Abstract:
Binocular visual plasticity can be initiated via either bottom-up or top-down mechanisms, but it is unknown if these two forms of adult plasticity can be independently combined. In seven participants with normal binocular vision, sensory eye dominance was assessed using a binocular rivalry task, before and after a period of monocular deprivation and with and without selective attention directed towards one eye. On each trial, participants reported the dominant monocular target and the inter-ocular contrast difference between the stimuli was systematically altered to obtain estimates of ocular dominance. We found that both monocular light- and pattern-deprivation shifted dominance in favour of the deprived eye. However, this shift was completely counteracted if the non-deprived eye\'s stimulus was selectively attended. These results reveal that shifts in ocular dominance, driven by bottom-up and top-down selection, appear to act independently to regulate the relative contrast gain between the two eyes.
摘要:
双目视觉可塑性可以通过自下而上或自上而下的机制启动,但尚不清楚这两种形式的成人可塑性是否可以独立结合。在7名双眼视力正常的参与者中,感官眼睛优势是使用双目竞争任务评估的,在单眼剥夺之前和之后,并且有或没有针对一只眼睛的选择性注意。在每次审判中,参与者报告了主导单眼目标,并且系统改变了刺激之间的眼间对比差异,以获得对眼优势的估计.我们发现,单目光线和模式剥夺都改变了优势,有利于被剥夺的眼睛。然而,如果有选择地参加非剥夺眼睛的刺激,这种转变是完全抵消的。这些结果表明,眼球优势的变化,由自下而上和自上而下的选择驱动,似乎独立地调节两眼之间的相对对比度增益。