Verbal Learning Ability and Adjustment to Recent-Onset Spinal Cord Injury.

Objective: Investigate the relation between verbal learning and adjustment in individuals in inpatient spinal cord injury (SCI) rehabilitation. Setting: A rehabilitation hospital in the southeastern United States. Study Design: At admission, verbal learning ability and depressive behavior were evaluated. Prior to discharge, acceptance of disability was assessed. Participants: One hundred seven individuals (age range=18-65; 82 men, 25 women; 73 Caucasian, 34 African American). Results: Verbal learning ability accounted for 7% of the variance in acceptance of disability after controlling for demographic variables and depressive behavior. Higher levels of verbal learning ability were associated with disability acceptance. Conclusions: Verbal learning ability is associated with adjustment. Assessment of verbal learning abilities may provide useful information concerning individuals at risk for more complicated adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Instrumental learning within the spinal cord: IV. Induction and retention of the behavioral deficit observed after noncontingent shock.

Spinalized rats given shock whenever 1 hind leg is extended learn to maintain that leg in a flexed position, a simple form of instrumental learning. Rats given shock independent of leg position do not exhibit an increase in flexion duration. Experiment 1 showed that 6 min of intermittent legshock can produce this deficit. Intermittent tailshock undermines learning (Experiments 2-3), and this effect lasts at least 2 days (Experiment 4). Exposure to continuous shock did not induce a deficit (Experiment 5) but did induce antinociception (Experiment 6). Intermittent shock did not induce antinociception (Experiment 6). Experiment 7 addressed an alternative interpretation of the results, and Experiment 8 showed that presenting a continuous tailshock while intermittent legshock is applied can prevent the deficit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Administration of a Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor prevents the learning deficit observed in spinal rats after noncontingent shock administration.

Research has shown that spinal rats given shock to the hind leg when it is in an extended position (contingent shock) will learn to maintain a flexion response. However, subjects that experience shock irrespective of leg position (noncontingent shock) do not exhibit this learning. The current studies examined the role of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in this learning deficit. Subjects were given intrathecal injections of CaMKII inhibitor solution or artificial cerebrospinal fluid (aCSF) 15 min prior to and immediately or 4 hr following noncontingent shock training. Results demonstrate that the CaMKII inhibitor successfully reversed the learning deficit when injected prior to and immediately following training. These results indicate the importance of CaMKII in the learning deficit present in spinal animals trained with noncontingent shock. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Timing in the absence of supraspinal input III: Regularly spaced cutaneous stimulation prevents and reverses the spinal learning deficit produced by peripheral inflammation.

In the absence of brain input, spinal systems can adapt to new environmental relations. For example, spinally transected rats given a legshock each time the leg is extended exhibit a progressive increase in flexion duration that minimizes net shock exposure, a simple form of instrumental learning. This capacity for learning is modulated by prior stimulation; both variable shock and inflammation produce a lasting inhibition of learning. An extended exposure to fixed spaced shock has no adverse effect on learning and opposes the consequences of variable shock. The present studies expand on these findings and demonstrate that fixed stimulation ameliorates the impact of peripheral inflammation. Spinally transected rats were administered 900 fixed spaced legshocks before (Experiment 1) or 1,800 legshocks after (Experiment 2) a subcutaneous hindpaw injection of capsaicin. Learning was assessed 24 hr later. Treatment with fixed shock attenuated the capsaicin-induced inhibition of learning. These findings suggest that fixed stimulation promotes adaptive plasticity and may foster recovery after injury. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Localization of Function Within the Dorsal Hippocampus: The Role of the CA3 Subregion in Paired-Associate Learning.

Computational models and electrophysiological data suggest that the CA3 subregion of the hippocampus supports the formation of arbitrary associations; however, no behavioral studies have been conducted to test this hypothesis. Rats with neurotoxin-induced lesions of dorsal dentate gyrus (DG), CA3, or CA1 were tested on object-place and odor-place paired-associate tasks to test whether the mechanism that supports paired-associate learning is localized to the CA3 subregion of the dorsal hippocampus or whether all hippocampal subregions contribute to paired-associate learning. The data indicate that rats with DG or CA1 lesions learned the tasks as well as controls; however, CA3-lesioned rats were impaired in learning the tasks. Thus, the CA3 subregion of the dorsal hippocampus contains a mechanism to support paired-associate learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factor Structure of the Rey Auditory Verbal Learning Test in Adults With Spinal Cord Injury.

