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Intrusions and perseverations
Shindler AG, Caplan LR, Hier DB.. Brain and language, 1984-09-01
Topic: Risk, prevention and care in population studies
Twenty-two subjects with presumed senile dementia of the Alzheimer's type (SDAT), twenty-two with dementia other than SDAT, twenty with aphasia, and seventeen healthy controls over 50 years of age were examined for intrusions and perseverations. Perseverations were defined as the immediate inappropriate repetition of a prior response whereas intrusions were defined as the inappropriate repetition of prior responses after intervening stimuli. Intrusions and perseverations occurred in demented and aphasic subjects, but were rare in controls. Intrusions occurred most often in SDAT or Wernicke aphasia, but also in dementia other than SDAT. Intrusions were not correlated with dementia severity. Intrusions are a useful sign of dementia, but they cannot be considered pathognomonic of SDAT. They appear to arise when subjects are unable to access correct responses from long-term memory and instead substitute erroneous responses selected from short-term memory. Perseverations were most common in the Wernicke aphasics and subjects with dementia due to communicating hydrocephalus. Although frontal lobe dysfunction is prominent in communicating hydrocephalus, it is absent in cases of Wernicke aphasia. Thus, we have confirmed prior suggestions that perseveration can occur in the absence of frontal lobe injury. Failure to self-monitor speech as well as an inability to change mental set probably plays an important role in the genesis of perseverations. There was no statistically significant correlation between dementia severity and number of perseverations. Low correlations were found between intrusions and perseverations suggesting that these seemingly similar behaviors are distinct and are probably produced by separate neuropsychological mechanisms.
Key findings
- Thus, we have confirmed prior suggestions that perseveration can occur in the absence of frontal lobe injury.
- There was no statistically significant correlation between dementia severity and number of perseverations.
- Low correlations were found between intrusions and perseverations suggesting that these seemingly similar behaviors are distinct and are probably produced by separate neuropsychological mechanisms.
Why it matters
This study examined intrusions and perseverations in subjects with dementia, aphasia, and healthy controls. It found intrusions were a useful sign of dementia but not specific to Alzheimer's type, and there was no significant correlation between dementia severity and perseverations.
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Study details
- Evidence strengthLow
How this study scored 36/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it. We have no data on institution's track record, so that was left out: it earned 35 of the 97 points we could judge it on, which is 36 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Brain and language) |
| Journal's citation record | 2 / 4 | Brain and Language: journal h-index 214 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1984 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 100 times (OpenAlex, 2026-10-10) |
| Citations per year | 1 / 5 | 2.3 citations a year over 44 year(s) since 1984 |
| Impact for its field and year | 3 / 6 | Cited 3.6× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 4 other studies in this library |
| Still being cited | 0 / 4 | Cited 1 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 1 / 4 | Last-listed author Andrea Gellin Shindler: h-index 5 (OpenAlex, whole career) |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 0 institution(s) in 0 countries — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 6206914) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 35 / 97 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 35 of the 97 points we could judge it on is 36 out of 100. |
| Total | 36 / 100 | — |
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Read the original
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Shindler, A. G., Caplan, L. R., & Hier, D. B. (1984). Intrusions and perseverations. Brain and language. https://doi.org/10.1016/0093-934x(84)90013-0
Vancouver
Shindler AG, Caplan LR, Hier DB. Intrusions and perseverations. Brain and language. 1984. doi:10.1016/0093-934x(84)90013-0. PMID: 6206914.
BibTeX
@article{shindler1984-6206914,
author = {Shindler, A. G. and Caplan, L. R. and Hier, D. B.},
title = {{Intrusions and perseverations}},
journal = {Brain and language},
year = {1984},
doi = {10.1016/0093-934x(84)90013-0},
pmid = {6206914},
url = {https://doi.org/10.1016/0093-934x(84)90013-0}
}
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