空间工作记忆和战略形成的成年人诊断注意缺陷多动障碍毕业论文外文翻译.docx

1、空间工作记忆和战略形成的成年人诊断注意缺陷多动障碍 毕业论文外文翻译Spatial working memory and strategy formation in adults diagnosed with attention deficit hyperactivity disorderSusan Young a,*, Robin Morris a, Brian Toone b, Carolyn Tyson cAbstractThe study investigated problem spatial working memory in ADHD adults. Twenty-seven p

2、atients diagnosed with ADHD in adulthood and 27 matched normal controls were tested using the Executive Golf Task, a test that also measures spatial strategy formation. Overall the ADHD patients were significantly impaired, the deficit increasing with task difficulty. They were also more impaired on

3、 a measure of task strategy formation, and when taking this into account in terms of memory performance the patient deficit remained, suggesting that their spatial working memory deficits are not wholly explained by problems with strategy formation.1. IntroductionWorking memory is defined as a cogni

4、tive system that provides temporary storage and manipulation of the information necessary for activities such as reasoning, language comprehension and learning (Baddeley, 1992). This process requires the ability to hold information on-line during a brief time until a decision and subsequent response

5、 is made (Goldman-Rakic, 1990). It has been postulated that there is a dissociation between basic memorial requirements of tasks and their executive components which control response selection, e.g. the adoption of an overall strategy or plan, or the utilization of specific attentional inhibitory me

6、chanisms. Thus performance is determined by two factors, one related to short-term spatial memory and the other to strategic factors (Robbins, 1996). Several studies have shown that spatial working memory deficits in patients with frontal lobe excisions may be related to the inefficient use of a par

7、ticular search strategy (Miotto, Bullock, Polkey, & Morris, 1996; Owen, Downes, Sahakian, Polkey, & Robbins, 1990; Owen, Morris, Sahakian, Polkey, & Robbins, 1996). This suggests that part of the deficit may arise from executive failure and use of a strategy can reduce the load on memory caused by i

8、nterference from previous choices.Spatial working memory deficits have been found in studies comparing ADHD and normal children (Karatekin & Asarnow, 1998; Gorenstein, Mammato, & Sandy, 1989; Shue & Douglas, 1992). However, most studies have not considered whether deficits in spatial working memory

9、may be accounted for by problems with strategy formation. The importance of strategy has been considered in other neurological or psychiatric disorders. For example, strategy formation impairment has been shown to be linked to spatial working memory impairment patients with frontal excisions (Miotto

10、 et al., 1996) but not for patients with Aspergers Syndrome (Morris et al., 1999).The current study explores spatial working memory deficits and strategy impairment of ADHD adults using the computerised Executive Golf task (cf. Feigenbaum, Polkey, & Morris, 1996), a development of the spatial workin

11、g memory task designed by Morris et al. (1988). Working memory is of relevance in the investigation of adult ADHD because it is thought to be particularly impaired in relation to other types of psychiatric disorders that have associated neuropsychological deficits (Gallagher & Blader, 2001). This ha

12、s been explored in a previous study by Dowson et al. (2004) using a different task but a similar methodology. In the Dowson et al. (2004) study the CANTAB method of measuring spatial working memory involves an array of spatial locations on a screen in which the participant has to avoid going back to

13、 previously successful locations.They found impairments on return errors and associated poor strategy when conducting the tasks. The Executive Golf task is more akin to a real life activity in that, as well measuring spatial working memory it simulates a game of golf, the participant searching for p

14、laces in which a golferis predicted to putt a ball, avoiding returning to these places during subsequent searches. The golf holes are presented using three dimensional computer graphics with the golfer presented in the distance. The task has a game-like format, with the golfer putting the balls into

15、 the golf holes when a correct golf hole has been selected by the golfer. Performance can be improved using the strategy of following a predetermined search sequence, beginning with a particular place and returning to the same place for every new search sequence. The aim of the study was to investig

16、ate whether patients with ADHD had a spatial working memory deficit in adulthood and to establish whether the deficit persisted if a measure of strategy formation was covaried in the analysis. It was hypothesised that ADHD patients would make a greater number of errors in relation to returning to pr

17、eviously successful locations (i.e. between subject errors), and that this deficit would increase with task difficulty.2. Methodology2.1. ParticipantsThe study included 27 (21 male, 6 female) adult ADHD patients at the Maudsley Hospital, London UK. All patients met the DSM-IV criteria for ADHD follo

