Introduction
Alzheimer's disease (AD) is one of common neurodegenerative disorders, characterized by a slowly progressive loss of memory and cognitive impairments. Some brain regions, notably the temporal areas, are involved in AD. These affected brain regions are related to cognitive functions such as spatial working memory (SWM), pattern recognition memory (PRM), and paired associates learning (PAL). These cognitive processes play crucial roles in daily functioning. This study aims to assess the performance of these three cognitive functions in the children of parents diagnosed with AD and healthy parents using the Cambridge neuropsychological test automated battery (CANTAB). By comparing the cognitive performance between these groups, we aimed to identify potential early markers that can be indicatives of the AD risk.

Method
In this comparative study, participants were 55 children, 31 children of parents diagnosed with AD and 24 children of healthy parents, recruited from a neurology clinic in Tehran, Iran. Inclusion criteria for the healthy group were having parents with no history of traumatic brain injury, major psychiatric disorders, vascular dementia, brain tumors, neurological disorders (such as Parkinson's disease), or orthopedic disorders that could impede test performance. Additionally, participants underwent neurocognitive tests to ensure cognitive competence for the study assessments. The tests assessed three cognitive domains: SWM, PRM, and PAL utilizing the CANTAB method. These tests were administered under controlled conditions, ensuring standardized testing procedures for all participants. Statistical analyses were performed in SPSS using independent t-test and Mann-Whitney U test to examine the differences in cognitive performance between the two groups.

Results 
Table 1 shows the mean scores of SWM, PRM, and PAL in two study groups. Regarding the SWM, there were significant differences between the two groups in the items measuring between errors and total errors.


These differences indicated a distinctive SWM domain among the children of AD patients. The PRM did not show significant differences between the two groups in mean correct latency and mean incorrect latency (P>0.05), but the difference was significant in mean latency and percent correct (P<0.05). This suggests a comparable PRM between the children of AD and healthy parents. The PAL performance demonstrated significant differences in all three parameters (first trial memory score, mean errors to success, and total errors) assessed between the two groups (P<0.01). These findings indicate potential cognitive markers associated with AD susceptibility among the children of affected parents. 

Conclusion
The observed differences in SWM and PAL between the children of AD parents and healthy parents can indicate the factors that may be associated with the AD risk. However, the absence of significant differences in PRM between the two groups in mean correct and incorrect latencies. Although this cognitive domain did not exhibit significant difference, it remains crucial to conduct more studies to assess its association with AD. In this regard, further longitudinal studies involving a different cognitive functions are recommended to expand these findings for more robust predictive models of AD onset.

Ethical Considerations
Compliance with ethical guidelines
Participation in this study was voluntary, and informed consent was obtained from all participants after explaining the study objectives and ensuring their confidentiality and the right to leave the study at any time. This study has ethical approval from the ethics committee of the University of Tabriz (Code: IR.TABRIZU.REC.1401.057).

Funding
This article was extracted from the PhD thesis of Sara Rabiei in neuroscience, brain and cognition, at the University of Tabriz. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Authors contributions
The authors contributed equally to preparing this paper.

Conflicts of interest
The authors declared no conflict of interest.

Acknowledgments
The authors would like to thank all participants for their cooperation in this study.

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