PSYC 001 Chapter 5: Sensory and Perception Flashcards
<p>What is sensation?</p>
<p>The detection of physical stimuli and transmission of that information to the brain. Physical stimuli can be light or sound waves, molecules of food or odor, or temperature and pressure changes. Sensation does not involve interpretation of what we are experiencing.</p>
<p>What is perception?</p>
<p>The brain's further processing, organization and interpretation of sensory information. Perception results in our conscious experience of the world. Essence of perception is the construction of useful/meaningful information about a sensation.</p>
<p>Steps from Sensation to Perception</p>
<p>Stimulus --> Sensation --> Sensory Coding --> Perception</p>
<p>What is this an example of? A green light emits physical properties in the form of photons (light waves).</p>
<p>Stimulus</p>
<p>What is this an example of? Sensory receptors in the driver's eyes detect this stimulus,</p>
<p>Sensation</p>
<p>What is this an example of? The stimulus is transduced (translated into chemical and electrical signals that are transmitted to the brain)</p>
<p>Sensory Coding</p>
<p>What is this an example of? The driver's brain processes the neutral signals and constructs a representation of a green light ahead. The brain interprets the representation of the light as a sign to continue driving.</p>
<p>Perception</p>
<p>What is bottom up processing?</p>
<p>Perception based on the physical features of the stimulus.</p>
<p>What is this an example of? You recognize a grapefruit squirt based on your experience of the strong scent, cool moisture, and sharp taste.</p>
<p>Bottom up processing</p>
<p>What is top down processing?</p>
<p>How knowledge, expectations, or past experiences shape the interpretation of sensory information.</p>
<p>What is this an example of? We are unlikely to see a blue, apple-shaped object as a real apple because we know from past experience that apples are not blue.</p>
<p>Top-down processing</p>
<p>What is this an example of? Your perception depends on which interpretation makes sense in the context ofthe particular word (higher level). e.g. Y0U C4N R3AD TH15 W3LL</p>
<p>Top-down processing</p>
<p>What is sensory coding?</p>
<p>Our sensory systems translate the physical properties of stimuli into patterns of neural impulses.</p>
<p>List the stimuli, receptors and pathways for the following sense: Vision</p>
<p>Stimuli: Light wavesReceptors: Light-sensitive rods and cones in retina of eye.Pathway to brain: Optic nerve</p>
<p>List the stimuli, receptors and pathways for the following sense: Hearing</p>
<p>Stimuli: Sound wavesReceptors: pressure sensitive hair cells in cochlea of inner earPathways to brain: Auditory nerve</p>
<p>List the stimuli, receptors and pathways for the following sense: Taste</p>
<p>Stimuli: Molecules dissolved in fluid on the tongueReceptors: cells in taste buds on the tonguePathways to brain: Portions of (1) facial (2) glossopharyngeal, and (3) vagus nerves</p>
<p>List the stimuli, receptors and pathways for the following sense: Smell</p>
<p>Stimuli: Molecules dissolved in fluid on membranes in the noseReceptors: Sensitive ends of olfactory mucous neurons in the mucous membranesPathways to brain: Olfactory nerve</p>
<p>List the stimuli, receptors and pathways for the following sense: Touch</p>
<p>Stimulus: Pressure on the skinReceptors: Sensitive ends of touch neurons in skinPathways to brain: Cranial nerves for touch above the neck, spinal nerves for touch elsewhere.</p>
<p>What is the typical pathway of sensory information after it has been transmitted?</p>
<p>Thalamus (middle of brain) to Cerebral cortex (where it is interpreted)</p>
<p>What two types of information does the brain need to function effectively when interpreting a stimulus?</p>
<p>Qualitative and Quantitative</p>
<p>What is the absolute threshold?</p>
<p>The minimum intensity of stimulation that must occur before you experience a sensation.</p>
<p>What is the difference threshold?</p>
<p>The minimum amount of change required for a person to detect a difference between two stimuli.</p>
<p>How do sensory receptors respond to qualitative differences?</p>
<p>They fire in different combinations.</p>
<p>How do sensory receptors respond to quantitative differences?</p>
<p>They fire at different rates.</p>
<p>What is the subfield that examines our psychological experiences of physical stimuli called?</p>
<p>Psychophysics</p>
<p>Who were the researchers who pioneered psychophysics?</p>
<p>Ernst Webet and Gustav Fechner</p>
<p>What is the absolute sensory threshold for taste?</p>
