, 2011 for individual brain differences in duration discrimination of the multiseconds range; see Kanai and Rees, 2011 for a review). Our results show that the representation

of the trained duration was associated with neurophysiological changes in functional activity, gray-matter volume, and white-matter connectivity within a sensory-motor circuit comprising occipital, parietal, and insular cortices, plus the cerebellum. Importantly, we found that these changes correlated with the training-induced behavioral changes on a subject-by-subject basis LY2835219 datasheet and that activity and gray-matter volume around the central sulcus before training predicted learning abilities as indexed after training. These findings provide us with the first neurophysiological evidence of structural and functional plasticity associated with the learning of time. Seventeen healthy volunteers were tested on a temporal discrimination task over five consecutive days. The experimental protocol took place from Monday to Friday and was structured in three distinct phases: pretraining, training, and posttraining (see Table 1). The pretraining (day 1) and posttraining this website (day 5) phases consisted of a psychophysics

session followed by an imaging session in which functional and structural (a high-resolution T1-weighted image and DTI) data were acquired. The psychophysics session served to estimate subject-specific temporal discrimination thresholds to be used during fMRI. The training phases (days 1–4) consisted of a single session of behavioral testing during which volunteers were trained in the visual modality only (for ∼1 hr). The task during training consisted of crotamiton the sequential

presentation of the two temporal intervals marked by four brief visual flashes and separated by a short gap (see Figure 1A and Experimental Procedures for more details). One of the two intervals was the “standard duration,” which was equal to 200 ms (T), and the other was the “comparison duration,” which was equal to the standard plus a variable, always positive ΔT1 value (T+ΔT1). Volunteers were asked to indicate which of the two intervals lasted longer. During training the duration of the comparison interval was adjusted adaptively across trials, in order to obtain the ΔT1 threshold leading to 79% correct discrimination. During the training sessions (days 1–4) and the pre- and posttraining psychophysics sessions (day 1 and 5) the standard duration was always 200 ms (T). We assessed whether learning had occurred in two different ways. We first analyzed the psychophysical data of pre- and posttraining sessions in order to identify participants, for whom the 4 days of training improved temporal discrimination performance. For each volunteer we computed the ratio (ΔT1pre − ΔT1post) / ΔT1pre. Positive values indicate lower thresholds in post- compared to pretraining and, thus, that learning did take place.