The Triune¹ Brain - IELTS Reading Answers & Explanations
From Road to IELTS Academic Reading Test 1 · Part 2 · Questions 14–26
Reading Passage
You should spend about 20 minutes on Questions 14–26, which are based on Reading Passage 2 below.
The Triune¹ Brain
The first of our three brains to evolve is what scientists call the reptilian cortex. This brain sustains the elementary activities of animal survival such as respiration, adequate rest and a beating heart. We are not required to consciously “think” about these activities. The reptilian cortex also houses the “startle centre”, a mechanism that facilitates swift reactions to unexpected occurrences in our surroundings. That panicked lurch you experience when a door slams shut somewhere in the house, or the heightened awareness you feel when a twig cracks in a nearby bush while out on an evening stroll are both examples of the reptilian cortex at work. When it comes to our interaction with others, the reptilian brain offers up only the most basic impulses: aggression, mating, and territorial defence. There is no great difference, in this sense, between a crocodile defending its spot along the river and a turf war between two urban gangs.
Although the lizard may stake a claim to its habitat, it exerts total indifference toward the well-being of its young. Listen to the anguished squeal of a dolphin separated from its pod or witness the sight of elephants mourning their dead, however, and it is clear that a new development is at play. Scientists have identified this as the limbic cortex. Unique to mammals, the limbic cortex impels creatures to nurture their offspring by delivering feelings of tenderness and warmth to the parent when children are nearby. These same sensations also cause mammals to develop various types of social relations and kinship networks. When we are with others of “our kind" – be it at soccer practice, church, school or a nightclub – we experience positive sensations of togetherness, solidarity and comfort. If we spend too long away from these networks, then loneliness sets in and encourages us to seek companionship.
Only human capabilities extend far beyond the scope of these two cortexes. Humans eat, sleep and play, but we also speak, plot, rationalise and debate finer points of morality. Our unique abilities are the result of an expansive third brain – the neocortex – which engages with logic, reason and ideas. The power of the neocortex comes from its ability to think beyond the present, concrete moment. While other mammals are mainly restricted to impulsive actions (although some, such as apes, can learn and remember simple lessons), humans can think about the “big picture”. We can string together simple lessons (for example, an apple drops downwards from a tree; hurting others causes unhappiness) to develop complex theories of physical or social phenomena (such as the laws of gravity and a concern for human rights).
The neocortex is also responsible for the process by which we decide on and commit to particular courses of action. Strung together over time, these choices can accumulate into feats of progress unknown to other animals. Anticipating a better grade on the following morning's exam, a student can ignore the limbic urge to socialise and go to sleep early instead. Over three years, this ongoing sacrifice translates into a first class degree and a scholarship to graduate school; over a lifetime, it can mean ground-breaking contributions to human knowledge and development. The ability to sacrifice our drive for immediate satisfaction in order to benefit later is a product of the neocortex.
Understanding the triune brain can help us appreciate the different natures of brain damage and psychological disorders. The most devastating form of brain damage, for example, is a condition in which someone is understood to be brain dead. In this state a person appears merely unconscious – sleeping, perhaps – but this is illusory. Here, the reptilian brain is functioning on autopilot despite the permanent loss of other cortexes.
Disturbances to the limbic cortex are registered in a different manner. Pups with limbic damage can move around and feed themselves well enough but do not register the presence of their littermates. Scientists have observed how, after a limbic lobotomy², "one impaired monkey stepped on his outraged peers as if treading on a log or a rock". In our own species, limbic damage is closely related to sociopathic behaviour. Sociopaths in possession of fully-functioning neocortexes are often shrewd and emotionally intelligent people but lack any ability to relate to, empathise with or express concern for others.
One of the neurological wonders of history occurred when a railway worker named Phineas Gage survived an incident during which a metal rod skewered his skull, taking a considerable amount of his neocortex with it. Though Gage continued to live and work as before, his fellow employees observed a shift in the equilibrium of his personality. Gage's animal propensities were now sharply pronounced while his intellectual abilities suffered; garrulous or obscene jokes replaced his once quick wit. New findings suggest, however, that Gage managed to soften these abrupt changes over time and rediscover an appropriate social manner. This would indicate that reparative therapy has the potential to help patients with advanced brain trauma to gain an improved quality of life.
¹ Triune = three-in-one
² Lobotomy = surgical cutting of brain nerves
Questions
Questions 14–22 Matching Features
Classify the following as typical of
A. The reptilian cortex
B. The limbic cortex
C. The neocortex
Questions 23–26 Sentence Completion
Complete the sentences below.
Write NO MORE THAN TWO WORDS from the passage for each answer.
- A person with only a functioning reptilian cortex is known as 23.
- 24 in humans is associated with limbic disruption.
- An industrial accident caused Phineas Gage to lose part of his 25.
- After his accident, co-workers noticed an imbalance between Gage's 26 and higher-order thinking.
