Evidence-Based Opioid Education That Reduces Prescribing: The 10 Principles of Opioid Prescribing in Foot and Ankle Surgery

Over half of opioid misusers last obtained access to opioids via a friend or relative, a problematic reflection of the opioid reservoir phenomenon, which results from an unused backlog of excess prescription opioids that are typically stored in the American home. We aim to determine if a voluntary educational intervention containing standard opioid and nonopioid analgesic prescribing ranges for common surgeries is effective in altering postoperative prescribing practice. We utilized a mixed methods approach and sent out a questionnaire to American podiatric physicians, including residents (baseline group A), via email in early 2020 for baseline data; then, we interviewed foot and ankle surgeons and the primary themes of these semistructured interviews informed us to target residents for an educational intervention. We repeated the survey 3 years later in summer 2022 (preintervention group B). We created an opioid guide and emailed it to residents in fall 2022. Another repeat survey was done in spring 2023 (postintervention group C). We used the Mann-Whitney U test to examine differences between the groups among their reported postoperative opioid quantities for a first metatarsal osteotomy surgical scenario. Groups A, B, and C had 60, 100, and 99 residents, respectively. There was no significant difference (p = .9873) between baseline group A and preintervention group B. There was a difference (p < .0001; -5 median) between preintervention group B and postintervention group C (same residency year). In postintervention group C, a majority (91/99) reported viewing the guide at least once, and the number of residents that reported supplementing with NSAIDs also doubled compared to preintervention group B. This novel opioid educational intervention resulted in meaningful change in self-reported postoperative prescribing behavior among residents.

Postoperative Opioid-Prescribing Practice in Foot and Ankle Surgery

BACKGROUND

Approximately 3,900 Americans die every month of opioid overdose. The total economic burden of the opioid epidemic is estimated to be more than $78 billion annually. We sought to determine whether postoperative opioid-prescribing practice variation exists in foot and ankle surgery.

METHODS

We administered a voluntary, anonymous, online questionnaire consisting of six foot and ankle surgery scenarios followed by a demographics section. The purpose of the demographics section was to gather characteristics of podiatric foot and ankle surgeons. We invited podiatric foot and ankle surgeons practicing in the United States to complete the questionnaire via e-mail from the American Podiatric Medical Association's membership list. For each scenario, respondents selected the postoperative opioid(s) that they would prescribe at the time of surgery, as well as the dose, frequency, and number of "pills" (dosage units). We developed multiple linear regression models to identify associations between prescriber characteristics and two measures of opioid quantity: dosage units and morphine milligram equivalents.

RESULTS

Eight hundred sixty podiatric foot and ankle surgeons completed the survey. The median number of dosage units never exceeded 30 regardless of the foot and ankle surgery. Years in practice correlated with reduction in dosage units at the time of surgery. Compared with the orthopedic community, podiatric foot and ankle surgeons prescribe approximately 25% less dosage units than orthopedic foot and ankle surgeons.

CONCLUSIONS

Postoperative opioid-prescribing practice variation exists in foot and ankle surgery. Further research is warranted to determine whether additional education is needed for young surgeons.

Opioid-Prescribing Approaches-One-Size-Fits-All versus Patient-Centric and Procedure-Focused-Among Podiatric Physicians: A Cross-Sectional Study

BACKGROUND

More than half of opioid misusers last obtained opioids from a friend or relative, a problematic reflection of the commonly known opioid reservoir maintained by variable prescription rates and, notably, excessive postoperative prescription. We examined the postoperative opioid-prescribing approaches among podiatric physicians.

METHODS

We administered a scenario-based, anonymous, online questionnaire via an online survey platform. The questionnaire consisted of five patient-foot surgery scenarios aimed at discerning opioid-prescribing approaches. Respondents were asked how many opioid "pills" (dosage units) that they would prescribe at the time of surgery. We divided respondents into two opioid-prescribing approach groups: one-size-fits-all (prescribed the same dosage units regardless of the scenario) and patient-centric and procedure-focused (prescribed varied amounts of opioid dosage units based on the patient's opioid history and the procedure provided in each scenario). We used the Mann-Whitney U test to determine the difference between the opioid dosage units prescribed at the time of surgery by the two groups.

