Sensory Processing and Perception

Continuity

A Gestalt principle that suggests that when we see visual information arranged in a continuous row or line, such as a row of football players, we will perceive the footballers as a "line" instead of individual people.

Correct rejection

A correct rejection involves a person correctly realizing that a stimulus is NOT present. Therefore, a correct rejection would occur if a sensory receptor was NOT activated and the person realizes that this means there was no stimulus, correctly rejecting any signal.

Bottom-up approach

A data-driven approach where statistical techniques are used to produce predictions about the likely characteristics of an offender.

Proprioreceptor

A receptor that responds to changes in body position, such as stretch on a tendon, or contraction of a muscle. These receptor allow us to be consciously aware of the position of our body parts.

A man is watching the sunset from his garden, when a wasp unexpectedly stings him. What information will an activated nociceptor send to the CNS? Select all that apply. A. The extent of mechanical damage to the skin B. How badly the sting hurts C. The location of the sting D. The "type" of stimulus which interacted with the skin

A, C, and D

Sensory adaptation describes how sensory receptors adapt to the presence of certain stimuli. Which of the following descriptions of sensory adaptation are correct? Select all that apply. A. On a cellular level, sensory adaptation would be a greater number of action potentials produced from the same intensity of stimulus. B. If Homa was searching for her friend Anne in a crowd, sensory adaptation would cause her to experience more incorrect rejections. C. Mark is demonstrating adaptation when he slowly begins to tune-out his roommate's distracting music. D. Sensory adaptation would increase the absolute threshold of sensation of a sensory receptor.

B, C, and D

Lauren is a nurse working in an ICU. One day, another nurse forgets to take out the trash and the ICU begins to smell. By the end of the day, Lauren no longer smells the trash. Which of the following concepts best explains why Lauren no longer smells the trash? A. Sensitization B. Adaptation C. Dishabituation D. Correct rejection

B. adaptation

Would a witness in court be more reliable using the "top-down" approach or "bottom-up" approach?

Bottom-up approach Top-down approaches to eye-witness testimony are more likely to cause erroneous false recall of information. A top-down approach to recall would be depicted as a witness who 'decides' the big picture events which they believe transpired and then colors them with data from memories. A bottom-up approach to witness testimony would be depicted by a witness who only presents evidence or memories that are based on data. Therefore, a bottom-up approach would make for a better witness testimony.

Leonard is in a room all by himself. At noon, the temperature in the room is 50 degrees Fahrenheit. The temperature slowly increases to 58 degrees, at which point Leonard notices that the room has warmed up substantially. He turns on the AC. At what temperature will he have noticed that the room has cooled down? A. 51 degrees B. 50 degrees C. 49 degrees D. 55 degrees

C. 49 degrees In this example, the temperature changed by 8 degrees, or 16%, before Leonard noticed. That means that the just-noticeable difference is always going to be a 16% change in temperature. When the temperature is 58 degrees, the room will need to drop in temperature by 16%, or 9.3 degrees before Leonard notices: 58 degrees x 0.16 = 9.3 degrees 58 - 9.3 = 48.7, which is closest to choice C.

An ICU nurse accidentally loses her way in the hospital and has to rely on clues in the environment to find a way out. This demonstrates: A. Sensory adaptation B. Decreased absolute threshold C. Bottom-up processing D. Context effects

C. Bottom-up processing

Gestalt closure principle

Closure suggests that when we see only a small part of an image, our brain can finish filling in the rest of the image.

Closure

Closure suggests that when we see only a small part of an image, our brain can finish filling in the rest of the image. In the example of a face, we have prior models about what a prototypical face looks like, and after having received some information about how part of a face looks (e.g. the eyes and nose) we can fill in where the rest of the details are in the image (e.g. we can imagine the mouth and ears).

John is a weightlifter doing bicep curls at the gym. He loads up 40 lbs on his barbell and curls a few reps. He adds extra pounds to his barbell, but notices they don't feel any heavier until 50 lbs. If he reduces the weight, at what weight will he notice the barbell feels lighter? A. 45 lbs B. 40 lbs C. 42.5 lbs D. 37.5 lbs

D. 37.5 lbs Weber's law suggests that the just-noticeable difference (difference to notice a stimulus change 50% of the time) for a change in stimulus intensity is a constant proportion of the original stimulus. John notices the weight has increased after it gets 25% heavier (in this case, 10 lbs added to the initial 40 lbs). Therefore, he will only notice the weight has decreased when it gets 25% lighter. 25% of 50 is 12.5; therefore, he will notice the weight has lightened when it reaches 37.5 pounds.

Which of these does NOT accurately depict signal detection theory? A. A person in a heightened state of physiological arousal is more likely to experience false alarms B. A person who is sleepy is more likely to experience correct rejections C. A person in a heightened state of physiological arousal is more likely to experience correct detections D. A person in a heightened state of physiological arousal is likely to experience more "misses"

D. A person in a heightened state of physiological arousal is likely to experience more "misses"

Which type of receptor detects the shape of a particular molecule? A. Photoreceptor B. Mechanoreceptor C. Proprioreceptor D. Chemoreceptor

D. Chemoreceptor Sensory receptors are specialized structures for detecting stimuli and converting them into information that can be interpreted by our body. The type of stimuli that a receptor can detect is determined by the structure of the receptor and whether or not its structure will be altered into an "active state" after interacting with a stimulus. A chemoreceptor has an active site that perfectly fits and binds to a particular ligand molecule.

All of the following are monocular visual cues EXCEPT: A. Relative object heigh in a plane B. Object size C. Object shape D. Retinal disparity

D. retinal disparity

True or false: A receptor's absolute threshold of sensation was achieved if the outcome of signal detection was a "correct rejection".

