Textbook Notes (368,413)
Canada (161,874)
Psychology (1,066)
PSY1101 (252)
Chapter 6

Chapter 6.docx

3 Pages
Unlock Document

Nigel Desouza

Chapter 6: Sensation and Perception Sensing the World: Some Basic Principles • Sensation – the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment • Perception – the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events • Bottom-up processing – analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information • Top-down processing – information processing guided by higher-level mental processes, and when we construct perceptions drawing on our experience and expectations THRESHOLDS • Psychophysics – the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them Absolute Thresholds • The minimum stimulation needed to detect a particular stimulus (light, sound pressure, taste or odor) 50% of the time Signal Detection • A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation and level of fatigue • Theorists seek to understand why people respond differently to the same stimuli, and why the same person’s reactions vary as circumstances change Subliminal Stimulation • Subliminal – below one’s absolute threshold for conscious awareness • Claims say recordings that supposedly speak directly to our brain are unconsciously sensed, and so these stimuli have extraordinary suggestive powers • Our absolute threshold is the point where we detect only 50% of stimuli – what about the other half? • Prime – the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or respose • Much of our information processing occurs automatically, out of sight • Scientist Anthony Greenwald concluded ‘subliminal procedures offer little or nothing of value to the marketing practitioner Difference Thresholds • The minimum difference between two stimuli required for detection 50% of the time. We experience the difference threshold as a just noticeable difference (jnd) • Weber’s law – the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount SENSORY ADAPTATION • Diminished sensitivity as a consequence of constant stimulation • After constant exposure to a stimulus, our nerve cells fire less frequently • Sensory adaptation reduces our sensitivity, but also gives us the freedom to focus on informative changes in our environment without being distracted • We perceive the world not exactly as it is, but as it is useful for us to perceive it Vision • Transduction – conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret THE STIMULUS INPUT : LIGHT ENERGY • Scientifically, what strikes our eyes isn’t colour, but pulses of electromagnetic energy that our visual system perceives as colour • Electromagnetic spectrum ranges from imperceptibly short waves of gamma waves, to the narrow bands we see as visible light, to the long waves of radio transmission and AC circuits • Wavelength – the distance from the p
More Less

Related notes for PSY1101

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.