RESULTS

Approximately half of the respondents used a one-size-fits-all postoperative opioid-prescribing approach. Podiatric physicians who used a patient-centric and procedure-focused approach reported prescribing significantly fewer opioid dosage units in scenarios 1 (partial toe amputation; -9.1; P = .0087) and 2 (incision and drainage with partial fifth-ray resection; -12.3; P = .0024), which represented minor procedures with opioid-naive patients.

CONCLUSIONS

Podiatric physicians who used a one-size-fits-all opioid-prescribing approach prescribed more postoperative opioid dosage units regardless of the scenario. Given that the patient population requiring foot surgery is diverse and may have multiple comorbidities, the management of postoperative pain, likewise, should be diverse and nuanced. The patient-centric and procedure-focused approach is suited to limit excess prescribing while defending the physician-patient relationship.

The Anesthetic Effects of Lidocaine with Epinephrine in Digital Nerve Blocks: A Systematic Review

There is a long-standing stigma associated with the use of epinephrine in digital nerve blocks (DNBs) over the concern of digital necrosis. We conducted a systematic review to assess the duration of anesthesia, onset of anesthesia, and complications of lidocaine with epinephrine compared with plain lidocaine for DNBs in adults. We searched Medline via Ovid, Cochrane Library, and ClinicalTrials.gov on January 28, 2020. We included randomized controlled trials that examined lidocaine with epinephrine 1:80,000 to 1:1,000,000 (1-12.5 µg/mL) and plain lidocaine for DNBs of fingers or toes in adults. We completed a blinded review of all unique articles, followed by full-text reviews, data extraction, and quality assessment of all eligible trials. Risk of bias was assessed to inform qualitative data analysis. We identified seven studies with a combined 363 adults and 442 DNBs that met the inclusion criteria. All five studies that reported duration of anesthesia established longer duration in the epinephrine-supplemented lidocaine group, with significant increases in three. Two of the three studies that reported the onset of anesthesia demonstrated significant differences. The two studies that reported complications did not have a single case of digital necrosis. In adults, the use of lidocaine with epinephrine 1:80,000 to 1:1,000,000 (1-12.5 µg/mL) for DNB yields a longer duration of anesthetic effect and seems to be as safe as plain lidocaine in healthy adults. Several studies had some concern for bias, and additional studies are warranted.

American Podiatric Surgeons' Postoperative Multimodal Analgesic-Prescribing Practice: A 2019-2020 National Survey

BACKGROUND

Surgery is a common setting for opioid-naive patients to first be exposed to opioids. Understanding the multimodal analgesic-prescribing habits of podiatric surgeons in the United States may be helpful to refining prescribing protocols. The purpose of this benchmark study was to identify whether certain demographic characteristics of podiatric surgeons were associated with their postoperative multimodal analgesic-prescribing practices.

METHODS

We administered a scenario-based, voluntary, anonymous, online questionnaire that consisted of patient scenarios with a unique podiatric surgery followed by a demographics section. We developed multiple logistic regression models to identify associations between prescriber characteristics and the odds of supplementing with a nonsteroidal anti-inflammatory drug, regional nerve block, and anticonvulsant agent for each scenario. We developed multiple linear regression models to identify the association of multimodal analgesic-prescribing habits and the opioid dosage units prescribed at the time of surgery.

RESULTS

Eight hundred sixty podiatric surgeons completed the survey. Years in practice was a statistically significant variable in multiple scenarios. Compared with those in practice for more than 15 years, podiatric surgeons in practice 5 years or less had increased odds of reporting supplementation with an anticonvulsant agent in scenarios 1 (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.11-5.18; P = .03), 3 (OR, 2.97; 95% CI, 1.55-5.68; P = .001), 4 (OR, 2.54; 95% CI, 1.56-4.12; P < .001), and 5 (OR, 2.07; 95% CI, 1.29-3.32; P = .003).

CONCLUSIONS

Podiatric surgeons with fewer years in practice had increased odds of supplementing with an anticonvulsant. Approximately one-third of podiatric surgeons reported using some form of a nonopioid analgesic and an opioid in every scenario. The use of multimodal analgesics was associated with a reduction in the number of opioid dosage units prescribed at the time of surgery and may be a reasonable adjunct to current protocols.

