Verbal Memory and New Learning

Challenges Post ABI

  • Difficulties with processing information via: working, short term, episodic, procedural, prospective, semantic and long term memory (CASLPO 2002)
  • Difficulties with either retention and/or retrieval of information that impacts overall communication competency

Verbal memory is divided into 3 stages: encoding (the taking in of new information), consolidation (storing memory for later use) and retrieval (extraction of the stored information). Wright & Schmitter-Edgecombe (2011) have suggested that individuals who sustain a traumatic brain injury have problems with encoding and the consolidation stages of memory. Over time the consolidating of information can improve; however, the encoding of information often remains problematic.

There are two types of memory aids: external and internal aids. External aids may be active high tech such as: computers, PDAs, and mobile phones and passive (no tech/low tech) including calendars, diaries, lists, timetables and dictaphones (McDonald et al., 2011;Sohlberg et al., 2007). As active aids become more readily available, there is a greater need to study their effectiveness in helping those with an ABI deal with prospective memory impairments.

Internal aids consist of strategies using word lists, word letter cuing or association. This module describes research evidence which investigated the use of active and passive external aids, and internal aids to enhance memory following brain injury.

Goals of Treatment

  • To assist individuals who have sustained an ABI organize and take in new information, store it effectively for later use, and retrieve stored information easily.

Treatment Strategies

 Computer assisted training

  • Use of electronic calendars to organize upcoming activities
  • Use of specific software to assist with memory and new learning deficits
  • Individualized reminder systems
  • Errorless Learning
  • Visual imagery

Materials and Devices

  • PDAs
  • Computers, electronic calendars (e.g., Google calendars), diaries, Smart Phones, I-Pads, Tablets
  • Pagers
  • Television Assisted Prompting
  • Calendars and diaries

Treatment for Verbal Memory and New Learning

With the current surge in electronic equipment and software, there are a variety of treatment options available. There are also several internal aids used to improve verbal memory, although these have not been studied as extensively as the external aids.

External Aids/Assistive Technology

Trial and Error Learning

In a recently published RCT, Powell et al. (2012) compared trial and error learning to systematic instruction. Twenty-nine individuals were randomized to either the systematic instruction group (n=15) or the trial and error group (n=14). Twelve 45 minute training sessions were given to each individual. Each session targeted selected skills on a PDA. The systematic instruction condition emphasized mastery while trial and error treatment (conventional) emphasized exploratory learning. Following treatment, five areas were evaluated: accuracy; maintenance accuracy; fluency; generalization, and social validity. At the initial post-treatment follow-up there were no significant differences between the groups; however, at the 30 day follow-up significant differences began to emerge. Those in the systematic instruction condition performed significantly better (p<0.05) than those in the conventional condition. As well, those in the systematic instruction group were found to be more fluent (or efficient) on task performance than those in the conventional instruction group (Powell et al., 2012).

Cognitive Teletherapy

In this study completed by Bourgeois et al. (2007), 38 subjects, along with one significant other for each subject, were assigned to either the spaced retrieval (SR) group or the didactic strategy instruction (SI) group. Subjects were asked to maintain a daily log where they would note all areas with which they were having difficulties. Treatment goals were developed based on areas of difficulty. Those in the SR group were given prompt questions and responses for each goal selected. Answers to the prompt questions were expected to be given in exactly the same way each time. Those in the SI group received time with a therapist to discuss memory strategies. All sessions were conducted by phone for both groups. Results indicate that the frequency of memory problems decreased in both groups over time. Significant improvement in goal mastery (p<0.05) was noted in the SR group but not in the SI group. Scores on the Cognitive Difficulties Questionnaire (CDS) indicate both groups were experiencing fewer difficulties following treatment. Post treatment, scores on the community integration questionnaire (CIQ), showed no significant differences between the two groups.

