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An Experimental Study

An Experimental Study. SENSATION & PERCEPTION. GOALS. Sensation vs. Perception. Sensation : When energy is detected by receptors on our sensory organs and transformed into neural energy ( Transduction)

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An Experimental Study

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  1. An Experimental Study SENSATION & PERCEPTION

  2. GOALS

  3. Sensation vs. Perception • Sensation: When energy is detected by receptors on our sensory organs and transformed into neural energy (Transduction) • Perception: The process of organizing and interpreting sensory information so that it makes sense

  4. PERCEPTION Occurs in the brain & is influenced by our Perceptual Sets (Experience & Expectations) as well as by Context, Emotions, & Motivation

  5. Signal Detection Theory • Signal Detection Theory predicts when we will detect weak signals (“hits” to “false alarms” ratios) in order to try and understand: • Why people respond differently to the same stimulus and • Why the same person’s reactions vary in differing circumstances

  6. Is it Really a Very Good Study? • Reliability = Does it provide a consistent result (even if it is wrong) • Validity = Does it measure what it says it measures (Does the steak cause a difference in the weight shown on the scale?) • Generalizability (External Validity) = Can we generalize the results of our study to other situations and people

  7. Emotion Guided Threat Detection: Expecting Guns Where There Are None • Like most quantitative researchers, Jolie Baumann and David DeSteno(2010) wanted to conduct and publish a good experimental study. • Specifically, they hypothesized that emotion (e.g., anger as the IV) causes people to perceive an object as a gun even if it is not a gun 

  8. Expecting guns where there are none:Sensation and emotion affect perception • Stimulus: • Object in a man’s hand • Perception: • The object is a gun! • …or not. Action: Press Z key on keyboard if gun or press / key if not gun • Sensation - Eyes: • Light Waves, Color, Forms • Emotion: • Angry, happy, or neutral Accurate Not accurate

  9. Sample • 84 undergraduates (49 Women, 35 Men) in partial fulfillment of a course requirement, were randomly assigned to one of three groups (Neutral, Angry, Happy)

  10. Procedures

  11. The numbers were crunched & the hypothesis was supported: Angry people are more likely, than happy or neutral people, to identify an object as a gun when it is not, but…. • How do we, as critical thinkers, determine whether: • The measures used in the study are reliable? • The statements about causality are valid? Does it measure what it says it measures? • The results/findings are generalizable?

  12. How do we know whether Baumann & DeSteno used… • Reliable measurements? • Emotion induction • It was a uni- or one-dimensional task [participants had to write one type of event – neutral, happy, angry] and it’s easier to interpret one-dimensional tasks. • “Threat detection” / “Perception Measure” • Video game, in its computerized presentation of images for a pre-specified amount of time (750 ms) on a computer screen, was stable as well as used repeatedly across several studies since 2002. • Computers, with their fancy calculations, are generally unbiased, accurate, precise, and reliable. • However I do want to point out that this one was “adapted”…

  13. Adaption #1 Changed shooting people who are believed to have guns to clicking a button to identify if the person is believed to be holding a gun

  14. Adaption #2 “Those not associate with stereotypes indicative of violence” So we will only use White Men as targets

  15. Given all of that… Is this a Reliable measure?

  16. How do we know whether thestatements of causality are valid? • Where was the experiment conducted? • We know that experiments conducted in laboratory settings- where there is more experimenter control of the setting and independent variables are manipulated - have higher internal validity. • Internal validity is about causal control (cause-effect) • This study WAS conducted in a lab setting • How were people put into groups? • Random assignment to groups • Rules out many threats to internal validity • Order of measures- Manipulation of emotion 1st, then computer task

  17. A closer look at internal validity • The degree of certainty with which statements can be made about relationships • How certain are you about the statements: • Emotion affects our perception of objects. • Anger causes people to perceive an object as a gun even if it is not a gun. • What conditions might affect our level of certainty?

