Biopsychology - AO3

Localisation of Function - strong research support via brain scans (strength)

P – There is strong support for localisation of brain function.

E – Peterson et al. (1988) used brain scans and found that Wernicke’s area was active during a listening task, while Broca’s area was active during a reading task, suggesting distinct roles in language processing. Similarly, Tulving et al. (1994) showed that semantic and episodic memories activate different regions of the prefrontal cortex. These findings support the idea that certain cognitive functions are anatomically localised.

C – The use of brain scanning techniques provides objective and replicable evidence, enhancing the scientific credibility of localisation theory.

H – However, some functions may be more distributed than localised. For instance, Lashley’s research on rats suggested that higher cognitive functions like learning are not confined to a single region, implying the brain works more holistically in some cases.

I/D: Holism vs Reductionism – Localisation of function supports a reductionist perspective, as it attempts to explain complex behaviours through the function of specific brain areas. While this allows for precise scientific investigation, it may overlook how different brain areas interact as part of a more holistic system.

Localisation of Function - plasticity suggests brain functions aren’t localised (limitation)

P: A key limitation of the localisation of function theory is the brain's ability to adapt and reorganise itself following injury, known as plasticity.

E: Research has shown that when areas of the brain become damaged due to stroke or trauma, other parts can take over the lost functions. Lashley referred to this as the law of equipotentiality, suggesting that intact brain areas can ‘chip in’ to compensate, enabling recovery of function.

C: This challenges the strict localisation view by demonstrating that the brain is dynamic and flexible, capable of reorganising itself in response to damage.

H: H–However, the fact that certain areas like Broca’s and Wernicke’s are consistently linked with specific functions still supports a degree of localisation, even if the brain can adapt when necessary.

I/D: Nature vs Nurture – This supports the idea that while biological structures (nature) play a role, environmental factors like learning and rehabilitation (nurture) significantly influence recovery and brain function.

Plasticity - Research into brain plasticity has had significant real-world benefits, particularly in the development of neurorehabilitation strategies (strength)

P: Research into brain plasticity has had significant real-world benefits, particularly in the development of neurorehabilitation strategies.
E: For example, after brain injury or stroke, spontaneous recovery may plateau, and targeted therapies such as movement therapy or electrical brain stimulation are used to support further recovery.
C: This shows how understanding neural plasticity has enabled more effective treatments, demonstrating psychology’s valuable contribution to medical practice.
H: However, not all patients respond equally to rehabilitation, and recovery outcomes can vary widely depending on individual differences such as age, lesion location, or overall health. This suggests plasticity, while powerful, has limitations that require personalised approaches.
I/D: Determinism vs Free Will – Neurorehabilitation implies a degree of determinism in recovery mechanisms, but the need for active intervention reflects an element of individual agency in the healing process.

Plasticity - plasticity can also have negative consequences, leading to maladaptive behaviours or conditions (limitation)

P: While brain plasticity can be adaptive, it can also have negative consequences, leading to maladaptive behaviours or conditions.
E: For instance, prolonged drug use can impair cognitive functioning and increase the risk of dementia later in life (Medina et al., 2007). Additionally, 60-80% of amputees experience phantom limb syndrome, where they feel sensations in a limb that no longer exists, often due to cortical reorganization (Ramachandran & Hirstein, 1998).
C: These findings highlight that the brain’s plasticity can sometimes lead to unwanted side effects, suggesting that while the brain can recover, these processes may not always result in positive outcomes.
H: However, such negative outcomes are not inevitable and are often linked to extreme or maladaptive conditions (like drug abuse). In many cases, plasticity is a helpful and necessary process for recovery, as seen in the rehabilitation of stroke victims.
I/D: Nature vs Nurture – The negative consequences of plasticity, such as phantom limb syndrome or cognitive decline from drugs, underline the interplay between genetic predispositions (nature) and environmental influences (nurture) in shaping brain function.

Split Brain Research - Sperry’s methodology in studying split-brain patients provided a highly controlled and effective way to study the lateralisation of brain function (strength)

P: Sperry’s methodology in studying split-brain patients provided a highly controlled and effective way to study the lateralisation of brain function.
E: Sperry used a clever technique where participants stared at a fixation point while one eye was blindfolded, and visual information was flashed for just one-tenth of a second to ensure that the information was only processed by one hemisphere of the brain at a time. This allowed Sperry to precisely control which hemisphere was receiving the information, ensuring a reliable test of hemisphere-specific functions.
C: The use of such a controlled and standardised procedure strengthened the reliability and validity of the findings, contributing significantly to our understanding of brain lateralisation.
H: However, while this methodological strength provides robust and clear data, the results may not be generalisable to the wider population, as split-brain patients are rare and may have unique brain adaptations that differ from the typical functioning of non-split-brain individuals.
I/D: Holism vs Reductionism – Sperry’s methodology, focusing on the separation of brain functions to isolate specific areas, aligns with a reductionist approach by isolating brain hemispheres to understand cognitive processes.