Google Calendar versus Standard Diary

McDonald et al. (2011) conducted an RCT cross over trial in which participants were randomly assigned to a Google calendar (see diagram 1) group or a standard diary group. Prior to randomization, participants were asked to identify routines they would like to complete within the next 15 weeks. Following this, individuals were randomized to either the Google calendar group (group A) or the standard diary group (group B). At the end of the 5 week baseline, phase group A began using the standard diary and group B began using the Google calendar. While both memory aids helped to improve prospective memory performance of all participants, Google calendar was more effective in improving prospective memory then the standard diary. Participants were able to achieve 82% of their targets using Google calendar but only 55% of targets were achieved using the standard diary.

In a randomized cross over trial conducted by Bergquist et al. (2009), 14 individuals participated in two internet-based interventions. Each group received 30 sessions on either an active calendar acquisition intervention (experimental condition) or 30 sessions of a control diary intervention (control condition). In the calendar condition, participants logged into the Instant Message (IM) system and worked with the therapist to become proficient in using the calendar to compensate for memory problems they were experiencing. Those in the diary condition spent an equal amount of time on line interacting with the therapist and keeping a log of their day-to-day events. Those in the calendar groups showed significant improvement in functioning (p<0.02) compared to those in the diary group. Of note, family members also found participants had fewer memory problems on the Neurobehavioural Functioning Inventory following treatment. 

Television Assisted Prompting versus Assistive Technology for Cognition

In a randomized crossover design Lemoncello and colleagues (2011) randomly assigned 23 individuals into one of two groups. Those assigned to group A, the Television Assisted Prompting (TAP) group, had the TAP system installed on their television where they received reminders of events to be completed. Those in group B, the Assistive Technology for Cognition (ATC) group, received reminders through more traditional methods (paper planner, cell phones or computers). Following the 10 week intervention Group A received reminders in the more traditional way and group B began receiving reminders through the TAP system. Cognitive impairments were measured using the Paced Auditory Serial Addition Test (PASAT – attention), the California Verbal Learning Test-2 (CVLT-2 – verbal memory and new learning), the Modified Six Elements subsets of the Behavioural Assessment of Dysexecutive Syndrome (BADS – prospective memory and time management), and the Everyday Memory Questionaire (EMQ – everyday memory). The TAP system was found to improve task completion. This finding adds to the growing body of literature supporting the use of assistive technology to improve prospective memory post ABI (Wilson et al., 2001; de Joode et al., 2010; Lemoncello et al., 2011). Of note, the TAP system is not yet commercially available (Lemoncello et al., 2011)

Compensatory Prospective Memory Training versus Self-Awareness Training

In another RCT, 45 individuals were randomly assigned into one of 4 treatment groups (Shum et al., 2011). The treatment groups consisted of 4 different intervention programs: self-awareness plus compensatory prospective memory training; self-awareness training plus active control; active control plus compensatory prospective memory training and active control only. Participants were assessed using the Cambridge Prospective Memory Test (CAMPROMPT). Post interventions scores were found to improve significantly for those in the compensatory training component group (p<0.017) indicating greater changes in strategies used to improve memory. Compensatory prospective memory training included use of a diary or organizational devices, and group members were encouraged to use written reminders, appointments and note taking. Of note, when family relatives were asked to assess the individuals’ everyday functioning pre and post intervention, no significant changes were found between the 4 groups.

Personal Digital Devices (PDAs)

Dowds et al. (2011) recruited 36 adults to participate in a RCT using two different personal digital assistant devices (PDAs) or a paper-based schedule book to assist them in remembering to complete various pre-selected tasks. Tasks completion rates were higher under the Microsoft Operating System (MOS) and the Palm Operating System (POS) conditions compared to pen and paper tasks. Participants using the POS PDA had a significantly higher task completion rate than those using the MOS PDA.

