VCAA Psychology How does sleep affect mental processes and behaviour?
15 sample questions with marking guides and sample answers
Which one of the following is an objective measure that could be used to investigate possible treatments that would reduce sleep disturbances?
electromyograph recording participants' brain wave patterns
video monitor recording the time and duration of participants' awakenings
a questionnaire with a rating scale measuring participants' anxiety about sleep
a sleep diary in which the participants would record how they felt after each night's sleep
Reveal Answer
electromyograph recording participants' brain wave patterns
An electromyograph (EMG) measures muscle activity, not brain wave patterns. An electroencephalograph (EEG) would be the correct instrument for measuring brain waves.
video monitor recording the time and duration of participants' awakenings
A video monitor provides an objective, observable, and quantifiable measure of sleep disturbances by directly recording the exact time and duration of awakenings without relying on participant self-reporting.
a questionnaire with a rating scale measuring participants' anxiety about sleep
A questionnaire relies on self-reporting of personal feelings like anxiety, making it a subjective measure rather than an objective one.
a sleep diary in which the participants would record how they felt after each night's sleep
A sleep diary is a subjective measure because it relies on the participants' personal feelings and self-reported experiences rather than observable, quantifiable data.
Compare and contrast the use of bright light therapy for people with Delayed Sleep Phase Syndrome (DSPS) and people with Advanced Sleep Phase Disorder (ASPD). As part of your answer, explain the biological mechanism that allows bright light therapy to be an effective treatment for both sleep disorders.
Reveal Answer
Bright light therapy (BLT) refers to the timed exposure to intense, bright but safe levels of (usually artificial) light. It’s an effective treatment as the biological mechanism, the suprachiasmatic nucleus (SCN), detects the light and transmits a message to the pineal glands to inhibit the release of melatonin. For people with DSPS, this would be most effective in the morning, as it would inhibit the release of melatonin for the day, making a person feel alert. For people with ASPD, it would be used in the afternoon/evening. This would again inhibit the release of melatonin, allowing a person to have increased feelings of wakefulness and decreased feelings of sleepiness. This essentially aims to reset a person’s sleep–wake cycle through the SCN.
| Descriptor | Marks |
|---|---|
Identifies a similarity in the use of bright light therapy for DSPS and ASPD | 1 |
Identifies a difference in the use of bright light therapy for DSPS and ASPD (DSPS requires morning exposure, ASPD requires afternoon/evening exposure) | 1 |
Explains that bright light is registered by the suprachiasmatic nucleus (SCN) | 1 |
Explains that this leads to a delay in melatonin release | 1 |
Explains that the overall effect is a sleep delay or the promotion of wakefulness | 1 |
Use the following information to answer the question.
Sunil is a young university student who has been experiencing disrupted sleep for several months. After extensive investigation and testing, a sleep therapist diagnosed Sunil with a condition known as nightmare disorder.
This disorder results in Sunil experiencing the same terrifying dream as soon as he enters REM sleep and, as a consequence, waking up five or six times per night.
In comparison to other people his age, Sunil is more likely to experience a higher proportion of which of the following stage(s) of sleep?
REM sleep
NREM stages 1 and 2
NREM stages 3 and 4
both REM and NREM sleep
Reveal Answer
REM sleep
Since Sunil wakes up as soon as he enters REM sleep, he will actually experience a significantly lower proportion of REM sleep compared to others.
NREM stages 1 and 2
Because Sunil wakes up five or six times a night, he must restart the sleep cycle frequently. This results in a higher proportion of time spent in the initial stages of sleep, NREM stages 1 and 2.
NREM stages 3 and 4
Frequent awakenings disrupt the sleep cycle, making it harder to reach and maintain the deeper sleep stages of NREM 3 and 4.
both REM and NREM sleep
While he experiences NREM sleep, his proportion of REM sleep is drastically reduced due to waking up as soon as it begins, so he does not experience a higher proportion of both.
Use the following information to answer the question.
Kahn et al. (2023) conducted an investigation involving 54 women to test whether mothers of infants with sleep difficulties were at an increased risk of poor driving. Participants were classified into three groups.
Group A: mothers of infants with sleep difficulties
Group B: mothers of well-sleeping infants
Group C: women without children
The women completed a questionnaire on their driving performance and sleep behaviours across a seven-day period. Following this, they completed a simulated driving task without any passengers.
