Unit 4: Sensations and Perceptions

Describe the characteristics of visible light, and explain the process by which the eye converts light energy into neural messages.

-visible light: cornea-->lens(which changes per accommodations-->the retina (covered with rods and cones) -cones(concentrated in the center of the retina or fovea) sensitive to bright light and color vision -the informatinon passes through horizontal cells to bipolar and amacrine cells-->optic nerves cross to the optic chiasma-->info travels to the primary visual cortex-->brain processes info received from vision

Define perceptual set and explain why the same stimulus can evoke different perceptions in different contexts.

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Explain how the contributions of restored vision, sensory deprivation, and perceptual adaptation research to our understanding of the nature-nurture interplay in our perceptions.

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State the basic assumption we make in our perceptions of motion, and explain how these perceptions can be deceiving.

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Explain how perceptual constancies help us to organize our sensations into meaningful patterns.

Constancy: we know that t a stimulus remains the same size, shape, brightness, weight and/or volume even though it does not appear to -ability to achieve constancy which is innnate and the experience, which is learned, both contribute to our development of the various types of constancy

Discuss the Gestalt psychologists viewpoint on how sensations are organized into perceptions

Gesatalt approach: top0down theory that this view holds the most perceptual stimuli can be broken down into figure-ground relationships

Explain the binocular and monocular cues we use to perceive depth.

Monocular Cues: that we need only one eye to see Binocular Cues: is something we need two eyes to see

Contrast place and frequency theories, and explain how they help us to understand pitch perception.

Place Theory: asserts that sound waves generate activity at different places along the basilar membrane Frequency theory: we sense pitch because the rate of neural impulses is equal to the frequency of a particular sound They help us understand how we hear high pitches and low pitches

Describe the auditory process, including the stimulus input and the structure and function of the ear.

auditory process: Structure: auditory canal, cochlea, basilar membran, ear: is to hear things

Explain how the Young-Helmholtz and opponent processing theories help us understand color vision.

Young-Helmotz/trichromoatic theory: the cones in the retina of the eyes are activated by light waves associated with blue, red and green -we see colors are a mix of these colors

Distinguish between absolute and difference thresholds, and discuss whether we can sense and be affected by subliminal or unchanging stimuli

absolute threshold: the minimal amount of stimulation needed to detect a stimulus and cause the neuron to fire 50% of the time difference threshold: minimum amount of distance between two stimuli that can be detected as a distinct -we can be affected by subliminal stimuli

Define feature detectors and parallel processing, and discuss their roles in visual information processing.

feature detectors: "see" different parts of the pattern, such as a line set at the specific angle to bg parallel processing: when the brain computes multiple pieces of information simultaneously -serial processing turns to parallel processing which the brain uses to process what a person sees

Discuss how our perceptions are directed and limited by selective attention, noting how we may or may not be affected by unattended stimuli

selective attention: attend one thing while ignoring another -the only thing we are going to be affected by is our name-->quickly be drawn to another conversation by key stiumuli cocktail party phenomenon: our ability to carry on and follow a single conversation in a room full of conversations

Contrast sensation and perception, and explain the difference between bottom-up and top-down processing.

sensation: study the relationship between physical stimulation and the psychological effects perception: how we recognize, interpret, and organize our sensations bottom-up processing: achieves recognition of an object by breaking it down into its component parts-->relies heavily on sensory receptors -brain's analysis and acknowledgement of the raw data top-down processing: when the brain labels a particular stimulus or experience

Describe the sense of touch, and distinguish between kinesthesis and the vestibular sense.

vestibular sense: involves sensation of balance -located in the semicircular canals of the inner ear kinesthesis: found in the joints and ligaments, transmites information about the location and position of the limbs and body parts Skin as cutaneous and tactile receptory that provide information about pressure, pain and temperature -receptor cells-->sensitive to pressure and movement are fast-conducting myelinated neurons, wich send information to the spinal cord --> goes to the medulla-->the thalamus and thn the somatosensory cortex