Psychology Quiz: Sensory System Properties
20 questions · exam conditions
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Sensory System PropertiesQuestion 1 of 20

A faint tone is detected on 3 of 6 trials. Its intensity is:

Above the absolute threshold
At the absolute threshold
Below the absolute threshold
A subliminal tone intensity
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Psychology Quiz

Psychology Quiz: Sensory System Properties

Practice Sensory System Properties in Psychology with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Sensory System Properties, giving you a quick way to practice the rules, question types, and explanations that matter most for Psychology.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A faint tone is detected on 3 of 6 trials. Its intensity is:

  1. Above the absolute threshold
  2. At the absolute threshold (correct answer)
  3. Below the absolute threshold
  4. A subliminal tone intensity
Explanation: Detecting a tone on 3 of 6 trials is 50 percent detection, which defines the absolute threshold: the intensity at which a stimulus is detected half the time. The tempting answer is subliminal tone intensity, but subliminal means below threshold and would be detected less than 50 percent, not exactly half.

Question 2

A 100 g weight just noticeably differs from a 104 g one. What is the Weber fraction?

  1. 0.04 (correct answer)
  2. 0.40
  3. 4.00
  4. 25.00
Explanation: The Weber fraction is the just noticeable difference divided by the original stimulus. The difference is 104 minus 100, which is 4 g, and the original weight is 100 g, so 4 / 100 = 0.04. The tempting error is choosing 4.00 because that is the raw difference in grams, but you must divide by the original weight to get the fraction.

Question 3

What is the immediate result of sensory transduction?

  1. A graded receptor potential (correct answer)
  2. An action potential in a nerve
  3. A change in sensory threshold
  4. An immediate felt sensation
Explanation: Sensory transduction converts a stimulus into a local change in membrane potential, called a graded receptor potential. This happens before any action potential is triggered, since action potentials occur only if the graded potential reaches threshold. The most tempting wrong answer is an action potential in a nerve, but that is a later step, not the immediate result of transduction.

Question 4

A constant smell fades from awareness, but a new smell is noticed. This shows:

  1. Receptors ignore every odor
  2. No transduction for any smell
  3. Threshold rises for all smells
  4. One odor adapts, others remain (correct answer)
Explanation: Sensory adaptation occurs for a constant stimulus, so that particular odor fades from awareness. A new, different odor has not been adapted to, so it is still noticed. The tempting error is thinking thresholds rise for every smell at once, but adaptation is specific to the odor you are exposed to.

Question 5

During dark adaptation, the absolute threshold for light:

  1. Increases as sensitivity rises
  2. Increases as sensitivity falls
  3. Decreases as sensitivity rises (correct answer)
  4. Decreases as sensitivity falls
Explanation: Dark adaptation makes your eyes more sensitive to light, so you need less light to detect a stimulus. The absolute threshold is the minimum light needed, so as sensitivity rises, that minimum falls. A tempting error is thinking threshold and sensitivity move together, but sensitivity rising means threshold dropping, not increasing.

Question 6

A beverage company conducts two taste tests. In Test 1, participants in a quiet room are given a series of drinks and asked to identify the one with the lowest detectable amount of a new artificial sweetener. In Test 2, participants are given a standard sweetened beverage and are then asked to identify which of several other samples has a just noticeably different level of sweetness. These two tests are designed to measure, respectively:

  1. signal detection; sensory adaptation.
  2. difference threshold; absolute threshold.
  3. absolute threshold; difference threshold. (correct answer)
  4. sensory adaptation; absolute threshold.
Explanation: Test 1 is measuring the minimum amount of a stimulus (the sweetener) that can be detected from a baseline of no stimulus, which is the definition of the absolute threshold. Test 2 is measuring the minimum change in a stimulus (sweetness level) that can be detected from a pre-existing stimulus, which is the definition of the difference threshold (or JND).

Question 7

A person spends 30 minutes in a very dark room (dark adaptation). They are then moved to a dimly lit room and asked to distinguish between gray squares of slightly different shades. Compared to a person who had just come from a brightly lit office, the dark-adapted person will have:

  1. a lower absolute threshold and a smaller difference threshold for light. (correct answer)
  2. a higher absolute threshold and a larger difference threshold for light.
  3. a lower absolute threshold but a larger difference threshold for light.
  4. a higher absolute threshold but a smaller difference threshold for light.
Explanation: Dark adaptation increases the sensitivity of the visual system, primarily by regeneration of photopigments in the rods. This increased sensitivity means that 1) a weaker light can be detected, so the absolute threshold is lower, and 2) smaller changes in light intensity can be discriminated, so the difference threshold (JND) is smaller.