The Diabetic Foot-Pain-Depression Cycle

BACKGROUND

More than 86,000 Americans with type 2 diabetes mellitus (T2DM) undergo nontraumatic lower-extremity amputations annually. The opioid-prescribing practice of podiatric surgeons remains understudied. We hypothesized that patients with T2DM who undergo any forefoot amputation while using antidepressant medication will have reduced odds of using opioids beyond 7 days.

METHODS

We completed a retrospective cohort study examining patients with T2DM who underwent forefoot amputation (toe, ray, transmetatarsal). Data were restricted to patients with a hemoglobin A1c level less than 8.0% and an ankle-brachial index greater than 0.8. The outcome was use of postoperative opioids beyond 7 days. Patients received an initial opioid prescription of 7 days or less. We developed simple logistic regression models to identify the odds of a patient using opioids beyond 7 days by patient variables: age, race, sex, amputation level, body mass index, antidepressant medication use, and marital status. Variables with P < .1 in the univariate analysis were included in the multiple logistic regression model.

RESULTS

Fifty patients met the inclusion criteria. Antidepressant use and marital status were the only statistically significant variables. Adjusting for marital status, patients with antidepressant use had decreased odds (odds ratio, 0.018; 95% confidence interval, 0.001-0.229; P = .002) of using opioids beyond 7 days after a diabetic forefoot amputation.

CONCLUSIONS

Patients with T2DM who used antidepressants had significantly reduced odds of using opioids beyond 1 week after forefoot amputations compared with those without antidepressant use. We proposed an underlying diabetic foot-pain-depression cycle. To break the cycle, podiatric surgeons should screen this population for depression preoperatively and postoperatively and not hesitate to make a mental health referral if warranted. Nontraumatic amputations can be a traumatic experience for patients; psychiatrists and other mental health providers should be members of limb preservation teams.

Cognitive Bias in Postoperative Opioid-Prescribing Practice

BACKGROUND

Given that excess opioid prescriptions contribute to the US opioid epidemic and there are few national opioid-prescribing guidelines for the management of acute pain, it is pertinent to determine whether prescribers can sufficiently assess their own prescribing practice. We investigated podiatric surgeons' ability to evaluate whether their own opioid-prescribing practice is less than, near, or above that of an "average" prescriber.

METHODS

We administered a scenario-based, voluntary, anonymous, online questionnaire consisting of five surgery-based scenarios commonly performed by podiatric surgeons. Respondents were asked the quantity of opioids they would prescribe at the time of surgery. Respondents were also asked to rate their prescribing practice compared with the average (median) podiatric surgeon. We compared self-reported behavior to self-reported perception ("I prescribe less than average," "I prescribed about average," and "I prescribe more than average"). Analysis of variance was used for univariate analysis among the three groups. We used linear regression to adjust for confounders. Data restriction was used to account for restrictive state laws.

RESULTS

One hundred fifteen podiatric surgeons completed the survey in April 2020. Less than half of the time, respondents accurately identified their own category. Consequently, there were no statistically significant differences among podiatric surgeons who reported that they "prescribe less," "prescribe about average," and "prescribe more." Paradoxically, there was a flip in scenario 5: respondents who reported they "prescribe more" actually prescribed the least and respondents who believed they "prescribe less" actually prescribed the most.

CONCLUSIONS

Cognitive bias, in the form of a novel effect, occurs in postoperative opioid-prescribing practice; in the absence of procedure-specific guidelines or an objective standard, podiatric surgeons, more often than not, were unaware of how their own opioid-prescribing practice measured up to that of other podiatric surgeons.

Postprocedural Opioid-Prescribing Practice in Nail Surgery

BACKGROUND

Ingrown toenails are a common condition requiring outpatient procedures in podiatric medical clinics. To prevent recurrence, chemical matrixectomy is often recommended. Postprocedural pain management is largely based on preferences rather than on a formal guideline. This study aims to explore the postprocedural prescribing behavior among practicing podiatric physicians to foster future guideline and policy development.

METHODS

We administered an open, voluntary, anonymous questionnaire via an online survey platform that included a common nail procedure scenario (chemical matrixectomy) and a prescribed demographics section. Podiatric physicians were asked what they would prescribe to manage postprocedural pain. Opioid and nonopioid options were provided. We developed two multiple logistic regression models to identify associations between prescriber characteristics and prescribing opioids after "standard" chemical matrixectomy.

