A five-item scale measuring a consumer's subjective experience of cognitive fatigue — the degree to which their thinking feels slow, unfocused, and incapable of handling complex mental demands. Items tap slowness of thought, concentration difficulty, perceived lack of mental clarity, attentional diffuseness, and difficulty thinking about complex matters. A subscale of the Shirom-Melamed Burnout Measure (SMBM), it has been adapted for consumer research contexts to assess whether manipulations of cognitive load or depletion are effective, and as a covariate in studies where mental fatigue moderates responses.
Shirom, Arie and Melamed Samuel (2006). A comparison of the construct validity of two burnout measures in two groups of professionals. International Journal of Human Resources Development and Management, 6(2), 148–159. [Applied in consumer context by: Touré-Tillery, Maferima and Maryam Kouchaki (2021). How do you feel about the 'decimal edition'? Journal of Marketing Research, 58(4), 733–750.]
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