Hands off my brain

Images of an MRI brain scan

Hands off my brain

Should the contents of the brain be private property?

We sometimes go to extreme lengths to prevent people knowing what we are thinking. The most successful poker players have deadpan faces so that other players do not know what kind of hands they have. Or, in everyday life, we might tell the odd little white lie, or not tell someone what we really think about them if we want them to help us.

But suppose our real, inner thoughts could be laid bare. Functional imaging provides a powerful view of our inner thought processes, revealing things that our outer expression may be hiding.

It has revealed that people respond differently to black faces than they do to white faces – evidence of hidden racial prejudice? And there is considerable interest in using such tools to spot when people are lying. There are characteristic patterns of brain activity that light up when people are not telling the truth (though brain scanners are not 100 per cent accurate as lie detectors at the moment).

This may be seen as intrusive. In the USA the Center for Cognitive Liberty and Ethics argues: “What and how you think should be private unless you choose to share it.”

Supporters say that brain scanning could be put to great use – identifying potential paedophiles seeking to work in schools, or helping the police solve crimes. On the other hand, even if they were infallible (and they are not) the meaning of scanning results is open to interpretation. We have instinctive responses but that does not mean we always act on them.

You are the regulator

Read through these case studies and decide for yourself your position. You may also like to debate and discuss these topics in the classroom.

Case study 1

Shifty Sam Fencer has been arrested by the police searching for missing bullion. He denies everything. They are convinced he is lying and would like to do a brain scan to prove it.

  • Should the police be allowed to scan Sam’s brain?
  • Would it make a difference if a child were missing rather than bullion?
  • Should there be any limits on how the police use brain scans to solve crimes?

Case study 2

Giselle Megabucks, a top R&B singer and noted celebrity, wants to scan her boyfriend’s brain to check that he really loves her.

  • Should she be allowed to?
  • If he agrees, is there any reason to refuse?
  • Should any limits be placed on the use of such scans?

Lead image:

David Foltz/Flickr CC BY NC

Further reading

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Neuroscience, Psychology
Issue:
Thinking
Education levels:
16–19, Continuing professional development

Descartes revisited

Image from Descartes’s ‘Optics: Discourse on methods’ (1639) showing an inverted image

Descartes revisited

The rich and fascinating internal life we experience is being reduced to the product of electrical activity. Does this diminish our view of humanity?

Descartes’s idea that the mind and body are distinct (see ‘Times past’) has been hugely influential. Partly it is because it is such an appealing notion – our sense of self is primarily a mental construct, based on our thoughts and personality, albeit one influenced by our physical form.

The consequences of this division run very deep. Some groups focus on the mind in a holistic, ‘whole-body’ sense: the exact nature of the ‘mind’ is less important than whether it is healthy, fulfilled and so on. How do collections of minds interact socially? Psychologists come at the brain from this direction, and it is the basis of psychological therapies such as cognitive behavioural therapy.

Over the past few decades, though, research has become increasingly dominated by a ‘reductionist’ approach, which seeks to break down complex biological phenomena into smaller pieces that can be analysed and understood.

This approach argues that the mind, whatever it is, is the product of the coordinated activities of brain cells. If we know how neurons work, individually and collectively, we will understand how conscious experience came about. This is the goal of neuroscientists, and the basis of pharmacological treatments of brain disorders, which manipulate brain chemistry to change mood or behaviour.

Although the models are not incompatible, there is a tendency for groups of researchers to work independently of one another. However, answers to the most interesting questions will probably combine both approaches – how does cognitive behavioural therapy affect brain biochemistry? What is the neuroscientific basis of the placebo effect? What cognitive processes underpin social communication?

Understanding humans

It is no longer a fanciful thought that one day we will be able to understand, in entirety and in a scientifically robust manner, all human experience. We still have a long way to go, but even the prospect of that understanding raises intriguing questions.

Some may find this conclusion hard to swallow, finding it difficult to accept that science can ‘explain’ the mysteries of love or morality. Or they may feel that it diminishes human dignity to think of the mind as an excitable neural network.