RESULTS

Of the 860 podiatrists who completed the survey, 8.7% opted to prescribe an opioid. Hydrocodone was most commonly chosen. A median of 18 opioid pills were prescribed. No prescriber characteristics were associated with prescribing opioids after chemical matrixectomy scenario. There is a large discrepancy and knowledge gap in the literature on the optimal postprocedural pain management for outpatient procedures, including procedures in specialties such as dentistry and dermatology. The median number of opioids prescribed by podiatrists is higher than that by dentists for management of third molar extraction. In contrast, opioid-prescribing behavior among the 8.7% of respondents is similar to dermatologic management of postprocedural pain in Mohs surgery.

CONCLUSIONS

Podiatric physicians cannot assume that their prescribing of opioids does not affect the opioid abuse problem in the United States. The presented study serves to be an initiation for procedure-specific opioid prescription benchmarking to foster future guideline and policy development. After nail procedures, opioids should not be routinely prescribed.

Age and recovery from brain injury: legal opinions, clinical beliefs and experimental evidence

Despite considerable scientific evidence to the contrary, many medical practitioners maintain that children recover from brain injury better than adults. This belief, which is commonly referred to as the "Kennard Principle", has important ramifications for personal injury compensation claims in which the amount of financial damages claimed is partly based on medical experts' prognoses for recovery and long-term outcome. The present study investigated whether legal practitioners' beliefs are consistent with those of medical practitioners. Lawyers were asked to estimate their confidence in consultant neurologists' estimates of recovery in four clinically-based but fictitious case studies which differed only in the reported age of the patient. The lawyers showed more confidence in estimates which coincided with the Kennard Principle than those which did not. These results support previous findings in showing widespread belief that "younger is better" in recovery from brain injury. In consequence, it is likely that financial compensation for children with brain injury is currently being underestimated in litigation, thereby prejudicing the long-term outcome of the child.

Assessing stroke patients’ prospective memory using virtual reality

There is a dearth of empirical evidence about prospective memory (remembering to perform actions in the future) in stroke patients. A probable reason for this is that it is difficult to perform a realistic and controlled assessment of prospective memory ability in a rehabilitation setting. Virtual reality may provide a solution to this difficulty by allowing prospective memory to be tested in a simulation of a real-life situation whilst retaining a laboratory level of scientific control. This exploratory study assessed the performance of stroke patients and age-matched control participants on event-, time- and activity-based prospective memory retrieval tasks in a personal computer-based virtual environment. Stroke patients were severely impaired at the event- and activity-based tasks compared with age-matched controls, but only marginally impaired at the time-based task. The additional knowledge gained from this form of assessment could direct rehabilitation more effectively towards specific impairments of individual patients.

The use of virtual reality in memory rehabilitation: current findings and future directions

There is considerable potential for using virtual reality (VR) in memory rehabilitation which is only just beginning to be realized. PC-based virtual environments are probably better suited for this purpose than more immersive virtual environments because they are relatively inexpensive and portable, and less frightening to patients. Those exploratory studies that have so far been performed indicate that VR involvement would be usefully directed towards improving assessments of memory impairments and in memory remediation using reorganization techniques. In memory assessment, the use of VR could provide more comprehensive, ecologically-valid, and controlled evaluations of prospective, incidental, and spatial memory in a rehabilitation setting than is possible using standardized assessment tests. The additional knowledge gained from these assessments could more effectively direct rehabilitation towards specific impairments of individual patients. In memory remediation, VR training has been found to promote procedural learning in people with memory impairments, and this learning has been found to transfer to improved real-world performance. Future research should investigate ways in which the procedural knowledge gained during VR interaction can be adapted to offset the many disabilities which result from different forms of memory impairment.

