2.5. Motion perception test
Previous work has suggested that patients with schizophrenia
might be impaired at detecting coherent motion (Chen et al., 2003,
2005; Slaghuis et al., 2007; Stuve et al., 1997). This raises the
possibility that the hypothesized lower survival probabilities in
patients with schizophrenia compared to healthy controls might
reflect difficulties with the perception of coherent motion rather
than attenuated effects of sensory predictions. To probe this possibility,
we conducted a psychophysical test to quantify each participant's
threshold to perceive coherent motion, and relate it to performance in
the main experiment.