Jane Powell | Goldsmiths, University of London (original) (raw)

Papers by Jane Powell

Archives of Physical Medicine and Rehabilitation, 1998

Powell JH, Beckers K, Greenwood RJ. Measuring progress and outcome in community rehabilitation af... more Powell JH, Beckers K, Greenwood RJ. Measuring progress and outcome in community rehabilitation after brain injury with a new assessment instrument--the BICRO-39 scales. Arch Phys Med Rehabil 1998;79:1213-25. Objective: Construction and validation of a new instrument, the Brain Injury Community Rehabilitation Outcome scales, to assess problems experienced by brain-injured patients living in the community.

Psychopharmacology, 2007

Rationale Smokers may show abnormal functioning in prefrontal cortex during acute abstinence, ref... more Rationale Smokers may show abnormal functioning in prefrontal cortex during acute abstinence, reflecting deficient activity in mesocorticolimbic circuitry. Cognitive correlates of this putatively include impaired response inhibition and other aspects of executive functioning. Objectives To investigate whether inhibitory control and other executive functions in smokers are impaired during acute abstinence relative to post-nicotine. Methods 145 smokers were tested twice after overnight abstinence—once after nicotine and once after placebo lozenges (order counterbalanced, double-blind)—on an antisaccade task, a continuous performance task (CPT), a delayed response spatial working memory task and a verbal fluency test. Results Compared with placebo, nicotine was associated with better inhibitory control on the antisaccade task and fewer impulsive responses to filler stimuli (motor errors) on the CPT; at the first assessment only, nicotine also reduced impulsive responses to ‘catch’ stimuli on the CPT. However, it did not affect CPT response bias (an index of impulsive vs cautious decision-making), spatial working memory, or verbal fluency. Conclusions Smoking abstinence appears to be associated with a difficulty in inhibiting prepotent motor responses, and with nicotine to attenuate this difficulty. However, more ‘cognitive’ forms of inhibitory control (e.g. decision-making) and the other aspects of executive function tested here appear to be unaffected.

Clinical Rehabilitation, 2001

We investigated the capacity of brain-injured patients to participate in an aerobic exercise prog... more We investigated the capacity of brain-injured patients to participate in an aerobic exercise programme early after injury. Design: Retrospective analysis of exercise achievements in patients participating in a randomized controlled trial. Setting and subjects: Ninety patients participated in an exercise training programme on a cycle ergometer at four inpatient neurological rehabilitation units for younger patients. At intake, impairments and function were rated on: Motricity Index, Ashworth Scale, Berg Balance Scale, Barthel Index and Functional Independence Measure. Interventions: Patients cycled for up to 30 minutes three times weekly for 24-36 sessions over 12 weeks. Main outcome measures: Exercise performance was measured by: (a) number of sessions to achieve a cycling time of 30 minutes, (b) overall mean cycling time per session over 24 sessions and (c) mean time per session cycling at >60% of age predicted maximum heart rate (HR max) over 24 sessions. Results: Fifty-five patients completed 24 sessions. Thirty-five withdrew, largely for logistic reasons, before completing training; they were significantly less disabled than the 55 who remained. Forty-four of the 55 patients trained for an average of at least 20 minutes per session, 18 training at >60% HR max for this time. There were no differences in performance on the three exercise parameters between two groups of patients with baseline Barthel scores of ≤12 and ≥13. Conclusions: Brain-injured patients with a range of disabilities have the capacity to participate in an exercise programme during early inpatient rehabilitation, though some may take longer to achieve adequate intensity of aerobic exercise.

Addictive Behaviors, 2007

Article title: The effects of smoking and abstinence on experience of happiness and sadness in re... more Article title: The effects of smoking and abstinence on experience of happiness and sadness in response to positively valenced, negatively valenced, and neutral film clips Year of publication: 2007 Citation: Dawkins, L. et al (2007) 'The effects of smoking and abstinence on experience of happiness and sadness in response to positively valenced, negatively valenced, and neutral film clips,' Addictive Behaviors 32 (2) 425-431 Link to published version: http://dx.

Psychopharmacology, 2006

Rationale Brain reward pathways implicated in addiction appear to be less reactive in regular dru... more Rationale Brain reward pathways implicated in addiction appear to be less reactive in regular drug users; behavioural manifestations may include decreased sensitivity to natural reinforcers. Objectives This study aimed to replicate earlier findings of abstinence-associated incentive motivation deficits in smokers and to determine whether these can be reversed with nicotine in the form of lozenge. Methods One hundred forty-five smokers were each tested twice, once after receiving nicotine, and once after receiving placebo lozenge in counterbalanced order. Participants completed various tests of incentive motivational functioning: a measure of subjective enjoyment, the Snaith–Hamilton pleasure scale (SHAPS); a simple card sorting task, the card arranging reward responsivity objective test (CARROT) with and without financial incentive; the modified emotional Stroop test; a cue-reactivity task; and a novel reaction time task to explore effects of signals of reward, the incentive motivational enhancement of response speed task. Results Compared with performance during abstinence (placebo condition), nicotine was associated with: higher self-reported pleasure expectations on the SHAPS; enhanced responsiveness to financial reward on the CARROT in smokers who smoked 15 or more cigarettes a day; and greater interference from appetitive words on the Stroop task. Conclusions These results are generally consistent with contemporary neurobiological theories of addiction and suggest that short-term smoking abstinence is associated with impaired reward motivation which can be reversed with nicotine.

