Brain scans convince us but behavioural measures more relevant, says expert  

Neuroimaging is a useful tool, but strong evidence that brain scans are an effective means of evaluating programs aimed at improving speech and reading is yet to be amassed, according to a leading international neuropsychologist speaking at the 47th APS Annual Conference in Perth this weekend.

Conference keynote speaker Professor Dorothy Bishop, from the Department of Experimental Psychology at Oxford University, said that brain scans were very seductive.

She said: “The ability to view the brain and examine the correlations between actions, emotions and brain activity is fascinating, but we must ensure that we apply the same rigorous standards of research design to neuroimaging studies as we do to other research.”

She said the critical test of any intervention for a developmental disorder, including those for language impairments, was if it improved abilities. Psychologists have a range of tests and assessments that can test performance before and after interventions to measure outcomes.

“You can’t look at a brain scan and tell if someone is reading better or able to speak with greater ease or fluency,” Professor Bishop said.  “You can only do that by observing and measuring the behaviour.”

Brain scans are increasingly used across many areas of research, and have been adopted by those marketing a variety of commercial programs.  Professor Bishop has reviewed a range of studies specifically related to language impairments which purport to use neuroimaging to show the effectiveness of interventions. She found many to be methodologically flawed.

“Neuroscience is very exciting but the truth is we don’t yet know how it can best be applied to assess programs for language problems,” she said.

Professor Bishop concluded: “At this stage it is better to spend research funds doing well-designed trials of behavioural treatments for language impairments to establish which methods are effective, rather than rushing into imaging studies of unproven treatments.”

The power of brain scans to convince

Professor Bishop says studies have shown that the general public are very swayed by neuroscientific evidence even if it isn’t logical.

One study, she cites, provided people with illogical articles about the capacity for TV watching to improve maths ability. Participants were provided with the same article, illustrated either with a bar graph, a brain image or text only version.  Researchers found that if a brain scan image was included, participants were more likely to rate the articles as having good scientific reasoning.