On the other hand, scientists would point to the extraordinary beauty apparent in the awe-inspiring complexity of the human brain, shaped by four billion years of evolution. Far from diminishing our sense of wonder, it enhances it further.

Lead image:

Wellcome Library, London CC BY

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Cell biology, Neuroscience, Psychology, History
Issue:
Thinking
Education levels:
16–19, Undergraduate, Continuing professional development

Strange times

Image showing a woman with a blurred face

Strange times

Some people with brain damage, or by a quirk of fate, lack a very specific mental function

Blindsight

Blindness usually results from damage to the eye, but damage to visual processing areas of the brain can also remove vision. Remarkably, some patients have no conscious vision but can still point at a coloured dot on a screen (they are told just to guess where it might be). This suggests that we can ‘see’ things without being consciously being aware of them. There appear to be two pathways of visual information in the brain, one linked to conscious awareness and one that bypasses it.

Synaesthesia

When a train pulls into a station, most of us hear a range of noises: squeaky wheels, hissing brakes and so on. Some people, though, see a variety of coloured shapes – each specific for a particular sound. Synaesthetes seem to have unusually wired brains, such that auditory signals, for example, link to visual areas. 

There are other types of synaesthesia, including:

  • grapheme–colour: in which letters/numbers are seen with a different colour
  • number–form: in which all numbers are visualised, even when thinking about only one
  • lexical–gustatory: in which sounds have a specific taste.

Prosopagnosia

People with agnosia lose the ability to recognise particular objects. This can be incredibly specific – they may fail to recognise just tools or animals. They can describe or draw a rake, say, but cannot say what it is. People with prosopagnosia are unable to recognise faces. These conditions imply that there are ‘modules’ in the brain specifically dealing with these features of the outside world.

Lead image:

Photograph showing a woman with a blurred face. People with the condition prosopagnosia cannot recognise faces.

Felipe Morin/Flickr CC BY NC ND

Further reading

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Neuroscience, Psychology
Issue:
Thinking
Education levels:
16–19, Continuing professional development

Animal personalities

Dog is on it's back and appears to be smiling

Animal personalities

Pet owners would probably argue that their animals have their own particular personalities, above and beyond that of their breeds. That could just reflect wishful thinking on the part of the owner, but there is some evidence that an animal like a dog does have individual personality traits

Animal psychology used to be a well-studied area, but received relatively little attention in the second half of the 20th century. There are signs, however, that interest is picking up. Partly this is because of interest in animal models of human behaviour (see ‘Animal models’), but it also reflects an interest in the behaviour of different animals, the genetic or physiologic basis for this behaviour, and variation in behaviour between individual animals. Of particular interest are cognitive skills and the extent to which human abilities (eg tool use, problem solving) are seen in animals.

Usually, though, research looks at groups of animals, to enable statistically valid conclusions to be drawn. There is less interest in individuals, except for companion animals such as dogs.

Different breeds of dog are good models to work with, as they are common and well-differentiated. Anecdotally, different breeds show different behaviour traits and scientifically this has also been reasonably well established. As for personality, one approach has been to see whether reliable personality traits can be developed for animals such as dogs, as they have for humans.

Although much less work has been done, it does seem that a set of criteria very similar to human personality traits can be applied to dogs. People independently and reliably score individual animals in a similar way.

It is not known, however, if dogs pick up the personality traits of their owners…

Lead image:

Elisa/Flickr CC BY NC ND

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Neuroscience, Ecology and environment, Psychology
Issue:
Thinking
Education levels:
16–19, Continuing professional development

Sleep work

Woman asleep on a counter-top

Sleep work

Want to improve your dance skills? Take to your bed

For many years the purpose of sleep has puzzled thinkers. In the past decade, one role has become increasingly clear: it helps us make memories.

However, there are different forms of memory and different types of sleep, so much remains to be learned. But many fascinating discoveries have been made recently.

