Presentation on theme: "Sensation and Perception: How the World Enters the Mind"— Presentation transcript:
1Sensation and Perception: How the World Enters the Mind
2Sensation and Perception The awareness of properties of an object or event when a sensory receptor is stimulatedPerceptionThe act of organizing and interpreting sensory input as signaling a particular object or event
3Illusions When perception does not accurately represent the world Note to instructor: This is a demo and the slide will change with each click.
4PsychophysicsStudy of the relationship between physical events and the corresponding experience of those eventsThresholdsAbsolute thresholdJust-noticeable difference (JND)Weber’s law
5Psychophysics: Detecting Signals Signal detection theoryA “signal” is always embedded in noiseSensitivityThreshold level for distinguishing signal from noiseBiasWillingness to report noticing a stimulusYesNoReported signal?Signal?YesNoHitMissFalsealarmCorrectrejection
6Detecting LightProperties of lightAmplitudeFrequencyWavelength
7Structures of the EyePupilIrisCorneaRetinaFoveaOptic nerve
8Rods and Cones Rods (100-120 million) Cones (5-6 million) Very sensitive to lightOnly register shades of grayNot in foveaCones (5-6 million)Sensitive to particular wavelengthsProduce color visionDenser near fovea
9Visual Processes Transduction Accommodation Dark adaptation Filling in the blanksDo the blind spot demo in Figure 4.6
10Detecting Color Properties of color Hue Saturation Lightness Differing wavelengthsSaturationPurity of input (amount of white that is “mixed in”)LightnessAmplitude of waves
11Color Vision Trichromatic theory Opponent process theory Afterimage Opponent cellsColor blindness
12Seeing Afterimages In the following slide, fix your eyes on the dot in the center of the flag
23Knowing More Than You Can See Top-down processingBottom-up processingPerceptual setB E F RB E F RNote to instructor: This is a demo and the slide will change with each click.
24Faces and Gazes Identifying faces Identifying gaze direction ProsopagnosiaFusiform face areaEvolution-based specific face mechanism?Identifying gaze directionIdentification of direction of gaze may be automaticLooking in that direction is voluntary
25On the next slide, locate the red T Selective AttentionOn the next slide, locate the red T