False A correct rejection involves a person correctly realizing that a stimulus is NOT present. Therefore, a correct rejection would occur if a sensory receptor was NOT activated and the person realizes that this means there was no stimulus, correctly rejecting any signal.

True or false: Linda can detect when a smell becomes 10% more smelly. Weber's law predicts that any time any smell changes in intensity by 10%, Linda will detect it half of the time.

False Although this answer choice almost describes Weber's law accurately, it misses one key detail. Weber's law breaks down at the extremes of sensory detection. Linda's nose will likely not be able to detect a change in smell intensity if a smell was originally extremely smelly (near the limits of smelliness) or not very smelly at all. Weber's law holds up only in moderate ranges of sensory intensity.

True or false: A person will detect a stimulus 100% of the time once the level of intensity of that stimulus passes the absolute threshold.

False The absolute threshold is the level of intensity that a stimulus must have in order to stimulate sensory neurons. In practical terms, scientists consider the absolute threshold as the lowest level of a stimulus that can be detected by a person 50% of the time.

True or false: Signal detection theory presupposes that the range of intensities for which we detect a signal in our environment are constant.

False The context in which we are attempting to detect a signal can increase or decrease the signal intensity required for us to notice the signal. For example, if you are incredibly focused on driving your car you might notice road hazards even if they present at a relatively low intensity. However, if you are sleepily driving your car, then a road hazard may need to present itself at a much higher intensity for your brain to correctly detect it and produce a "hit".

True or false: Mechanoreceptors detect mechanical stimuli while proprioceptors and baroreceptors do not.

False This statement is false. Mechanoreceptors detect mechanical stimuli, while proprioceptors and baroreceptors are subtypes of mechanoreceptors that detect specific kinds of mechanical stimuli.

False alarm

If a stimulus was not present thus not activating a sensory receptor, but a person believed they had detected the stimulus, this would lead to a false alarm.

Hit

If a stimulus was present and it had an intensity above the absolute threshold of sensation, it would activate a sensory receptor and lead to a hit, meaning the person correctly realizes a signal is present.

Miss

If a stimulus was present but had an intensity below the absolute threshold, it would not activate a sensory receptor and lead to a miss, failing to detect a signal.

True or false: Interoceptors detect proximal stimuli, while exteroceptors detect distal stimuli.

Interoceptors are sensory receptors which detect stimuli inside of your body (e.g. muscle stretch detected by a propriocepter), while exteroceptors are sensory receptors which detect stimuli from outside of your body (e.g. light).

Monocular view

Object shape is a characteristic of an object which is detectable via one (either) eye

Perception

Our interpretation of the signals

Sensation

Physical signals picked up by our sensory organs and processed by the CNS

Gestalt's pragnanz principle

Pragnanz suggests that when we see an image with lots of complex details, we simplify it to the smallest and simplest image possible. For example, seeing the Olympic logo instead of 5 individual rings.

Pragnanz

Pragnanz suggests that when we see an image with lots of complex details, we simplify it to the smallest and simplest image possible. For example, seeing the Olympic logo instead of 5 individual rings.

Proximity

Proximity suggests that objects which are closer together in our visual field are perceived as together, sometimes even perceived as the same object or belonging to a greater whole.

Sensory adaptation

Sensory adaptation suggests that when we overstimulate a receptor it becomes less responsive to further stimulation. A photoreceptor for grey might become overstimulated by the background grey color and become less responsive when attempting to "count" the individual grey boxes.

Signal detection theory

Signal detection theory suggests that the combined effects of perceptual processing and sensory detection can cause us to correctly or incorrectly detect stimuli in the environment. Ex: If signal detection processes went awry, someone might incorrectly reject the detection of white boxes, causing them to count fewer than they normally would. They may also have incorrectly counted extra black boxes, because of a "false alarm" detection.

Top-down approach

Start with the largest items of the project and break them down

Psychophysical testing

Testing whether or not a person can tell the difference in stimulus intensity (detecting the just noticeable difference in stimulus intensity) is an example of psychophysical testing.

Visual context

The context of a situation can cause us to misinterpret the sensory data which we have collected. Several factors involved in visual context (shape and background coloration, shape orientation, relative location of shapes, past knowledge and expectations) can cause us to incorrectly see what is right in front of us.

Gestalts law of proximity

The law of proximity suggests that when objects in an image are closer together than other objects in the image, our brain sees them as related objects.

True or false: Object shape is a monocular visual cue.

True

True or false: We use binocular visual cues to create a single "perceived" image out of two "detected" images.

True

A flexible battle plan is analogous to a top-down model/schema/outline, which is then adapted with information as needed.

True!

Scientists put Anna in a room and showed her cards covered in red dots. Each card had a slightly different shade of red coloring the dots. The scientists determined the change in color intensity Anna could differentiate between 50% of the time. What is the name for this sort of testing? A. Psychophysical discrimination testing B. Weber's Law C. Signal detection testing D. Color association testing

A. Psychophysical discrimination testing Testing whether or not a person can tell the difference in stimulus intensity (detecting the just noticeable difference in stimulus intensity) is an example of psychophysical testing. Why not the others? None of the other are forms of testing

Olfactory receptors in the nose are what kind of receptors

chemoreceptors

Binocular view

cues which require two eyes to gather, including retinal disparity and object convergence.

Hair cells in the ears which are involved in hearing are what kind of receptors

mechanoreceptors

Proprioceptors in the muscles are what kind of receptors

mechanoreceptors

Cells in the retina are what kind of receptors

photoreceptors

What is sensitization?

the process by which our receptors increase their response to a given stimuli

What is dishabituation?

the process by which we resensitize ourselves to stimuli which we have become adapted or habituated to.