Question 8

A neuro-engineer is designing a prosthetic limb that can experience a sense of touch. The device has sensors that can accurately measure pressure and temperature, and it has a direct interface with the somatosensory cortex. However, clinical trials fail, with patients reporting no tactile sensations. The failure is most likely due to an omission of a component that performs which of the following processes?

  1. Accommodation
  2. Adaptation
  3. Transmission
  4. Transduction (correct answer)
Explanation: Transduction is the critical process of converting stimulus energy (like pressure or heat) into neural impulses that the brain can understand. The device can measure the physical properties but lacks the mechanism to convert that physical data into the electrochemical language of the nervous system, which is why the brain cannot perceive it.

Question 9

An individual moves into an apartment next to a hospital and is initially bothered by the frequent sound of sirens. After a few weeks, they no longer have a strong emotional or attentional reaction to the sound. This change is best described as habituation. How would this differ from sensory adaptation to the sound?

  1. Sensory adaptation would involve the hair cells in the cochlea becoming less sensitive to the specific frequency of the siren. (correct answer)
  2. Habituation is a permanent change in hearing, whereas sensory adaptation is temporary and resets each day.
  3. Sensory adaptation would only occur if the siren sound were continuous and unchanging, not intermittent.
  4. Habituation involves a shift in the absolute threshold for hearing, while adaptation affects the difference threshold.
Explanation: The key distinction is physiological versus cognitive. Sensory adaptation is a 'bottom-up' process involving a change in the responsiveness of the sensory receptors themselves. Habituation is a 'top-down' form of learning where the brain learns to ignore a repeated, unimportant stimulus. Choice A correctly identifies the physiological change at the receptor level (hair cells) that would characterize sensory adaptation.

Question 10

When entering a room with a strong air freshener, the scent is immediately noticeable. After 10 minutes, the scent seems to have faded significantly, even though the concentration of odorant molecules in the air is unchanged. This occurs because the olfactory receptors have:

  1. transduced the chemical signal into a different neural code that the brain interprets as less intense.
  2. sent signals that are progressively inhibited by the thalamus before reaching the cortex.
  3. decreased their rate of firing in response to the continuous stimulation from the odorant molecules. (correct answer)
  4. exhausted their supply of neurotransmitters, preventing any further signaling until the stimulus is removed.
Explanation: This is a classic example of sensory adaptation. The direct physiological mechanism is that the sensory receptors, when exposed to a constant and unchanging stimulus, reduce their firing rate over time. This leads to a decrease in perceived intensity. Choice B is a plausible distractor, but olfaction largely bypasses the thalamus, and the primary change is at the receptor level.

Question 11

In a signal detection task, a participant initially demonstrates a conservative response bias, resulting in a low number of hits but also a very low number of false alarms. If the experimenter successfully modifies the participant's strategy to be more liberal, which outcome is expected?

  1. A decrease in misses and a decrease in correct rejections. (correct answer)
  2. An increase in hits and an increase in correct rejections.
  3. A simultaneous increase in sensory sensitivity (d') and the response criterion.
  4. A simultaneous decrease in misses and false alarms.
Explanation: A conservative bias means the participant is reluctant to say 'signal present', leading to few hits and few false alarms, but many misses and many correct rejections. Shifting to a liberal bias means they say 'signal present' more often. This will increase hits (reducing misses) but will also increase false alarms (reducing correct rejections).

Question 12

Which of the following statements best articulates the fundamental role of transduction in the broader process of perception?

  1. Transduction is the final stage of perception where sensory information is consciously experienced.
  2. Transduction serves as the translation step, converting external physical energy into the internal neural language used for perception. (correct answer)
  3. Perception and transduction are parallel processes, with perception handling cognitive interpretation and transduction handling physical detection.
  4. Effective transduction is sufficient for accurate perception, regardless of attention or past experience.
Explanation: Perception is the brain's process of interpreting sensory information. For this to happen, the external world's physical energy (light, sound, pressure, chemicals) must first be converted into electrochemical signals that neurons can process. This conversion, or translation, is the specific and essential role of transduction.

Question 13

After wearing a new ring for several days, an individual no longer feels its presence on their finger, unless they consciously think about it. Which of the following provides the best physiological explanation for this change in sensation?

  1. The brain's reticular formation has filtered the constant sensory input, a process known as habituation.
  2. The touch receptors in the skin have reduced their firing rate in response to the continuous, unchanging pressure. (correct answer)
  3. The absolute threshold for pressure on that specific part of the finger has been permanently elevated.
  4. The process of transduction in the relevant mechanoreceptors has ceased entirely for the stimulus of the ring.
Explanation: This scenario describes sensory adaptation, which is a physiological process where sensory receptors become less responsive to a constant, unchanging stimulus. The reduced firing rate of the touch receptors is the direct cause of the diminished sensation. Habituation is a cognitive process of reduced attention, not a physiological change at the receptor level.

