Modified Camel and Cactus Test (MCCT)
Background
The original Camel and Cactus Test (CCT) was published by Sasha Bozeat and colleagues in 2000 as a measure of semantic knowledge and was designed as an extension of the 1992 published Pyramids and Palm Trees Test (PPTT) by David Howard and Karalyn Patterson. Both tests involve asking participants to select a picture (or word) match to a target picture (or word). While the PPTT provides only two options to choose from, the CCT provides four and is therefore assumed to be more sensitive than its predecessor.
In 2022, Katrina Moore and colleagues developed a modified and publicly available version of the CCT (Modified Camel and Cactus Test, mCCT) on behalf of the Genetic FTD Initiative (GENFI) to a) cut down on testing time, b) make the test independent of language (it's entirely visual) and c) make the test easier to integrate into larger testing batteries.
The mCCT has been shown to be highly sensitive to the deterioration of semantic knowledge, a core feature of neurodegenerative conditions like semantic dementia (a subtype of frontotemporal dementia). It can detect changes relatively early (e.g. in the presymptomatic stages of certain genetic forms of frontotemporal dementia) and patient performance on the mCCT correlates with structural changes (e.g. brain atrophy).
Task Procedure
Participants work through 3 practice trials (and receive feedback) to get familiar with the testing procedure. Then they work on 32 test trials. The 32 test trials run in a fixed order and do not provide performance feedback. Each trial provides the participant with the photograph of one target object (e.g. a bottle of wine) and four additional photographs as response options. The participant's task is to select the image that has the closest semantic relationship to the target object (e.g. grapes). Each selected item is highlighted in yellow. Participants can change selections if needed. To reach the next trial, participants must submit their choice by selecting the 'next' button.
What it Measures
The Modified Camel and Cactus Test (mCCT) is a test of semantic memory and knowledge of relationships between objects independent of language
Psychological domains
- *Semantic Memory: Conceptual knowledge about the world, including facts, meanings, and relationships between objects
- *Visual Perception: Ability to process and identify photographs of objects, animals, and scenes.
- Visual Search and Attention: Ability to focus, to scan, and analyze the target image against the four alternative options
Main Performance Metrics
- mCCTScore: the total score of 32 test trials; measure of semantic memory
Psychiatric Conditions
The following patient groups show impaired performance on the mCCT test
- Frontotemporal Dementia (FTD)
- Alzheimer's Disease (AD)
- Semantic Aphasia / Stroke Patients
The MCCT is a test of semantic memory independent of language.
References
Search Google Scholar for peer-reviewed, published research using the Inquisit Modified Camel and Cactus Test (MCCT).
Bozeat, S., Lambon Ralph, M. A., Patterson, K., Garrard, P., & Hodges, J. R. (2000). Non-verbal semantic impairment in semantic dementia. Neuropsychologia, 38(9), 1207–1215. doi:10.1016/S0028-3932(00)00034-8
Moore, K et al (2022). A modified Camel and Cactus Test detects presymptomatic semantic impairment in genetic frontotemporal dementia within the GENFI cohort. APPLIED NEUROPSYCHOLOGY: ADULT 2022, VOL. 29, NO. 1, 112–119 https://doi.org/10.1080/23279095.2020.1716357