The rey-osterrieth complex figure test (ROCF)

ROCF Is a neuropsychological assessment where subject are asked to reproduce a complicated line drawing. Participants need to copy the image then copy it by memory. Engage in this task elicits many cognitive abilities when performed correctly, therefor it can be used to evaluate different functions, such as visuao-spatial abilities, memory, attention, planning and the working memory/ executive functions. One aspect of this test was to differentiate between primary effects which is the direct results of the head injury and secondary effect which is developed out the subjective reactions determined by the loss of awareness from physical impairments.  In neuropsychology, the ROCF may be used to localize and assess the magnitude of brain damage. In education, the ROCF may be used to evaluate input processing of a child suspected of having a learning disability. Strength of this test is that it can be applied to a broad range of people such as children and adults that are normal, have learning difficulties and brain damage patients. The critique about this test is that the test has been widely used but there is a limited amount of published research articles suggesting the need for survey across a broad spectrum of test user such as neuropsychologist, clinical psychologist and school psychologist. The score criteria in relation to normative data and test results showed significant deviation not only from the standardized procedures set forth by Osterreith, but from one researcher to another. This deviation is appropriate with regards to normative data, but it is an area of concern with regards to other aspects of the test. For example, evaluation of test results must include consideration of the copy score derived from the elements of the ROCF design within the context of the organizational approach. Consideration must also be given to the subject's age as the research indicated a correlation between age and score and also implied that it may not be appropriate to administer the ROCF to children under 9 years old

Memory

Memory related to procedural memory such as developing new skill and habit can sometime be formed without the hippocampus…

The frontal cortex is involved with planning and foresight, it also selects actions and behaviour. The basal ganglia is involved in guiding and directing voluntary movement. There are connections from basal ganglia to the thalamus that send information to the prefrontal cortex. Every time a complex motor action is executed by the prefrontal cortex that was guided by the basal ganglia, particularly the caudate nucleus and putamen, the loop via the thalamus back to the prefrontal cortext help to strengthen the activity of those circuits. This then lead the process were practiced movement become habits whereas they are able to be performed automatically without conscious effects such as playing the piano, which was initially a conscious effect at first then became automatic as it was directed by the prefrontal cortex. This system works independently from the limbic forms of learning and memory. Therefore someone that has bilateral damage to the hippocampus, that is similar to the case of H.M., can be taught to play the piano by practising everyday but they would not have memories of practising, but if you were to ask them if they can play the piano they would say no.  However if you asked them to try they would be able to play, but would not be able to explain how and why they are playing this is because the frontal cortex and the basal ganglia circuit would have learned independently and separately from the damaged limbic system circuit.

Hippocampus  

  The hippocampus is a brain structure that I located under the medial temporal lobes in both hemispheres. The hippocampus plays an important role in the formation of new autobiographical and factual memories it can be identified as a path way in which new memories need to go through before being sorted in the long term memory. Damage to this area can lead to anterograde amnesia; this is the loss of ability to form new memories while previous memory before injury may still be intact.

the frontal lobe - Autism and Asperger Syndrome

Further reading on The theory of Mind – Autism and Asperger Syndrome

Theory of mind is the ability to understand mental state such as beliefs, feeling, desire, hope and intentions. This ability develops rapidly in young children but has slow rates in autism. The sally –Anne test is commonly used to test theory of mind. Neuroimaging studies has located specific region that are activated during theory of mind tasks such as the anterior paracingulate cortex, the superior temporal sulci and the temporal poles bilaterally. However those that have Asperger syndrome show significantly lower activation in this brain region which has been identified as importation for engaging in mentalising task in normal people.      

