Optimization of perceptual learning: Effects of task difficulty and external noise in older adults

Abstract

Previous research has shown a wide array of age-related declines in vision. The current study examined the effects of perceptual learning (PL), external noise, and task difficulty in fine orientation discrimination with older individuals (mean age 71.73, range 65–91). Thirty-two older subjects participated in seven 1.5-hour sessions conducted on separate days over a three-week period. A two-alternative forced choice procedure was used in discriminating the orientation of Gabor patches. Four training groups were examined in which the standard orientations for training were either easy or difficult and included either external noise (additive Gaussian noise) or no external noise. In addition, the transfer to an untrained orientation and noise levels were examined. An analysis of the four groups prior to training indicated no significant differences between the groups. An analysis of the change in performance post-training indicated that the degree of learning was related to task difficulty and the presence of external noise during training. In addition, measurements of pupil diameter indicated that changes in orientation discrimination were not associated with changes in retinal illuminance. These results suggest that task difficulty and training in noise are factors important for optimizing the effects of training among older individuals.

Improving Vision Among Older Adults

“…The sample size was determined based on pilot studies and previous research demonstrating an effect of training in older and younger participants (Andersen et al, 2010; Bower & Andersen, 2011; Bower et al, 2013; DeLoss et al, 2014). All observers were paid for their participation in the experiment.…”

“…Only one of these studies found complete specificity to an untrained retinal location (Andersen et al, 2010), while numerous other studies found partial to complete transfer to an untrained task, orientation, or stimulus (Bower & Andersen, 2011; Bower et al, 2013; DeLoss et al, 2014). This decreased specificity may be due to decreased neural inhibition, as well as decreased orientation and direction neuronal selectivity (Schmolesky et al, 2000).…”

Perceptual Learning: Toward a Comprehensive Theory

“…In addition, it has been found that training older people on a visual task leads to better performance (Andersen et al 2010, Bower et al 2013, Deloss et al 2013). This raises the possibility that visual training can restore or at least improve a variety of visual abilities in older people that have declined with aging (Andersen 2012).…”

Multisensory perceptual learning is dependent upon task difficulty

“…One aspect of perceptual training that might influence the extent of multisensory perceptual learning is task difficulty. For example, in the visual domain, the difficulty of the task appears to be a strong determinant of whether learning will or will not occur (Ahissar and Hochstein 1997; Seitz et al 2006; Wang et al 2010; DeLoss et al 2014). Furthermore, based on evidence from other studies of perceptual training, it has been suggested that the greatest changes in behavioral performance are observed when the stimuli presented are challenging while also eliciting sufficiently rewarding feedback (Mishra and Gazzaley 2014).…”