Sunday, January 31, 2010

Luria-- Semantic fragments for repetition and recall

These stories have layers of meaning and complexity

1. Tolstoy's  The Hen and the Golden Eggs-  A man had a hen which laid golden eggs.  He wanted to get more of the eggs at once, and so he killed the hen.  But inside he found nothing; it was just a hen like any other.

2.  Tolstoy's The jackdaw and the Pigeons.  A jackdaw heard that some pigeons had plenty of food.  She painted herself white and flew into the pigeons house.  The pigeons thought she was a pigeon, and took her in.  However, she forgot herself and cried like a jackdaw.  The pigeons then realized she was a jackdaw and sent her away.  She went back to her family, but they did not recognize her, and would not have her either.

3.  Tolstoy's The Ant and the Pigeon.  An ant went down to the stream to drink.  A wave swamped him and he began to drown.  A pigeon flew past him and threw him a  twig.  He climbed on the twig and was saved.

The next day, a hunter set a net and caught the pigeon.  When he took it from the net, however, the ant crawled up stealthily and bit the hunter on his hand.  The hunter cried out and the pigeon flew away. 

4.  The Lion and the mouse.  A lion was asleep and a mouse ran over his body.  The lion awoke and caught the mouse.  The mouse begged him to let her go.  The lion laughed and let her go.  The next day, a hunter caught the lion and tied him with a rope to a tree.  The mouse came through stealthily, gnawed through the rope, and set the lion free.

5.  The Lion and the Fox.  The Lion grew old and  could no longer hunt animals.  So the lion had to learn how to live by cunning.  He lay in his den and pretended to be ill.   The animals came up to him and he ate them.  One day a fox came but would not go into his den.  The lion asked her "Why don't you come in?" The fox replied, " I can see tracks coming into your den but none coming out." 

6.  The Stupid Dog.  A dog was walking over a bridge at night and saw the reflection of the moon in the water. The dog decided it was cheese and jumped into the water.  But of course, she found nothing and only got wet.

Results  patients who had trouble recalling individual words sometimes had no trouble with semantic fragments, and normals had no trouble with 2 successive fragments.  Amnesics would present the semantic content of one part of the story but forget the second part (retroactive inhibition). 

Luria-- sentence repetition-- aphasia or amnesia??

AR Luria.  The Neuropsychology of Memory VH WInston and Sons, Washington , D.C. 1976 p. 103

Patients with vascular lesions could repeat one sentence, had trouble with the second one.  Patient either reverts to first sentence or contaminates elements, displaying "recency effect" but also simplifying the structure of the sentence while maintaining its elements.  However, patients with temporal lesions showed no "freezing or inert repetition" as in frontal lesions.

Sentence recall-- Luria

Although list learning requires multiple presentations, normals can easily recall one and then a second 7 or 8 word sentence (simplified if aphasic) and then repeat both sentences in order. 

first sentence:  "Apple trees grew in the garden  behind the high fence" or "The hunter killed a wolf on the edge of the forest.  "  Second sentence  :  " In Tashkent there was an earthquake and many houses were destroyed" or "In Tushino there was an air display and parachute jumps." 

Simpler versions "The boy is cold" or "the girl is asleep" or "the boy hit the dog" or "the girl drinks tea"

Results: Amnesics could repeat the sentences immediately, or after empty or filled pauses, with some trouble if the pause was filled with rapid speech.  However, when given a second sentence, they either lost the first or mixed up the elements. 

Disturbance of seriality due to left temporal lesions

Luria in Neuropsychology of memory states that left temporal lesions cause a disturbance of retroactive inhibition in which the last word of the list inhibits recall of predecessors on the list, especially with longer lists.  The effect only occurs with lists presented and reproduced verbally.  Luria gives original credit to Lashley

Lashley KS.  Functional determination of cerebral localization.  Arch Neurol Psych 38: 1937.

Learned motor responses.