People with autism suffer from the lack of central coherence which is the cognitive ability to combine together a group of separate features in to a single coherence, object or concept. There is evidence that suggest that test for factual knowledge and focuses attention to detail can lead to high performances whereas test tapping in common sense comprehensions can show low performances. This therefore shows differences in information processing style rather than a deficit. For example when retelling a story normal individual finds it easier to recall gist of the story rather than the specific detail. Whereas those with autism do the opposite therefore suggesting that they have a weak coherence  

The Gestalt psychology argues that it is not the inability to combine information together but rather that they have an enhanced discrimination of individual element. Suggesting that the early stage of sensory processing are intact in autism, but the top-down modulation of these early processing stages which extract global feature of stimulus is not functioning properly.

In addition many have suggested that it is an innate ability however there has been controversial argument that it is a learnt behaviour and perhaps autistic children find it difficult to learn.  

Example of the sally- Anne test

A sally- Ann test is used to judge whether a person has a theory of mind. A child is presented with two doll, sally and Ann each doll has their own box. Sally put a marble in her own box and pop out the room  them Ann pay a tick on sally and takes the marble and hid it under her box, sally come back in the room, the researcher askes the child were would sally look for her marble .     

A child that has a theory of mind, know that Anne played a tick  on her and would look in her own (Sally) box however a child that lack the theory of mind would see the situation through her own point of view and would say that Sally should look under Anne box, children between 6-7 are able to perform well on this task even some children as little as 3.

There is also evidence to suggest that some intelligent autistic can do the test through logical deduction without having the ability of theory of mind whereas those with low intelligence would perform poor on this test.

 Frontal lobes

Describe the main components of the frontal lobes

The Cerebrum: The cerebrum or cortex is the largest part of the human brain, associated with higher brain function such as thought and action. The cerebral cortex is divided into four sections, called "lobes": the frontal lobe, parietal lobe, occipital lobe, and temporal lobe. Here is a visual representation of the cortex:

• Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, and problem solving
• Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli
• Occipital Lobe- associated with visual processing
• Temporal Lobe- associated with perception and recognition of auditory stimuli, memory, and speech

The cerebrum into two halves, known as the left and right hemispheres. The two hemispheres look mostly symmetrical yet it has been shown that each side functions slightly different than the other. Sometimes the right hemisphere is associated with creativity and the left hemispheres is associated with logic abilities. The corpus callosum is a bundle of axons which connects these two hemispheres.

Evaluate the function of the frontal lobes

Compare some of the testing for frontal lobes dysfunction

The problem of measuring frontal lobe abilities is that the test of frontal lobe function does not always measure the ability of the patient

Common methods of measuring frontal lobe ability

1.      Sequent events logically and temporally

2.      To reason abstractly – Wisconsin card sorting test – giving a stack of card  containing  broken down in 4 section red triangle -2 green star  3 yellow cross 4 blue circles  they are giving 2 set of card 64x=128 and are told to organised them in to either colour shape or number and must change after ten correct response to another organising order – results how that patient with frontal lobe damage perform  poorly more error and fail to complete the sorting – other problems is sorting card of 6 into two pile of 3 based on the designs of the card and building block according to high colour and shape – tower of London task  see page 168

3.      To be have spontaneously

4.      Verbal fluency – measured by the controlled oral word association from the multilingual aphasia examination – this test require for the patient to name as many name possible begging with the letter giving – results show that patient perform poorly compared to  controlled group

Give example of symptoms of frontal lobes dysfunctions  

Answer these questions

Do the frontal lobes mediate intelligence?

 How do the frontal lobes effect decision making and reasoning task?

 Are the frontal lobes necessary for the theory of mind?  

Hemispheric Lateralisation

Further Reading on handedness.

Why is there a dominance of right hander this pattern and been observed for over 5000 years. Animal tend to show an equal distribution between left and right pawed, whereas humans show a preference for the right hand. The two cerebral hemisphere process information differently, brain research has put forward the idea that left-handedness is the produced by abnormities in the bran such as a defect caused by a reduction of blood supply to the left hemisphere during the fatal growth. Damage to the left hemisphere can case a shift of dominant limb function to the right hemisphere. However these finding ate not see with premature birth, prolonged labour and breech birth. Another conception is that testosterone can slow down development in the left hemisphere in male foetus suggesting that high levels of testosterone is responsible for left handedness unsurprising this result was  unsubstantial.      

