Cathy Blair

 2012/2013 Joint winner supervised by Anne Edmundson (UCL)

“Investigating semantic impairments in people with aphasia using mouse-tracking technology: the effect of semantic distractors in a single word comprehension task”

Semantic impairments in aphasia are often assessed using word-to-picture matching tests such as PALPA 47 and 48. However, these lack sensitivity, so a score within normal limits does not guarantee an intact semantic system (Nickels 2004). Mouse-tracking programmes are thought to trace the real-time cognitive processing occurring during semantic decision-making. Trajectories produced are purported to show greater deviation towards distractor items that are more closely related to the target, for example, phonologically or semantically. In my study, eight participants with aphasia and nine control participants completed PALPA 47, 48 and 49 and a MouseTracker-adapted version of PALPA 47. The project compared responses on the standard pen-and-paper test to responses on the Mouse-Tracker version. Accuracy on the mouse-tracking task reflected accuracy on pen-and-paper semantic tests. However, distractor type did not significantly influence trajectories in people with aphasia or the control group. Trajectories therefore did not distinguish those with semantic impairments from those without.  Further investigation involving a larger and more varied sample would be beneficial, as would some adjustments to the procedure.