Subject is asked to raise his left hand to one tap, and his right hand to 2 taps, or to raise his hand to one tap and to refrain from raising his hand to 2 taps. 

More complicated version: patient is asked to respond to a fist with a finger, or to a finger with a fist.  Or, he is asked to responnd to two taps with one tap, and to one tap with 2 taps. 

More complicated yet.  the subject is asked to respond to a weak tap with a powerful hand movement, and to a powerful tap with a weak hand movement.  Or, to respond to a short acoustic stimulus with a slow movement, and a long stimulus with a prolonged movement. (cf  Marushevskii M, Disturbance of the simplest forms of voluntary action in local lesions of the frontal lobes.  in Luria AR, Khomskaya ED (eds), The frontal lobes and the regulation of psychological processes. Moscow, MGU Press, 1966.

Luria's adaptation:  He would give one task, and when mastered give a second, then without repeating instructions, go back to the first, and then the second task.  Normals had little trouble either learning the task or switching.  Neither empty or filled paused had much effect, (except occipital lesions for visual tasks and temporal lesions for auditory tasks).  Massive tumors had problems with task. 

Patients with thalamic lesions could learn the task, but not do it verbally.  These patients learned the task, were not affected by interference, but could not talk about it. 

Unadze illusion fixed set test

From Luria's book Neuropsychology of  Memory

Unadze DN.  Experimental psychological investigations.  Moscow.  Nauka.  1966.

A subject is given 2 balls of different sizes to squeeze (one per hand) 10-15 times for several seconds per squeeze.  He compares their sizes and reports his finding.  Then, without visual inspection he is given 2 balls of equal size and asked to compare the sizes.  The result is that the hand that held the larger ball now reports it is holding a smaller ball, and is maintained even after 12-18 trials.

Luria's variation was to test normal, mildly and severely impaired subjects on the test.  He found that in severely amnesic subjects only, and only with interference, the fixed set effect was achieved but rapidly forgotten, underlying the importance in interference on somatic memory. Pauses less than 2 minutes had little effect on retention, as with other types of learning.

Saturday, January 30, 2010

Gerstmann's syndrome reader

Kombos T,  Picht t, Suess O.  Electrical Excitability of the Angular Gyrus. Journal of Clinical Neurophysiology 25(6) December 2008 .
Comment.  This is the first report of direct electrical stimulation of AG in humans. Stimulation resulted in responses in contralateral upper extremity in 3/5 patients.  No lower extremity stimulation was found.

Anema HA.a,  Kessels RPCcd, de Haan EHFe,  Kappelle L,  Leijten F, van Zandvoort Martine , Dijkerman,H.  Differences in finger localisation performance of patients with finger agnosia

 19(14) September 2008 . 
Comment : 3 patients with AG lesions were able to point with their finger effectively
to  a tactile stimulus (body schema intact) but unable to do so with a drawing  of hand or to name the finger. 
Other body parts did not have this dissociation between body schema and body image.

Tamura I, Kikuchi S, Otsuki M, Tashiro K. The writing of arabic numerals, kanji, and kana in brain-damaged patients. 14(6), 6 May 2003, pp 861-865.
Comment.  4 patients with Gerstmann's syndrome and 4 with Wernicke's aphasia were compared.  All patients could copy letters, and were righthanded.  Subjects were presented with coins, and then asked to write the respective number value in kana , Kanji and Arabic numerals. For GS patients, kanji writing was better than Arabic, that was better than kana writing.  For WA aphasia patients, Arabic numeral writing was better than kana and kanji. Discussion: "In the case of GS, there was a problem in the concept of number.  In the case of WA, the concept of number was relatively well preserved." GS subjects made substitution errors in Arabic number writing.  Authors postulate a deficiency processing recall of somesthetic graphemes linked to the  concept of number.