 There has been a debate that left – handedness many have genetic components. This argument claim that it is inherited, whereas left handed parent are more likely to have left handed children evidence to support this claim was adoption studies indicated that adopted children handedness  resembled their birth parent rather than their adopted parent. Additionally researcher  have stated that there is a single gene that in found in right hander and individual that do not have this gene exhibit random handedness however other have rejected this hypothesis because if both parent are left handed and left handedness was a recessive trait then all their children should be left handed. This show that there may be more than one gene involved or other factors may play a role.     

Handedness has many definitions, but is commonly known as the hand that a person uses to write. With this this context there has been debate about this vague definition. Other identifies it as the hand that performs the fastest and precisely, alternatively it can be seen as the hand that is preferred regardless of performances. There has been dispute about the different type of handedness, left or right. Whereas other feel that ambidexterity should also be included in the category. Furthermore there has been critique suggestion that there is two different type of ambidexterity. Paul Broca claim that the person handedness was the opposite side of the of the specialised area, this propose that a right handed person most likely have left hemisphere language dominance specialisation  however there has also been evidence to suggest that left hander also show dominance for language in the left hemisphere. While half of left handers use their right hemisphere, some left hander control writing completely and independently by the right hemisphere in the bran.

Summary of the Topic

The two cerebral hemisphere are not exactly alike. Each hemisphere have specialised functions, in addition some of the neural mechanisms are located primarily in one half of the brain. Paul Broca was the first to suggest that cognitive function is localised in the brain, for instance speech and language abilities showed dominance in the left hemisphere. Wernicke found other area in the left hemisphere that was responsible for language comprehension. Clinical reports have shown not hat around 70-95  of human have a left hemisphere language specialisation therefore around 5- 30 of humans have an abnormal pattern of specialisation  such as showing dominance of language in the right hemisphere or little literalised specialisation. 

Movement Disorders

Movement disorders

Cerebral palsy is another movement disorder. That effect movement and posture. It cannot be categorised as one single syndrome, disorder or conditions as this motor deficit can take many form. It is usually caused by brain damage. Lesions to the corticospinal tracts, basal ganglia, brain stem and cerebellum are responsible for this disorder but there are difficulties labelling the lesions with clinical finding. Brain abnormities may develop during fetal development or periods up to 3 years after birth. There are three main types cerebral palsy which are:

•       Spastic cerebral palsy
•       Dyskinesia cerebral palsy
•       Ataxic cerebral palsy  

movement disorder is the inability to produce and control movements. Simple movement require a complex system of control and impairment to the prefrontal and premotor cortex can cause movement that are too week, too forceful too uncoordinated, or too poorly controlled for the hands and in addition unwanted movement can occur unexpectedly. Examples of this disorder are:

•          Parkinson disease
•          Huntington disease
•          Tourette syndrome
•          Restless leg syndrome

 Movement is produced and coordinated by several interacting brain structures this includes the motor cortex, the cerebellum and the basal ganglia which are group structure that are deep within the brain.

 The cerebellum and the motor cortex send information to the basal ganglia to control involuntary movements whereas the basal ganglia send out information to the motor cortex to help initiate, regulate pattered movements.

Kolb, B., & Whishaw, I. Q. (2003). Fundamentals of Human Neuropsychology (5th ed.). New York: Worth Publishers.

Neglect - blindsight

Neglect in dyslexia

Not only is neglect a spatial disorder it can be found in words

-the case of NT

- AGE 9 – diagnosed of having language problems (Friedman and Nachman – Katz 2004)

- Did not have any visual brain damage or abnormities –but had left word base neglect dyslexia 

-  He was unable to read the left side of words – this was demonstrated through his drawing

-His native language is Hebrew – so he wrote from left to right- so when he write he  leave out or substitute the final words of single letters on the left hand side  – finding show 96%   of his words show these irregularities

- When giving pair of words or sentences – he neglect the left part of the word but not the whole word on the left hand side of the paper

- Improvement are made – by making the neglect word part different colour or making it flash (in other world making it stand out)- also by presented the word vertically than horizontally

-finally does not sown neglect for numbers or symbols

Neglect

Spatial neglect – is the inability to respond, report or attend to the stimuli or event that is in the opposite side of the brain injury

The effect of neglect can happen after months and years of the lesion.

