Psychology Depth Cues

Depth Cues Without depth perception, we would perceive the world as a two-dimensional surface. Eleanor Gibson used the visual cliff experiment to determine whether or not babies perceive depth. The infant did not crawl on a glass table. Other experiments demonstrated that depth perception develops when we are three months old. MONOCULAR CUES  Linear Perspective: A cue used to imply depth in drawings.  Relative Size Cue: Closer objects are larger and farther objects are smaller in drawings.  Interposition: When something closer blocks our view of something farther in a drawing.  Texture Gradient: When farther objects have less detail than closer objects in drawings.  Shadowing: Implying where the light source is in a drawing. BINOCULAR CUES We see the world with our eyes a certain distance apart.  Binocular Disparity: Each of our eyes sees any object from a different angle. The brain gets both images. If the image is farther away, the image will be similar. If the object is closer, the more disparity there will be from the images coming from each eye.  Convergence: As an object gets closer to our face, our eyes must move toward each other to keep focused on the object. The brain receives feedback from the muscles controlling eye movement. Effect of Culture on Perception Some perceptual rules psychologists once thought were innate are actually learned. Some cultures that do not use monocular depth cues in art do not see depth in pictures using these cues. States of Consciousness Dualism: Dualists believe humans consist of two materials: thought and matter. They believe that this is what gives humans free will and some believe it continues existing after the brain dies. Monism: Monists disagree and believe everything is the same substance. LEVELS OF CONSCIOUSNESS Different levels of consciousness can focus on different things. Mere-Exposure Effect: When we prefer stimuli we have seen before over novel stimuli even if we do not consciously remember seeing the old stimuli. Priming: When someone responds more quickly and/or accurately to questions they have seen before. Blind Sight: When a blind person knows where an object is even though they cannot see due to a level of consciousness tracking the object. Not all researchers agree about what the specific levels are, but these are some of the possible levels of consciousness:  Conscious Level: The information about yourself and your environment you are currently aware of.  Nonconscious Level: Involuntary body processes that we are not (usually) aware of.  Preconscious Level: Information about yourself or your environment you are not currently think about but could if you wanted to.  Subconscious Level: Information we are not consciously aware of but know must exist due to behavior.  Unconscious Level: Psychoanalytic psychologists believe some events and feelings are unacceptable to our conscious mind and are repressed into the unconscious mind. SLEEP Sleep Cycle Circadian Rhythm: The pattern our metabolic and thought processes follow during a 24-hour day. Sleep Cycle: Our typical pattern of sleep that is recorded by using an EEG machine. Sleep Onset: The period when we are falling asleep. This is the stage between wakefulness and sleep. We might experience mind hallucinations before actually falling asleep and entering stage 1. While we are awake in stages 1 and 2, our brains produce high frequency, low-amplitude, theta waves. Theta waves get progressively slower and higher in amplitude as we go through stages 1 and 2. In stage 2, the EEG shows short bursts of rapid brain waves. We then move into stages 3 and 4, called Delta sleep. Delta sleep is important to replenish the body’s chemicals, releasing growth hormones in children, and fortifying our immune system.