Take a task in which subjects had to type a series of numbers – say, 2-4-7-2-4-7 – as accurately and quickly as they could. After practice, subjects got quicker and more accurate. If retested 12 hours later, they were no better, but after a night’s sleep they were 20 per cent faster and their error rate fell by 36 per cent. Even a 90-minute nap led to a 16 per cent improvement in speed. A second night’s sleep improved performance even more.

In a test of motor skills, where subjects had to draw a line on a tablet PC while the computer tried to push the line aside, sleep again led to better performance. Also, during deep sleep there was an increase in the amount of brain activity specifically in the part of the brain involved in the task. If this pattern was blocked, no improvement in performance was seen.

So it seems that the regions of the brain needed for a task are active while we sleep, preparing themselves to perform the task when we wake up. (A similar thing seems to happen when we are awake and restful.)

And it is not just simple learning tasks that benefit from sleep. Complex activities such as dancing also improve, and people get better at mind-bending puzzles.

In one remarkable experiment, subjects were taught a complex mathematical technique to which there was actually a simple alternative. When tested again 12 hours later, the likelihood that they discovered the alternative more than doubled if they had had a night’s sleep, even though they did not know there was an alternative to discover.

Sadly there is less evidence that sleep enhances memory for facts or for events. In rats, sleep seems to enhance spatial memory – rats are better in mazes after a night’s sleep. Rapid eye movement (REM) sleep seems to be important here – and may also be important in enhancement of emotionally charged memories in humans.

Although not certain, it appears that we need sleep so that the brain can sort itself out without interference from conscious activity. We may not know it, but we wake up better prepared for the world than when we went to sleep.

Lead image:

Leif Harboe/Flickr CC BY NC ND

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Neuroscience, Psychology
Issue:
Thinking
Education levels:
16–19, Continuing professional development

Animal consciousness and thinking

Surface detail of the brain of a macaque monkey

Animal consciousness and thinking

Can animals be said to be conscious? Or to have a mind? The answers are not obvious

Given how difficult it is to study consciousness in people, it is not surprising that the nature of animal consciousness is even less well understood. The debate about the use of animals in research makes this an even more difficult area.

In 1974, Thomas Nagel published an influential article ‘What is it like to be a bat?’ He was arguing that it was essentially impossible to put oneself into someone else’s head and share their subjective experiences. We certainly couldn’t possibly imagine what was going on inside a bat’s brain.

But how about other aspects of consciousness, such as awareness? Do animals have anything approaching theory of mind? The obvious problem with animal studies in this area is that animals cannot tell us what they are thinking. So the causes of any action have to be deduced and their implications inferred.

A classic problem is to distinguish between an association and a thought-through action. A simple creature like a slug will soon learn to avoid an unpleasant stimulus by conditioned learning or association (like Pavlov’s dogs), but that does not mean it has thought about the consequences of the stimulus. But what about a rat? Or a dog? Might they be able to think things through?

Gathering evidence

These issues are beginning to be tackled experimentally. For example, rats have been shown to be able to learn from observation and then apply this knowledge in a different situation – which would not be possible through learning by association. Birds such as crows seem to have similar abilities. Some go as far as to suggest that crows and parrots, the smartest avians, may have the same brainpower as apes.

And there is at least some evidence that macaque monkeys can imagine what others are perceiving (in an experiment, a macaque could tell whether a human handler could see a grape or not, stealing it when the handler could not see it). They may thus possess some level of theory of mind.

Lead image:

Surface detail of the brain of a macaque monkey. The original image was produced from an magnetic resonance image (MRI) scan of a single brain to highlight the surface of the cortex, producing an elaborately folded sheet. This surface data was then processed by an computer algorithm that attempts to capture the 3D curves into a 2D representation using thousands of circles of varying diameter. The resulting image gives a larger dynamic range of detail, even if in a very stylised form.

Parashkev Nachev, Wellcome Images CC BY NC ND

References

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Psychology, Neuroscience
Issue:
Thinking
Education levels:
16–19, Continuing professional development

Reading the mind

Deck of cards being dealt as part of a magic trick

Reading the mind

Scientists can now predict what a person is seeing just by looking at their brain, even in the absence of conscious awareness

Among the components of a scene recognised by visual areas of the brain are sloping grids of lines. Functional magnetic resonance imaging (fMRI) reveals that different neurons respond to grids of different orientation.