Source: Adapted from M Kahn et al., 'Sleepless on the road: Are mothers of infants with insomnia at risk for impaired driving?' Journal of Sleep Research, 2023, https://doi.org/10.1111/jsr.14083 Licensed by CC-BY 4.0 https://creativecommons.org/licences/by/4.0/
Which one of the following results would most likely be found from this study?
Group A demonstrated greater lane deviation and higher maximum speed.
Group A was able to drive best when the simulator featured simple and repetitive roads.
Both Groups A and B showed improved driving ability during shorter trips compared to Group C.
Both Groups A and B showed more caution in their driving and reduced speeds compared to Group C.
Reveal Answer
Group A demonstrated greater lane deviation and higher maximum speed.
Sleep deprivation from caring for an infant with sleep difficulties impairs cognitive and motor functions, leading to poorer driving performance such as greater lane deviation and poorer speed control.
Group A was able to drive best when the simulator featured simple and repetitive roads.
Simple, repetitive roads typically decrease arousal and vigilance, which would worsen the driving performance of sleep-deprived individuals rather than improve it.
Both Groups A and B showed improved driving ability during shorter trips compared to Group C.
Sleep deprivation impairs driving ability, so Group A would likely perform worse, not better, than well-rested women without children (Group C).
Both Groups A and B showed more caution in their driving and reduced speeds compared to Group C.
While drivers might attempt to compensate for fatigue, sleep deprivation generally impairs reaction time and vehicle control, making poor driving outcomes more likely than uniformly cautious behavior.
Which one of the following statements is true regarding the suprachiasmatic nucleus (SCN)?
It is part of the pineal gland.
It uses daylight to reset every 24 hours.
It is part of the sympathetic nervous system.
It operates independently on an ultradian rhythm.
Reveal Answer
It is part of the pineal gland.
The suprachiasmatic nucleus (SCN) is a tiny region located in the hypothalamus, not the pineal gland, although it does send signals to the pineal gland to regulate melatonin production.
It uses daylight to reset every 24 hours.
The SCN serves as the brain's primary biological clock and uses light information received from the retina to entrain or reset its circadian rhythm to a 24-hour cycle.
It is part of the sympathetic nervous system.
The SCN is a structure within the central nervous system (specifically the brain's hypothalamus), not the peripheral sympathetic nervous system.
It operates independently on an ultradian rhythm.
The SCN operates on a circadian rhythm (approximately 24 hours), rather than an ultradian rhythm, which refers to biological cycles that are shorter than 24 hours.
Use the following information to answer the question.
Sleep quality and room temperature are connected. In one study, 10 healthy young adults slept in a temperature-controlled room. Each participant spent the first night of the study sleeping in a room set at 25 °C and the second night set at 29 °C.
Participants were required to record their self-reported sleepiness level before and after each sleep episode on a rating scale from 0 (not sleepy) to 5 (very sleepy). The results are presented in the table below.
| Room temperature (°C) | Average reduction in self-reported sleepiness level |
|---|---|
| 25 | 1.8 |
| 29 | 1.1 |
Room temperature is considered a zeitgeber for sleep as it
operates on a 24-hour circadian rhythm.
is found to impact the rate of cortisol release.
is an external cue that can regulate the body's circadian rhythm.
is controlled by the same autonomic nervous system processes as sleep.
Reveal Answer
operates on a 24-hour circadian rhythm.
A zeitgeber is an external environmental cue that influences the circadian rhythm, rather than an internal biological process that operates on a 24-hour cycle itself.
is found to impact the rate of cortisol release.
While temperature may indirectly affect hormone levels, a zeitgeber is defined by its role as an external cue that synchronizes the circadian rhythm, not specifically by its impact on cortisol release.
is an external cue that can regulate the body's circadian rhythm.
A zeitgeber is defined as an external environmental cue, such as light or temperature, that helps entrain or regulate the body's internal circadian rhythms.
is controlled by the same autonomic nervous system processes as sleep.
Room temperature is an external environmental factor, meaning it is independent of and not controlled by the individual's autonomic nervous system.
Which of the following statements about the sleep-wake cycle is most accurate?
The timing of meals is not related to the regulation of the sleep-wake cycle.
Internal factors have a stronger influence on the sleep-wake cycle than external factors.