Benzylpenicillin differentially conjugates to IFN-gamma, TNF-alpha, IL-1beta, IL-4 and IL-13 but selectively reduces IFN-gamma activity

It is known that beta-lactam antibiotics can conjugate to lysine and histidine residues on proteins via the carbonyl group of the opened beta-lactam ring. However, it is not known which proteins these drugs target and there is little work addressing whether conjugation is preferential for some proteins over others or if conjugation has functional consequences for the protein. We have previously shown that the beta-lactam antibiotic benzylpenicillin (BP) conjugates to IFN-gamma and reduces its activity. This interaction demonstrates selectivity, as BP does not bind to IL-4. Here, we extend our study to include other Th1 and Th2 cell-associated cytokines and two cytokines associated with inflammatory responses. We demonstrate by Western blotting that BP also conjugates to IL-1beta, IL-2, IL-5, IL-13 and TNF-alpha but not to IL-10. Densitometric analysis of leading cytokine bands on blots revealed that IFN-gamma always gave more intense BP-positive bands than any other cytokine analysed. Cytokines pre-incubated with BP at 37 degrees C in a protein-containing, serum-free medium were assayed for their biological activity. By in vitro bioassay, BP inhibited the ability of IFN-gamma but not IL-1beta or TNF-alpha to induce CD54 expression on epithelial cells. In addition, BP did not affect IL-4 or IL-13 inhibition of mast cell proliferation. When the pre-incubation temperature was reduced to 4 degrees C, BP did not conjugate to IFN-gamma or modulate its activity. BP retained its inhibitory effect on IFN-gamma activity when 20% FCS was added to the pre-incubation medium. In conclusion, BP conjugates to some cytokines but not others and this does not appear to be related to primary protein structure. Furthermore, of the cytokines studied, conjugation only to IFN-gamma is accompanied by inhibition of activity. This phenomenon is temperature dependent and occurs in the presence of serum. These findings provide further evidence for differential, direct drug-cytokine interactions. Such interactions may have therapeutic implications in terms of targeting cytokines to regulate their activity.

Support for children following traumatic brain injury: the views of educational psychologists

PURPOSE

For many years, neuroscientific research appeared to support the view that the young brain was more resilient and better able to withstand damage than the mature brain. More recent neuroscience research has questioned this view. Nevertheless, the view that 'younger is better' continues to be accepted by many medical practitioners. The present study sought to establish whether the training and experience of educational psychologists has made them aware that young children are particularly vulnerable to long-term effects of brain injury.

METHOD

Educational psychologists were asked to estimate the need for additional social/family and educational support, and how long such additional support would be needed, in four fictitious but clinically-based case studies which differed only in the reported age of the child/adolescent at the time of the injury.

RESULTS

Educational psychologists consistently rated young children with brain injuries as needing more additional social/family support for longer than adolescents.

CONCLUSIONS

These results suggest that there is an appreciation of the additional needs of young children who have sustained brain injuries within our educational system.

An exploratory investigation into the usability and usefulness of training people with learning disabilities in a virtual environment

PURPOSE

Two studies sought to answer the following questions. Are people with learning disabilities capable of using a virtual environment? Are they motivated to learn using this training method? Do they show any benefit from using a virtual environment? Does any benefit transfer to improved real world performance?

METHOD

In the first study, 30 students with learning disabilities were sequentially allocated to an active or a passive experimental group. Active participants explored a virtual bungalow searching for a toy car. Passive participants watched the exploration undertaken by the preceding active participant and searched for the toy car. All participants then performed spatial and object recognition tests of their knowledge of the virtual environment. In the second study, the errors of 45 participants on a real steadiness tester task were noted before they were randomly allocated to three groups-a real training group, a virtual training group and a no training group. After training, the participants performed a second test trial on the real steadiness tester.

RESULTS

The students were capable of using a virtual environment and were motivated to use this training method. Active exploration of a virtual environment was found to enhance their memory of the spatial layout of the bungalow but not their memory of the virtual objects. In the second study, virtual training was found to transfer to real task performance.

CONCLUSIONS

These two laboratory-based studies provide answers to four important questions concerning virtual training of people with learning disabilities. Hopefully, the findings will encourage this training aid to be used more widely.

An evaluation of the efficacy of training people with learning disabilities in a virtual environment

PURPOSE

To evaluate the efficacy of using a virtual kitchen for vocational training of people with learning disabilities.

