BRS 214 Introduction to Psychology Sensation & Perception 2013-2014

1. BRS 214Introduction to PsychologySensation & Perception2013-2014 Ms. Dawn Stewart BSC, MPA, PHD

2. KEY POINTS • Distinguish between sensation and perception • Psychophysics: absolute threshold and difference threshold • Identify each major sensory system, their receptors, and type of sensory information each receives • Perception: selection, organization and interpretation

3. Sensation & Perception • Sensation: • stimulation of sensory receptors. • transmission of sensory information to the brain. • Perception: • Process by which sensations are organized and interpreted, forming an inner representation of the world.

4. Sensation and Perception Sensation occurs: Sensory organs absorb energy from a physical stimulus in the environment. Sensory receptors convert this energy into neural impulses and send them to the brain.

5. Sensory Systems • Vision • Hearing • Smell (olfaction) • Taste (gustation) • Vestibular sense (balance) • Kinethesis (body movement) • Touch (pressure, pain, temperature)

6. Sensation and Perception Sensations can be defined as the passive process of bringing information from the outside world into the body and to the brain. Sensation refers to the process of sensing our environment through touch, taste, sight, sound, and smell. The process is passive in the sense that we do not have to be consciously engaging in a "sensing" process.

7. Sensation and Perception Perception can be defined as the active process of selecting, organizing, and interpreting the information brought to the brain by the senses Perception is the way we interpret these sensations and therefore make sense of everything around us.

8. Sensation and Perception Perception can be defined as the active process of selecting, organizing, and interpreting the information brought to the brain by the senses Perception is the way we interpret these sensations and therefore make sense of everything around us. 

9. Sensation and Perception Perception follows: a) The brain organizes the information and translates it into something meaningful.

10. Vision • Visual receptor cells located on retina:rods for night vision and cones for color vision • The eye captures light and focuses it on the visual receptors, which convert light energy to neural impulses sent to the brain

11. Hearing • Audition (hearing) occurs via sound waves, which result from rapid changes in air pressure caused by vibrating objects • Receptors located in the inner ear (cochlea) tiny hair cells that convert sound energy to neural impulses sent along to brain

12. Smell and Taste • Olfaction (smell) receptors are located at top of nasal cavity • Gustation - (taste) receptors are taste buds on tongue. Four basic tastes: sweet, salty, sour and bitter

13. Body Senses • Vestibular sense (sense of balance) results from receptors in inner ear • Kinethesis - (body posture, orientation, and body movement) results from receptors in muscles, joint and tendons • Skin senses detect touch (pressure, temperature and pain)

14. Processing • Sensory reduction - filtering and analyzing of sensations before messages are sent to the brain • Transduction - process of converting receptor energy into neural impulses the brain can understand • Adaptation- decreased sensory response to continuous stimuli

15. Psychophysics • Study of the relationship between the physical properties of stimuli and a person’s experience of them • Absolute threshold - minimum amount of energy we can detect • Difference threshold - (jnd) the smallest change in a stimulus we can detect

16. Perception • “…a constructive process by which we go beyond the stimuli that are presented to us and attempt to construct a meaningful situation”.

17. Perceptual Processing • Top-down: perception is guided by higher-level knowledge, experience, expectations, and motivations • Bottom-up: perception that consists of recognizing and processing information about the individual components of the stimuli

18. Perception-Key Concepts • Selection • Organization • Interpretation • Subliminal perception and ESP

19. 1. Three Major Factors of Selection • Selective attention • Feature detectors • Habituation

20. 2. Organization • Form (Gestalt) • Constancy(size, shape, color, brightness) • Depth • Color

21. Gestalt Principles • Rules that summarize how we tend to organize bits and pieces of information into meaningful wholes

22. Gestalt Psychology: Form • figure ground • proximity • closure • contiguity • similarity

23. Constancy • Size constancy • Shape constancy • Color constancy • Brightness constancy

24. 3. Four Major Factors of Interpretation • Perceptual adaptation • Perceptual set • Individual motivation • Frame of reference

25. Subliminal Perception • Stimuli that occur below the threshold of our conscious awareness but have a weak, if any effect on behavior

26. 4. Extrasensory Perception (ESP) • Alleged perception in the absence of sensory data • Types of ESP - telepathy, precognition, clairvoyance, and psychokinesis