biopsychology

What are the two main components of the Central Nervous System (CNS)?

The brain, which handles conscious and most unconscious processing, and the spinal cord, which transmits information and handles some reflex processing.

What is the primary function of the Somatic Nervous System (SNS)?

It controls skeletal muscles for movement and is responsible for voluntary actions under conscious control.

What are the physiological effects of the Sympathetic branch of the Autonomic Nervous System?

It increases heart rate, breathing rate, and sweat, dilates pupils, inhibits digestion, and releases noradrenaline during the fight or flight response.

How does the Parasympathetic branch differ from the Sympathetic branch?

The parasympathetic branch decreases bodily activities (rest and digest), releases acetylcholine, slows heart rate, constricts pupils, and stimulates digestion.

What is the role of homeostasis in the nervous system?

It is the regulation of the internal environment by balancing the influences of the sympathetic and parasympathetic systems.

Describe the structure and function of sensory neurons.

They carry information from the PNS to the CNS, have long dendrites and short axons, and typically have the cell body positioned to the side.

What is the specific role of relay neurons?

They connect sensory neurons to motor neurons and are located exclusively within the CNS.

What are the structural characteristics of motor neurons?

They have short dendrites and long axons, and they carry signals from the CNS to the PNS to control muscle contraction and relaxation.

What occurs at the synaptic cleft during synaptic transmission?

The electrical signal (action potential) is converted into a chemical messenger (neurotransmitter) that diffuses across the gap to the postsynaptic membrane.

What is the purpose of reuptake or enzymatic destruction of neurotransmitters?

To prevent continued stimulation of the postsynaptic neuron, which would otherwise cause repeated, unwanted impulses.

How do excitatory neurotransmitters affect the postsynaptic neuron?

They increase the likelihood of an action potential by making the electrical charge inside the cell more positive (depolarisation).

What is the definition of summation in neural transmission?

The combined effect of all excitatory and inhibitory influences on a neuron; if the threshold is reached, a new action potential is generated.

What are SSRIs and how do they function?

Selective Serotonin Reuptake Inhibitors are drugs that block the reabsorption of serotonin into the presynaptic cell, prolonging its effect in the synapse.

Which gland is known as the 'master gland' and what does it release?

The pituitary gland; it controls other glands and releases hormones such as ACTH.

What is the function of the pineal gland?

It modulates sleep patterns and maintains the circadian rhythm by releasing melatonin.

Which gland is responsible for regulating blood sugar levels?

The pancreas, which releases insulin and glucagon.

What is the role of the adrenal glands during stress?

They regulate the fight or flight response by secreting adrenaline and cortisol.

What is the SAM pathway in the context of stress?

The Sympathomedullary pathway, which is activated by the hypothalamus to trigger the sympathetic nervous system and adrenal medulla to release adrenaline.

What is the difference between acute and chronic stress?

Acute stress is a response to immediate, short-term pressure, while chronic stress is a long-term response to prolonged, often uncontrollable pressure.

What is the 'freeze' response as proposed by Gray (1988)?

The theory that the first reaction to a threat is to freeze to gather information before deciding whether to fight or flee, suggesting fight or flight is a limited explanation.

What is the 'tend and befriend' response proposed by Taylor et al. (2000)?

A stress response strategy observed in females, involving protecting young and forming social alliances, which challenges the universality of the fight or flight response.

What are the long-term health consequences of chronic stress?

Constant activation of the fight or flight response can suppress immune and digestive systems, leading to high blood pressure, heart disease, obesity, and depression.

What is meant by 'localisation of function' in the brain?

The concept that specific functions, such as speech, memory, and movement, are performed in distinct, localized regions of the brain.

What is the function of the hypothalamus in the endocrine system?

It links the nervous system to the endocrine system, maintains homeostasis, and releases CRH.

What is the role of the thyroid gland?

It modulates the body's metabolism by releasing the hormone thyroxine.

What is the cerebral cortex?

The outer layer of the brain's hemispheres, divided into four lobes, each associated with different functions.

What is the primary function of the motor cortex?

It coordinates movements across multiple joints and muscles to achieve smooth, purposeful actions.

What is the role of Broca's area?

Located in the left hemisphere, it is responsible for speech production and articulation.

What is the function of the auditory cortex?

It analyzes and categorizes different sound frequencies and patterns.

What is the role of Wernicke's area?

Located in the left hemisphere, it is responsible for language comprehension and understanding word meanings.

What is the function of the visual cortex?

It receives, segments, and integrates visual information.

What does the somatosensory cortex process?

It processes somatic sensations.

What did the case of Phineas Gage demonstrate regarding brain localization?

It linked personality changes to damage in the frontal lobe, suggesting specific regions control personality traits.

What did Lashley (1950) conclude from his research on rats?

He concluded that cognitive functions are shared holistically across the cortex rather than being localized to one specific region.

What is meant by hemispheric lateralization?

The concept that each hemisphere of the brain is specialized to perform different functions, such as language in the left and visuospatial tasks in the right.

What does the term 'contralateral' mean in brain function?

Each hemisphere controls the opposite side of the body; for example, a left-hemisphere stroke causes weakness on the right side.

What is the function of the corpus callosum?

It acts as a bridge connecting the two hemispheres, allowing them to send messages and work together.

What were the findings of Sperry's (1968) split-brain research?

Information presented to the left hemisphere could be spoken, while the right hemisphere could draw or select objects with the left hand, suggesting independent hemispheric capabilities.

What is brain plasticity?

The brain's ability to adapt its function and structure in response to environmental changes, learning new skills, or brain damage.

What is the difference between positive and negative plasticity?

