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Cognitive Neuropsychology and the Discoveries of Broca and Wernicke

Updated on August 07, 2015
The frontal (pink), parietal (yellow), occipital (purple) and temporal (green) lobes of the human brain
The frontal (pink), parietal (yellow), occipital (purple) and temporal (green) lobes of the human brain | Source

Branches of Psychology

Neuropsychology lies within the field of cognitive psychology and focuses on the interrelationship between the physical brain and the cognitive functions of the mind. Cognitive psychology assumes that details of cognitive mechanisms can be inferred through careful use of experimentation with normal human participants. Cognitive neuropsychology believes only when the complete system goes wrong is it possible to grasp the complexity of the mechanisms involved.

The development of neuropsychology can be traced back to the discoveries of Paul Broca and Carl Wernicke in the late 1800's. After an era where attention was being given to phrenology and the study of the skulls contours, they provided vital evidence for the physical connection between specific areas of the human brain and our cognitive functions of speech production and comprehension.

Phrenology

The earliest cognitive neuropsychologists where the phrenologists, who believed our mental abilities were located in different parts of the brain and the contours of the skull revealed the extent of an individuals’ abilities.

Phrenology was based on the idea that mental abilities and functions were located in brain ‘organs’ which had distinct areas on the surface of the brain and could be detected through feeling ‘bumps’ on the outside of the skull. Those 'organs' that were used regularly increased in size and those which were not used decreased in size. According to the phrenologists, this is why the skull changes in contour as an individual develops.

Images from the Brockhaus and Efron Encyclopedic Dictionary published in Imperial Russia in 1890-1907
Images from the Brockhaus and Efron Encyclopedic Dictionary published in Imperial Russia in 1890-1907 | Source
A phrenology ceramic head
A phrenology ceramic head | Source

During the phrenology era in the early 1800s, it was not possible to study the brains of the living, only the brains of those who had died could be examined and dissected. Phrenology today has largely been dismissed although its theories and readings are still of great interest to many.

The study of behaviour had yet to be established particularly in those with neurological damage. There was therefore very little information available at the time regarding an individual’s personality and behaviour and how these attributes related to the brain itself.

Modern Neuropsychologists

In the early 20th Century, neurologists were studying brain damaged patients for treatment purposes. Today, cognitive neuropsychologists have a number of goals depending on the type of work they are doing.

Clinical neuropsychologists work with patients who have suffered brain damage and are interested in trying to get a good overall profile of the patients problems and strengths with a view to providing appropriate support.

Research neuropsychologists aim to discover what a patients problems tell us about cognitive functions that have been affected by brain damage and what might be done to aid individual patients.

Broadly, there are four main goals of neuropsychologists:

  • lesion localization
  • assessment of a patients deficit
  • building models of normal cognition
  • localization of different cognitive functions within the brain

The Hemispheres of the Human Brain

Hemispheres of the brain and the functions they support. Note the right hemisphere supports the left side of the body and the left hemisphere the right side of the body
Hemispheres of the brain and the functions they support. Note the right hemisphere supports the left side of the body and the left hemisphere the right side of the body | Source

Such goals illustrate the breadth of neuropsychology but cognitive neuropsychology is part of a much larger field of research; that of neuroscience. This is a multi-disciplinary approach bringing together a number of diverse ways of looking at the brain and cognition including cell anatomy, pathology and neurology. The difference between approaches lies primarily in the level of neural or cognitive functioning being analysed and the research methods employed.

Influential Memory Neuropsychologist, Brenda Milner

Neuropsychological Evaluation

Before brain imaging methods were developed, ‘paper and pencil’ techniques were relied upon to build up a picture of the site of brain damage and its effects. The Wisconsin Card Sorting Test (WCST) is one example (Berg, 1948).

Example cards in the Wisconsin Card Sorting Test
Example cards in the Wisconsin Card Sorting Test | Source

A Card Sorting and Feedback Test

The WCST was designed to assess the ability of a patient to change their behaviour as result of receiving external feedback:

  • A pack of cards was used that differed in shape, colour and number of objects on each card
  • The patient's task was to sort the cards according to the dimensions chosen by the experimenter, but not told to the patient
  • The experimenter gives feedback on the sorting by the patient i.e. correct or incorrect
  • The experimenter may start by wanting cards sorted by shapes, then after few trials, change and want them sorted by colour
  • The idea is that patients, through trial and error, will infer what the examiner is looking for and what the new dimensions are by the feedback in which they receive

View of the frontal lobes of the human brain from above
View of the frontal lobes of the human brain from above | Source

Frontal Lobe Brain Damage

It is known that patients with frontal lobe damage have problems with this task. Specifically, they tend to continue to sort cards according to one dimension such as shape despite feedback indicating that dimension is no longer relevant to the rules.