Split Brain Research - Sperry’s findings have led to an oversimplified view of brain function, particularly the rigid distinction between the roles of the left and right hemispheres (limitation)

P: Sperry’s findings have led to an oversimplified view of brain function, particularly the rigid distinction between the roles of the left and right hemispheres.
E: Although Sperry’s work used the labels ‘verbal’ and ‘non-verbal’ to describe hemispheric function, modern neuroscientists argue that these distinctions are less clear-cut. The brain’s hemispheres are in constant communication, and many behaviors typically attributed to one hemisphere can be performed by the other hemisphere when needed.
C: This challenges the idea that the functions of the left and right hemispheres are fixed and highlights the brain’s remarkable flexibility.
H: However, while the division of labor between hemispheres may not be as rigid as once thought, Sperry’s work still provided valuable insights into lateralisation and the early understanding of brain function.
I/D: Nature vs Nurture – This debate is relevant because while Sperry’s research focused on innate brain functions, modern interpretations emphasize the adaptability and learning capacity of the brain, suggesting that environmental factors play a significant role in how brain functions develop.

Endo. Pacemakers and Exo. Zeitgebers - The influence of exogenous zeitgebers, such as light, on regulating circadian rhythms may be overstated (limitation)

P: The influence of exogenous zeitgebers, such as light, on regulating circadian rhythms may be overstated.
E: Miles et al. (1977) described a blind man whose circadian rhythm was 24.9 hours, and despite exposure to social cues, his sleep/wake cycle could not be adjusted. Similarly, studies of people in Arctic regions, where the sun doesn’t set during summer, show that they maintain normal sleep patterns despite prolonged exposure to light.
C: These examples indicate that internal biological rhythms can operate independently of exogenous cues, questioning the extent of their influence.
H: However, although these cases challenge the power of exogenous zeitgebers, they don’t undermine the importance of light and other external cues in regulating the sleep-wake cycle for most individuals.
I/D: Determinism vs Free Will – The debate here involves whether our sleep-wake cycles are primarily determined by biological factors (internal) or external influences (such as light exposure), suggesting a potential conflict between these forces in regulating behavior.

Endo. Pacemakers and Exo. Zeitgebers - significant methodological issues with studies, particularly with replicability and internal validity (limitation)

P: There are significant methodological issues with studies investigating endogenous pacemakers and exogenous zeitgebers, particularly with replicability and internal validity.
E: The findings from Campbell & Murphy’s study have not been replicated, and critics argue that there may have been unaccounted light exposure to participants, which would be a confounding variable. Additionally, isolating light as the only exogenous zeitgeber fails to account for other potential zeitgebers and their interactions.
C: These methodological flaws suggest that the results of studies on circadian rhythms may not be reliable, limiting our understanding of the complex interaction between endogenous and exogenous factors.
H: However, despite the limitations, Campbell & Murphy’s study offers valuable real-world application, as it demonstrates how environmental factors, such as light exposure, can influence our biological rhythms, potentially informing practical interventions for individuals with circadian rhythm disorders.
I/D: Holism vs Reductionism – This debate is relevant because isolating one exogenous zeitgeber (light) reduces a complex biological process to a single factor, potentially oversimplifying the interaction between multiple environmental cues and internal rhythms.

Circadian Rhythms - Knowledge of circadian rhythms has given researchers a better understanding of the adverse consequences that can occur as a result of their disruption - desynchronisation - shift workers (strength)

P: Knowledge of circadian rhythms has given researchers a better understanding of the adverse consequences that can occur as a result of their disruption - desynchronisation.

E: Boivin (1996) found that night workers who engage in shift work experience a period of reduced concentration around 6am, meaning mistakes and accidents are more likely. Research also suggests a link between shift work and poor health—Knutson (2003) found that shift workers are three times more likely to develop heart disease, potentially due to the stress of adjusting to different sleep/wake cycles or poor quality sleep during the day.

C: Thus, research into the sleep-wake cycle may have economic implications in terms of how best to manage worker productivity and well-being.

H: However, while circadian rhythm research focuses on the biological aspects of sleep/wake cycles, it is important to consider a more holistic approach that includes psychological, environmental, and social factors. A reductionist approach focusing solely on biological rhythms might overlook crucial factors like job stress, work environment, and coping mechanisms.

I/D: Holism vs. Reductionism – The research into circadian rhythms and shift work can be seen as a balance between reductionism (focusing on the biological factors) and holism (considering the complex interplay between biological, psychological, and environmental influences). The question is whether we should focus on just the biological rhythms or adopt a more integrated approach that includes broader social and environmental factors.

