SENSATION AND PERCEPTION
REVIEW OF RELATED LITERATURE (FOREIGN)
(Douglas A. Bernstein, Edward J. Roy, Thomas K. Skull, Christopher D. Wickens)
BIOLOGICAL ASPECTS OF PSYCHOLOGY
The diagram above illustrates some of the relationships between different aspects of psychology through sensation. What happens if people are denied on this contact, if they deprived of stimulation form the senses? However, recent research has made it more difficult to draw a clear line between sensation and perception. That research shows that the process of interpreting sensations begins in the sense organs ...view middle of the document...
The second step in sensation is transduction, which is the process of converting incoming energy into neural activity. Just as radio receives energy and transduce it into sounds, the ears receive sound energy and transducer it into neural activity that people recognizes as voices, music, and other auditory experience. Transduction takes place at structures called receptors, cells that are specialized to detect certain forms of energy. These sensory receptors are distinct from neurotransmitter receptors. But both types of receptors translate one kind of signal into a different kind of signal. Sensory receptors respond best to changes in energy. A constant level of stimulation usually produces adaption, a process through which responsiveness to an unchanging stimulus decreases over time.
Next, the output from receptors is transferred to the brain via sensory nerves. For all the senses but smell, the information is taken first to the thalamus, which relays it to the cerebral cortex. It is in the cortex that the most complex processing occurs.
Sound is a repetitive fluctuation in the pressure of a medium like air; it travels in waves that can be represented as waveforms. The frequency (which is inversely related to wavelength) and amplitude sound waves produce the psychological dimensions of pitch and loudness, respectively. Timbre, the quality of sounds depends on complex wave patterns that are added on to the basic frequency of the sound.
Visible light is electromagnetic radiation with a wavelength of about 400 to 750 nanometers. Light intensity, or the amount of energy in light, determines its brightness. Differing light wavelengths are sensed as different colors. The accessory structure of the eye includes the cornea, pupil, iris, and lens. Through accommodation and other means, these structures focus light rays on the retina, the netlike structure of cells at the back of the eye. Photoreceptors in the retina—cones and rods—have photopigments and can transducer light into neural activity. Rods and cones differ in their shape, their sensitivity in light, their ability to discriminate colors, and their distribution across the retina. The fovea, the area of the highest acuity, has only cones, which are color sensitive. Rods are more sensitive to light but do not discriminate colors.
The color of an object depends on which the wavelengths striking it are absorbed or which it was reflected. The SENSATION of color has three (3) psychological dimensions: hue, which is the determined by the dominant wavelength in the mixture of light; Saturation, which depends on the relative intensity of a single wavelength; and brightness, which is a function of the overall intensity of all the wavelengths. According to the trichromatic theory, color vision results from the fact that the eye includes three (3) types of cone, each of which is most sensitive to short, medium, or long wavelengths; information from the which it can...