FRONTAL LOBE DAMAGE 735 DISCUSSION We have described 3 patients,each of whom had sustained head injuries in which the area of focal damage lay in frontal regions.The 3 patients performed well on those cognitive tests which were not designed to load specifically on 'frontal functions'.On 'frontal'tests their performance varied.Case 3 performed poorly on a number of such tests.A second(Case 2)performed generally satisfactorily except for a borderline impairment on the Petrides and Milner Self-Ordered Memory.The third (Case 1) performed very satisfactorily on all standard 'frontal'tests.In daily life,however,all 3 appeared unable to act effectively on their own initiative as they organized virtually no nonroutine activities.In addition 2(Cases 1,2)were reported to have problems in carrying out multiple subgoal tasks such as shopping and the third (Case 3)avoided such activities These difficulties were mirrored in the 2 tests where they had to perform multiple activities,the Six Element Test and Multiple Errands.The 2 tasks required the subject to carry out a number of fairly simple activities in an efficient manner.One,the Six Element,basically involved the devising of a simple plan,scheduling the subtests efficiently and keeping a check on time.The second involved dovetailing the activities in a more real-life setting where minor unforeseen events could occur.All 3 patients performed both quantitatively and qualitatively worse than the normal controls. If one considers what is involved in carrying out these multiple subgoal tasks,then at a very general level,four basic types of process are relevant.Motivational and memory processes are clearly required and so are a variety of special-purpose cognitive processes of the sort that standard neuropsychological tests assess.In addition there are certain bridge processes which enable the special-purpose cognitive processes to be used to satisfy motivational requirements.A deficit in basic special-purpose cognitive processes pnl 8. seems an implausible explanation of their difficulties on the experimental tasks,given the performance of the patients on the baseline tests.Indeed the most difficult Multiple Errands subtest gave problems for some of the controls as well as the patients;it was the least sensitive part of the procedure.However,frontal patients often manifest inappropriate affect and have frequently been described as apathetic or impulsive(Blumer and Benson,1975),and also they can have memory problems (e.g.,Hecaen,1964) The possibility of motivational or memory difficulties therefore needs to be considered, especially as the patients,when asked to account for some action,often said that they had completely forgotten their prior intention. A possible motivational explanation of the impaired performance of the 3 patients is that they require continuous social reinforcement to carry out psychological tasks, and without it their spontaneous motivation would tend to dwindle rapidly;without it they do not persevere.This account is unsatisfactory.Case I was given the entire AH6 followed by the Watson-Glaser Critical Thinking Appraisal (Watson and Glaser,1980) FRONTAL LOBE DAMAGE 735 a heated argument with a shop assistant as he asked her to give him a birthday card free (which would have also broken the buying rule)! Comment As with the Six Element task, all 3 patients had quantitatively impaired performance, in particular as far as rule breaks and inefficiencies were concerned. Their performance was also qualitatively unusual. DISCUSSION We have described 3 patients, each of whom had sustained head injuries in which the area of focal damage lay in frontal regions. The 3 patients performed well on those cognitive tests which were not designed to load specifically on 'frontal functions'. On 'frontal' tests their performance varied. Case 3 performed poorly on a number of such tests. A second (Case 2) performed generally satisfactorily except for a borderline impairment on the Petrides and Milner Self-Ordered Memory. The third (Case 1) performed very satisfactorily on all standard 'frontal' tests. In daily life, however, all 3 appeared unable to act effectively on their own initiative as they organized virtually no nonroutine activities. In addition 2 (Cases 1, 2) were reported to have problems in carrying out multiple subgoal tasks such as shopping and the third (Case 3) avoided such activities. These difficulties were mirrored in the 2 tests where they had to perform multiple activities, the Six Element Test and Multiple Errands. The 2 tasks required the subject to carry out a number of fairly simple activities in an efficient manner. One, the Six Element, basically involved the devising of a simple plan, scheduling the subtests efficiently and keeping a check on time. The second involved dovetailing the activities in a more real-life setting where minor unforeseen events could occur. All 3 patients performed both quantitatively and qualitatively worse than the normal controls. If one considers what is involved in carrying out these multiple subgoal tasks, then at a very general level, four basic types of process are relevant. Motivational and memory processes are clearly required and so are a variety of special-purpose cognitive processes of the sort that standard neuropsychological tests assess. In addition there are certain bridge processes which enable the special-purpose cognitive processes to be used to satisfy motivational requirements. A deficit in basic special-purpose cognitive processes seems an implausible explanation of their difficulties on the experimental tasks, given the performance of the patients on the baseline tests. Indeed the most difficult Multiple Errands subtest gave problems for some of the controls as well as the patients; it was the least sensitive part of the procedure. However, frontal patients often manifest inappropriate affect and have frequently been described as apathetic or impulsive (Blumer and Benson, 1975), and also they can have memory problems (e.g., Hecaen, 1964). The possibility of motivational or memory difficulties therefore needs to be considered, especially as the patients, when asked to account for some action, often said that they had completely forgotten their prior intention. A possible motivational explanation of the impaired performance of the 3 patients is that they require continuous social reinforcement to carry out psychological tasks, and without it their spontaneous motivation would tend to dwindle rapidly; without it they do not persevere. This account is unsatisfactory. Case 1 was given the entire AH6 followed by the Watson-Glaser Critical Thinking Appraisal (Watson and Glaser, 1980) by guest on April 8, 2016 http://brain.oxfordjournals.org/ Downloaded from