Behavioral Sciences 2 Sensation and Perception

Behavioral Sciences 2: Sensation and Perception Definitions Hearing Sensory Receptors: Sensory nerves that respond to stimuli. Outer Ear: Pinna (auricle), external auditory canal, tympanic membrane. Sensory Ganglia: Collection of cell bodies outside the CNS. Middle Ear: Connected to nasal cavity by Eustachian tube. Ossicles: Acronym MIS and HAS. Malleus: Hammer Incus: Anvil Stapes: Stirrup. Footplate of stapes rests in the oval window of cochlea. Projection Areas: Areas in the brain that analyze sensory input. Absolute Threshold: The min of stimulus energy that will activate a sensory system. Threshold of The minimum stimulus energy that will create a Conscious Perception: signal large enough in size and long enough in Inner Ear: Bony Labyrinth: Filled with perilymph. Membranous Labyrinth: Filled with endolymph. Membranous labyrinth consists of cochlea (sound), utricle & saccule (linear acceleration) and semicircular canals (rotational acceleration & balance). duration to be brought into awareness. Difference Threshold: The min difference in magnitude between two stimuli before one can perceive this difference. Weber’s Law: Just Noticeable Difference (JND) for a stimulus is proportional to the magnitude of the stimulus. Projection Areas: Superior Olive: Localizes sound. Located in brain stem. Inferior Colliculus: Startle reflex. Also used by both eyes and ears in the vestibulo-ocular reflex which keeps the eyes fixed on a single point as the head rotates. Signal Detection Refers to the effects of nonsensory factors, such Theory: as experiences, motives, and expectations on perception of stimuli. Accounts for response bias. Adaptation: Refers to a ¯ or " in sensitivity to a stimulus. Vision Cornea: Gathers and filters incoming light. Iris: Controls size of pupil. Colored part of eye. Divides front of the eye into the anterior & posterior chamber. It contains 2 muscles, the dilator and constrictor pupillae. Lens: Refracts incoming light to focus it on the retina. Aqueous Produced by the ciliary body. Nourishes the eye and gives Humor: the eye its shape. Drains through the canal of Schlemm. Retina: Rods: Detect light / dark. Contain rhodopsin. Cones: Color. Short / medium / long. Cones are in the fovea, which is part of the macula. Pathway from retina: Rods/Cones bipolar cells ® ganglion cells ® optic nerve Retinal Disparity: Space between eyes; allows for binocular vision and depth. Horizontal & Integrates signals from ganglion cells and performs edgeAmacrine Cells: sharpening. Support: Vitreous on inside. Sclera and choroid on outside. Processing: Parallel Processing: Color, form, and motion at same time. Magnocellular Cells: Motion. High temporal resolution. Parvocellular Cells: Shape. High spatial resolution. Auditory Pathway cochlea vestibulocochlear nerve medial geniculate nucleus (MGN) auditory cortex Other Senses Smell: The detection of volatile or aerosolized chemicals by the olfactory chemoreceptors (olfactory nerves) in the olfactory epithelium. Smell info bypasses the thalamus. Pheromones: Chemicals given off by animals that have an effect on social foraging, and sexual behavior. Taste: The detection of dissolved compounds by taste buds in papillae. Sweet/sour/salty/bitter/umamai. Somatosensation: Refers to the four touch modalities: Pressure, vibration, pain, temperature. Two-Point Threshold: Minimum distance necessary between 2 points of stimulation on the skin such that the points will be felt as two distinct stimuli. Physiological Zero: The normal temp of skin to which objects are compared to. Nociceptors: Pain reception. Gate theory of pain. ¯ JND for pain. Kinesthetic Sense: Proprioception Object Recognition Visual Pathway eye optic nerves optic tracts visual radiations optic chiasm lateral geniculate nucleus (LGN) visual cortex Top-Down The recognition of an object by memories and expectations. Processing: Little attention to detail. Uses background knowledge.Details Bottom-Up whole. Recognition of objects by featuredetection. Not Processing: influenced by background knowledge. Gestalt Proximity, similarity, continuity, closure. All are governed by Principles: the Law of Prägnanz.