Poor performance such as this on this task was generally taken as an indication of damage to a patients frontal lobes.

Today, Magnetic Resonance Imaging (MRI) can give accurate images of brain damage through the use of non-invasive scanning of patients brains. However, in some cases an MRI scan may show no clear damage despite an obvious display of problems by patients. Standardised tests such as the WCST are therefore still used in some cases.

Read about the remarkable Phineas Gage who in 1848 suffered the most horrific of injuries when an iron rod went through his skill, exiting through his frontal lobes, and he survived. His injuries and the personality changes he experienced as a result changed the path of neuropsychology for ever.

The Discoveries of Broca and Wernicke

Paul Broca is attributed with founding modern neuropsychology. His famous case study, Tan, had suffered a stroke. He found Tan had problems making intelligible words, only being able to produce a few syllables at once, but he could understand fully what was being said to him.

Broca suggested that the part of Tan’s brain that was damaged was the part responsible for coordinating muscle movements needed for speech. Therefore, Tan was experiencing problems with speech production. Post-mortem analysis of Tan’s brain in 1861 confirmed that his brain damage as a result of the stroke was localised to a particular area in the brain, with the rest of his brain remaining intact. This area is now known as Broca’s area.

Portraits of Paul Broca and Carl Wernicke
Portraits of Paul Broca and Carl Wernicke | Source

In 1874, Carl Wernicke worked with patients showing the reverse of Tan’s problems. These patients appeared to be able to speak fluently but had difficulties understanding what was being said to them. Closer inspection found their speech was in fact full of errors and hard to understand.

Wernicke suggested such cases had damage in the brain to the area responsible for storing sound patterns of words, therefore, they were experiencing problems understanding speech. Post-mortem examination of Wernicke’s patients showed a specific area of damage in the temporal lobe and slightly further back than the previously identified Broca’s area.

Although Wernicke’s explanation accounted for poor comprehension, it did not explain why patients experienced speech problems. This is still not fully understood, however this area of the brain is now known as Wernicke’s area due to this early research.

Areas of the brain responsible for speech production and comprehension

Lateral Views of Broca's and Wernicke's Areas
Lateral Views of Broca's and Wernicke's Areas | Source

Both Broca and Wernicke were ‘localizationalists’ because they believed cognitive functions were firmly located in particular areas of the brain; speech for Broca’s area and comprehension for Wernicke’s area.

Such lesion localization and assessment within the brain were once the most important goals in neuropsychology. However, with the development of cognitive psychology in recent years, these have now changed to create and test models of cognition to help us understand and explain complex cognitive processes, for example reading.

Analysis of fMRI Images
Analysis of fMRI Images | Source

Summary

The development of neuroimaging techniques such as Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI) and Functional Magnetic Resonance Imaging (fMRI) was a significant factor in the evolution of cognitive neuropsychology.

It was no longer necessary to wait until post-mortem to confirm predictions and theories and no need to rely on assumptions. Images can now be obtained of damage in a living brain which has a significant impact on being able to treat patients. Images can also show surgeons exactly where they need to operate and accurate information on which parts of the brain is damaged. This, alongside the early discoveries of Broca and Wernicke has enabled a huge leap forward within neuroscience and cognitive neuropsychology.

References

  1. E. A. Berg. (1948). A simple objective technique for measuring flexibility in thinking J. Gen. Psychol. 39: 15-22
  2. Franz, S.I., (1912) “New Phrenology”, Science, N.S. 35 (896), pp321-32
  3. Walsh, K. W. (1978). Neuropsychology: A clinical approach. Churchill Livingstone

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    • Samprita profile image

      Dr. Samprita Sahu 2 years ago from Indore, India

      Quite informative!!!! Thank you

    • PsychGeek profile image
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      PsychGeek 2 years ago from UK

      Thank you Samprita, I am glad you enjoyed the article!

    • deborahmorrison1 profile image

      Deborah Morrison 2 years ago from Hamilton, Ontario, Canada

      I found this hub to be highly informative. Phrenology is an interesting science, which has given way to modern neuropsychology. New technology has played a large part in the evolution of cognitive neuropsychology. The discoveries about left and right areas of the brain that are connect with our various abilities are a source of important and useful knowledge. We have come a long way in understanding the brain during the past fifty years. What is even more interesting is to ponder the fact that there is so much more yet to discover about the workings of the brain. The next fifty years are sure to bring new discoveries and information about the brain that will benefit our understanding, development, abilities, and healing approaches.

