Cognition, Behavior, and Memory
Author: Juan Ignacio Segura | Email: jisegura@mail.austral.edu.ar
Juan Ignacio Segura1°2°, Guillermina Alvarez1°2°, Thiago Casetta1°4°, Martina López1°3°, Ana Paula Colombini1°, Bautista Elizalde Acevedo1°2°, Lucía Alba-Ferrara1°2°
1° ENyS – Hospital el Cruce – CONICET – UNAJ, Argentina
2° Facultad de Ciencias Biomédicas, Universidad Austral.
3° Facultad de Psicología, Universidad de Montevideo
4° Facultad de Humanidades, Universidad de Belgrano
Emotional prosody encodes vocal affection and has right hemisphere dominance. It remains unclear how attentional processing modulates lateralization. We study the neural correlates of goal-directed attention to prosody perception.
33 controls underwent an fMRI dichotic prosody task, with two stimuli (emotional or neural voices) presented simultaneously (one in each ear). Subjects attended to one ear and ignored the other. Brain activations were calculated for laterality processing (trials attending the right or left ear) and attentional processing, trials with emotion display in the unattended ear (Top-Down) or in the attended ear (bottom-up).
RTs were shorter in “bottom-up” compared to “top-down” trials, reflecting less cognitive demand. “Top-down” trials activated the left temporal (parahippocampal and medial temporal gyri) and frontal lobe (L superior frontal and R paracentral frontal gyri). There were shorter RTs when attending the left ear compared to the right, indicating rightward lateralization. Focussing on the left ear activated the insula, L medial occipital gyrus, cingulate gyrus and R superior frontal gyrus. Attending the right ear activated the L temporal lobe (superior temporal, medial temporal and superior temporal gyri), R precentral and angular gyri, L superior frontal gyrus.
Frontal recruitment reveals greater cognitive demand for top-down and the shorter RT for the left ear indicates rightward lateralization of prosody.