Positive plasticity strengthens network connections through challenge, while negative plasticity weakens connections due to lack of activity.

What did Maguire et al. (2000) find regarding taxi drivers?

London taxi drivers showed increased grey matter in the posterior hippocampus, a region linked to spatial navigation.

What is synaptic pruning?

The process where frequently used synapses become stronger, while unused synaptic connections are lost to make the brain more efficient.

What is axonal sprouting?

A mechanism of recovery where existing neurons grow new axons to connect to adjacent neurons.

What is functional recovery?

The process where undamaged areas of the brain take over functions previously performed by damaged or lost areas.

What factors affect the brain's ability to recover from damage?

Age (children recover better), gender (women often show better recovery), and the intensity of rehabilitative therapy.

What did the case study of EB (Danelli et al., 2013) demonstrate?

After a left hemispherectomy, the right hemisphere was able to take over language functions, showing the brain's capacity for functional recovery.

What is the 'cognitive reserve' theory in brain injury?

The idea that individuals with higher IQs and educational backgrounds often have better outcomes after traumatic brain injury.

What is a limitation of the research on Wernicke's area?

Modern research shows that damage to this area does not always result in language comprehension problems, suggesting it involves more than one region.

What is a major criticism of studies on brain plasticity like those by Maguire or Draginski?

They are often correlational studies, which do not establish a definitive cause-and-effect relationship.

What is a limitation of split-brain research?

Split-brain patients represent a restricted population, which limits the generalizability of the findings to the wider population.

Define spatial resolution in the context of brain imaging.

The level of accuracy in identifying the exact location of a brain structure or activity.

Define temporal resolution in the context of brain imaging.

The level of accuracy in identifying the exact time of a brain activity.

What is the primary limitation of post-mortem examinations of the brain?

The findings are correlational because the brain is not studied while living, meaning damage could be due to other factors.

How does an fMRI scan detect brain activity?

It detects blood flow; more active areas require more oxygenated blood, which is compared to lower activation areas.

What is a major disadvantage of using fMRI for brain research?

It has poor temporal resolution due to a delay in blood flow and is expensive/inconvenient as participants must remain still.

What does an EEG measure?

It measures the total electrical activation of the brain cortex under electrodes attached to a scalp cap, displayed as brain waves.

How do ERPs differ from EEGs?

ERPs use the same equipment as EEGs but present a stimulus multiple times to remove background electrical noise, isolating specific cognitive responses.

What is a circadian rhythm?

A biological rhythm that lasts approximately 24 hours, regulating sleep-wake cycles, hormone release, body temperature, and blood pressure.

What did Siffre's (1975) cave study suggest about the sleep-wake cycle?

It suggested that the internal body clock (endogenous pacemaker) is free-running but naturally lasts longer than 24 hours, requiring entrainment.

What is the practical application of Folkard et al.'s (1980) research on desynchronisation?

It highlights the negative effects of disrupting sleep-wake cycles, leading to advice for employers to avoid long-term night shift work.

Define infradian rhythms.

Biological cycles that last longer than 24 hours.

What is Seasonal Affective Disorder (SAD)?

A type of depression occurring during winter months, linked to higher melatonin secretion due to darker, longer days.

What did Rosen et al. (1990) find regarding the prevalence of SAD?

SAD rates were higher in more northern latitudes and among people over 35, suggesting a link to longer, darker winter days.

What is an ultradian rhythm?

A biological cycle that lasts less than 24 hours and can occur multiple times during the day.

What are the two main features measured in EEG brainwaves?

Frequency (waves per second in Hz) and amplitude (size of the wave/voltage change).

Describe the EEG characteristics of N3 sleep.

Deepest sleep with slow frequency and large amplitude delta waves; very difficult to wake.

What characterizes REM sleep?

The brain is active, the body is paralyzed, and it is characterized by rapid eye movement and dreaming.

What did Dement & Kleitman (1957) discover about the relationship between eye movements and dreams?

They found a positive correlation where eye movement patterns matched the content of the dream (e.g., vertical movements for climbing).

What is the role of the Suprachiasmatic Nucleus (SCN)?

It acts as the endogenous pacemaker for the sleep-wake cycle, signaling the pineal gland to regulate melatonin release based on light.

How does light affect melatonin levels?

Light detected by the SCN stops the pineal gland from releasing melatonin, promoting wakefulness; darkness increases melatonin, promoting sleep.

What did DeCoursey et al. find when destroying the SCN in hamsters?

The sleep-wake cycle disappeared, and the hamsters were more vulnerable to predators, showing the SCN's control over the cycle.

What are exogenous zeitgebers?

External environmental cues (like light, social cues, or temperature) that help entrain or alter body clocks.

What did Campbell & Murphy (1998) demonstrate regarding light as an exogenous zeitgeber?

They showed that light shone on the back of the knees could shift the sleep-wake cycle, suggesting light does not necessarily rely on the eyes.

What is a limitation of using animal research (like hamsters) to study human biological rhythms?

Findings may not be fully generalizable to human cognitive and neurological abilities.

Why is the study of SAD considered biologically reductionist?

It explains a complex disorder solely in terms of melatonin levels, overlooking psychological and social factors.

What is a major limitation of ERP research?

Some cognitive processes cannot be studied because they cannot be presented a large number of times with the same response.

What is the main advantage of EEG over fMRI?

EEG has good temporal accuracy, measuring brain activation in milliseconds, whereas fMRI has poor temporal resolution.

What is the primary function of the pineal gland in the sleep-wake cycle?

It releases melatonin in response to signals from the SCN to promote sleep during darkness.