By backward masking, researchers can eliminate conscious awareness of the orientation of a grid that a subject has been exposed to. Even so, distinctive patterns can be seen in a brain scan, so a researcher can predict which image the subject saw.

The brain has captured, subconsciously, information about a scene. Although the subject has no recollection of it, the image has been imprinted in the brain and can be ‘read’ by a researcher. In effect, scientists have managed to take a snapshot of someone’s subconscious – a simple form of mind reading.

Lead image:

Seth M/Flickr CC BY NC ND

Further reading

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Cell biology, Neuroscience, Psychology, Biotechnology and engineering
Issue:
Thinking
Education levels:
16–19, Continuing professional development

Amnesia and deliberate forgetting

No memory flight information board

Amnesia and deliberate forgetting

Amnesia – loss of memory – takes many forms and can be hugely distressing

Amnesia is one of the fiction writer’s favourite ploys. Typically, the victim of an assault has no memory of the incident so cannot say ‘whodunit’. Better still they wake up with no recollection of who they are. Then there are those whose traumatic memories are ‘suppressed’ but gradually or spontaneously return.

In reality, because memory is not a single simple system, amnesia is similarly complex and takes many forms. In general terms, the nature of the amnesia depends on the nature of the damage to the brain.

One of the most striking forms of amnesia is the inability to make new memories (anterograde amnesia). This often follows damage to the hippocampus, which is needed to establish new memories that are then stored elsewhere in the brain. People may have perfect memories up to the point that they suffered the damage, but can then make no new memories. Researcher Eleanor Maguire of University College London describes how people she studies can get confused if she leaves the room: they may be unable to recall what they are doing with her.

Case studies

One of the most heart-rending tales is that of Clive Wearing. After a viral infection, he lost the ability to make new memories, as well as much of his past memory. In effect he ‘wakes up’ every few seconds, unable to remember what has just happened in his life. (His story was told in the 2005 ITV documentary ‘The Man with the 7 Second Memory’, and a poignant account of his relationship with his wife appeared in the ‘Daily Telegraph’ – ‘The man who keeps falling in love with his wife’.)

Perhaps sadder still is the case of a patient known as ‘HM’ or ‘Henry M’. Henry grew up normally enough in Hartford, Connecticut in the 1920s, but in late adolescence developed epilepsy. By the 1950s, he was enduring several seizures a week. With no other options available at the time, he underwent surgery. A significant chunk of his brain was removed – including most of his hippocampus, which at that point was not known to be important in memory making.

From that moment on, Henry was unable to add new memories. He has been studied intensively, providing new insight into many aspects of memory. He seems to have learned to cope, though worries about making friends – he forgets people minutes after seeing them. He has to be reintroduced to his doctors every morning. Most sadly, at regular intervals he relives the grief of discovering his mother has died.

Interestingly, Henry (like Clive Wearing) can still remember how to do things and can learn new skills (though cannot remember learning them). This shows how different aspects of memory are handled by different parts of the brain.

Being particularly associated with damage to the hippocampus, anterograde amnesia is rare. More common is retrograde amnesia, where memories made before a trauma cannot be recalled. The effect may be temporary, with memories gradually returning, or long term.

Head injury may cause various forms of amnesia. Impaired memory of events just before the head trauma reflects the absence of memory consolidation during the traumatic episode. Loss of memory is also a characteristic feature of neurodegenerative disorders such as Alzheimer’s disease. Some (but not all) aspects of memory are impaired in old age, such as short-term memory.

Lead image:

Cesar Astudillo/Flickr CC BY NC

Further reading

About this resource

This resource was first published in ‘Thinking’ in September 2006 and reviewed and updated in August 2014.

Topics:
Neuroscience, History
Issue:
Thinking
Education levels:
16–19, Continuing professional development

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