Wingard E, Barrett  A, Crucian G, Doty, L, Heilman, KM.  The Gerstmann syndrome in Alzheimer's disease. Journal of Neurology, Neurosurgery & Psychiatry  72(3) March 2002 .
Comment  :  among 38 patients with Alzheimer's disease, the four constituent components of Gerstmann's syndrome did not cluster together, leading the authors to speculate that their association is fortuitous due to contiguous networks, and that the four features of Gerstmann's syndrome do not share a common network.

Baciul M, Koenig O, Vernier M,  Bedoin N, Rubin C, Segebarth C. Categorical and coordinate spatial relations: fMRI evidence for hemispheric specialization. Neuroreport 10(6) April 1999.
Comment: 16 healthy males were examined on a coordinate and a category task using fMRI paradigm.  The category task was whether a dot was above or below a horizontal line. The coordinate task was whether the distance between the dot and the line was within a reference distance.  The coordinate task related to right AG activation which decreased over time.  The category task depended upon Left AG activation which did not decrease over time and in fact increased over time.  Results subserve the hypothesis that the left hemisphere subserves the development of new spatial categorization.

Thursday, January 7, 2010

Cognition and Fragile X syndrome

Fragile X problems persist into adulthood (even though it is considered a pediatric disease). Two separate conditions exist. Patients with the premutation (55-200 repeats of the FMR1 gene) have RNA toxicity but not full blown cognitive abnormalities. RNA toxicity can include primary ovarian insufficiency, fragile X associated tremor ataxia syndrome (FXTAS), fibromyalgia, hypothyroidism, and psychiatric issues such as anxiety and depression. Boys in this range can experience shyness, social anxiety disorders, ADHD and autism spectrum disorders. This is due to excess FMR1 gene.

Patients with the full mutation (greater than 200 repeats) have LACK of FMR1 and Fragile X syndrome (opposite of above in which there is excess RNA present). They present with severe cognitive abnormalities. In boys this manifests as autism, in girls as severe learning disabilities. They also have connective tissue disorders, agression, and psychiatric problems as above. Males with FXS usually have IQ below 70 (severe) but 15 % are "high functioning" with IQ above. High functioning is due to mosaicism within cells or within methylation and the degree of impairment is related to the amount of FMRP present. Among girls, 40 % have a normal IQ, 35 % are borderline, and 25 % have an IQ below 70. The activation percentage (pct of normal X that is active) correlates with disease and that and amount of FMRP available also affects functioning of offspring.

FXS is the most common cause of intellectual impairment and of autism spectrum disease. The full mutation occurs in 1:2500 in population, and the premutation occurs in 1:250 girls and 1:800 boys in the general population. Genetics: FXS patients always have their mother as a carrier. Fathers often pass the premutation on, to their daughters and it does not expand to a full mutation. Mothers with premutation often have expansion to full mutation in their offspring, especially if the number of repeats is greater than 100.

See also posts on FXS and FXTAS on

Sunday, January 3, 2010

Cognition and dystrophinopathy

Duchenne's muscular dystrophy has associated delayed milestones especially language, global cognitive impairment, and occassionally autism. Becker's muscular dystrophy has less common findings, but also, compared to general population, has more learning disabilities with normal intelligence, autism, attention and behavioral problems. Orofacial problems may occur.

Botteron S, Verdabout CM, Jeannet PY, Kiliardis S. Orofacial dysfunction in Duchenne Muscular Dystrophy. Arch Oral Biol 2009; 54(1): 26-31.

Cyrulnik SE, Fee RJ, De Vivo DC, et al. Delayed developmental language milestones in children with Duchenne's muscular dystrophy. J Pediatr 2007; 150 (5): 474-478.

Hinton VJ, Fee RJ, Goldstein EM, De Vivo DC. Verbal and memory skills in males with Duchenne muscular dystrophy. Dev Med Child Neurology 2007; 49 (2): 123-128.

Young HK, Barton BA, Waisbren S, et al. Cognitive and psychological profile of males with Becker muscular dystrophy. J Child Neurol 2008; 23 (2): 155-162.