Browsing by Subject "Face"

Now showing 1 - 4 of 4
  • Thumbnail Image
    ItemOpen Access
    Faces evoke spatially differentiated patterns of BOLD activation and deactivation.
    (Neuroreport, 2003-05-23) Pelphrey, Kevin A; Mack, Peter B; Song, Allen; Güzeldere, Güven; McCarthy, Gregory
    Using fMRI techniques sensitive to blood oxygen-level dependent (BOLD) contrast, we measured brain activity in participants (n=8) as they viewed images of faces presented periodically within a continuously changing montage of common objects. Consistent with prior studies, we identified regions of ventral extrastriate cortex, primarily in the fusiform and inferior temporal gyri and nearby cortex, that were activated by faces as measured by an increase in BOLD signal. In addition, we made the novel observation that faces deactivated other areas of ventral extrastriate cortex, primarily in the lingual and parahippocampal gyri and medial to activations. These deactivated regions, identified by a decrease in BOLD signal, may reflect populations of neurons that decrease their activity when faces appear, possibly as a consequence of category-specific inhibition.
  • Thumbnail Image
    ItemOpen Access
    Genetic mapping of brain plasticity across development in Williams syndrome: ERP markers of face and language processing.
    (Dev Neuropsychol, 2013) Mills, DL; Dai, L; Fishman, I; Yam, A; Appelbaum, LG; St George, M; Galaburda, A; Bellugi, U; Korenberg, JR
    In Williams Syndrome (WS), a known genetic deletion results in atypical brain function with strengths in face and language processing. We examined how genetic influences on brain activity change with development. In three studies, event-related potentials (ERPs) from large samples of children, adolescents, and adults with the full genetic deletion for WS were compared to typically developing controls, and two adults with partial deletions for WS. Studies 1 and 2 identified ERP markers of brain plasticity in WS across development. Study 3 suggested that, in adults with partial deletions for WS, specific genes may be differentially implicated in face and language processing.
  • Thumbnail Image
    ItemRestricted
    Neural mechanisms of context effects on face recognition: automatic binding and context shift decrements.
    (J Cogn Neurosci, 2010-11) Hayes, Scott M; Baena, Elsa; Truong, Trong-Kha; Cabeza, Roberto
    Although people do not normally try to remember associations between faces and physical contexts, these associations are established automatically, as indicated by the difficulty of recognizing familiar faces in different contexts ("butcher-on-the-bus" phenomenon). The present fMRI study investigated the automatic binding of faces and scenes. In the face-face (F-F) condition, faces were presented alone during both encoding and retrieval, whereas in the face/scene-face (FS-F) condition, they were presented overlaid on scenes during encoding but alone during retrieval (context change). Although participants were instructed to focus only on the faces during both encoding and retrieval, recognition performance was worse in the FS-F than in the F-F condition ("context shift decrement" [CSD]), confirming automatic face-scene binding during encoding. This binding was mediated by the hippocampus as indicated by greater subsequent memory effects (remembered > forgotten) in this region for the FS-F than the F-F condition. Scene memory was mediated by right parahippocampal cortex, which was reactivated during successful retrieval when the faces were associated with a scene during encoding (FS-F condition). Analyses using the CSD as a regressor yielded a clear hemispheric asymmetry in medial temporal lobe activity during encoding: Left hippocampal and parahippocampal activity was associated with a smaller CSD, indicating more flexible memory representations immune to context changes, whereas right hippocampal/rhinal activity was associated with a larger CSD, indicating less flexible representations sensitive to context change. Taken together, the results clarify the neural mechanisms of context effects on face recognition.
  • Thumbnail Image
    ItemOpen Access
    Object files can be purely episodic.
    (Perception, 2007) Mitroff, Stephen R; Scholl, Brian J; Noles, Nicholaus S
    Our ability to track an object as the same persisting entity over time and motion may primarily rely on spatiotemporal representations which encode some, but not all, of an object's features. Previous researchers using the 'object reviewing' paradigm have demonstrated that such representations can store featural information of well-learned stimuli such as letters and words at a highly abstract level. However, it is unknown whether these representations can also store purely episodic information (i.e. information obtained from a single, novel encounter) that does not correspond to pre-existing type-representations in long-term memory. Here, in an object-reviewing experiment with novel face images as stimuli, observers still produced reliable object-specific preview benefits in dynamic displays: a preview of a novel face on a specific object speeded the recognition of that particular face at a later point when it appeared again on the same object compared to when it reappeared on a different object (beyond display-wide priming), even when all objects moved to new positions in the intervening delay. This case study demonstrates that the mid-level visual representations which keep track of persisting identity over time--e.g. 'object files', in one popular framework can store not only abstract types from long-term memory, but also specific tokens from online visual experience.