Damaged to the right hemisphere  can lead to neglect of stimuli  on the left hand side and damage to the left hemisphere can lead to neglect of the stimuli on the right however this is not as serve as right damage .

Short term memory * spatial working memory

Short term memory can also appear with neglect symptoms when there is damage to the right parietal lobes  

A study was conducted to test the different in impairment with those that have right neglect and non parietal damage with those with parietal damages using a imagery test that consist of a map of familiar piazzas

Results show that those that had right neglect with parietal damager were significantly more impaired than those that had no injury to the parietal lobe    

Not being able to hold spatial information in the working memory can lead to patients being unable to remember the locations of stimuli- Malhotra et al 2004

Case study

Patient BI

Symptoms of left neglect and right temporal haemorrhage- lead to impairment of spatial location - when giving a visual search task e.g. – mark as many T that u see on the page that are among mix letters  -results show that repeatedly search on the right side-  returned to item that were already noted and saw them as new items

Results show that subtle memory deficit (damage) may affect the performances   with performances of neglect patient 

In regard to the different type of neglect they can be defined by their underling mechanising:

-inattention underlies sensory and perceptual neglect

- Disorder if action and intention underling motor neglect

-representation underlies the neglect of the visual and metal images

Examples of neglect

Difficulties in reading the time

Missing food on one side of the place

Dressing up on one side of the body

 Patient are normal unaware of this behaviour – (anasagnosia) until it pointed out to them

 How to test for spatial neglect

Test

Line bisection – patient are giving lines that are vertical or horizontal and are instructed to put a mark in the middle of the line those that have neglect mark the line closer to the right side when the line is horizontal and the upper end of the line when it is vertical –

Reducing spatial neglect

Recovery can be slow – from 18^th to indefinably

Flashing a red light to the left side of a patient when they are reading copying or cancelling reduces neglect – this works because patient pay attention to one side of an imagery task

Making salient on the right hand side less important to can also reduce neglect  

Vibrating the left posterior neck muscles - this stimulate the neck muscles to generate a body centred frame, the vibration corrects the displaced body- centred frame

Caloric vestibular stimulation – it elicit a vestibular ocular reflex – this can reduce eye movement in the opposite direction to the Attention bias

Opokinetic stimulations – improves voluntary eye gaze direction  

Result 

17 of out of 18 improved when giving spatial neglect test – improvement were short term

These strategies seem to be used rectify inability to automatically to shift attention to the neglect side

 Location of lesions is the spatial neglect 

Lesions are found in the right parieto –temporal cortex

Injury   the inferior and temporal cortex

Damage to the basal ganglia and thalamus following a subcortical stroke – all linke to sensory neglect 

Conception to explain neglect

Pragmatic map - Damage to the perceptuomotor cortical and subcortical can lead to neglect  when they are stimulated this activate spatial awareness – each map have different mechanism and responsibilities for head arm and leg movement

the eye

Why do we need to move ours across a scene?

The information that is recorded in the retinal region only contains 50% of what is sent to the brain through the optic nerve.

When we move our eyes to focus on a specific region of an image or object, we are essentially placing the foveal region of the eye on top of the area which is currently within main focus of the lens in our eye. letting the foveal region register the image, the brain get the highest resolution possible for the image of the interesting area to process

·         The human visual field spans about 220 degree

·         divided in 3 main regions: foveal, parafoveal, and peripheral region

·         register visual data through the foveal region which constitutes less than 8% of the visual field

Would it not be easier if we could see the whole scene in front of us at once?

