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A longitudinal study of semantic memory impairment in patients with Alzheimer’s disease
The Swedish National Road and Transport Research Institute, Linköping, Sweden.
Clinical Memory Research, Lund University, Sweden.
Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
2013 (English)In: Cortex, ISSN 0010-9452, Vol. 49, no 2, 528-533 p.Article in journal (Refereed) Published
Abstract [en]


The present study explored the nature of the semantic deterioration normally displayed in the course of Alzheimer’s disease (AD). The aim was to disentangle the extent to which semantic memory problems in patients with AD are best characterized as loss of semantic knowledge rather than difficulties in accessing semantic knowledge.


A longitudinal approach was applied. The same semantic tests as well as same items were used across three test occasions a year apart. Twelve Alzheimer patients and 20 matched control subjects, out of a total of 25 cases in each group, remained at the final test occasion.

Results and Conclusions

Alzheimer patients were impaired in all the semantic tasks as compared to the matched comparison group. A progressing deterioration was evident during the study period. Our findings suggest that semantic impairment is mainly due to loss of information rather than problems in accessing semantic information.

Place, publisher, year, edition, pages
Elsevier, 2013. Vol. 49, no 2, 528-533 p.
Keyword [en]
Alzheimer’s disease; Semantic memory impairment; Longitudinal study
National Category
URN: urn:nbn:se:liu:diva-89593DOI: 10.1016/j.cortex.2012.02.004ISI: 000316926800016PubMedID: 22445445OAI: diva2:608433
Available from: 2013-02-27 Created: 2013-02-27 Last updated: 2013-05-15Bibliographically approved
In thesis
1. Cognitive erosion and its implications in Alzheimer’s disease
Open this publication in new window or tab >>Cognitive erosion and its implications in Alzheimer’s disease
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Kognitiv erosion och dess betydelse vid Alzheimers sjukdom
Abstract [en]

The aim of the present thesis was twofold, first to map the semantic memory decline in Alzheimer patients over time, second to take the patient’s perspective and create a multifaceted picture of the individual with Alzheimer’s disease through the study of memory, awareness, central coherence and emotions. Further issues concerned how Alzheimer individuals handled their cognitive erosion in everyday life and if they were well calibrated with their spouse in disease related matters.

Two studies were performed, the first involved a longitudinal study of sematic deterioration, the second had a mixed methods design involving both quantitative and qualitative measures as in neuropsychological assessment and interviews.

Through the longitudinal study it could be concluded that the nature of semantic deterioration is best described as loss of memory information rather than problems in accessing the information. It was further concluded that semantic concepts gradually lose their specific features during course of illness.

The results from the second study revealed that the Alzheimer individuals were aware of their disease although they could not foresee the implications of their cognitive shortcomings in their everyday life. They evidenced weak central coherence, in that they were unable to infer details into a meaningful whole. This implies that they perceive their surrounding world in a fragmented way as consisting of separate objects rather than a comprehensible context. Concerning emotions it was found that they responded to negatively valenced words in the same way as normal ageing individuals, although being impaired in their response to positively and neutral words. Finally, the Alzheimer individuals and their spouses were not well calibrated regarding disease related issues.

The findings of the present thesis have important clinical implications and gives valuable input to the understanding of the individual with Alzheimer’s disease.

Abstract [sv]

Föreliggande avhandling hade två huvudsyften; dels att kartlägga försämringen av semantiskt minne hos Alzheimerpatienter över tid; dels att ta patientens perspektiv och skapa en mångfacetterad bild av individen med Alzheimers sjukdom. Fyra begrepp studerades i relation till detta, nämligen minne, medvetande, central koherens och emotioner. Ytterligare aspekter som studerades var hur Alzheimerindivider hanterar sina kognitiva tillkortakommanden i sin vardag samt hur väl kalibrerade de är med sin make/maka angående sjukdomsrelaterade frågor.

Två studier genomfördes varav den första var en longitudinell studie av semantisk minnesförsämring och den andra hade en ’mixed methods’ design, inkluderande både kvantitativa (neuropsykologiska tester) och kvalitativa (intervjuer) metoder.

Resultaten från den longitudinella studien avslöjade att semantiska begrepp som inte längre är välrepresenterade hos individen har gått förlorade snarare än att det skulle vara från om att individerna inte kan plocka fram informationen. Vidare kunde konstateras att semantiska begrepp gradvis tappar sina nyanser i takt med att sjukdomen fortskrider.

Den andra studien visade att Alzheimerindividerna var medvetna om sin sjukdom och sina minnesproblem men att de inte kunde förutsäga vilka problem deras kognitiva tillkortakommanden skapade i deras vardag. De konstaterades ha svag central koherens vilket innebär att de ser sin omgivning på ett fragmentariskt sätt utan att kunna få ihop de olika objekten runt omkring sig till en meningsfull kontext. Vad gäller emotioner så kunde konstateras att Alzheimerindivider reagerar likadant som normalt åldrande individer på negativt laddade ord men att de är signifikant försämrade i förmågan att känna igen positiva och neutrala ord. Alzheimerindividerna och deras make/maka var inte väl kalibrerade vad gäller sjukdomsrelaterade frågor.

Avhandlingens resultat har viktiga kliniska implikationer och ger ett värdefullt bidrag till förståelsen av en individ med Alzheimers sjukdom.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2013. 72 p.
Linköping Studies in Arts and Science, ISSN 0282-9800 ; 582Linköping Studies in Behavioural Science, ISSN 1654-2029 ; 175Studies from the Swedish Institute for Disability Research, ISSN 1650-1128 ; 49
Alzheimer’s disease, longitudinal study, mixed methods design, semantic memory, awareness, metacognition, central coherence, emotions, Alzheimers sjukdom, longitudinell studie, mixed methods design, semantiskt minne, medvetande, metakognition, central koherens, emotioner
National Category
Medical and Health Sciences
urn:nbn:se:liu:diva-91890 (URN)978-91-7519-612-1 (print) (ISBN)
Public defence
2013-05-24, Eklundska salen, Hus I, Campus Valla, Linköpings universitet, Linköping, 13:00 (Swedish)
Available from: 2013-05-03 Created: 2013-05-03 Last updated: 2013-05-05Bibliographically approved

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