  18. Internal validity • The degree to which causality can be inferred from a study • Is the independent variable producing the changes in the dependent variable? • Anger (IV) [influences perceptual categorization and] causes people to misidentify (DV) neutral objects as guns

  19. Indications that Baumann & DeStento’s findings are valid • Random assignment of participants to groups • Writing about an angry event; writing about a happy event; writing about a normal day (control) • Participants thought the experiment was about memory, not perception • Two checks regarding specific emotions: • Emotion apparent in written piece (checked by one researcher) • Participants self-reported on a 7-point scale questionnaire about how they were feeling to see if the writing task caused participants to select related feelings of anger, happiness, etc. • All tasks corresponded within groups AND significantly differed from the emotions reported in other groups

  20. Indications that Baumann & DeStento’s findings are valid • The outcome variable (accuracy calculation of object identification) was assessed after the experimental task. • The order is important. Emotion manipulation first, then the computerized task of object identification makes the statement “emotion affects perception of object” more valid.

  21. Generalizability (aka External Validity) • You tell me, are the results generalizable to a larger population? • It is difficult to say to whom the result could be generalized to since we don’t have the demographics of the sample used • The results were transferable to later studies, which counts for something in the research world • It was a sample of convenience…in fact, it was, in part, a course requirement to participate in research study • Common practice, but might it affect results? Ideally, researchers need a sample of a given population where participants are chosen by chance • Can the results be generalized into an interaction on State St. • No, but they can support a concept and build a foundation for future studies to explore this further

  22. So what do you think? • What does our critical examination of the research mean? • How does this study make you feel? • What did it make you think? • What do you want to know? • What are your hypotheses? Really Very Good

  23. Research as a tool for Social Justice

  24. References Baumann, J. & DeSteno, D. (2010). Emotion guided threat detection: Expecting guns where there are none. Journal of Personality and Social Psychology, 99 (4), 595-610. Myers, D. (2014). Exploring psychology in modules (9th ed.). New York, Worth Publishers. Sanders, L. D. ((2010). Discovering research method in psychology. West Sussex, BPS Blackwell. Verdugo, E. (1998). Practical problems in research methods: A casebook with questions for discussion. Los Angeles, Pyrczak Publishing

  25. References [Untitled illustration of closure]. Retrieved February 17, 2014 from http://brianlande.com/category/culture/ [Untitled illustration of ear]. Retrieved February 17, 2014 from http://www.dizziness-and-balance.com/disorders/bppv/otoliths.html [Untitled illustration of brain]. Retrieved February 17, 2014 from http://www.ikono.org/category/optical-illusions/ [Untitled illustration of figureground]. Retrieved February 17, 2014 from http://www.next.cc/journey/language/figure-ground [Untitled illustration of depth perception ]. Retrieved February 17, 2014 from http://people.eecs.ku.edu/~miller/Stereo/Section_01/Page_0010.php [Untitled illustration of a spotted dog ]. Retrieved February 17, 2014 from http://downwiththekids.62stockton.com

  26. References [Untitled illustration of eye beautiful ]. Retrieved February 17, 2014 from http://www.atelier.net/en/trends/articles/ [Untitled illustration of checkerboard ]. Retrieved February 17, 2014 from http://ocw.mit.edu/courses/brain-and-cognitive-sciences/9-35-sensation-and-perception-spring-2009/ [Untitled illustration of glass half full ]. Retrieved February 17, 2014 from http://www.healthcare-informatics.com/blogs/ mark-hagland/getting-glass-half-full-perspective-healthcare-it [Untitled illustration of sound wave]. Retrieved February 17, 2014 from http://www.kinoko.us/2013/08 [Untitled illustration of absolute threshold ]. Retrieved February 17, 2014 adapted from http://www1.appstate.edu/~kms/classes/psy3215/Measure/absolute.htm [Untitled illustration of senses]. Retrieved February 17, 2014 from http://www.gvsu.edu [Untitled illustration of eye]. Retrieved February 17, 2014 from http://www.iblindness.org/images/eye-diagram.jpg [Untitled illustration of spotted dog grouping]. Retrieved February 17, 2014 from http://www.blinn.edu/socialscience/LDThomas/MyNotes/08Perception%20&%20Gestalt%20Psychology.htm Happy http://powertochange.com/wp-content/uploads/2011/01/happyperson.jpg Angry baby http://powertochange.com/wp-content/uploads/2011/01/happyperson.jpg Neutal face http://dericbownds.net/uploaded_images/w_unsexy.jpg Chess Pieces http://mesosyn.com/mental8-8q.jpg

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