An early perceptual locus of absolute pitch.

Absolute pitch (AP) refers to the naming of musical tone without external reference. The influential two-component model states that AP is limited by the late-emerging pitch labeling process only and not the earlier perceptual and memory processes. Over the years, however, support for this model at the neural level has been mixed with various methodological limitations. Here, the electroencephalography responses of 27 AP possessors and 27 non-AP possessors were recorded. During both name verification and passive listening, event-related potential analyses showed a difference between AP and non-AP possessors at about 200 ms in their response toward tones compared with noise stimuli. Multivariate pattern analyses suggested that pitch naming was subserved by a series of transient processes for the first 250 ms, followed by a stage-like process for both AP and non-AP possessors with no group differences between them. These findings are inconsistent with the predictions of the two-component model, and instead suggest the existence of an early perceptual locus of AP.

The effect of task on object processing revealed by EEG decoding.

Recent studies showed that task demand affects object representations in higher-level visual areas and beyond but not so much in earlier areas. There are, however, limitations in those studies including the relatively weak manipulation of task due to the use of familiar real-life objects, the low temporal resolution in functional magnetic resonance imaging (fMRI) and the emphasis on the amount and not the source of information carried by brain activations. In the current study, observers categorised images of artificial objects in one of two orthogonal dimensions, shape and texture, while their brain activity was recorded with electroencephalogram (EEG). Results showed that object processing along the texture dimension was affected by task demand starting from a relatively late time (320- to 370-ms time window) after image onset. The findings are consistent with the view that task exerts an effect on the later phases of object processing.