05). Neurons this website with a significant main effect were defined as differential neurons. For each facial model, one-way anova was also performed. Responses to three frontal faces with three gaze directions, and those to right and left profile faces with two gaze directions were compared by Tukey post hoc tests (P < 0.05). Neurons with significantly different responses toward gaze directions were defined as gaze-differential neurons (Tukey post hoc tests, P < 0.05). Neurons with significantly different responses toward face orientations were defined as face orientation-differential neurons (Tukey post hoc

tests, P < 0.05). For other stimulus categories (cartoon faces, eye-like patterns, face-like patterns and simple geometric patterns), one-way anovas were also performed within the same stimulus category. Neurons with a significant main effect were defined as cartoon face-differential, eye-like pattern-differential, face-like pattern-differential and simple geometric pattern-differential neurons, respectively. Stimulus information conveyed by visually responsive neurons (bits/s) was computed as described in previous studies (Skaggs et al., 1993; Panzeri et al., 1996). These parameters were calculated as follows, We also analysed response latency to KU-57788 manufacturer each visual stimulus. For each neuron, one peri-event histogram was

constructed using the entire set of data for all trials and all stimuli. Neuronal response latency was defined as the interval from the onset of stimulus presentation to the time at which the neuronal firing rate exceeded the mean ± 2 SD of the baseline firing rate. Furthermore, for each neuron, individual peri-event histograms were constructed using data for each of the different stimulus categories. We compared the latencies to various stimulus categories to determine whether the characteristics of the specific visual stimuli could modulate the latencies of the pulvinar neurons. All data were expressed as mean ± SEM.

Multidimensional scaling (MDS) is a method used to simplify the analysis of relationships that exist within a complex array of data. Cediranib (AZD2171) MDS constructs a geometric representation of data to show the degree of relationship between stimuli represented by the data matrix (Young, 1987). MDS has been used to examine taste relationships in the gustatory system (Nishijo & Norgren, 1990, 1991), face categorization in the inferotemporal cortex (Young & Yamane, 1992) and spatial discrimination in the septal nuclei (Nishijo et al., 1997) by using data matrices representing neural activity in response to the particular stimulus array (i.e. taste solutions, photos of faces and photos of locations, respectively). In the present study, the 49 visual stimuli were used to elicit neural activity in pulvinar neurons.