Procedural Memory Following Moderate-Severe Traumatic Brain Injury: Group Performance and Individual Differences on the Rotary Pursuit Task.

Arianna Rigon,Nathaniel B Klooster,Samantha Crooks,Melissa C Duff

doi:10.3389/fnhum.2019.00251

Abstract

The impact of traumatic brain injury (TBI) on procedural memory has received significantly less attention than declarative memory. Although to date studies on procedural memory have yielded mixed findings, many rehabilitation protocols (e.g., errorless learning) rely on the procedural memory system, and assume that it is relatively intact. The aim of the current study was to determine whether individuals with TBI are impaired on a task of procedural memory as a group, and to examine the presence of individual differences in performance. We administered to a sample of 36 individuals with moderate-severe TBI and 40 healthy comparisons (HCs) the rotary pursuit task, and then examined their rate of learning, as well as their retention of learning. Our analyses revealed that while individuals with TBI spent a significantly shorter amount of time on target as a group, they did not retain significantly less procedural learning, and as a group their rate of learning was not different from HCs. However, there were high individual differences in both groups, indicating that some individuals might not be able to take advantage of treatment methods designed to leverage intact procedural memory system. Future work is needed to better assess and characterize procedural memory in individuals with TBI across a larger battery of tasks in experimental and clinical setting as memory and learning status may predict rehabilitation success.

Highlights

Traumatic brain injury (TBI) affects almost 2 million people annually in the US alone, and leads to high socio-economic costs for both survivors of TBI and their families and caregivers (Roozenbeek et al, 2012, 2013; Schiller et al, 2012)
Our aims here were twofold: first, we examined the presence of group differences on both rate of learning and retention of motor learning between individuals with TBI and healthy comparisons (HCs)
We found an overall significant effect of group on the first trial, Retention of Learning Figure 3B shows the distributions of the effect of trial for TBI and HC groups, showing a high overlap in the distribution of the two groups

Summary

Introduction

Traumatic brain injury (TBI) affects almost 2 million people annually in the US alone, and leads to high socio-economic costs for both survivors of TBI and their families and caregivers (Roozenbeek et al, 2012, 2013; Schiller et al, 2012). Long-term memory, in turn, is composed of declarative (episodic) memory (the ability to acquire and recall new facts and events) and non-declarative (procedural) memory (the ability to acquire and use skills, habits, and preferences) These distinct forms of memory are specialized in the type of information they process, the time course over which information is encoded, and the flexibility of information retrieval and use (Eichenbaum and Cohen, 2001). Non-declarative learning is characterized as incremental, inflexible, and not accessible to consciousness (Reber et al, 1996), consciousness alone does not reliably distinguish memory systems (Hannula and Greene, 2012) While these memory systems are distinct and specialized, in healthy adults they operate in parallel to support the acquisition and use of a wide range of complex human behaviors (e.g., communication, skill learning, social cognition, creativity) critical for interpersonal relationships, academic, vocational, and recreational pursuits, and independent living (Poldrack et al, 2001; Skidmore, 2015)

Objectives

Methods

Results

Conclusion