Dementia Eliminates the Ability to Daydream

A study published in PNAS found people with one type of early-onset dementia may have completely lost the ability to daydream, reports New Atlas . The researchers compared 37 cognitively healthy controls with 24 participants with Alzheimer's and 37 with frontotemporal dementia. The third condition typically starts manifesting in the late 40s, and is characterized by the progressive death of spindle neurons in the frontal and/or temporal lobes. "Individuals with frontotemporal dementia become very rigid in their thinking," notes University of Sydney Professor Muireann Irish. "They are unable to visualize alternatives, to think of solutions to problems, or to deviate from their everyday routines. In previous work, we have shown that their ability to remember the past and to imagine the future is severely compromised." Using visual stimuli, the researchers determined the healthy older adults engaged extensively in mind wandering, while those with frontotemporal dementia were completely tethered to the stimulus before them. "When asked what they were thinking about, they either reported 'Nothing' or that they were thinking only about the stimulus itself," Irish says. Meanwhile, participants with Alzheimer's reported the same volume of mind wandering as the healthy controls. The implication is the neuronal damage that occurs in frontotemporal dementia appears to correlate with the brain networks that govern introspective thought.