    • PsychGeek profile image
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      PsychGeek 2 years ago from UK

      Hi Deborah, it is so very exciting in how neuroscience is moving forward and I agree, there is so much more to discover and learn. It does make me wonder what we are going to find and be able to do with the brain in 50 years time. Thank you for stopping by and your comments!

    • Hendrika profile image

      Hendrika 2 years ago from Pretoria, South Africa

      Thanks for this research. I find it interesting because my son was in an accident and had brain damage at the back of his brain. He had to learn to walk and write again and is now fine.

    • PsychGeek profile image
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      PsychGeek 2 years ago from UK

      Hi Hendrika, thank you for reading and commenting, I am glad you found the article interesting. That is great your son has fully recovered. It is quite amazing what the brain can do and how it can recover from brain injury.

    • Kristen Howe profile image

      Kristen Howe 21 months ago from Northeast Ohio

      This was real interesting to know about cognitive neuropsychology. Very informative. Voted up!

    • PsychGeek profile image
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      PsychGeek 21 months ago from UK

      Thank you Kristen. Glad you enjoyed the Hub!

    • Kristen Howe profile image

      Kristen Howe 21 months ago from Northeast Ohio

      You're welcome. It was real interesting.

    • Kristen Howe profile image

      Kristen Howe 21 months ago from Northeast Ohio

      You're welcome. It was real interesting.

    • abhishekpandey777 profile image

      abhishek kumar pandey 19 months ago from lucknow Uttar Pradesh India

      it's a very interesting psychological article.great research work by all of you.

    • jgshorebird profile image

      jgshorebird 19 months ago from Earth

      Thanks for taking the time. Great information. I am interested since I know someone with Aspergers...and other issues. Am always trying to understand it and how it may relate to OCD etc.

    • Pert H 19 months ago

      Very interesting and well written. Enjoyed reading it.

    • Kristen Howe profile image

      Kristen Howe 19 months ago from Northeast Ohio

      Though I've commented on this a while back, congrats on HOTD!

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Hi Kristen, thank you very much!

    • Kristen Howe profile image

      Kristen Howe 19 months ago from Northeast Ohio

      HI there. You've very welcome.

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Hi Pert H, thank you for reading and taking the time to comment. I am glad you enjoyed the article!

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Hi jgshorebird, it is such an interesting area. The brain and mind are so complex and there is so much to discover about different areas and functions and how they can affect our behaviour. I am glad you enjoyed reading and found it interesting, thank you for stopping by!

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Thank you abhishekpandey777, I really enjoyed researching this one and learnt a great deal putting it together. I don't think we will ever stop learning and discovering when it comes to the brain!

    • krillco profile image

      William E Krill Jr 19 months ago from Hollidaysburg, PA

      Outstanding!

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Thank you Krillco! I have just been reading through some of your Hubs, fascinating work. Yours is a profile I will most definitely be visiting again!

    • heidithorne profile image

      Heidi Thorne 19 months ago from Chicago Area

      Very interesting and so worthy of Hub of the Day! Congrats!

    • Harishprasad profile image

      Harish Mamgain 19 months ago from India

      You bring up very interesting and informative materials for us to read and to be enlightend. Contrats on getting HOD award. The brain has always posed a great challenge to people from all walks of life. Maybe some day scientists could unravel the great mystery of brain. Voted up. I want to share it but can't find the button.

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Hi Heidi, thank you so much! I am glad you found the Hub interesting.

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Hi Harish, thank you for your lovely comments! I am absolutely fascinated with the brain, it's functions and relationship with the mind. So much to learn and understand and I agree, one day maybe scientists will truly uncover the mysteries that remain.

      Ahh the elusive share buttons, they seem to move, appear and disappear at will. Thank you for the thought though, much appreciated!

    • ncyp13 profile image

      ncyp13 19 months ago

      very useful and informative material great explanation.

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Thank you ncyp13, I am glad you enjoyed the Hub and found it interesting. It was a great article to put together this one!

    • ncyp13 profile image

      ncyp13 19 months ago

      I wanted detail in neuropsychology but i am a microbiology lover need detail on it.

    • PsychGeek profile image
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      PsychGeek 19 months ago from UK

      Hi ncyp13, I hope you found the article interesting - thank you for stopping by!

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