Rehabilitation of the central executive component of working memory: a re-organisation approach applied to a single case.

This paper describes and evaluates a programme of neuropsychological rehabilitation which aims to improve three sub-components of the working memory central executive: processing load, updating and dual-task monitoring, by the acquisition of three re-organisation strategies (double coding, serial processing and speed reduction). Our programme has two stages: cognitive rehabilitation (graduated exercises subdivided into three sub-programmes each corresponding to a sub-component) which enables the patient to acquire the three specific strategies; and an ecological rehabilitation, including analyses of scenarios and simulations of real-life situations, which aims to transfer the strategies learned to everyday life. The programme also includes information meetings. It was applied to a single case who had working memory deficits after a surgical operation for a cerebral tumour on his left internal temporal ganglioglioma. Multiple baseline tests were used to measure the effectiveness of the rehabilitation. The programme proved to be effective for all three working memory components; a generalisation of its effects to everyday life was observed, and the effects were undiminished three months later.

Acquisition of a novel vocabulary in an amnesic patient.

This study explored the ability of a severe amnesic patient (AC) to acquire new vocabulary words. We compared AC's knowledge of words entered into the French lexicon during three different periods: before 1920, between 1965 and 1985, and after 1986 (i.e. after the onset of his amnesia). AC's knowledge was assessed by asking him to give, for each word, its definition (word-definition task), the general domain to which the word belonged ("domain" task), and to generate a sentence containing the word (sentence-generation task). Finally, we administered a recognition task in which AC had to select, for each word, its correct definition amongst four definitions. For all of these tasks, the results showed that AC's performance was similar to that of four control subjects matched for age, education, and profession. In particular, there was no difference with regard to AC's knowledge of words entered into the language after the onset of his amnesia. Therefore, these results indicate that, despite his profound amnesia, AC was able to learn normally new vocabulary words. More generally, they confirm that, at least is some cases, semantic learning can be spared in amnesia.

[A case of metamorphopsia restricted to faces and different familiar objects]. / Etude d'un cas de métamorphopsie limitée aux visages et à certains objets familiers.

The case of a 19-year old patient suffering of transient metamorphopsia restricted to familiar faces and familiar objects is reported. This clinical sign resulted from a small right occipitotemporal haemorrhage due to a sub-cortical metastasis. The patient claimed that faces are distorted and look more pleasant. There were neither visual field defects nor visual agnosia. MRI revealed a small high signal area in the right fusiform gyrus. The structural and functional aspects of the metamorphopsia are documented and discussed in relation to aperceptive prosopagnosia. More specifically, it is suggested that facial metamorphopsia and aperceptive prosopagnosia express the same underlying disorder differing only in terms of severity.

Effects of age, brain damage, and task complexity on the sensitivity of reaction time to the delay between the warning signal and the stimulus.

Four age groups of normal subjects were given a visual reaction time task with three levels of uncertainty. The speed of response improved when the interval between the auditory warning signal and the imperative visual stimulus increased in the range from 1 to 3 s. This delay effect decreased when the level of uncertainty was increased, irrespective of the age. This phenomenon was globally reiterated in two control experiments. A set of 21 brain-injured subjects with clinical complaints concerning attention was also given the test. These subjects were also able to benefit from the delay. The benefit was affected neither by the task complexity nor by the slowness of the reaction times.

Attention and brain damage: a clinical study of response latency under various degrees of uncertainty.

Wyns and Bruyer in 1988 proposed a visual attention test that is easy to use and sensitive both to the age of the subjects and the level of uncertainty about the response required. This test was designed as a fine gauge of attention deficits in brain-damaged subjects with poorly structured complaints. We present here a preliminary application of the test to a group of 48 such persons. Analysis of response accuracy indicated that 27 subjects were deficient in this respect. Of the 21 remaining subjects whose reaction times were analyzable, only one-third appeared as entirely normal.