<p>1 teaspoon of sugar in 2 gallons of water.</p>
<p>What is the absolute sensory threshold for smell?</p>
<p>1 drop of perfume diffused into the entire volume of six rooms.</p>
<p>What is the absolute sensory threshold for touch?</p>
<p>A fly's wing falling on your cheek from a distance of 0.04 inches.</p>
<p>What is the absolute sensory threshold for hearing?</p>
<p>The tick of a clock at 20 feet under quiet conditions.</p>
<p>What is the absolute sensory threshold for vision?</p>
<p>A candle flame seen at 30 miles on a dark, clear night.</p>
<p>What is Weber's Law?</p>
<p>The just noticeable difference between two stimuli is based on a proportion of the original stimulus rather than on a fixed amount of difference.</p>
<p>What is signal detection theory? (long definition)</p>
<p>This theory states that detecting a stimulus is not an objective process. Detecting a stimulus is instead a subjective decision with two components: (1) sensitivity to the stimulus in the presence ofdistractions from other stimuli, and (2) the criteria used to make the judgment from ambiguous information</p>
<p>Draw the signal detection theory matrix (hint: 2x2)</p>
<p>Stimulus Signal On/Off AND Response Given Yes/NoOn, Yes = HitOn, No = MissOff, Yes = False alarmOff, No = Correct Rejection</p>
<p>How is a participant's sensitivity to the signal computed?</p>
<p>A formula comparing the hit rate with the false alarm rate. This corrects for any bias the person brings into the testing situation.</p>
<p>What type of person is someone who experiences many false alarms?</p>
<p>"yea-sayer"</p>
<p>What type of person is someone who is biased towards denying that a signal occurred?</p>
<p>"nea-sayer"</p>
<p>Describe the method of a research study on signal detection.</p>
<p>Any research study on signal detection involves a series of trials in which a stimulus is presented in only some trials. In each trial, the participant must state whether heor she sensed the stimulus. A trial of this kind, in which a participant judges whether an event occurs, can have one of four outcomes: hit, miss, false alarm and correct rejection.</p>
<p>What is a response bias?</p>
<p>a participant’s tendency to report detecting the signal in an ambiguous trial. The participant might be strongly biased against responding and need a great deal of evidence that the signal is present. Under other conditions, that same participant might need only a small amount of evidence.</p>
<p>What is signal detection theory? (short definition)</p>
<p>A theory of perception based on the idea that the detection of a stimulus requires a judgment—it is not an all- or nothing process.</p>
<p>What is sensory adaptation?</p>
<p>A decrease in sensitivity to a constant level of stimulation. (e.g. the start or stop of the stimulus is noticeable but you get used to the constant noise).</p>
<p>What is synesthesia?</p>
<p>the experience of one sensory stimulus producing an unrelated perception. Cross sensory experiences (1 in 2000 to 1 in 200)</p>
<p>What is this an example of? When Bill drives the sight of road signs taste gross.</p>
<p>Synesthesia</p>
<p>List the primary sensory areas and their location on the brain (four lobes, five senses)</p>
<p>(1) Frontal lobe: Smell, Taste(2) Parietal lobe (top right): Touch(3) Occipital lobe (bottom right): Vision(4) Temporal lobe (bottom of brain): Hearing</p>
<p>Where does visual information travel in the "what" stream from the occipital lobe?</p>
<p>To the temporal lobe</p>
<p>Where does visual information travel in the "where" stream from the occipital lobe?</p>
<p>To the parietal lobe</p>
<p>Transduction is the process of:</p>
<ul> <li>(a) detecting envrionmental energy through a sense organ</li> <li>(b) converting sensory stimuli into neural activity</li> <li>(c) converting perceptions into neural activity</li> <li>(d) perceiving information</li></ul>
<p>b</p>
What is the cornea?
Thick, transparent outer layer which focuses light
What happens after the light enters the lens?
It is bent further inwards and focused to form an image on the retina.
Is the lens adjustable?
Yes
Which focuses more light, the cornea or the lens?
The cornea
What is presbyopia?
As people get older, the lens hardens and it becomes more difficult to focus on close images.
What is the retina?
The thin inner surface on the back of the eyeball – it’s the only part of the brain visible outside of the skull.
It is a part of the central nervous system.
What are rods?
Retinal cells that respond to low levels
of light and result in black-and-white
perception.