Objective: To develop a conceptual framework to guide interpretation of the Rey Auditory Verbal Learning Test (A. Rey, 1958) and similar list-learning tasks across the adult life span for individuals with spinal cord injury (SCI). Study Design: Factor analysis with comparisons of sample-based and norm-based factor scores across age groups. Participants: 221 individuals with SCI undergoing inpatient rehabilitation. Results: The retained model consisted of 3 correlated factors: General Verbal Learning, Auditory Attention, and Inaccurate Recall. Cross-sectional age trends suggest decreased auditory attention and verbal learning with increasing age. The inverse pattern was observed for inaccurate recall. Conclusions: These factors are consistent with other models using similar methodology. The results offer a means of identifying barriers to meeting the educational and therapeutic goals of post-SCI rehabilitation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Instrumental learning with sociopaths: A test of clinical theory.

27 incarcerated sociopaths, 27 incarcerated nonsociopaths, and 27 normals were instructed to draw 3-in lines while blindfolded. Knowledge of results was the verbal response "correct," "too long," or "too short," plus mild electric shock for incorrect responses. All groups showed rapid improvement during the treatment trials. Contrary to some recent experimental findings, the incarcerated sociopaths improved with reinforcement and, in addition, demonstrated the most rapid acquisition and greatest resistance to extinction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Preliminary Study of Acute Family Needs After Spinal Cord Injury: Analysis and Implications.

Objective: To address the paucity of research on family needs following spinal cord injury (SCI). Study Design: Prospective cross-sectional design. Setting: Inpatient SCI rehabilitation unit within a Level 1 trauma center. Participants: Family members of 17 inpatients with SCI. Main Outcome Measure: Family Needs Questionnaire (FNQ). Results: Eighteen of the 40 FNQ needs were rated as important or very important by 100% of the respondents. Health Information Needs were rated as most important and Instrumental Support Needs as least important. Involvement With Care Needs were most often met, whereas Emotional Support Needs were most often unmet. Conclusions: The FNQ is a promising measure of family members' needs after SCI and treatment planning and program evaluation tool. Findings affirm that family education is important during rehabilitation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spinal Cord Injury Pain: Impact, Classification, Treatment Trends, and Implications From Translational Research.

Pain following spinal cord injury (SCI) has been recognized as a significant problem in the literature for over half a century. Prevalence estimates have varied widely, with most reports suggesting this to be an extremely common condition (60%-90%). Severe pain is reported by perhaps 25%, but for these persons, pain is literally the "insult added to injury." Effective treatments with a substantial body of empirical support did not exist until recently, and research progress has been compromised by lack of a standardized method for classifying and assessing pain. Encouraging developments for both assessment and treatment have occurred and are reviewed. There have been parallel developments in research using animal models of SCI pain that argue for exploration of translational work from animals to humans. Areas of research in which psychologists have been active and/or could become active are reviewed, both in clinical and translational research arenas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Treatment of Depression Following Spinal Cord Injury: An Evidence-Based Review.

Study Design: Evaluative research review. Objective: Depression is a significant secondary complication of spinal cord injuries (SCI); this study applies the D. L. Sackett (1989) research criteria to evaluate the quality of intervention studies of the treatment of depression among persons with SCI. Method: An extensive range of peer-reviewed published research was identified through established databases, critical reviews, and published meta-analyses. Results: Nine studies met the inclusion criteria. One antidepressant study was rated above Level III; although the psychological intervention studies had control groups, these were not randomized. Conclusion: This review demonstrates the need for randomized clinical trials of psychological and pharmacological interventions for depression and distress among persons with SCI. so that informed decisions concerning cost-effective treatments can be made. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Prevalence of Posttraumatic Stress Disorder in Persons With Spinal Cord Injuries: The Mediating Effect of Social Support.