Diary to Improve Memory

Ownsworth and McFarland (1999) evaluated two different training approaches in the use of a diary to compensate for memory problems. They randomly assigned 20 ABI volunteers (15 TBI; 5 ABI) to either a Self-Instructional Training (SIT) approach or to a task-specific learning approach. The Diary-SIT approach trains compensation using higher cognitive skills of self-regulation and self-awareness. That is, participants where taught to question themselves with the following script: W-what are you going to do; S-select a strategy for the task; T-try out the strategy; C-Check out how the strategy is working (WSTC), It was suggested that this training approach provides direct, internal feedback, which can generalize to other situations involving memory. In contrast the Diary-Only approach taught subjects how to use the diary. Results indicated that those in the Diary-SIT group made consistently more diary entries, reported a reduction in everyday memory problems and made more positive ratings on treatment efficacy compared to the Diary-Only group.

Neuropage Paging System

Wilson et al. (2001) conducted a randomized controlled cross-over trial with 143 memory impaired patients. Of the 143 participants 93.7% had sustained an ABI. The objective for this study was to evaluate a paging system designed to improve independence in people with memory problems as well as to reduce deficits in executive function. Results demonstrated that the pager system significantly increased patients’ ability to carry out daily tasks, and successful task achievement was more efficient after the pager intervention was introduced.

Virtual Reality

In an RCT conducted by Grealy and colleagues (1999), the effects of exercise and virtual reality on individuals with ABI while still in rehabilitation was investigated. During this exercise program, patients were asked to use a stationary bicycle in conjunction with a non-immersive virtual reality program. Treatment was administered over a minimum of 4 weeks. The treatment group consisted of 13 patients currently in rehabilitation, while the control group was selected from a group of patients who had previously been in rehabilitation. Pre intervention scores and post intervention scores were compared for both groups. Results for those in the treatment group showed significant improvement on learning and memory tasks post intervention. Similarly, when compared to the controls, the experimental group fared significantly better on digit symbol as well as visual and verbal learning tasks.

Computer Assisted Memory Retraining

Self-practice, presentation of attractive stimuli, multi-sensory feedbacks and personalized training contents were the four different forms of computer-assisted cognitive re-training programmes that Tam and Man (2004) used to evaluate people with post-head injury amnesia. Participants were randomly assigned to one of four treatment groups (matched diagnostically and demographically): (1) self-paced group, which allowed individuals to move at their own pace in a non-threatening environment; (2) feedback group, which involved immediate provision of feedback in a non-judgmental fashion; (3) personalized group, whereby the computer presented training contents showed the participant’s actual living environment and routines; and (4) the visual presentation group, which was a provision of attractive and bright presentation designed to help individuals engage in the activity. Each group went through one of the four computer-assisted memory re-training strategies. Results revealed that the patients in the experimental group showed positive improvements on all of the four memory training methods as compared to the control group. However, there were no statistically significant differences among the four training methods. Nonetheless, this study showed that computer-assisted memory retraining yielded positive results for patients with post-head injury amnesia.

Memory Retraining Programs

Thick-Penny and Barker-Collo (2007) randomly assigned 14 individuals to either the treatment or control groups. Those in the treatment group (Memory Rehabilitation Group-MRG) participated in a memory rehabilitation program which consisted of 8 learning modules each 60 minutes long that ran twice a week for 4 weeks. During each session, materials were presented using a combination of didactic teaching and small group activities. Memory improvement and difficulties were evaluated. Overall, a reduction in memory impairment was noted at the end of the 4 weeks of intervention and again at the one month follow-up time period.

In a recent study by O’Neil-Pirozzi et al. (2010), individuals with ABI participated in twelve 90-minute sessions which were held twice a week. The intervention included memory education, and to improve memory function the study emphasized internal strategy acquisition. Primary emphasis was placed on semantic association followed by semantic elaboration/chaining and imagery.  Results from the Hopkins Verbal Learning Test indicated significant differences between the groups and those with a severe ABI performed more poorly than those with a moderate injury. Despite this finding, those with severe ABIs did perform better than those in the control group. In all, memory performance was seen to improve for all in the intervention group compared to the control group.

