Lecture 1: Introduction to the module and neuropsychological approach

What is neuropsychology?

-            Broadly the term refers to the brain (neuro) and the mind (psychology), so could include various aspects of psychology that involve understanding the brain. For example, when used broadly, it includes brain imaging, EEG and animal lesion studies

-            However typically the term refers to: clinical or research investigations of patients with brain damage with an attempt to understand the psychological result/s of that damage. Damage occurs at the level of the neuron but usually we refer to regions of damage

-            Neuropsychology consists of two approaches:

1.        Using a research approach, we hope to uncover new findings about the non-damaged human brain/mind. It is sometimes referred to as cognitive neuropsychology precisely because researchers usually try to uncover aspects of cognition by studying neuropsychological patients

2.        Using clinical approach, we attempt to diagnose the neuropsychological disorder, find out its origins and hopefully devise a suitable way forward for the patient (e.g., patient care and rehabilitation)

-            In general, the neuropsychologist often needs to be an investigator of the brain/mind. To include possible causes and interpret behaviour

The approach in relation to neuropsychology and neurodiversity:

-            Neuropsychology emerged from a scientific/medical model of the brain, and from the 1980s developed into an informational approach to understand structure and function

-            This course follows the current standard understanding of Neuropsychology (e.g., BPS Neuropsychology, Sterling & Elliot, 2008), by looking at neurodevelopmental, acquired and progressive disorders.

-            Neurodiversity: the word has become used in some areas of neuropsychology, most notably in autism where it is seen as a spectrum within a neurodiversity approach (that highlights strengths). Many clinical services now use the terms neurodiversity and neuropsychology to describe their services. This is in the area that typically has been called ‘neurodevelopment disorders’

-            Neurodiversity in this context is the natural variation of our brains based on genetics and the environment. So, we need to think differently about things like autism, ADHD and Tourette’s. disorders such as acquired brain damage and dementia however (although sometimes natural in variation), are not (yet) included in this neurodiversity approach, probably because they are associated with unwanted deficits and outcomes. Therefore, acquired and progressive disorders are discussed in the context of a more traditional medical-diagnostic approach (e.g., Alzheimer’s is defined and labelled a disease)

What do we know about the human brain?

-            The human brain is around 3 lb / 1.5 kg

-            20-25% of the energy consumed by the entire body; 500/2000 calories just to keep functioning

-            However, the human brain only takes up 2% of the body’s mass

-            86 billion neurons in the adult human brain- the most neurons in any cortex in the animal kingdom

-            By comparison the elephant brain is 11lb/ 5kg but has only 5.6 billion neurons in their cerebral cortex

-            In summary considering our relatively small body mass the human brain has a very high concentration of neurons in the cortex than other animals and requires a quarter of our energy

What does a neuropsychologist assess?

-            Some symptoms of brain injuries are clear (e.g., severe memory loss)

-            Most are more subtle and complex

-            Therefore, brain injury is often called a ‘hidden disorder’

Who does neuropsychology?

-            Neurologist

o   Education: medical degree then specialise

o   Specialist in children, older adults; senior: consultant

-            Clinical psychologist

o   Education: BSc Psychology, clinical doctorate; could specialise clinical neuropsychologist, senior: consultant

-            Cognitive neuropsychologist

o   Education: BSc psychology, academic doctorate, senior: professor

Key concepts:

Structure: the regions of the brain, the physical structure that exists

Function: what the brain and its specific areas actually do

-            If a structure is different than usually it has a different use or function (e.g., in birds, wings have its own structure and function;

-            A lot of neuropsychology is about the association between structure and function, and what that means for understanding aspects like memory

Franz Josef Gall:

-            1758-1828

-            One of the main proponents of phrenology; the localisation

-            Idea that the brain has specific centres for different functions of cognition and personality

-            These would be sometimes observable by ‘bumps’ on the scalp

-            Later in the mid-1800s these ideas of phrenology and localisation fell out of fashion

An early history:

-            The brain hypothesis (the idea that the brain is seat of cognition, emotions and movement) emerged from Hippocrates and Plato, then Galen who witnessed the effects of brain damage on gladiators (around 100 AD)

-            However, ‘the heart hypothesis’ persisted for many thousands of years despite this

-            Descartes, who first mentioned the mind-body problem, cited the pineal gland as the seat of sensory awareness- this was later debunked

-            It became widely known that the brain hypothesis was correct

-            Early neurologists (Broca, Wernicke) examined patients’ behaviour then examined their brains after death (at post-mortem). They largely assumed that individual parts of the brain could be responsible for entire cognitive functions (e.g., producing speech). This was the modularity approach- which grew out of phrenology.

-            The idea that dominated next in psychology was behaviourism; a ‘mechanistic approach’ to human psychology. One neuropsychologist, Luria, wanted to focus on the patient in a more humanistic way.

-            Luria’s legacy was to change Neuropsychology into something more human and something that emphasised the functional connectivity between parts of the brain.

-            Luria also established the idea of a functionally connected system, rather than individual units in the brain.

-            Functional systems

-            Then cognitive neuropsychology emerged (e.g., Kc, Tulving 1985)

-            Can involve a lot of box-and-arrow models

-            Coltheart and the case study approach versus group studies

-            Enduring success of neurocase, and ‘the case study’ in general.

The modern view of neuropsychology:

-            Rather than a modular view, as in without this part of the brain, this function is affected

-            It is a complex system of interacting nodes

-            The modern view of neuropsychology is about a complex interacting functional system, with feedback and feedforward and connections between different regions

-            E.g., not just hippocampus but the fornix network, medial temporal lobe and the way it connects with prefrontal cortex, angular gyrus

Advantages of neuropsychology over standard cognitive psychology:

-            In contrast to experimental cognitive psychology, where small adjustments to stimuli/method, can affect the outcomes, in neuropsychology, effects can be large and counterintuitive (Shallice, Ch1, 1988. From Neuropsychology to Mental Structures [available on Library online])

-            A pessimist’s view of experimental cognitive psychology could be that it is a “succession of mirages” (Shallice, 1988, p.5), with no ability to independently verify claims. Neuropsychology can draw upon detailed medical knowledge of the brain (neuroanatomy), with clear deficits after injury (e.g., aphasia/deficit of language), which can provide a more definitive picture of cognitive processes.

-            As we will see in more depth, there are more advantages, and it is the causal nature of the structure-function link that gives it a “head start” over many neuroimaging techniques.