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Biomedical subjects

C Papagno

Publications and source records attributed to C Papagno.

At least 19 recordsLinked to original sources
PubMed1998

Transient retrograde amnesia associated with impaired naming of living categories.

A ease of pure retrograde amnesia following mild head injury is reported. The patient, who also showed a deficit in verbal fluency and a living/non-living dissociation in naming during the amnesic period, recovered progressively in about ten days post-trauma. Both a psychogenic and an organic origin could be taken into account. A mechanism (no matter if psychogenic or organic) can be hypothesized, which produces a functional inhibition also involving performances that are unlikely to be affected by psychological factors.

Adult↗
PubMed1998

Proper name anomia: a case with sparing of the first-letter knowledge.

In this article we describe the case of GC, a woman affected by severe proper name anomia due to progressive brain atrophy that mainly affected the left temporal pole. Proper name comprehension and semantic knowledge about the people she was unable to name were normal. GC showed a sparing of initial letter knowledge of proper names, while other phonological characteristics were not equally available. At a later stage of her illness, the naming impairment began to affect common names as well as proper names, though at a lesser extent. Whereas there was no category effect between names of animate and inanimate stimuli, we observed a relative sparing of first letter knowledge selectively for animate categories, although less marked than with proper names. This case is discussed within the theoretical framework of two-stage models of name production. Knowledge of the initial letter of proper names supports the psychological reality of the "phonological address" as a preliminary stage of the production of this class of names. Moreover, the qualitative similarity between errors observed with proper names and with names of animate objects suggests that the production of names belonging to these classes may conform, at least in part, to analogous algorithms.

Anomia↗
PubMed1998

The phonological loop as a language learning device.

A relatively simple model of the phonological loop (A. D. Baddeley, 1986), a component of working memory, has proved capable of accommodating a great deal of experimental evidence from normal adult participants, children, and neuropsychological patients. Until recently, however, the role of this subsystem in everyday cognitive activities was unclear. In this article the authors review studies of word learning by normal adults and children, neuropsychological patients, and special developmental populations, which provide evidence that the phonological loop plays a crucial role in learning the novel phonological forms of new words. The authors propose that the primary purpose for which the phonological loop evolved is to store unfamiliar sound patterns while more permanent memory records are being constructed. Its use in retaining sequences of familiar words is, it is argued, secondary.

Adolescent↗
PubMed1997

Confabulation in a dysexecutive patient: implication for models of retrieval.

A confabulating patient MM is described who, despite clear evidence of a dysexecutive syndrome, showed normal prospective and retrospective memory in everyday life and preserved autobiographical memory. He also performed well on many, but not all laboratory-based measures of learning and memory that were given. His confabulation typically involved going well-beyond the information he could genuinely recall, and was attributed to a defect in memory monitoring resulting from his frontal lobe damage. Implications for the role of "stop rules" in memory retrieval are discussed.

Adult↗
PubMed1997

Dual-task performance in dysexecutive and nondysexecutive patients with a frontal lesion.

Patients with defined frontal lobe lesions were assigned to 1 of 2 groups based on whether they showed a behaviorally assessed dysexecutive syndrome or were behaviorally normal. All participants were tested on dual-task performance and on 2 tasks assumed to measure frontal lobe function, the Wisconsin Card Sorting Test and verbal fluency. The dysexecutive group differed significantly from the nondysexecutive in showing impaired capacity for dual-task coordination, but there were no significant differences on the Wisconsin Card Sorting Test and verbal fluency. Results are interpreted in terms of a multicomponent central executive, whose function is linked to, but not coterminous with, the operation of the frontal lobes.

Adult↗
PubMed1997

Transcallosal approach to tumors of the third ventricle. Surgical results and neuropsychological evaluation.

