Psych 289 - Chapter 4 - Sensation and
Perception UPDATED ACTUAL Questions
and CORRECT Answers
Sensation - CORRECT ANSWER The stimulation of sense organs.
Perception - CORRECT ANSWER The selection, organization, and interpretation of sensory input
Psychophysics - CORRECT ANSWER The study of how physical stimuli are translated into
psychological experience.
Threshold - CORRECT ANSWER A dividing point between energy levels that do and do not have
a detectable effect.
Absolute threshold - CORRECT ANSWER The minimum amount of stimulation that an organism
can detect for a specific type of sensory input.
Stimulus intensity detected 50% of the time.
Just Noticeable Difference (JND) - CORRECT ANSWER The smallest difference in the amount of
stimulation that a specific sense can detect.
Weber's Law - CORRECT ANSWER The theory stating that the size of a just noticeable difference
is a constant proportion of the size of the initial stimulus.
Fechner's law - CORRECT ANSWER A psychophysical law stating that larger and larger increases
in stimulus intensity are required to produce perceptible increments in the magnitude of sensation.
Signal-detection Theory - CORRECT ANSWER A psychophysiological theory proposing that the
detection of stimuli involves decision processes as well as sensory processes, which are influenced by a
variety of factors besides the physical intensity of a stimulus.
,ie: perceiving hits, misses, false alarms, or correct rejections. This theory attempts to account for the
influence of decision-making processes on stimulus detection.
Hits - CORRECT ANSWER Detecting signals when they are present
Misses - CORRECT ANSWER Failing to detect signals when they are present
False Alarms - CORRECT ANSWER Detecting signals when they are not present
Correction Rejection - CORRECT ANSWER Not detecting signals when they are absent
Subliminal Perception - CORRECT ANSWER The registration of sensory input without conscious
awareness.
ie: imperceptible messages in magazines or in commercials.
Sensory Adaptation - CORRECT ANSWER A gradual decline in sensitivity to prolonged
stimulation. (You stop smelling garbage odour as you get used to it.)
Is automatic, keeps you tuned to changes in sensory input rather than constant.
Light - CORRECT ANSWER Three properties:
Wavelength, amplitude, and purity.
Wavelength affects perceptions of colour/hue.
Amplitude: brightness
Purity: saturation
, Visible Spectrum - CORRECT ANSWER A slim portion of the total range of wavelengths; vision
is a filter
-other animals have different capabilities, such as seeing ultraviolet spectrum or the infrared spectrum
Amplitude - CORRECT ANSWER Perceived in loudness.
Measured in dB.
Principal determinant of loudness, but loudness ultimately depends on an interaction between amplitude
and frequency.
Wavelength - CORRECT ANSWER Described in terms of frequency (Hz)
(Frequency determines psychological perception of pitch)
Purity of Colour - CORRECT ANSWER Influences perfection of the saturation or richness of
colours
Lens - CORRECT ANSWER The transparent eye structure that focuses the light rays falling on the
retina.
Made up of soft tissue, capable of adjustments that facilitate "accommodation." (Curvature of lens adjusts
to alter visual focus.)
Pupil - CORRECT ANSWER The opening in the centre of the iris that helps regulate the amount of
light passing into the rear chamber of the eye.
Retina - CORRECT ANSWER The neural tissue lining the inside back surface of the eye; it
absorbs light, processes images, and sends visual information to the brain.
Contains complex network of specialized cells.
Optic disk - CORRECT ANSWER A hole in the retina where the optic nerve fibres exit the eye.
Perception UPDATED ACTUAL Questions
and CORRECT Answers
Sensation - CORRECT ANSWER The stimulation of sense organs.
Perception - CORRECT ANSWER The selection, organization, and interpretation of sensory input
Psychophysics - CORRECT ANSWER The study of how physical stimuli are translated into
psychological experience.
Threshold - CORRECT ANSWER A dividing point between energy levels that do and do not have
a detectable effect.
Absolute threshold - CORRECT ANSWER The minimum amount of stimulation that an organism
can detect for a specific type of sensory input.
Stimulus intensity detected 50% of the time.
Just Noticeable Difference (JND) - CORRECT ANSWER The smallest difference in the amount of
stimulation that a specific sense can detect.
Weber's Law - CORRECT ANSWER The theory stating that the size of a just noticeable difference
is a constant proportion of the size of the initial stimulus.
Fechner's law - CORRECT ANSWER A psychophysical law stating that larger and larger increases
in stimulus intensity are required to produce perceptible increments in the magnitude of sensation.
Signal-detection Theory - CORRECT ANSWER A psychophysiological theory proposing that the
detection of stimuli involves decision processes as well as sensory processes, which are influenced by a
variety of factors besides the physical intensity of a stimulus.
,ie: perceiving hits, misses, false alarms, or correct rejections. This theory attempts to account for the
influence of decision-making processes on stimulus detection.
Hits - CORRECT ANSWER Detecting signals when they are present
Misses - CORRECT ANSWER Failing to detect signals when they are present
False Alarms - CORRECT ANSWER Detecting signals when they are not present
Correction Rejection - CORRECT ANSWER Not detecting signals when they are absent
Subliminal Perception - CORRECT ANSWER The registration of sensory input without conscious
awareness.
ie: imperceptible messages in magazines or in commercials.
Sensory Adaptation - CORRECT ANSWER A gradual decline in sensitivity to prolonged
stimulation. (You stop smelling garbage odour as you get used to it.)
Is automatic, keeps you tuned to changes in sensory input rather than constant.
Light - CORRECT ANSWER Three properties:
Wavelength, amplitude, and purity.
Wavelength affects perceptions of colour/hue.
Amplitude: brightness
Purity: saturation
, Visible Spectrum - CORRECT ANSWER A slim portion of the total range of wavelengths; vision
is a filter
-other animals have different capabilities, such as seeing ultraviolet spectrum or the infrared spectrum
Amplitude - CORRECT ANSWER Perceived in loudness.
Measured in dB.
Principal determinant of loudness, but loudness ultimately depends on an interaction between amplitude
and frequency.
Wavelength - CORRECT ANSWER Described in terms of frequency (Hz)
(Frequency determines psychological perception of pitch)
Purity of Colour - CORRECT ANSWER Influences perfection of the saturation or richness of
colours
Lens - CORRECT ANSWER The transparent eye structure that focuses the light rays falling on the
retina.
Made up of soft tissue, capable of adjustments that facilitate "accommodation." (Curvature of lens adjusts
to alter visual focus.)
Pupil - CORRECT ANSWER The opening in the centre of the iris that helps regulate the amount of
light passing into the rear chamber of the eye.
Retina - CORRECT ANSWER The neural tissue lining the inside back surface of the eye; it
absorbs light, processes images, and sends visual information to the brain.
Contains complex network of specialized cells.
Optic disk - CORRECT ANSWER A hole in the retina where the optic nerve fibres exit the eye.