Answers & Explanations Summary
| # | Answer | Evidence | Explanation |
|---|---|---|---|
| Q14 | C | The ability to sacrifice our drive for immediate satisfaction in order to benefit later is a product of the neocortex | Excerpt/Passage Explanation: The passage states that the neocortex is the specific part of the brain that lets us give up what we want right now so that we can have something better in the future. Answer Explanation: The answer C refers to the neocortex, which is the part of the brain responsible for higher-level thinking. Reason For Correctness: The correct answer is C because the passage explains that the neocortex allows people to think about the future rather than just the present. This part of the brain gives us the power to 'sacrifice' things we want right now, like having fun with friends, to achieve a 'benefit later', like getting a good grade or a degree. This ability to choose a long-term goal over 'immediate satisfaction' is a unique feature of the neocortex. |
| Q15 | A | The first of our three brains to evolve is what scientists call the reptilian cortex. This brain sustains the elementary activities of animal survival such as respiration, adequate rest and a beating heart | Excerpt/Passage Explanation: The passage says that the reptilian cortex is the first part of the brain to develop and it takes care of the simple things animals need to do to live, such as breathing and having a heart that beats. Answer Explanation: The answer is the reptilian cortex (Choice A), which is the part of the brain that keeps the body alive and working. Reason For Correctness: The correct answer is Choice A because the passage describes the reptilian cortex as the part of the brain that handles 'elementary activities of animal survival.' These are basic tasks like breathing (respiration) and keeping the heart beating, which are the essential bodily functions needed to stay alive. |
| Q16 | B | Listen to the anguished squeal of a dolphin separated from its pod or witness the sight of elephants mourning their dead, however, and it is clear that a new development is at play. Scientists have identified this as the limbic cortex | Excerpt/Passage Explanation: The passage says that when a dolphin makes a sad sound because it is alone or when elephants show sadness for a dead friend, it is because of the limbic cortex. Answer Explanation: The answer B points to the limbic cortex, which is the part of the brain that manages emotions and social bonds. Reason For Correctness: The correct answer B is chosen because the text explains that only mammals have a limbic cortex, which allows them to feel complex emotions and form social groups. Unlike reptiles, which do not care about others, mammals show signs of sadness and loss. The passage specifically mentions dolphins being upset when they are separated from their group and elephants mourning when someone dies. These behaviors, which represent 'the pain of losing another', are linked directly to the limbic cortex. |
| Q17 | B | These same sensations also cause mammals to develop various types of social relations and kinship networks. When we are with others of “our kind" – be it at soccer practice, church, school or a nightclub – we experience positive sensations of togetherness, solidarity and comfort | Excerpt/Passage Explanation: The passage says that the limbic brain makes mammals build different kinds of relationships and family-like groups. It also explains that being with similar people gives us good feelings of belonging together. Answer Explanation: The answer B means that the limbic cortex is the section of the brain that handles making friends and living together in groups. Reason For Correctness: The correct answer is B because the passage explains that the limbic cortex is what drives mammals to create social relations and kinship networks. It mentions that we feel good when we are around people we share things in common with, such as at school or in clubs. These feelings of togetherness and solidarity are what lead to the formation of communities and social groups. |
| Q18 | C | The neocortex is also responsible for the process by which we decide on and commit to particular courses of action | Excerpt/Passage Explanation: The passage explains that the neocortex is the part of the brain that handles making a choice and following the steps to finish that choice. Answer Explanation: The answer identifies the neocortex as the part of the brain used for choosing a plan and then following through with it. Reason For Correctness: The correct answer is C because the text specifically credits the neocortex with the ability to make choices and stick to them. While the other parts of the brain handle basics like survival or feelings, the neocortex allows for 'logic' and 'reason.' The passage mentions that this part of the brain is in charge of how we 'decide on' (make a decision) and 'commit to' (carry out or stay dedicated to) specific ways of acting. |
| Q19 | A | When it comes to our interaction with others, the reptilian brain offers up only the most basic impulses: aggression, mating, and territorial defence | Excerpt/Passage Explanation: The passage explains that the reptilian brain is the source of very simple, natural urges, such as fighting, finding a mate, and protecting one's own space or land (territorial defence). Answer Explanation: The answer means that protecting a piece of land or territory is a behavior controlled by the reptilian cortex. Reason For Correctness: The correct answer is A because the passage describes the reptilian brain as the part responsible for basic survival and simple animal behaviors. One of the specific behaviors listed is 'territorial defence.' In this context, 'territory' refers to an area of land that an animal or person considers their own, and 'defence' means guarding or protecting it against others. |