Question 14

A chef finds they must add 5 grams of a spice to a 100-gram dish for its flavor to be just noticeably stronger. According to Weber's Law, if the chef prepares a 400-gram version of the same dish, how much of the same spice must be added for the flavor to be just noticeably stronger?

  1. 5 grams
  2. 10 grams
  3. 15 grams
  4. 20 grams (correct answer)
Explanation: Weber's Law states that the just noticeable difference (JND) is a constant proportion (k) of the original stimulus intensity (I). In this case, the proportion is k = 5g / 100g = 0.05. To find the JND for the 400-gram dish, we multiply this constant by the new intensity: JND = 0.05 * 400g = 20g.

Question 15

A new air traffic controller is trained to be extremely cautious, reporting any radar blip that could possibly be an unauthorized aircraft. According to signal detection theory, this cautious response strategy will most likely affect the controller's performance by increasing the number of:

  1. hits and misses.
  2. hits and false alarms. (correct answer)
  3. correct rejections and misses.
  4. correct rejections and false alarms.
Explanation: Adopting a cautious or liberal response criterion (i.e., being more willing to say 'yes, there is a signal') increases the likelihood of detecting true signals (hits). However, it also inevitably increases the likelihood of incorrectly identifying noise as a signal (false alarms). This represents a shift in response bias, not sensory sensitivity.

Question 16

An audiologist determines that a participant's absolute threshold for a specific tone is 10 decibels. Which of the following is the most accurate interpretation of this finding?

  1. The participant is physically incapable of hearing any sound below 10 decibels.
  2. The participant will report hearing the tone on approximately 50% of the trials when it is presented at 10 decibels. (correct answer)
  3. The participant's difference threshold for that tone is also 10 decibels.
  4. Any sound above 10 decibels will be perceived by the participant as being equally and maximally loud.
Explanation: The absolute threshold is defined statistically, not as a fixed, all-or-none point. It is the minimum stimulus intensity that an organism can detect 50% of the time. Therefore, at 10 decibels, the participant's detection of the tone is expected to be at chance level.

Question 17

A food scientist determines that the Weber fraction for the taste of sugar in water is 0.10. If the just noticeable difference (JND) for a new beverage is found to be an addition of 3 grams of sugar, what was the original amount of sugar in the beverage?

  1. 0.3 grams
  2. 3.1 grams
  3. 30 grams (correct answer)
  4. 300 grams
Explanation: Weber's Law is expressed as ΔI = k * I, where ΔI is the JND, k is the Weber fraction, and I is the original stimulus intensity. The problem provides ΔI = 3 grams and k = 0.10. To find the original intensity (I), the formula is rearranged to I = ΔI / k. Therefore, I = 3 grams / 0.10 = 30 grams.

Question 18

A researcher presents light stimuli of varying intensities to a subject and records the percentage of trials on which the subject reports seeing the light. The data show detection rates of 10% at 4 units, 30% at 6 units, 50% at 8 units, and 80% at 10 units. Based on these data, the subject's absolute threshold for this light is:

  1. somewhere between 4 and 6 units.
  2. somewhere between 6 and 8 units.
  3. exactly 8 units. (correct answer)
  4. impossible to determine from the data provided.
Explanation: The absolute threshold is operationally defined as the stimulus intensity that is detected 50% of the time. According to the data provided, the light with an intensity of 8 units was detected on exactly 50% of the trials, making it the absolute threshold.

Question 19

A coffee taster is attempting to determine which of two cups of coffee has a slightly higher concentration of a certain flavor compound. The taster sips from one cup, then the other, repeating until they can reliably identify the stronger cup. This procedure is an attempt to measure a:

  1. difference threshold. (correct answer)
  2. absolute threshold.
  3. level of sensory adaptation.
  4. signal detection bias.
Explanation: The taster is not determining the minimum amount of flavor they can detect from nothing (absolute threshold). Instead, they are trying to find the minimum detectable difference between two already existing stimuli (the two cups of coffee). This is the definition of a difference threshold, or just noticeable difference (JND).

Question 20

In the human ear, the mechanical vibration of the stapes against the oval window causes fluid to move within the cochlea. This fluid movement, in turn, causes the basilar membrane to vibrate, bending hair cells. This bending of hair cells is the critical event for hearing because it is the point at which:

  1. sound waves are amplified to a detectable level.
  2. the process of sensory adaptation begins.
  3. mechanical energy is transduced into a neural signal. (correct answer)
  4. the absolute threshold for a given sound frequency is determined.
Explanation: The entire sequence of events prior to the bending of hair cells involves the transmission and amplification of mechanical energy. The bending of the hair cells is the pivotal moment of transduction, where this mechanical force is converted into an electrical change in the cell's membrane potential, which initiates a neural signal.