A series of 34 patients with tumours of the third ventricle were operated on by a transcallosal route. Basal extrinsic lesions compressing or invading the ventricle as well as tumours located in the pineal area were excluded from this review. Tumours were approached by a transforaminal entry in 16 cases (47%), by an interforniceal route in 11 (32%), by a subchoroidal entry in 4 (14%) and by a combined transforaminal and subchoroidal entry in 3 (9%). Four out of 34 patients were submitted to a second operation, through the same approach corridor: 2 for an incomplete removal of an intrinsic tumour and 2 for a late regrowth. Postoperative mortality rate accounted for 5.8% (2 patients). Major post operative complications were hemiparesis (4 patients) and diabetes insipidus (4 patients), that were transient in 3. Akinetic mutism like status was observed in only 1 patient. Postoperative psychic disturbances were noticed in 5 cases. Nine out of 21 patients (62%) with preoperative hydrocephalus required a permanent CSF shunt. Histology revealed that 21 tumours (62%) were intraaxial (4 pilocitic astrocytoma, 10 low grade glioma, 1 giant cell astrocytoma, 1 subependymoma, 4 ependymoma/ependymoblastoma, 1 neurocitoma) and 13 (38%) were extraaxial (8 colloid cyst, 2 craniopharingioma, 1 ectopic pituitary adenoma, 1 lymphocytic hypophysitis and 1 metastasis). Total excision of third ventricle tumours was achieved in all patients with extraaxial tumours and in 62% and 71% of intraaxial tumours with the first and second surgical procedure respectively. Ten out of 34 patients of this series were submitted to a complete neuropsychological evaluation at an interval of 2-9 years after surgery. Memory tests were pathological in 2. Disconnection signs were constantly absent. Control function were preserved. Transcallosal approach remains the best microsurgical method of third ventricle tumours treatment. This route provides the capability for a superior visualization of the entire cavity of the third ventricle through different corridors. Permanent neurological and neuropsychological deficits are not frequent. Epilepsy, that accounted for 28% in patients submitted to transcortical transventricular approach to third ventricle tumours, was never noticed in this series operated on through a transcallosal route.

Adolescent↗
PubMed1996

Perseveration in two aphasic patients.

In this paper we report the perseverative behavior of two aphasic patients, AB and MT. They were submitted to a standardized Language Examination and to verbal and nonverbal tasks designed to elicit perseveration. Some of the features pointed out in the literature were not confirmed. Perseveration was not semantically related to the target; a correct response did not have any special status; in many instances the perseveration had not been produced as a correct response and could reappear immediately or after many stimuli; the production of two consecutive correct responses did not inhibit the spontaneous recurrences and could again be followed by the perseveration of a previous wrong response. Perseveration did not set in in the same circumstances for the two patients: in AB it set in when the patient was unable to find the correct response; MT, on the contrary, while knowing the correct response, was unable to change her perseverative behavior from one response to the other. For both patients, however, it seems as if no inhibitory system stops pre-existing motor or verbal behavior.

Adult↗
PubMed1995

Improvement of left visuo-spatial hemineglect by left-sided transcutaneous electrical stimulation.

The effects of transcutaneous electrical stimulation on left visuo-spatial hemineglect, assessed by a visuo-motor exploratory task (letter cancellation), were investigated in patients with right hemisphere lesions. In Experiment 1 left neck stimulation temporarily improved the deficit in 13 out of 14 patients (93%), while stimulation of the right neck had no positive effects, worsening exploratory performance in nine patients (64%). Experiment 2 showed that left neck stimulation temporarily improved neglect also when head movements were prevented by a chin-rest. In Experiment 3, stimulation of both the left hand and left neck had comparable positive effects on visuo-spatial hemineglect. These results are interpreted in terms of: (1) non-specific activation of the right hemisphere, contralateral to the stimulation side; (2) specific directional effects of left somatosensory stimulation on the egocentric co-ordinates of extra-personal space, which in neglect patients are distorted towards the side of the brain lesion.

Adult↗
PubMed1995

Transient left-sided alien hand with callosal and unilateral fronto-mesial damage: a case study.

A patient who showed a transient left alien hand after a subarachnoid haemorrhage, due to a ruptured aneurysm of the anterior communicating artery, is described. No left agraphia and left apraxia could be found. A CT-scan including coronal sections showed a right medial frontal hypodensity and different ischaemic lesions in the anterior part of the corpus callosum. The possible anatomic site of the lesion responsible for the permanent form of alien hand is discussed.

Adult↗
PubMed1995

Vestibular stimulation, spatial hemineglect and dysphasia, selective effects.

The selectivity of the effects of vestibular stimulation was investigated in a left brain-damaged patient suffering from right visuo-spatial hemineglect and severe dysplasia. Vestibular stimulation temporarily improved the former but not the latter disorder. These results support the view that this treatment improves hemineglect by a specific effect, running counter the rightward distortion of egocentric co-ordinates, rather than by a general hemispheric activation.