Temperature changes are found to have a greater impact on ultradian rhythm patterns than light.
The timing of the sleep-wake cycle can be improved by internal factors but only ever impaired by external factors.
Reveal Answer
The timing of meals is not related to the regulation of the sleep-wake cycle.
The timing of meals acts as an exogenous zeitgeber (external cue) that helps regulate and entrain the sleep-wake cycle.
Internal factors have a stronger influence on the sleep-wake cycle than external factors.
Endogenous pacemakers, such as the suprachiasmatic nucleus, can maintain a roughly 24-hour sleep-wake cycle even in the absence of external cues, demonstrating their primary influence.
Temperature changes are found to have a greater impact on ultradian rhythm patterns than light.
The sleep-wake cycle is a circadian rhythm, not an ultradian rhythm, and light is generally considered the most powerful external cue for regulating it.
The timing of the sleep-wake cycle can be improved by internal factors but only ever impaired by external factors.
External factors, known as exogenous zeitgebers (like sunlight), are crucial for entraining the internal biological clock to the 24-hour environment, thereby improving and maintaining its accuracy.
Which of the following is a characteristic shared by both Delayed Sleep Phase Syndrome (DSPS) and Advanced Sleep Phase Disorder (ASPD)?
Both are equally common with the elderly.
Both result from not receiving enough light early in the morning.
Both feature the presence of long periods of REM sleep early in the sleep episode.
Neither result in any sleep deprivation if the person can sleep at times dictated by their body clock.
Reveal Answer
Both are equally common with the elderly.
ASPD is more common in older adults, whereas DSPS is more frequently seen in adolescents and young adults.
Both result from not receiving enough light early in the morning.
While a lack of morning light can contribute to DSPS, ASPD is typically associated with an early circadian phase and is not caused by a lack of morning light.
Both feature the presence of long periods of REM sleep early in the sleep episode.
Early onset of REM sleep is a characteristic of conditions like narcolepsy or depression, rather than circadian rhythm sleep disorders like DSPS or ASPD.
Neither result in any sleep deprivation if the person can sleep at times dictated by their body clock.
Both DSPS and ASPD are circadian rhythm disorders where the individual's sleep architecture and duration are normal. Sleep deprivation only occurs when they are forced to adhere to conventional societal schedules.
Sleep changes as we age.
Which one of the following statements best describes a noticeable change that occurs?
The time spent sleeping overall increases as we age.
The proportion of time spent in NREM sleep increases as we age.
As we progress over time from infancy to old age, the proportion of time spent in stages 1 and 2 of NREM sleep significantly decreases.
The proportion of time spent in REM sleep significantly decreases from infancy and then remains steady as we continue ageing.
Reveal Answer
The time spent sleeping overall increases as we age.
Total sleep time generally decreases as we age, rather than increasing.
The proportion of time spent in NREM sleep increases as we age.
While the proportion of NREM sleep increases from infancy to childhood, the amount of deep NREM sleep (stages 3 and 4) actually decreases as we reach old age.
As we progress over time from infancy to old age, the proportion of time spent in stages 1 and 2 of NREM sleep significantly decreases.
It is the deep sleep stages (stages 3 and 4) of NREM sleep that significantly decrease with age, not the lighter stages 1 and 2.
The proportion of time spent in REM sleep significantly decreases from infancy and then remains steady as we continue ageing.
Infants spend about 50% of their sleep in REM, which drops to around 20-25% by childhood and remains relatively stable throughout adulthood.
Use the following information to answer the question.
Charini is a 15-year-old who is having trouble staying awake at school. Despite being tired, Charini finds it hard to fall asleep until at least 11 pm.
Charini's sleep is likely to change after several nights of reduced sleep.
According to the restorative theory of sleep, Charini is likely to
move straight from NREM to REM sleep.
spend more time than she usually would in REM sleep.
spend more time than she usually would in NREM sleep.
experience the same REM and NREM sleep cycles as she usually would.
Reveal Answer
move straight from NREM to REM sleep.
While sleep architecture can change after deprivation, individuals typically still progress through the standard NREM stages before entering REM sleep rather than skipping them entirely.
spend more time than she usually would in REM sleep.