Objectives: To evaluate the prevalence of posttraumatic stress disorder (PTSD) and to identify risk factors of PTSD in persons with spinal cord injury (SCI). Main Outcome Measures: PTSD and social support were assessed by using the Harvard Trauma Questionnaire (R. F. Mollica et al., 1992) and the Crisis Support Scale (S. Joseph, W. Yule, R. Williams, & B. Andrews, 1993). Participants: One hundred sixty-eight persons with SCI, who were an average of 14 years after injury, filled in the questionnaire. Results: The prevalence of PTSD was 7.1%. Risk factors for PTSD included complete injury, being single, and low level of social support. Conclusions: The prevalence of PTSD after SCI is similar to that in the general population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social Support and Adjustment After Spinal Cord Injury: Influence of Past Peer-Mentoring Experiences and Current Live-In Partner.

Objective: To compare the impact of 2 types of social support, past peer-mentoring experience (PME) and current live-in partner (LIP), on adjustment after spinal cord injury (SCI). Participants: Sixty-two individuals with SCI (mean age=42 years: 11.7 years since injury). Design: Cross-sectional survey. PME (yes vs. no) and LIP (yes vs. no) were nearly equally balanced, affording 2X2 factorial analyses. Outcome Measures: Craig Handicap Assessment and Reporting Technique, Brief Symptom Inventory, and Satisfaction With Life Scale. Results: PME, which typically concluded over 10 years ago, was associated with higher occupational activity and life satisfaction, whereas having an LIP was associated with greater mobility and economic self-sufficiency. Conclusion: PME positively complements more traditionally studied sources of social support, which is encouraging for the use of PME as a clinical intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pre- and Postinjury Substance Misuse Among Veterans With Spinal Cord Injury.

Objective: To identify rates of substance misuse with onset before and after spinal cord injury (SCI) and to investigate whether patients with a history of substance misuse are more likely to report being intoxicated at the time of injury. Participants: One hundred twenty-four veterans with traumatic SCIs. Measures: Alcohol and nonalcohol psychoactive substance use disorder (PSUD) sections of the Structured Clinical Interview for DSM-III-R. Results: Forty (32%) had a lifetime PSUD. Of those, 55% recalled the onset of their PSUD occurring preinjury, 27.5% recalled the onset occurring postinjury, and 17.5% could not recall their age at onset. Compared with participants who reported postinjury onset of PSUD, those with reported preinjury onset were more likely to report intoxication at time of injury. No significant relation was found between intoxication at injury and presence of a lifetime PSUD. Conclusion: Intoxication at injury does not necessarily substantiate the existence of an underlying substance misuse problem. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Instrumental and Pavlovian incentive processes have dissociable effects on components of a heterogeneous instrumental chain.

Two experiments compared the effects of Pavlovian stimuli and incentive learning on the performance of a heterogeneous chain of instrumental actions. Using a Pavlovian-instrumental transfer design, the authors found that only a stimulus paired with the same outcome as that earned by performance of the chain produced positive transfer, an effect that was restricted to the action in the chain most proximal to reward delivery. In contrast, after a shift to a nondeprived state, only animals that had previously consumed the instrumental outcome when they were nondeprived decreased instrumental performance. Furthermore, this effect of the incentive learning treatment was limited to performance of the distal action. Together these data suggest that Pavlovian and instrumental incentive manipulations have dissociable effects on instrumental performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioned Activity and Instrumental Reinforcement Following Long-Term Oral Consumption of Cocaine by Rats.

Food-reinforced conditioned activity and instrumental responding were measured in rats after 50 weeks of continuous access to a cocaine-saccharin solution in their home cages. The elevation of conditioned activity produced by acute access to the cocaine-saccharin solution in the home cage during testing was abolished by long-term preexposure to the cocaine solution, an effect that was reversed by systemic administration of cocaine immediately prior to testing. By contrast, chronic cocaine preexposure enhanced instrumental responding for both cocaine-sucrose and pure sucrose solutions. These results support the idea that long-term cocaine exposure enhances subsequent reinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neonatal hind-paw injury disrupts acquisition of an instrumental response in adult spinal rats.

