Browsing by Subject "Face network"

Visual working memory refers to the cognitive system responsible for the short-term storage and manipulation of visual information. Prevailing view suggests that there is a trade-off between memory capacity and precision: we can hold more items in memory with lower precision or fewer items with higher precision. Recent functional magnetic resonance imaging (fMRI) studies suggest distributed visual working memory representations in multiple brains areas from sensory visual to the parietal and frontal cortex. This thesis consists of a visual working memory fMRI study, using human faces as stimuli. The purpose of this thesis was to examine the visual working memory precision for angry, neutral and happy faces and the memory representations in the face network, and to directly compare the neural activity while participants discriminated and memorized faces. The participants discriminated and remembered faces precisely and were highly aware of occasional memory lapses, as shown by the confidence ratings of responses. In the primary visual cortex (V1) and fusiform face area (FFA), happy faces elicited higher brain activation than angry or neutral faces. The multivariate analysis of fMRI activation patterns showed correlations between the perception and memory tasks in these areas. Overall, the activations and correlations were higher in the right hemisphere, as expected. The correlations between perception and memory conditions were surprisingly low given the identical stimuli in these conditions. Even small positive correlations in the right V1 and FFA, however, support their role in maintaining facial information in visual working memory.