18、wing a full ADHD assessment (see Young & Toone, 2000). The assessment included a comprehensive psychiatric evaluation which included a semi-structured interview based on the DSM-IV criteria for ADHD. Each positive self-rating had to be endorsed by the assessor on the basis of supplementary questioni

19、ng or other information (e.g. documentation). Additionally a parent was interviewed to establish whether there was a history of ADHD features during early childhood (i.e. before the age of 7). This judgement was based upon an unstructured interview although in addition, and in order to obtain a fina

20、l positive rating, a score of 15 or more was required on the Conners Global Index- Parent Scale CGI-P (Conners, 2000). For cases in which Conners ratings were equivocal, a final positive rating was made if school reports and/or other childhood documentation provided evidence of hyperactivity and att

21、entional difficulties. Of the 27 patients, 22 met criteria for ADHD,Combined Type; 3 for ADHD, Predominantly Inattentive Type and 2 for ADHD, Predominantly Hyperactive-Impulsive Type.All participants were tested off-medication. They agreed to refrain from taking stimulant medication for 48 h prior t

22、o the assessment and confirmed this when seen. Exclusion criteria included a history of learning disability, a history of severe psychiatric disorder (this includes schizophrenia, bipolar and major depressive disorder), a primary diagnosis of substance abuse disorder, autistic disorders and/or a his

23、tory of neuropsychological impairment or head injury. None of the participants in the sample fitted any of these exclusion criteria and hence none were excluded on this basis. Their mean age was 24.85 years (SD = 7.00, range 1642). Their mean predicted full scale IQ from the Intelligence Quotients (

24、IQ) derived from the National Adult Reading Test-Restandardised (NART-R) (Nelson, 1982; Nelson & Willison, 1991) was 101 (SD = 20) and their mean paternal social class score, using the HMSO classification of occupation, was 2.93(SD = 2.32).Patients were compared with 27 healthy local community contr

25、ols recruited through advertisements in GP Health Centres. Controls did not differ significantly from them on the following variables:sex (15 males, 12 females: v2 = 2.08, df = 1, p = .15), age (mean = 25.78, SD = 4.89, Range 1836: t(52) = .56, p = .58) predicted full scale IQ (mean = 105, SD = 16;

26、t(52) = 1.69, p = .10) and paternal social class (mean = 2.59, SD = 1.97: t(52) = .57, p = .57).2.2. Tests and procedureThe Executive Golf task is presented on a colour monitor with a touch sensitive screen. The participant is shown firstly an image of a golf course and a golfer. The course has a va

27、rying number of golf holes into which the golfer can putt a ball. Initially, the participant is instructed to guess into which hole the ball will be putted and respond by touching it. If correct, the computer emits a specific tone and the ball is shown going into the hole. For incorrect responses, a

28、 different tone is given, and the participant has to try again until the correct hole is found. Effectively they are instructed to search around the holes until they find the target one.After this, the target hole then moves to a new location. Only one ball can be putted into each hole in any one tr

29、ial, such that, on subsequent trial searches the participant has to avoid choosing previously successful locations. The participant is specifically told to avoid going back to successful holes on subsequent searches. A series of searches are made until all the holes have had balls putted into them.

30、After all the holes have had balls putted into them, the word finished is presented at the top of the screen and the participant informed that a new trial is about to begin with new balls and holes.The task contains five increasing levels of difficulty (i.e. levels 2, 3, 4, 6 and 8) represented by a

31、n increasing number of holes used in each trial. Each level of difficulty has a set number of trials as follows: Level 2 has two; Levels 3 and 4 have three; Levels 6 and 8 have four trials; (Levels 5 and 7 were excluded from the design to keep the length of the test reasonable whilst maintaining the

32、 size range). The participant starts with the easier trials and proceeds to the more difficult ones. In order to prevent chance selections causing variability in the number of holes that a person needs to explore during each search, the number of such holes to be tried before finding the target one

33、(discounting responses to previously used holes) is predetermined by the computer in a pseudo-random fashion (i.e. the same number of holes for each person).For each trial the computer records two types of errors. The first, Between Search Errors, involves selecting a hole into which a ball has already been putted during that trial.