According to the restorative theory, REM sleep is essential for mental and cognitive restoration. After several nights of reduced sleep, Charini will likely experience REM rebound, spending a greater proportion of her sleep time in REM sleep to compensate for the loss.
spend more time than she usually would in NREM sleep.
While some deep NREM sleep may be recovered, the most prominent and characteristic compensatory mechanism following general sleep deprivation is an increase in REM sleep (REM rebound).
experience the same REM and NREM sleep cycles as she usually would.
Sleep deprivation alters normal sleep architecture. The body will attempt to compensate for the sleep debt by altering the cycles, specifically by increasing the amount of REM sleep.
Consciousness is
individual and continuously changing.
stored in an individual’s long-term memory.
directly observed through the behaviours of individuals.
objective and can be measured directly using tools such as an electroencephalograph, electromyograph or electro-oculograph.
Reveal Answer
individual and continuously changing.
Consciousness is defined as our subjective awareness of ourselves and our environment, which is unique to each individual and constantly shifting, often described as a "stream of consciousness."
stored in an individual’s long-term memory.
Consciousness refers to current, moment-to-moment awareness, whereas long-term memory is a storage system for past experiences and knowledge, not consciousness itself.
directly observed through the behaviours of individuals.
Consciousness is a subjective, internal experience. While we can infer someone's conscious state from their behavior, we cannot observe their consciousness directly.
objective and can be measured directly using tools such as an electroencephalograph, electromyograph or electro-oculograph.
Consciousness is inherently subjective, not objective. While tools like an EEG can measure physiological correlates of consciousness (like brain waves), they cannot directly measure the subjective experience itself.
Use the following information to answer the question.
Researchers conducted a study to compare the effects of a single night of partial sleep deprivation (less than five hours of sleep) to no sleep deprivation (eight hours of sleep) on participants’ performance in a driving simulator. The results showed that a night of partial sleep deprivation had an impact on behavioural measures of sleepiness.
The results of this study would show that participants with a night of partial sleep deprivation have
increased motor control.
impaired decision-making.
a higher percentage of eye closure.
a decrease in their ability to concentrate.
Reveal Answer
increased motor control.
Sleep deprivation typically decreases motor control, and motor control is not classified as a behavioural measure of sleepiness.
impaired decision-making.
While sleep deprivation does impair decision-making, this is considered a cognitive measure rather than a behavioural measure of sleepiness.
a higher percentage of eye closure.
A higher percentage of eye closure is a direct, observable behavioural measure of sleepiness that would increase following partial sleep deprivation.
a decrease in their ability to concentrate.
A decrease in the ability to concentrate is a cognitive effect of sleep deprivation, not an observable behavioural measure.
Use the following information to answer the question.
A study was conducted on 24 healthy Year 10 students at a local high school. Half of the participants were administered 30 minutes of bright light therapy (BLT) each morning for four weeks. The other half of the participants did not use any BLT throughout the four weeks. After four weeks, participants were then tested on their amount of high-frequency, low-amplitude (beta) brain-wave presence while awake in the early morning using an EEG and a mathematics test performance.
The results are shown below.
| Group | Mean percentage of high-frequency, low-amplitude (beta) brain waves | Mean mathematics test performance (out of 30) |
|---|---|---|
| BLT group | 86.2% | 22.4 |
| No BLT group | 78.5% | 18.5 |
Which explanation best accounts for the results from this study?
BLT can delay sleep onset and increase total sleep time.
BLT reduces melatonin release, thus enhancing neurotransmission throughout the brain.
Melatonin can activate parts of the amygdala that are used in higher-order mathematics problems.
There is a positive relationship between low-frequency brain-wave patterns and higher levels of awareness.
Reveal Answer
BLT can delay sleep onset and increase total sleep time.
Morning bright light therapy is typically used to advance the sleep-wake cycle, not delay sleep onset. Furthermore, increased total sleep time does not directly explain the specific increase in beta brain waves and cognitive performance.
BLT reduces melatonin release, thus enhancing neurotransmission throughout the brain.
Bright light therapy suppresses the release of the sleep-promoting hormone melatonin. This reduction in melatonin increases morning alertness (indicated by higher beta wave activity) and cognitive function (indicated by better math performance).
Melatonin can activate parts of the amygdala that are used in higher-order mathematics problems.
Melatonin promotes sleepiness rather than cognitive activation. Additionally, the amygdala is primarily involved in emotional processing, whereas higher-order mathematics relies more on the prefrontal cortex.
