Abstracts for selected publications

Gade, A. (1982). Amnesia after operations on aneurysms of the anterior communicating artery. Surgical Neurology, 18, 46-49.

  All patients with ruptured aneurysms admitted to neurosurgical departments in Denmark after April, 1978, are the subjects in the prospective study that includes neuropsychological examinations. Data from 48 patients with aneurysms of the anterior communicating artery have been analyzed. Trapping of the aneurysm was done in 11 patients and resulted in an amnesic syndrome in 9. Thirty-seven patients were operated upon by ligation of the neck of the aneurysm or similar procedures, resulting in 6 cases of amnesia. Trapping invariably disrupts blood supply through newly described dorsal perforating branches from the anterior communicating artery. These perforating branches may supply areas of vital importance to memory function.
 
Gade, A., & Mortensen, E.L. (1990). Temporal gradient in the remote memory impairment of amnesic patients with lesions in the basal forebrain. Neuropsychologia, 28, 985-1001.

  Recall and recognition of premorbid public events were studied in four groups of subjects. Dementia patients showed equal losses from all time periods compared to normal controls. In contrast, two groups of amnesic patients showed extensive remote memory losses, which were most marked for the last few years prior to onset. The difference between recall and recognition was similar in the groups. The results indicate that the retrograde amnesia associated with aneurysms of the anterior communicating artery cannot be distinguished from that of amnesia with other etiologies. Implications of the finding of a temporal gradient in the retrograde amnesia of non-alcoholic amnesics are discussed.
 
Mortensen, E.L., & Gade, A. (1993). On the relation between demographic variables and neuropsychological test performance. Scandinavian Journal of Psychology, 34, 305-317.

  This paper reports a study of the relation between demographic variables and neuropsychological test performance in a sample of 141 normal subjects. A preliminary analysis demonstrated the importance of age, educational level, sex, and Verbal IQ for the prediction of neuropsychological test performance. The main study is a detailed analysis of the relation betweeen these four variables and neuropsychological test performance. The results are presented in the form of standardized regression coefficients and are discussed in relation to the problem of predicting expected premorbid performance in neuropsychological tests.
 
Gade, A. (1994). Imagery as a mnemonic aid in amnesia patients: effects of amnesia subtype and severity. In M.J. Riddoch & G.W. Humphreys (Eds.), Cognitive neuropsychology and cognitive rehabilitation. Hove: Erlbaum. pp.571-589.

  Thirty five amnesic patients, in four subgroups, were studied in the paired associate task introduced by Jones (1974). Three lists of concrete noun pairs were presented and tested in three learning trials and retention one hour later. The first list was presented under standard conditions, i.e. without requests of any specific strategy. The second list was presented with imagery instructions and illustrative pictures. For the third list the patients were requested to generate their own images.
Improvement under imagery conditions was seen in all subgroups. However, severely amnesic patients benefited minimally from imagery. Patients with moderate deficits improved considerably from illustrative pictures, but less so with self-generated imagery. Mildly amnesic patients improved greatly, and the improvement was maintained with self-generated images.
These results indicate that severity of amnesia may be decisive in determining whether imagery instructions aid amnesics, and this could explain why previous studes have produced conflicting results.
  Versions of a dual code hypothesis attributing a dominant role to the right hemisphere in the visual imagery effect are not supported by the results .