Bateman A, Culpan FJ, Pickering AD, Powell JH, Scott OM, Greenwood RJ. The effect of aerobic trai... more Bateman A, Culpan FJ, Pickering AD, Powell JH, Scott OM, Greenwood RJ. The effect of aerobic training on rehabilitation outcomes after recent severe brain injury: a randomized controlled evaluation. Arch Phys Med Rehabil 2001;82:174-82.

Addiction, 1997

Aims. To investigate the effects of (a) nicotine abstinence and (b) cigarette smoking after absti... more Aims. To investigate the effects of (a) nicotine abstinence and (b) cigarette smoking after abstinence, on reward responsiveness and cognitive functions which are putatively dependent on activity in the dopaminergic system implicated in smoking. Design. During Ramadhan, Muslim smokers elected to abstain from smoking either for the whole month (RAMQUIT) or during daylight hours (DAYQUIT). These groups, and non-smokers (NOSMOKE), were assessed on two occasions 6 hours apart (TEST1 and TEST2). DAYQUIT participants had abstained for 6 hours at TEST1 and smoked a single cigarette immediately prior to TEST2. RAMQUIT participants had abstained for at least 10 days prior to TEST1 and remained abstinent at TEST2. NOSMOKE and RAMQUIT participants ate a small snack prior to TEST2 to control for non-specific consummatory effects. Setting. TEST1 was conducted at the mosque and TEST2 in participants' homes. Participants. All were male; mean age was 26.7years. Modal cigarette consumption prior to Ramadhan by both the 13 DAYQUIT and the 11 RAMQUIT smokers was 21-30 per day. DAYQUIT subjects rated themselves as more dependent. Measurements. The Card Arranging Reward Responsivity Objective Test (CARROT), testing behavioural responsiveness to small financial incentive; digit span, measuring attention; verbal fluency, indexing frontal lobe function; and the two-choice guessing test (2CGT; at TEST1 only), measuring response stereotypy. Findings, At TEST1, compared with non-smokers, both smoking groups showed greater stereotypy (2CG) and lower reward responsiveness (CARROT). DA YQUIT participants improved on all measures after smoking a single cigarette. No marked changes were seen in the other groups. Conclusion. These data suggest that (i) abstaining smokers have impaired dopaminergic function and (ii) nicotine consumption may boost their dopaminergic activity.

Drug and Alcohol Dependence, 1990

There is general agreement that the term 'craving' requires clarification. This present report pr... more There is general agreement that the term 'craving' requires clarification. This present report presents a pilot study in which groups of opiate addicts and cigarette smokers completed a brief rating scale to describe the frequency and intensity with which they had certain feelings while craving for their own drug of dependence.

Addiction, 1993

A controlled trial studied whether cue exposure prevented relapse in opiate addiction. Subjects w... more A controlled trial studied whether cue exposure prevented relapse in opiate addiction. Subjects were randomly allocated to one of two inpatient treatment settings: a drug dependence unit with a special 10 week program and 4 weeks in a behavioural/general treatment unit without such a program. In each setting, following drug-withdrawal, subjects had either cue exposure for at least six sessions over 3 weeks, or a control condition. Subjects were followed up twice, at about 6 weeks and 6 months post-treatment. 186 subjects were randomly allocated; 69 were assessed post-detoxification, and of these 43 completed cue exposure or control treatments. Cue exposure and control subjects did not differ in cue reactivity. This was evaluated post-treatment for cue exposure subjects and at a comparable time point for controls. All groups showed a significant decrement in cue-elicited craving, withdrawal responses and negative mood. Cue exposure and control subjects did not differ at either of the two follow up interviews.

Addictive Behaviors, 1990

Substance Use & Misuse, 1991

A major problem in treating opiate addiction is relapse within a few months after withdrawal. Lea... more A major problem in treating opiate addiction is relapse within a few months after withdrawal. Learning models of relapse offer some promise toward understanding this problem. The present pilot study examines whether cue-exposure treatment to drug-related cues, in hospital and real life, might reduce relapse. Fourteen opiate addicts were withdrawn on clonidine over 6 days, and 10 of those were exposed to drug-related cues in hospital for 1 week and in real life for another. There were then followed as outpatients up to 6 months. Craving was elicited in half of the 10 patients exposed to drug cues who showed within- and between-session habituation. Four cases were opiate-free at 6 months follow up and 1 at 3 months. Half of the cases had relapsed to heroin at various times up to 6 months. Habituation to craving responses was not obviously related to outcome whereas vocational factors were. The operational use of craving in research is discussed.

Addiction, 1992

Subjective craving for drugs is frequently reported by detoxified addicts. Explanatory models emp... more Subjective craving for drugs is frequently reported by detoxified addicts. Explanatory models emphasizing classical conditioning (CC) and cognitive mechanisms have been proposed, and the mechanisms postulated by the two approaches are discussed here. There are three major variants of the CC model, arguing that craving is associated with conditioned changes which are respectively drug-agonistic, opponent-process, or withdrawal reactions. The cognitive model highlights the role of ‘outcome expectancies’ as determinants of both appetitive and avoidant motivations. The present investigation has identified correlates of craving predicted by the above models, and tested them empirically. Detoxified opiate addicts participated in a Craving Test requiring them to rate their craving, physical state, and emotions during exposure to both neutral and drug-related material. Other measures, including personality and outcome expectancies for drug use, were also taken, and interrelationships among the variables were explored statistically. Whilst some of the predictions of the CC formulations were borne out, the cognitive model received more consistent support. The theoretical and treatment implications of these data are considered.