Attentional modulation of repetition suppression effects in human face- and voice-sensitive cortex

TY - GEN

T1 - Attentional modulation of repetition suppression effects in human face- and voice-sensitive cortex

AU - Kikuchi, Yukiko

AU - Ip, Jennifer

AU - Mossom, James

AU - Barraclough, Nick

AU - Petkov, Chris

AU - Vuong, Quoc

PY - 2014

Y1 - 2014

N2 - An important property of the brain is that its neurons reduce their responses to the repetition of the same or similar environmental stimuli. There is considerable interest in understanding how repetition suppression is influenced by attention, such as when people focus their attention on properties of the repeating stimuli. However whether comparable repetition effects operate in different sensory modalities and whether attention modulates repetition effects in a similar way across the modalities was unclear. We asked how attention modulates repetition effects in the auditory and visual modalities, either by changing the gain of repetition effects (affecting the intercept of the stimulus repetition function) or by selectively sharpening repetition effects (affecting the slope of the repetition function). Nine volunteers participated in separate auditory and visual fMRI experiments in which they directed their attention to voice or face identity changes or to changes of the respective stimuli in their spatial location. By morphing between pairs of different face or voice identities, we aimed to modulate the strength of repetition effects which are stronger for repetition of more similar stimuli. The spatial difference was manipulated by systematically changing the screen position for face pairs or the virtual acoustic location for voice pairs. We also equated performance on the identity and spatial tasks across the two modalities. For each volunteer we functionally localised face- and voice-sensitive regions of interest (ROI). For both face and voice ROIs there was a significant change to the slope of the stimulus repetition function when volunteers attended to identity differences but not to spatial differences (interaction between attention and identity differences, F(2,16)=4.9, p=.02, but no interaction between attention and spatial differences, F<1.0). Moreover, the attentional modulation seemed to be specific to face/voice-sensitive cortex because it was not evident in temporal lobe areas outside of these ROIs. Overall the results suggest comparable repetition effects and attentional modulations of these effects in human face- and voice-sensitive cortex. CIP and QCV: joint senior authors; JI and JCM contributed equally.

AB - An important property of the brain is that its neurons reduce their responses to the repetition of the same or similar environmental stimuli. There is considerable interest in understanding how repetition suppression is influenced by attention, such as when people focus their attention on properties of the repeating stimuli. However whether comparable repetition effects operate in different sensory modalities and whether attention modulates repetition effects in a similar way across the modalities was unclear. We asked how attention modulates repetition effects in the auditory and visual modalities, either by changing the gain of repetition effects (affecting the intercept of the stimulus repetition function) or by selectively sharpening repetition effects (affecting the slope of the repetition function). Nine volunteers participated in separate auditory and visual fMRI experiments in which they directed their attention to voice or face identity changes or to changes of the respective stimuli in their spatial location. By morphing between pairs of different face or voice identities, we aimed to modulate the strength of repetition effects which are stronger for repetition of more similar stimuli. The spatial difference was manipulated by systematically changing the screen position for face pairs or the virtual acoustic location for voice pairs. We also equated performance on the identity and spatial tasks across the two modalities. For each volunteer we functionally localised face- and voice-sensitive regions of interest (ROI). For both face and voice ROIs there was a significant change to the slope of the stimulus repetition function when volunteers attended to identity differences but not to spatial differences (interaction between attention and identity differences, F(2,16)=4.9, p=.02, but no interaction between attention and spatial differences, F<1.0). Moreover, the attentional modulation seemed to be specific to face/voice-sensitive cortex because it was not evident in temporal lobe areas outside of these ROIs. Overall the results suggest comparable repetition effects and attentional modulations of these effects in human face- and voice-sensitive cortex. CIP and QCV: joint senior authors; JI and JCM contributed equally.

M3 - Conference contribution

BT - Neuroscience Meeting Planner

PB - Society for Neuroscience

ER -