METHOD

Twenty four catering students with learning disabilities participated in the study. Half the students were currently being trained in the kitchen on which the virtual kitchen was modelled but the remaining students were unfamiliar with this kitchen. Students were first pre-tested on four food preparation tasks and identification of 12 hazards in their own training kitchens. They were subsequently trained on one food preparation task and three hazards in their own training kitchens, one food preparation task and three hazards in the virtual kitchen, and one food preparation task and three hazards in specially designed workbooks. They were then retested in their own training kitchens on all the food preparation tasks and all the hazards.

RESULTS

Virtual training was found to be as beneficial as real training and more beneficial than workbook and no training in the food preparation tasks. However, virtual, real and workbook training were found to be equally beneficial in the hazard identification task. Students who were unfamiliar with the kitchen on which the virtual kitchen was modelled benefited from virtual training to the same extent as students who were familiar with the kitchen.

CONCLUSIONS

Vocational students with learning disabilities were able to use the virtual environment and were motivated to learn using this training method. Depending on the task being trained, virtual training had a more beneficial effect on real task performance than workbook training, even when the virtual kitchen was not modelled on the real training kitchen.

Penicillin conjugates to interferon-gamma and reduces its activity: a novel drug-cytokine interaction

Beta-lactam antibiotics are the class of drug most frequently associated with IgE-mediated allergy but the mechanisms underlying this response are poorly understood. IFN-gamma is a key cytokine in immunity with regulatory actions on monocytes, NK cells, epithelial cells, and T and B lymphocytes. IFN-gamma promotes Th1 responses and inhibits Th2- and IgE-mediated responses. In this study we show, by Western blotting, that the prototype beta-lactam benzylpenicillin (BP) conjugates to human IFN-gamma but not to IL-4. The interaction of BP with IFN-gamma inhibited the cytokine's detection by immunoassay and impaired its activity, as assessed in three different assays: upregulation of MHC molecules on monocytes plus induction of nitric oxide synthesis and expression of monocyte chemoattractant protein-1 mRNA by epithelial cells. This is the first reported example of a direct drug-cytokine interaction and suggests a mechanism by which penicillin may disrupt IFN-gamma-dependent immune responses and promote allergy.

Training in virtual environments: transfer to real world tasks and equivalence to real task training

Virtual environments (VEs) are extensively used in training but there have been few rigorous scientific investigations of whether and how skills learned in a VE are transferred to the real world. This research aimed to measure and evaluate what is transferring from training a simple sensorimotor task in a VE to real world performance. In experiment 1, real world performances after virtual training, real training and no training were compared. Virtual and real training resulted in equivalent levels of post-training performance, both of which significantly exceeded task performance without training. Experiments 2 and 3 investigated whether virtual and real trained real world performances differed in their susceptibility to cognitive and motor interfering tasks (experiment 2) and in terms of spare attentional capacity to respond to stimuli and instructions which were not directly related to the task (experiment 3). The only significant difference found was that real task performance after training in a VE was less affected by concurrently performed interference tasks than was real task performance after training on the real task. This finding is discussed in terms of the cognitive load characteristics of virtual training. Virtual training therefore resulted in equivalent or even better real world performance than real training in this simple sensorimotor task, but this finding may not apply to other training tasks. Future research should be directed towards establishing a comprehensive knowledge of what is being transferred to real world performance in other tasks currently being trained in VEs and investigating the equivalence of virtual and real trained performances in these situations.

A preliminary investigation into the use of virtual environments in memory retraining after vascular brain injury: indications for future strategy?

PURPOSE

In a preliminary investigation of the use of Virtual Environments (VEs) in neurorehabilitation, this study compares the effects of active and passive experience of a VE on two types of memory in vascular brain injury patients and controls.

METHOD

Forty-eight patients with vascular brain injury and 48 non-impaired control participants were randomly assigned to active and passive VE conditions. The active participants explored a virtual bungalow seeking a particular object; the passive participants observed, but did not control movement through the VE, also seeking the object. Afterwards, both active and passive participants completed spatial recognition and object recognition tests.

RESULTS

Expectedly, the patients were impaired relative to the controls but were able to perform the virtual tasks. Active participation in the VE enhanced memory for its spatial layout in both patients and controls. On object recognition, active and passive patients performed similarly, but passive controls performed better than active controls.

CONCLUSIONS

The findings are discussed in relation to their implications for memory rehabilitation strategies.

