Short-term retention of proprioceptive information

Abstract

The Joint Position Reproduction test (JPR), one of the most widely used measurements to estimate proprioceptive accuracy, requires the short term storage of proprioceptive information. It has been suggested that visuospatial sketchpad plays a fundamental role in the memorization of proprioceptive information. The current study aimed to investigate this assumption. To do so, we developed and used a novel JPR protocol to measure the retention capacity with respect to sequences of different positions. Our goal was to develop the original task further to make it comparable with other widely used short-term memory measurements, in which the memory capacity was determined by the number of the items participants retain (memory span). We compared participants’ (N=39) performance in this task to that of results of Corsi block-tapping task (capacity of the visuospatial sketchpad) and Digit span task (capacity of the phonological loop). Proprioceptive memory capacity did not correlate either with spatial or verbal memory capacity. The exploratory analysis revealed that proprioceptive span correlated positively with the performance if 5 joint positions had to be retained. Further associations with verbal span for 6 or 7 positions, and spatial span for 5 positions were found. Our findings do not support the idea that visuospatial sketchpad plays a fundamental role in the storage of proprioceptive information. The independence of span measures indicates that proprioceptive information might be stored in a subsystem independent of the visuospatial sketchpad or phonological loop.

The retention of proprioceptive information is suppressed by competing verbal and spatial task

“…The results of Goble and colleagues (2012) , which showed a positive association between spatial memory span and improvement in proprioceptive accuracy for longer presentation time of joint positions in patients with cerebral palsy, is partly in accordance with this conclusion. In contrast, proprioceptive memory capacity did not correlate either with spatial or verbal memory capacity in the study of Horváth and colleagues (2020) . These differences can be explained by multiple reasons.…”

“…In a similar vein, motor tasks do not disrupt the retention of verbal and spatial information (Smyth et al, 1988). The existence of the independent visual and spatial subsystem is further supported by correlation studies where capacity measures of the two modality were not associated (Horváth et al, 2020;Ichikawa, 1983). However, the position of the motor subsystem is less understood.…”

“…To measure proprioceptive memory span, we adapted and modified the task developed by Horváth and colleagues (2020) for assessing the ability to memorise and reproduce sequences of elbow joint positions. For the assessment, a custom-made motor-driven device (proprioceptor, see Figure 1 ) was used, which enabled us to accurately set (with a precision of ±0.5°) and measure (±0.1°) the angle of the elbow joint.…”

“…However, this conclusion was not supported by the findings of another study. Horváth and colleagues (2020) investigated the association between proprioceptive span (i.e., the maximal number of proprioceptively determined joint positions that one can store in short-term memory) and verbal or spatial short-term memory span (assessed with the digit span task and the Corsi task, respectively) in a sample of university students. Proprioceptive span proved to be independent of verbal and spatial spans, which suggests that proprioceptive information might be stored in another subsystem.…”

“…Thus, executing a motor task while encoding sequences of joint positions should lead to a decreased performance, whereas other tasks (verbal, spatial, visual) would not impact it. For this purpose, we adapted and modified the task used by Horváth and colleagues (2020) to assess proprioceptive short-term memory span in a within-subject research design with five different experimental conditions: (a) without competing task/interference (baseline condition), (b) with motor interference, (c) with verbal interference, (d) with spatial interference, and (e) with visual interference.…”