In order to investigate differences between two cases of verbal long-term and short-term memory impairments following left temporoparietal and left upper parietal lesions, short-term memory tasks were carried out according to two conditions, i. E. auditory presentation and visual presentation. Results showed no differences between these conditions in the temporoparietal lesion patient, but in the upper parietal lesion patient results significantly declined under visual presentation. This disparity between patients may indicate separate mechanisms. These results partly agreed with Soma's schema of the phonological loop of working memory (Soma 1997).

View full abstract

    It has been suggested that cases of amnesic syndrome following rupture of an aneurysm of the anterior communicating artery (basal forebrain amnesia) exhibit the following aspects (Damasio et al. 1985). Firstly, patients are able to learn separate stimuli, but cannot properly integrate those differently learned components. Secondly, patients do not develop a time-tag for the separate stimuli that they learn. Lastly, cueing strongly benefits recall and recognition, of both anterograde and retrograde memories. But more recently, retrosplenial amnesia was shown to be impaired in acquiring temporal information about new stimuli (Bowers et al. 1988) , thereby suggesting that memory impairment for temporal order may not occur in basal forebrain amnesia alone. In our study, to clarify Damasio's hypothesis, 11 amnesic patients of various types (4 basal forebrain, 5 Korsakoff, 1 retrosplenial, 1 temporal lobe) were examined for memory for temporal order. Results showed that recognition memory and memory for temporal order varied among the basal forebrain amnesia cases, that not only basal forebrain amnesia but also Korsakoff patients lose memory for temporal order, and that retrosplenial amnesia does not cause a decrease in memory for temporal order. Three out of four basal forebrain patients who showed decrease in memory for temporal order had not only basal forebrain lesion, but also orbitofrontal cortex lesion. Therefore, memory disorders for temporal order may require an orbitofrontal cortex addition to the basal forebrain lesion.

View full abstract

    The purpose was to evaluate the usefulness of cognitive examinations for differentiating Pick complex (PiC) from Alzheimer's disease (AD). The patients included 11 with frontotemporal dementia (FTD), 17 with primary progressive aphasia (PPA), 3 with semantic dementia and 24 with probable AD. All patients were examined using the Wechsler Adult Intelligence Scale Revised (WAIS-R), Mattis Dementia Rating Scale (DRS), Western Aphasia Battery (WAB) and Frontal Behavioral Inventory (FBI). We measured regional brain volumes using brain MRI and a computer program. We compared results of the examinations among the clinical groups, applied discriminant analysis to predict the most useful examination to classify groups, and correlated cognitive functions with brain volume. The results showed a significant difference in the scores of FBI and some subtests of DRS and WAIS-R between PiC and AD, and in the scores of WAB among the clinical types of PiC. Discriminant analysis showed that FBI was a significant discriminant factor, classifying 69.6% of the patients correctly. In FTD and PPA, scores of WAB and WAIS-R showed a trend toward correlation with the total brain volume, while the results of language-dependent examinations (WAB, DRS, verbal portion of WAIS-R) correlated significantly with the left frontotemporal or parietal brain volumes. We used brain volume ratios in order to eliminate various factors influencing brain volume. The results of WAB and DRS showed a tendency toward correlation with the left temporal ratio only in PPA. We concluded that FBI may be useful in discriminating PiC from AD, and WAB in discriminating PPA from FTD and AD. Based on brain volume-cognition relationship being observed only in PiC, we assumed that dementia in PiC comprises an accumulation of region-specific cognitive deficits, while dementia in AD is based on impairment of more diffusely distributed cognitive functions.

View full abstract

    We reported a case of a 77 year-old right-handed woman who presented right unilateral agraphia due to left frontal lobe infarction. MRI revealed the lesion was isolated to the area from the left posterior middle frontal gyrus, so-called Exner's area, to the anterior precentral gyrus. At the end of 1994, she noticed a slight difficulty in speaking when she talked with her family at noon. She also noticed a difficulty in writing when she tried to take notes. Neurological examinations revealed no abnormalities except right unilateral palatal paralysis. Furthermore, no weakness of the right upper extremity was revealed. Though her speech was a little slow, apraxia of speech, limb kinetic apraxia and constructual disturbance were not detected. Copying and drawing abilities were well preserved. Her writing was slow and laborious. In both spontaneous and dictatorial writings, her ability to scribe (kanji, kana, number) with right hand only showed deterioration. Most of the letter formation was poor. She could not remember the way she used to write. However, writing with her left hand was unimpaired. The present agraphia is assumed to be caused by abnormalities on translating stored writing motor images in parietal lobe into motor programs in frontal lobe.

View full abstract

    Patients with ideational apraxia (IA) who display impairment in the use of objects in test situations, sometimes show proper and effortless tool-use performance in everyday life. The purpose of this study was to examine the dissociation between the faulty use of objects under experimental conditions and their preserved performance in daily living. Tool-use performance in four patients with IA was observed and analyzed in various experimental settings. The patients were required to use a spoon in several experimental situations, from those where semantically relevant information about the spoon was omitted, to those where actual meals were served on plates together with a spoon as in a normal eating situation. All patients showed significantly better performance in the situations where abundant relevant information about the spoon, such as plates or food, was provided, while they showed severe IA in utilizing the spoon in isolation. These results indicated that tool use is possibly influenced by situations in which the tool is surrounded by information, and that IA could be influenced by a patient's situated cognition. The neuropsychological dissociation between tool use in experimental conditions and in everyday life has conventionally been regarded as “dissociation automatico-volontaire” according to the principle of Baillarger and Jackson, but situated cognition may be another important factor to explain the phenomenon.

View full abstract

    This study investigated a shift of the error pattern in phonemic paraphasias in course of time. Repetition tasks were performed by a patient with conduction aphasia periodically. The results showed the error pattern change in moraic error position in a word, the error ratio of consonant to vowel and the error ratio of similar phonemes to similar ones. The results suggested that the error pattern of phonemic paraphasia was transitional in course of time. However, almost error patterns observed did not match to those reported in other papers. The definite regularities of the transitional error pattern were not found.

View full abstract