LOVE 2013 Programme with Abstracts (PDF) - Judith M Shedden ...

RAJEEV RAIZADANeural population codes:Representations, regularities andbehaviourAbstract: In seeking to understand how the human brain represents theworld, neuroimaging faces a serious problem: brain images do not revealmental representations. Recent work in neural decoding has shownthat classifier algorithms can recover information from individual subjects’fMRI data about the tasks and stimuli that evoked that activation.However, that decoding does not in itself tell us whether the classifiersextract information that is actually used by the brain. Nor does it tell ushow the brain represents that information. Addressing the first of thosequestions, I will present evidence from speech perception showing thatpeople’s multivoxel fMRI patterns can predict individual differences inbehavioural performance. Addressing the second, I will show how thestructure of mental representations can be related to the structure ofsimilarity relations between neural activation patterns. Moreover, theseneural similarity structures reveal how different people’s representationsare alike, and can cast new light on how the brain represents linguisticmeaning. Finally, I will discuss some of the challenges and newquestions raised by this research.5