The impact of extrafoveal information on visual short-term memory for object position

Abstract

The role of extrafoveal information in visual short-term memory has been investigated relatively little, and, in most existing studies, using verbalisable stimuli susceptible to the recruitment of long-term memory (LTM). In addition, little is known about the impact of extrafoveal information available pre- and posttarget foveation, as it is typical to provide extrafoveal information prior to the foveation of memory targets. In this study, two object-position recognition experiments were conducted (each with two conditions) to establish the impact of extrafoveal information provided before and after the foveation of memory targets. Stimuli comprised 1/f noise discs that minimised the recruitment of LTM by eliminating verbal and semantic cues. Overall, a greater hit rate was found where extrafoveal information was available; however, performance analyses in which extrafoveal information was considered relative to the temporal lag at which target stimuli were foveated reveals both costs and benefits. A beneficial effect arose only where extrafoveal information was provided after the target had been foveated, but not prior to target foveation. Findings are discussed in terms of recency and extrafoveal perception effects, incorporating a postfoveation object-file refresh mechanism.

Keywords:

• Extrafoveal perception
• 1/f noise
• Nonverbal stimuli
• Object file theory
• Visual short-term memory

Notes

¹The term “extrafoveal”, in our experiments, refers to visual information acquired simultaneously from retinal areas other than the fovea, except where programming a saccade from one stimulus to the next.

²A validation experiment requiring that observers maintain fixation at the screen centre while matching stimuli shown first at a random eccentricity from 8 to 13°, and then at the screen centre, showed ceiling performance for detecting the presence of a stimulus, and a matching rate well above chance level (≥1.0 d').