In order for us to accumulate all the information of a scene at one our skull need to be bigger as a normal size skull is unable to deal with all the information. In addition the high spatial resolution is located in a small section of the retina.

For this to be possible we would need to have slightly bigger eyes and brain to register the information that is sent. You would also need more reception and structures to process that information this would then increase the amount of neurons and photo receptor. Therefore this would increase the need to feed those neurons and photo receptor therefore incensement in energy consumption. Also you Need the photo receptor spread all across the retina not just in the fovea  you would need high density mean that you can get everything from the scene but you going to get lot of information that you do not need.

The brain consume a lot of energy glucose hungry structure – when looking an anorexic  person the brain and the cognitive activities  are normally ok  but the mussels fade away because  a lot so the energy that is need for  the brain is protected through evolutions . The energy that the brain is consuming is not going to be available muscles start to decrease. – When looking at extreme anorexia there are mechanism that are emplaces to  protect the brain as it steel the energy from other part of the body.

When the brain does not have the bare minimum that it need it put the body in a comma so it perceives it by not being active. You would not see an extremely hungry person that would be anxiety to find food but when the energy supply is so low they would enter a stage where they are unable to move and are waiting to die – this is seen with cases of extreme farming –no energy to move hence the reason why they do not get up and search for food.

Animals effect – we seen that some animal have smaller brain and bigger bodies this is because  the motor control that they have is smaller and the energy  that is consumed there the brain need less energy. Save energy by not having highly developed contrive skills

What does FEF mean? And what is its role in vision?

FEF it the abbreviation for frontal eye field it is located in the frontal cortex and controls generation for motor commands for pointing the eye and directing   the eye to desire location and play a role in directing spatial attention.

Topic of the week

Agnosia is a recognition disorder. Visual information is only useful when objects can be recognised by the brain. Brain damage can lead to several problems with the visual perception Visual Agnosia inability to recognize objects even though elementary visual functions remain unimpaired.

Can be broken down in to two subsections

·         Apperceptive Agnosia

Impairment occur during the perceptual processing

The case of HJA- he suffered from bilateral stroke was unable to recognise picture but give a reasonable description of it parts.

e.g.  a carrot – bottom bit seem solider the other bit seem feathery

Diagnosis is that his has difficulties in perceptual grouping mechanisms  

·         associative Agnosia

Impairment occurs during visual memory representation. (lissaure 180)

Object constancy – object remain the same even in different positions and lighting condition   

Studies have shown that they are able to name and recognise objects from a usual view rather than an unusual- (Humphreys& riddoch 1984)- this happen when there is damage to the right parietal lobes

The parietal lobes – may have mechanisms to extract the structure of an object and for rotating objects so that it can be identified at different view points

  

   Object Agnosia

Unable to decide the correct orientation of an object or whether the two objects presented have the same orientation even thought they can recognise the object.  

FMRI studies show that using pair of object that are different size and view point can test object constancy. For the reason that when the same object are pair repeatedly the response of the neuron decreases over time. Therefore you can correlate the different factors such as size and view point with the responses of the FMRI results.

Finding suggest that left infero – temporal region response irrespective of view point for size whereas view point was important for the comparable region in the right hemisphere

Prosopagnosia

The inability to recognise previous familiar faces.  

Face recognition – Bruce and Young (1986) the is a different between the process used to recognise familiar and unfamiliar faces.

Familiar faces are recognised by matching it to a stored face data base description

De Renzi (1986) – was unable to recognise some of his family members but was able to identify them through their voices and other non facial information

The fusiform face area in the right hemisphere may specialize in faces Kanwisher(2000)

Category perspective – a area of the brain that can recognise different categories of objects such as animal, face, body and words.

Further studies has identified that there are other part of the brain that is related to visual recognitions which is:

Parahippocampal- place are this is reasonable for scene that are more than objects and extrastriate body are – responds to the human body more than faces and objects.