There is a positive relationship between low-frequency brain-wave patterns and higher levels of awareness.
This statement is factually incorrect. High-frequency brain waves (such as beta waves), rather than low-frequency waves (like delta or theta), are associated with higher levels of awareness and active thinking.
Use the following information to answer the question.
Researchers conducted a study to compare the effects of a single night of partial sleep deprivation (less than five hours of sleep) to no sleep deprivation (eight hours of sleep) on participants’ performance in a driving simulator. The results showed that a night of partial sleep deprivation had an impact on behavioural measures of sleepiness.
Researchers want to extend the current study to compare the equivalent effects of one night of full sleep deprivation and blood alcohol concentration (BAC) on mood.
Which one of the following research questions would be most suitable?
How do attention levels compare between individuals with a BAC of 0.05 and those experiencing a night of full sleep deprivation?
How do levels of irritability compare between individuals with a BAC of 0.05 and those experiencing a night of full sleep deprivation?
How does problem-solving ability compare between individuals with a BAC of 0.10 and those experiencing a night of full sleep deprivation?
How do levels of emotional regulation compare between individuals with a BAC of 0.10 and those experiencing a night of full sleep deprivation?
Reveal Answer
How do attention levels compare between individuals with a BAC of 0.05 and those experiencing a night of full sleep deprivation?
A BAC of 0.05 is equivalent to 17 hours of sleep deprivation, not a full night (24 hours). Additionally, attention is a cognitive measure, not a measure of mood.
How do levels of irritability compare between individuals with a BAC of 0.05 and those experiencing a night of full sleep deprivation?
Although irritability is related to mood, a BAC of 0.05 is equivalent to 17 hours of sleep deprivation, not a full night (24 hours) of sleep deprivation.
How does problem-solving ability compare between individuals with a BAC of 0.10 and those experiencing a night of full sleep deprivation?
While a BAC of 0.10 is the correct equivalent for a full night of sleep deprivation, problem-solving ability is a cognitive measure rather than a measure of mood.
How do levels of emotional regulation compare between individuals with a BAC of 0.10 and those experiencing a night of full sleep deprivation?
A BAC of 0.10 is the correct equivalent for a full night (24 hours) of sleep deprivation, and emotional regulation is an appropriate measure of mood.
Use the following information to answer the question.
Researchers conducted an experiment to investigate the influence of the chemical theophylline on the circadian rhythm of rats in dark conditions. Theophylline is found naturally in brewed tea and acts to stimulate central nervous system activity. The study was conducted on 10 rats, which were administered a single theophylline dose (0.5 mg/kg) one hour before they fell asleep, and were then monitored for two days using an electroencephalograph (EEG) with no access to natural or artificial light. Three major states of consciousness were analysed during the 48 hours of observation: waking, NREM sleep and REM sleep.
The study monitored the rats for two days using an EEG.
Which of the following is a likely observation from the study?
Presence of theophylline results in a reduction of awakenings.
Presence of theophylline results in REM sleep brain waves that closely match waking brain waves.
Neural activity during REM sleep would include high-amplitude, low-frequency waves given the inhibition of melatonin release.
In the absence of light, the influence of theophylline will decrease the total time spent with high-amplitude, low-frequency waves.
Reveal Answer
Presence of theophylline results in a reduction of awakenings.
Theophylline is a central nervous system stimulant, so it would likely increase, rather than reduce, the number of awakenings during sleep.
Presence of theophylline results in REM sleep brain waves that closely match waking brain waves.
REM sleep brain waves naturally resemble waking brain waves (low-amplitude, high-frequency) in all healthy subjects, so this is not a result specific to the presence of theophylline.
Neural activity during REM sleep would include high-amplitude, low-frequency waves given the inhibition of melatonin release.
REM sleep is characterized by low-amplitude, high-frequency waves. High-amplitude, low-frequency waves (delta waves) are characteristic of deep NREM sleep.
In the absence of light, the influence of theophylline will decrease the total time spent with high-amplitude, low-frequency waves.
High-amplitude, low-frequency waves (delta waves) occur during deep NREM sleep. Because theophylline acts as a central nervous system stimulant, it would decrease the amount of deep sleep, thereby reducing the total time spent with these waves.