| Q20 | C | We can string together simple lessons (for example, an apple drops downwards from a tree; hurting others causes unhappiness) to develop complex theories of physical or social phenomena (such as the laws of gravity and a concern for human rights) | Excerpt/Passage Explanation: The passage says that human beings can take small, easy-to-understand facts and connect them to build large, complicated explanations about how things happen in life. Answer Explanation: The answer is the neocortex, which is the most advanced part of the human brain. Reason For Correctness: The correct answer is C because the passage describes the neocortex as the part of the brain that handles logic and reasoning. It allows humans to move beyond simple facts and instead create "complex theories" or detailed explanations for how the physical world and society work, such as the laws of gravity. |
| Q21 | B | Unique to mammals, the limbic cortex impels creatures to nurture their offspring by delivering feelings of tenderness and warmth to the parent when children are nearby | Excerpt/Passage Explanation: The passage states that the limbic cortex is only found in mammals and pushes them to take care of their children by giving parents feelings of love and warmth when their babies are around. Answer Explanation: The answer B means that 'Looking after one's young' is a behavior linked to the part of the brain called the limbic cortex. Reason For Correctness: The correct answer is Choice B because the passage explains that the limbic cortex, which is only found in mammals, causes animals to care for and protect their babies. This is described as 'nurturing' their 'offspring' or 'children'. In contrast, the passage notes that the reptilian cortex (Choice A) does not care about its young, and the neocortex (Choice C) is more about logic and thinking rather than basic instincts like childcare. |
| Q22 | A | The reptilian cortex also houses the “startle centre”, a mechanism that facilitates swift reactions to unexpected occurrences in our surroundings | Excerpt/Passage Explanation: The passage explains that the reptilian part of our brain has a special area that helps us act very fast when something unexpected happens near us. Answer Explanation: The answer is A, which refers to the reptilian cortex part of the brain. Reason For Correctness: The correct answer is A because the reptilian cortex is responsible for survival and fast reactions. It contains what scientists call a 'startle centre,' which is a part of the brain meant to help us react immediately to surprises around us. This matches the idea of 'responding quickly' to 'sudden' events like noises or movements. |
| Q23 | brain dead | The most devastating form of brain damage, for example, is a condition in which someone is understood to be brain dead. In this state a person appears merely unconscious – sleeping, perhaps – but this is illusory. Here, the reptilian brain is functioning on autopilot despite the permanent loss of other cortexes | Excerpt/Passage Explanation: The passage states that being "brain dead" is a condition where the reptilian brain still works automatically, even though the other parts of the brain are gone and will not come back. Answer Explanation: The answer refers to a medical condition where a person's body still works automatically because of the reptilian brain, but they have lost all other higher brain functions. Reason For Correctness: The correct answer is found in the section about brain damage. The text explains that when someone has lost all their brain layers except the reptilian cortex—which handles automatic things like breathing—this specific condition is known as being "brain dead." In this context, "functioning on autopilot" means the reptilian brain is still working while the "permanent loss of other cortexes" means the rest of the brain has stopped working. |
| Q24 | sociopathic behaviour | In our own species, limbic damage is closely related to sociopathic behaviour | Excerpt/Passage Explanation: The passage says that in humans, if the limbic part of the brain is hurt or broken, it leads to acting in a sociopathic way. Answer Explanation: The answer refers to a specific type of antisocial and uncaring way of acting that occurs in people. Reason For Correctness: The correct answer is supported by the text which explains that problems within the limbic cortex are linked to specific behavioral issues in humans. The passage uses the term 'limbic damage' as a synonym for 'limbic disruption' and states it is 'closely related to' (associated with) 'sociopathic behaviour'. |
| Q25 | neocortex | One of the neurological wonders of history occurred when a railway worker named Phineas Gage survived an incident during which a metal rod skewered his skull, taking a considerable amount of his neocortex with it | Excerpt/Passage Explanation: The passage says that a man named Phineas Gage had an accident where a metal bar went through his head and took away a large piece of his neocortex. Answer Explanation: The answer identifies the specific area of the brain that was damaged when Phineas Gage had an accident. Reason For Correctness: The correct answer is neocortex because the text states that an incident involving a metal rod resulted in Phineas Gage losing a 'considerable amount' of this specific brain part. The passage describes the neocortex as the 'third brain' and links it directly to Gage's injury. |
| Q26 | animal propensities | Though Gage continued to live and work as before, his fellow employees observed a shift in the equilibrium of his personality. Gage's animal propensities were now sharply pronounced while his intellectual abilities suffered | Excerpt/Passage Explanation: The passage explains that Phineas Gage's work friends noticed his personality became unbalanced. His basic animal-like behaviors became much more obvious, while his ability to think smartly and logically was harmed. Answer Explanation: The answer refers to the natural behaviors or basic instincts that humans share with animals, such as simple survival or raw emotions, rather than advanced logic. Reason For Correctness: The correct answer is found in the section describing Phineas Gage's personality change. The passage states that after his accident, his coworkers (fellow employees) saw a change in his 'equilibrium'—which is a synonym for balance. It explains that his 'animal propensities' became very strong (sharply pronounced) while his 'intellectual abilities'—a synonym for higher-order thinking—became weaker. In the sentence completion, 'animal propensities' fills the gap to show what was out of balance with his higher thinking skills. |