Cranial Electrotherapy Stimulation

Michaels et al. (1993) studied cranial electrotherapy stimulation and its effect on post-traumatic memory impairment in clinical care patients with closed head injury. Patients received CES or sham CES treatments for 40 minutes daily over a period of four weeks. The group receiving CES treatment did not improve in their memory performance, nor did their immediate or delayed recall improve. Further, with retesting, both the CES and the sham CES group showed a similarly significant trend with no group performing any better than the other. These results suggest that CES stimulation in brain-injured patients does not improve memory functioning. 

Computer Assisted Training

In a RCT conducted by Dou et al. (2006), participants were randomized to one of two groups: the computer assisted memory training group (CAMG-treatment - group 1) or the therapist administered memory training group (TAMG-treatment - group 2) with each receiving one month memory training. Memory training was similar between the groups but they were delivered differently. The treatment groups received 20 training sessions with each running for 6 days per week and lasting approximately 45 minutes. The control group received no training. Sessions consisted of: training basic component memory skills in (1) the management of typical daily tasks utilizing/integrating the component memory skills, (2) customized programs and (3) skill consolidation as well as in the generalization of those skills in practice. Scores on the Neurobehavioural Cognitive Status Examination (NCSE) showed significant improvement in the TAMG and CAMG groups (p<0.015, p<0.02 respectively) compared to the control group. Results from the Rivermead Behavioural Memory Test (Cantonese version) showed the CAMG improved significantly compared to the control group (p<0.0001).Those in the TAMG showed no significant improvement.

Conclusions

There is Level 2 evidence supporting the use of electronic calendars to assist in improving memory post-ABI (McDonald et al. 2011; Bergquist et al., 2009).

Results from a study conducted by Grealy et al. (1999) show there is Level 2 evidence suggesting virtual reality exercise programs have a positive impact on learning and working memory.

There is Level 2 evidence suggesting memory group interventions can improve everyday memory functioning (Thickpenny-Davis & Barker-Collo, 2007).

There is Level 1b evidence, from one RCT, that cranial electrotherapy stimulation did not help to improve memory and recall following brain injury (Michaels et al., 1993).

Results from one RCT indicate there is Level 2 evidence suggesting general cognitive functioning does benefit from computer assisted cognitive retraining. Further study confirming these findings need to be conducted (Dou et al., 2006). 

 

The use of electronic calendars has been shown to be effective in improving memory post ABI.

Virtual reality programs are effective in improving learning and working memory.

Cranial electrotherapy stimulation was not shown to be an effective treatment to enhance memory and recall abilities following brain injury.

Although computer assisted training has been found to benefit cognitive retraining following a brain injury, further study confirming these findings need to be conducted. 

 

Internal Aids

Aids to Improve Verbal Memory and New Learning

In a recent study, Potvin et al. (2011) assigned 30 moderate to severe ABI patients to either an experimental group (n=10) or a control group (n=20). Both groups were matched based on age and education. All participants were initially assessed using the Test Ecologique de Memoire Prospective(TEMP). Those in the experimental group participated in ten prospective memory training sessions. Each session lasted 90 minutes. The prospective memory (PM) program was divided into 5 phases: understanding PM functioning; training to visualize simple images; learning visual imagery techniques; applying visual imagery in PM; and applying visual imagery in everyday situation. The scores on the TEMP, following treatment, improved for those in the experimental group. Study authors also noted that those in the experimental group reported fewer symptoms of depression than the control group.

Twum and Parente (1994) randomly assigned 60 ABI patients into one of 4 groups (one control and three mnemonic strategy groups) counterbalanced. The research demonstrated improved performance for subjects who were taught a strategy (either verbal labelling or visual imagery) while learning paired-associations. Treatment groups showed greater efficiency in learning and greater delayed recall information.

Errorless Learning and Impact on Memory

Tailby and Haslam (2003) also examined how learning can improve or limit later recall of information. Twenty-four ABI subjects were matched on basis of age, gender, pre-morbid and current intellectual status divided into 3 groups based on performance of verbal memory (mild, moderate & severe). Each group (n=8) was assigned to one of 3 learning conditions: errorless learning, self-generated; errorless learning, experimenter generated; and errorful learning. Results showed that regardless of severity level, subjects recalled more information in the errorless learning conditions (with self-generated superior to experimenter generated) than in the errorful learning condition.