Circadian Rhythms - Studies can be criticised for poor control, for example, although participants in the studies discussed were deprived of natural light, they still had access to artificial light (limitation)

P: Studies can be criticised for poor control, for example, although participants in the studies discussed were deprived of natural light, they still had access to artificial light.

E: For instance, Siffre turned on a light every time he woke up, which remained on until he went to bed. It was assumed by him and others that artificial light, unlike daylight, would have no effect on the free-running circadian rhythm. However, Czeisler et al. (1999) were able to adjust participants' circadian rhythm from 22 to 28 hours using dim lighting.

C: This suggests that researchers may have ignored an important confounding variable in circadian rhythm research, potentially undermining the validity of earlier studies.

H: However, the use of artificial light as a confounding variable in studies such as Siffre’s can be seen as a practical limitation, which could lead to a better understanding of how circadian rhythms are impacted by different forms of light exposure when future studies control for such variables.

I/D: Nature vs. Nurture – The study highlights the interaction between biological processes (nature) and environmental factors (nurture), with the light exposure influencing circadian rhythms. This debate is central to understanding the extent to which our internal biological rhythms are shaped by external factors versus being predetermined by genetics.

Infradian and Ultradian Rhythms - SAD has practical application in the development of phototherapy (strength)

P: SAD has practical application in the development of phototherapy.

E: Phototherapy is one of the most effective treatments for Seasonal Affective Disorder (SAD), utilizing lightboxes that stimulate strong light to reset melatonin levels in sufferers. A study by Eastman (1998) found that phototherapy relieved symptoms in up to 60% of SAD sufferers, highlighting its potential effectiveness as a treatment.
C: This suggests that knowledge of SAD and the mechanisms behind its onset has been beneficial in developing a treatment that helps many individuals.
H: However, Eastman’s study also showed a placebo effect of 30% when using a ‘sham negative-ion generator,’ raising questions about the true efficacy of phototherapy and whether its success is more due to patients' expectations than the treatment itself.
I/D: Determinism vs. Free Will
This research raises the question of whether the treatment effects are purely determined by biological processes (the light therapy) or if the placebo effect, driven by participants' expectations and beliefs, reflects an element of free will influencing their outcomes.

Infradian and Ultradian Rhythms - There are many factors that affect change in a woman’s menstrual cycle, including stress, changes in diet, exercise, etc. These may have acted as confounding variables (limitation)

P: There are many factors that affect change in a woman’s menstrual cycle, including stress, changes in diet, exercise, etc. These may have acted as confounding variables.
E: This means that any supposed pattern of synchronisation, (for example, in studies like Stern and McClintock’s), is no more likely to have occurred than it would have by chance. Moreover, research involves small samples of women and relies on women self-reporting their own cycles, and subsequent studies (e.g., by Trevathan et al., 1993) failed to find any evidence of menstrual synchrony in all-female samples.
C: This suggests that important aspects of synchronisation studies may lack validity.
H: However, some researchers argue that these studies may still provide valuable insights, as the findings could be valid within a larger, more diverse population, where more sophisticated methods of control for confounding variables might reveal more reliable results.
I/D: Holism vs. Reductionism

The methodological limitations in menstrual synchrony research highlight the debate between holism (where multiple variables are considered) and reductionism (where the focus is on isolating one factor, like menstrual synchrony). Researchers who adopt a more holistic approach may be more likely to consider a wider range of factors that affect menstrual cycles, while reductionist approaches might attempt to isolate specific variables for clearer conclusions.

Ultradian rhythms - Dement and Kleitman’s study provides strong support for the existence of ultradian rhythms, particularly the REM/NREM sleep cycle.

P: Dement and Kleitman’s study provides strong support for the existence of ultradian rhythms, particularly the REM/NREM sleep cycle.
E: EEG recordings showed that participants regularly entered REM sleep approximately every 90 minutes, with vivid dreams reported when woken during this stage.
C: This supports the idea that sleep follows a consistent ultradian pattern made up of distinct stages, especially REM and NREM.
H: However, the artificial lab setting and small sample size limit the generalisability of the findings to real-world sleep behaviour.
I/D: This links to the reductionism debate, as the study focuses narrowly on brainwave patterns and biological rhythms, overlooking psychological or environmental influences on sleep.

Ultradian rhythms - Research by Tucker et al. highlights the importance of individual differences in ultradian rhythms.

P: Tucker et al.'s research highlights individual differences in ultradian rhythms, specifically in the sleep cycle.
E: They found significant variation in the duration of stages 3 and 4 of sleep across participants, even under controlled conditions.
C: This suggests that ultradian rhythms are not uniform and that sleep stages may differ naturally between individuals.
H: However, much of sleep research uses a nomothetic approach, assuming universal sleep patterns and generalising findings.
I/D: This links to the idiographic vs nomothetic debate, as it shows the value of an idiographic approach in recognising natural individual differences in biological rhythms like ultradian cycles.