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
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 .