We use cognitive models to evaluate three theories of the change in semantic memory caused by Alzheimer’s disease. We use data from 14,096 clinical assessments of 3602 Alzheimer’s patients and their caregivers. Each patient completed a semantic memory task involving the odd-one-out comparison of animal names. Each patient was also independently evaluated to determine their level of impairment. Our cognitive models assume a feature-based representation of the animals and odd-one-out choice probabilities based on common-feature similarities. We find no evidence for the restructured representation hypothesis, which claims that impairment causes changes in the features used to represent stimuli. We also find no evidence for the attention change hypothesis, which claims that impairment causes greater attention to be given to concrete features at the expense of more abstract features. We do find evidence for the noisy access hypothesis, which claims that odd-one-out choices become less determined by semantic similarity and more prone to the simple response strategy of choosing the last option. We conclude that the noisy access hypothesis provides a simple account of odd-one-out choice behavior throughout the progression of Alzheimer’s disease. More elaborate theories involving changes to underlying mental representations and attention processes need to provide evidence they are superior to the noisy access account.

我们使用认知模型来评估阿尔茨海默病引起的语义记忆变化的三种理论。我们使用来自 3602 名阿尔茨海默病患者及其护理人员的 14,096 次临床评估的数据。每个患者都完成了一项语义记忆任务，涉及动物名称的奇一比较。每个患者也被独立评估以确定他们的损伤水平。我们的认知模型假设基于特征的动物表示和基于共同特征相似性的奇一选择概率。我们没有发现重组表征假说的证据，该假说声称损伤会导致用于表征刺激的特征发生变化。我们也没有发现注意力变化假设的证据，它声称损伤会导致对具体特征的更多关注，而以牺牲更抽象的特征为代价。我们确实找到了噪声访问假说的证据，该假说声称奇一出的选择不再由语义相似性决定，并且更倾向于选择最后一个选项的简单响应策略。我们得出结论，嘈杂的访问假设提供了一个简单的解释，说明了阿尔茨海默病整个进程中的奇一选择行为。涉及潜在心理表征和注意力过程变化的更详细的理论需要提供证据，证明它们优于嘈杂的访问帐户。它声称奇一出的选择不再由语义相似性决定，更倾向于选择最后一个选项的简单响应策略。我们得出结论，嘈杂的访问假设提供了一个简单的解释，说明了阿尔茨海默病整个进程中的奇一选择行为。涉及潜在心理表征和注意力过程变化的更详细的理论需要提供证据，证明它们优于嘈杂的访问帐户。它声称奇一出的选择不再由语义相似性决定，更倾向于选择最后一个选项的简单响应策略。我们得出结论，嘈杂的访问假设提供了一个简单的解释，说明了阿尔茨海默病整个进程中的奇一选择行为。涉及潜在心理表征和注意力过程变化的更详细的理论需要提供证据，证明它们优于嘈杂的访问帐户。