Using Visual Imagery to Enhance Recall of Names and Faces

By using various visual imagery techniques to aid learning and recall, researchers have demonstrated that increasing the saliency of features encoded, results in an increase in the amount recalled. Milders et al. (1998) examined performance on a name learning task by increasing the meaningfulness of people’s names with various strategies (e.g. when learning a new name-face association try to think of an occupation or object with the same name or a famous person with a similar name etc). When subjects (13 severe ABI vs. 13 matched controls) were tested on 3 different memory tasks, results indicated a significant difference following training, more so for the control group than the ABI group. Also, learning procedures were more effective on one task (where subjects were required to learn the name-occupation-and town) compared to the other two tasks (famous-faces or name learning).

Glisky and Delaney (1996) evaluated implicit memory (priming using a stem completion task) and the use of vanishing cues when learning semantic information in a small number of ABI patients (n=8 & 4) who were still experiencing post traumatic amnesia (PTA) and a matched control group. Findings revealed that learning and recall of information (once PTA has resolved) had occurred, albeit at reduced levels compared to controls.

Modeling versus Hand over Hand for Learning and Recall

In a study investigating the effects of two instructional techniques (modeling and moulding) 16 participants were instructed to learn a sequence of 7 hand movements in the correct order (Zlotowitz et al., 2010). In the moulding condition, participants were taught the hand movements using a hand over hand technique. The modeling condition had participants model the hand movements as presented by the experimenter. Participants were tested on recall 5 minutes after their sequence recall and 30 minutes later. Results indicated there was no difference between the techniques after the short delay recall; however, after the longer delay, recall was significantly better after the modeling condition compared to the moulding condition (Zlotowitz et al., 2010).

Memory Training

Berg et al. (1991) randomly assigned 38 individuals to one of three groups (strategy rehabilitation, pseudorehabilitation (drill and practice) and no treatment). In the strategy group, individuals were taught general cognitive principles of memory functioning and aids (i.e., internal and external strategies were taught and practiced). Participants in this group participated in daily homework exercises 3x/week for 6 weeks. Here severely brain injured patients showed improved on objective measures of memory (15 Words Test, Face-Names Learning Test, and Shopping List) at 4 months following training in a strategy-use group compared to a pseudo-treatment and a no treatment control group. The pseudorehabilitation group individuals were given memory tasks and games that they were asked to practice and do as homework. More efficient ways of dealing with any assigned task was not provided to group members. Those in the no treatment group were not given any task to complete and no training was provided to them. All participants were tested at the same time. Reaction times for the no treatment group was slower than the other two groups and remained so for the duration of the study. Those in the strategy training group showed significant improvement on all memory performance measures.

In a follow up study, Milders and colleagues (1995) retested 31 of the original 38 individuals on the same memory tests. All memory tests were re-administered to all participants. Although the mean scores of the memory tests show no significant differences between the post-training and long –term testing for the groups as a whole, results from the pseudorehabilitation group inidicated a significant improvement (p<0.5).

The reader is encouraged to review the aforementioned studies within Table 7.2 at the end of this module for further details.

Conclusions

There is Level 2 evidence that internal memory strategies appear to be an effective aid in improving recall performance(Berg et al., 1991; Milders et al., 1995)

Potvin et al. (2011) found Level 2 evidence to support the use of visual imagery techniques to improve prospective memory.

There is Level 1b evidence, based on a study by Zlotowitz et al. (2010), suggesting that modeling techniques (patient mirroring target) are more effective then hand-over-hand moulding techniques.

 

Memory groups have been shown to improve everyday memory functioning and improve the use of memory strategies amongst those with ABI.

Internal strategies appear to be an effective aid in improving recall performance.

Modeling instructional techniques may be more effective then hand-over hand moulding instructional techniques for aiding retention and recall of hand teaching action sequences particularly for delayed recall requests.