Primacy and recency in primed free association and associative cued recall

Two experiments compared the serial positions of primed words in an implicit free association test with words recalled in a cued recall test. In both tests, weakly or strongly related word pairs were studied, and the first words of each pair formed the test cues. In the implicit test, weakly related words pairs showed primacy and extended recency effects but strongly related word pairs did not. In the explicit test, both weakly and strongly related word pairs showed primacy and extended recency effects. These functional dissociations between implicit and explicit memory tests indicate that strongly related word pairs are encoded together because they have unitized memory representations that function as integrated units without requiring any additional associative links to be made, but that an additional system or process is required to strengthen weakly related word pairs during encoding. In addition, a further additional system or process is accessed by explicit retrieval.

Virtual environments in brain damage rehabilitation: a rationale from basic neuroscience

The potential of virtual environments in assessment and training of cognitive function is a more than adequate reason for their application to neurorehabilitation. However, there is a more fundamental justification, and one which is firmly rooted in the neuroscience literature. Over the last half century there has been a wealth of published evidence that enriching the environments of laboratory rats stimulates neuroplastic change in the cerebral cortex, enhances learning and problem solving in normal rats and reduces cognitive impairment in brain damaged rats. Central to all three effects of enrichment are the increased levels of interaction with the physical environment engendered by enrichment. Placing humans who have damaged brains in virtual environments is one way of enhancing their levels of environmental interaction which, because of cognitive impairments and sensory and motor disabilities, is otherwise difficult to achieve. In this chapter we explore the potential of virtual environments as enriched environments within the rehabilitation regime. The underlying assumption, that interaction with a virtual environment is functionally equivalent to interaction with a real environment, is examined. Three lines of relevant evidence are reviewed, neuroimaging studies and psychophysiological studies of people in virtual environments and studies of transfer of training from virtual to real tasks. An agenda for future research in this are is proposed.

The specificity of memory enhancement during interaction with a virtual environment

Two experiments investigated differences between active and passive participation in a computer-generated virtual environment in terms of spatial memory, object memory, and object location memory. It was found that active participants, who controlled their movements in the virtual environment using a joystick, recalled the spatial layout of the virtual environment better than passive participants, who merely watched the active participants' progress. Conversely, there were no significant differences between the active and passive participants' recall or recognition of the virtual objects, nor in their recall of the correct locations of objects in the virtual environment. These findings are discussed in terms of subject-performed task research and the specificity of memory enhancement in virtual environments.

Virtual environments in neuropsychological assessment and rehabilitation

Brain damage constitutes a major problem for those affected, for their families and friends and for society as a whole. The need for effective rehabilitation strategies is clear. Yet, until the early 1960s, the brain was generally considered to be a somewhat fixed and inflexible organ. In consequence the impairments associated with brain damage were generally regarded as "incurable". Since that time neuroscientists have had reason to change their views dramatically. However, much remains to be done. Progress depends upon a co-ordinated multidisciplinary approach within which assistive technology will be a key player. Within the area of assistive technology, one of the developments which holds particular promise for the field of neurological rehabilitation is the computer technology underlying virtual environments (commonly known as virtual reality). In this chapter we describe the new opportunities offered by virtual reality to pursue several aspects of the rehabilitation process. The value of the technology of virtual environments in this context is that it allows us to immerse people with brain damage in relatively realistic interactive environments which, because of their patterns of impairment, would otherwise be unavailable to them.

Age differences in memory for prospective compared with retrospective subject-performed tasks

In two experiments, younger and older adults studied three lists of verbal phrases, each of the latter describing a simple action. One list was studied and recalled verbally; one was recalled verbally, but the actions were performed at study [retrospective SPTs (subject-performed tasks)]; and one was studied verbally and the actions were performed at test (prospective SPTs). With long lists, but not with short ones, retrospective-SPT recall exceeded verbal recall and older adults recalled fewer SPTs than did younger adults. Prospective-SPT recall did not exceed verbal recall at either list length, and in each of these prospective-SPT tests, older adults recalled fewer action phrases than did younger adults. Thus, it appears that when retrospective and prospective tasks are equated there are marked age differences that are generally consistent with the view that memory impairment in the elderly is more likely to occur in tasks that make higher attentional processing demands.