retina that convert photon energy to neural signals are called photoreceptors (rods and cones).
• The visual system adjusts its sensitivity to be maximally sensitive in the current environment through adaptation.
• The theory that explains that the perceived color of an object is determined by the ratios of the responses of the three cone types in the retina of the eye is the Trichromatic Theory.
• The theory that suggests that the visual system responds differently to opponent color pairs, where one color excites a cone while the opponent color inhibits that cone, is the Opponent Process Theory.

Depth Perception

• The cues to depth that can be achieved with only one eye include shading, texture gradient, and linear perspective.
• The cues to depth that require the use of both eyes include binocular disparity and convergence.

Color Perception

• The theory that suggests that people from all cultures and of all ages choose similar color boundaries is the Universal Color Model.
• The factor of color that is determined by the relative activity of the three cone types is hue.

Brain Regions and Functions

• The Thalamus LGN is not responsible for conscious awareness of visual stimuli.
• The function of the V1 in the Visual Cortex is to process simple features such as line orientation and color.
• The function of the V4 in the Visual Cortex is to process complex features such as shapes and objects.
• The function of the V5 in the Visual Cortex is to process motion.

Perception

• The role of Gestalt principles in perception is to organize visual information into meaningful wholes.
• Perceptual constancy refers to the tendency for perception to remain stable despite changes in the sensory input.
• The method used to systematically measure our perception is Psychophysics.
• The term for the minimum difference in intensity required for us to notice a change is the Just Noticeable Difference (JND).
• The factor that does not affect the JND is the absolute magnitude of the stimulus.
• The term for the constant ratio between the JND and the magnitude of the stimulus is the Weber Fraction.
• The method used to measure the threshold by slowly increasing or decreasing the intensity of a stimulus until it is detected or no longer detected is the Method of Limits.
• The probability of detection in the Method of Constant Stimuli depends on the intensity of the stimulus and the sensitivity of the observer.

Sound Perception

• The theory that suggests that the location of maximal excitation on the basilar membrane determines the perceived frequency of a sound is the Place Theory.

Touch Perception

• The type of touch receptor responsible for sensing low frequency vibrations, such as objects slipping from grasp, is the Meissner's corpuscle.
• The type of touch receptor responsible for sensing fine spatial details, such as patterns in Braille, is the Merkel's disc.
• The theory that suggests that pain can be controlled by stimulating other sensory modalities, such as heat, cold, or light touch, is Gate Control Theory.

Depth Cues

• The cue to depth perception that involves the assumption that closer objects are usually brighter and that light sources come from above is the Shading cue.
• The cue to depth perception that involves the assumption that each eye sees the world from a slightly different angle is the Binocular Disparity cue.