The present study was designed to evaluate the impact of neonatal injury on adult spinal plasticity in rats. Subjects were randomly assigned to 1 of 4 experimental conditions: (a) hind-paw injury at Postnatal Day (PD) 2, (b) hind-paw injury at PD 5, (c) anesthesia exposure only on PD 2, or (d) anesthesia exposure only on PD 5. Subjects receiving a unilateral neonatal hind-paw injury showed decreased mechanical threshold (hyperalgesia) on the previously injured hind paw throughout development. This decrease in threshold survived spinal transection (at T2) at 12 weeks of age. Injured subjects also showed significant impairment in a spinal instrumental learning task performed by the previously injured hind paw. This disruption of learning indicates a disruption of spinal plasticity that may be due to induction of long-term changes in nociceptive processing within the spinal cord. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neural Substrates of Coping Behavior in the Rat: Possible Importance of Mesocorticolimbic Dopamine System.

This study measured expression of Fos protein, an indicator of neural activation, in 116 brain regions of rats that were able to control a stressor (i.e., avoid and/or escape an electric shock), and compared the changes with those observed in yoked rats that received the same shocks but without having control over them. The authors' interest was to find brain regions where elevated activity occurs in conjunction with control. Activity in these brain regions might be responsible for the consequences of having control, such as reduction of stress responses. Eleven brain regions were found in which rats with control showed significantly more Fos expression than was seen in yoked rats that did not have control. Six of these brain regions were part of the mesocorticolimbic dopamine system. These results point to the mesocorticolimbic dopamine system as being importantly involved in the mediation and/or the consequences of coping behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cluster Analysis and Chronic Pain: An Empirical Classification of Pain Subgroups in a Spinal Cord Injury Sample.

Objective: To determine the existence of homogeneous spinal cord injury (SCI) pain subgroups. Design: Prospective longitudinal design. Participants: Persons with traumatic onset SCI (N = 1,334) with self-reported pain, pain interference, and depression. Outcome Measures: Pain (Numerical Rating Scale); pain interference (item from the Short Form-12); and depression (Brief Patient Health Questionnaire). Results: Multivariate clustering revealed 4 SCI pain subgroups: low pain (low pain intensity, pain interference, and depression); positive adaptation to pain (high pain intensity, low pain interference and depression); minimal distress (high pain intensity, high pain interference, and low depression); and chronic pain syndrome (high pain intensity, pain interference, and depression). Conclusions: The characteristics of homogeneous SCI pain subgroups may be important for clinicians to consider in treatment planning and research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of D-cycloserine on the extinction of appetitive operant learning.

Four experiments with rat subjects examined whether D-cycloserine (DCS), a partial NMDA agonist, facilitates the extinction of operant lever-pressing reinforced by food. Previous research has demonstrated that DCS facilitates extinction learning with methods that involve Pavlovian extinction. In the current experiments, operant conditioning occurred in Context A, extinction in Context B, and then testing occurred in both the extinction and conditioning contexts. Experiments 1A and 1B tested the effects of three doses of DCS (5, 15, and 30 mg/kg) on the extinction of lever pressing trained as a free operant. Experiment 2 examined their effects when extinction of the free operant was conducted in the presence of nonresponse-contingent deliveries of the reinforcer (that theoretically reduced the role of generalization decrement in suppressing responding). Experiment 3 examined their effects on extinction of a discriminated operant, that is, one that had been reinforced in the presence of a discriminative stimulus, but not in its absence. A strong ABA renewal effect was observed in all four experiments during testing. However, despite the use of DCS doses and a drug administration procedure that facilitates the extinction of Pavlovian learning, there was no evidence in any experiment that DCS facilitated operant extinction learning assessed in either the extinction or the conditioning context. DCS may primarily facilitate learning processes that underlie Pavlovian, rather than purely operant, extinction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)