Aged↗
PubMed1995

Verbal short-term memory and vocabulary learning in polyglots.

Polyglot and non-polyglot Italian subjects were given tests assessing verbal (phonological) and visuo-spatial short-term and long-term memory, general intelligence, and vocabulary knowledge in their native language. Polyglots had a superior level of performance in verbal short-term memory tasks (auditory digit span and nonword repetition) and in a paired-associate learning test, which assessed the subjects' ability to acquire new (Russian) words. By contrast, the two groups had comparable performance levels in tasks assessing general intelligence, visuo-spatial short-term memory and learning, and paired-associate learning of Italian words. These findings, which are in line with neuropsychological and developmental evidence, as well as with data from normal subjects, suggest a close relationship between the capacity of phonological memory and the acquisition of foreign languages.

Adult↗
PubMed1993

Preserved vocabulary acquisition in Down's syndrome: the role of phonological short-term memory.

We report the study of a 23-year-old Italian girl, FF, with Down's syndrome (trisomy 21). FF showed a remarkably good developmental acquisition of Italian language and vocabulary and was able to learn English and French, although the latter with less proficiency. FF showed an entirely preserved function of the phonological short-term store and articulatory rehearsal components of verbal short-term memory. By contrast, she was impaired in a wide range of tasks assessing verbal and non-verbal reasoning, visuo-spatial perception and memory, and verbal long-term memory. These findings, in line with evidence from brain-damaged patients, normal subjects and children, suggest that phonological short-term memory plays a crucial role in vocabulary acquisition, which may occur in the presence of substantial deficits of general intelligence and episodic memory.

Adult↗
PubMed1993

Ideomotor apraxia without aphasia and aphasia without apraxia: the anatomical support for a double dissociation.

This study aimed to verify the existence of a double aphasia/apraxia dissociation. Apraxic patients without aphasia and aphasic patients without apraxia were included in a consecutive series of patients with cortical or subcortical CT documented vascular lesions in the left hemisphere. Of 699 patients, 10 were found to be apraxic but not aphasic and 149 aphasic but not apraxic. These findings indicate an aphasia/apraxia double dissociation. This suggests that praxis and language make use of two different, partly overlapping networks.

Aged↗
PubMed1991

Long-term recency effects and phonological short-term memory. A neuropsychological case study.

Long-term recency effects were investigated in a left brain-damaged patient, PV, who had a pathologically low auditory-verbal span and a lack of the normal recency effects in immediate free recall of auditorily presented lists of words, attributed to the abnormally reduced capacity of the phonological short-term store component of memory (Vallar and Papagno, 1986). In a task requiring the delayed free recall of a list of anagram solutions the patient showed both a recall performance level and a long-term recency effect comparable to the control group. These findings dissociate long and short-term recency phenomena, which would reflect the operation of different memory components. A collateral finding was PV's difficulty in anagram solving, which may be traced back to the defective function of her phonological short-term store.

Adult↗
PubMed1990

Parkinson's disease patient's behaviour in a covered maze learning task.

A computerized maze task was constructed that allowed only partial vision of the maze structure and produced measurements for separate analysis of cognitive processes described as impaired in Parkinson's disease. Eighteen patients suffering from mild Parkinson's disease and 18 individually matched normal controls were investigated. Baseline task response times were found to be identical for both groups. Differences between patients' and controls' performance could be related to (a) a response bias in Parkinson patients that favoured repetition of the previous action and slowed down shifting and (b) an impairment of multistep plan generation. It is speculated that the response bias reflects the disinhibition of cortico-thalamo-cortical reverberation loops which results from striatal dopamine depletion.

Aged↗
PubMed1990

Language and verbal memory after right hemispheric stroke: a clinical-CT scan study.

The performances on language and verbal memory tests of 26 right-hemisphere damaged subjects (RHD) have been compared with normal controls and 11 non-aphasic left-hemisphere damaged subjects. While phonological and syntactic performance was unimpaired, a small subgroup of RHD patients, with CT scan evidence of subcortical lesion, was mildly impaired in naming tasks. The performance of RHD patients on free recall was characterized by a reduced recency effect. The implications of these findings for theories about the participation of the right hemisphere in linguistic functions are discussed.

Adult↗