Two operations In character recognition: A partial replication

Subjects carried out a choice reaction time experiment in which they were required to press one lever ifa tachistoscopically flashed numeral was a member of a previously memorized list of numerals and a second lever if it was not a member of the list. The number of numerals in the list was varied from one to four. On half of the trials the numeral was partially masked by a pattern of visual noise. For one group a single fixed pattern of noise was used; for a second group four patterns presented in random order were used. Reaction time from the onset of the numeral to the lever press was found to be a linear function of list size, confirming Sternberg’s hypothesis that the list is scanned serially to determine a match. Partial masking was found to add a constant increment to reaction time for both groups, independent of set size. The increment was equal for both groups. The constancy of the reaction time increase contradicts Sternberg’s results in which the increment was found to be, in part, a function of list size. The results of the present study indicate that one cannot dismiss the possibility that Ss identify the character to the point of labeling prior to an attempt to determine list membership.     

Relational perception and modes of perceiver operation

Judgments were made of the size of a small, luminous (inner) square appearing in the center of a somewhat larger, variable (outer) square, the whole pattern appearing in the dark. Accuracy of judgment was greatest when the outer square was constant from trial to trial but deteriorated when the outer square also varied in size, reaching a lower limit less than the accuracy produced under the absolute judgment condition (no outer square presented). An application of multiple discriminant analysis and the use of a maximum likelihood observer model provided estimates of the extent to which Os responded to inner and outer size variation as separate aspects of stimulation. Although Os differed markedly in this respect, their ability to identify inner square size under the various conditions did not reflect this difference.     

Cognitive rehabilitation of chronic alcohol abusers

The current literature suggests that individuals who chronically abuse alcohol exhibit a wide variety of cognitive deficits resulting from cerebral dysfunction that is either directly or indirectly related to their alcohol consumption history. Cognitive deficits have been hypothesized as having implications for standard alcohol treatment efficacy as they may directly affect cognitively impaired individuals’ abilities to utilize various treatment modalities. Although evidence is accumulating that suggests this is actually the case, the majority of alcohol treatment programs neither directly consider the impact cognitive deficits have on treatment efficacy nor do they employ cognitive rehabilitation treatment strategies to remediate identified cognitive deficits. Few studies exist that investigate the remediability of neurobehavioral deficits or the efficacy of integrating cognitive rehabilitation strategies into more traditional treatment programs. Empirical investigations conducted to date indicate that some cognitive deficiencies secondary to alcoholism are amenable to cognitive rehabilitation and this remediation is generalizable. Rigorous well-controlled treatment outcome investigations are needed in order to determine the efficacy of cognitive rehabilitation techniques in naturalistic settings using ecological outcome measures. Also, emphasis should be placed on integrating cognitive rehabilitation techniques with proven efficacy into traditional alcoholism treatment programs.     

Evaluation of a “mental effort” hypothesis for correlations between cortical metabolism and intelligence

Previous research indicates that low scores on the Raven's Advanced Progressive Matrices (RAPM) test are associated with increased cortical glucose utilization during problem solving. We hypothesized that previous results may reflect the neurophysiological consequences of patterns of effort requirements; that is, high-effort expenditure from lower aptitude participants (for whom the problems are hard) and low-effort expenditure from higher aptitude participants (for whom the problems are easy). In this experiment, positron emission tomography (PET) data were gathered on participants (N = 28) who solved easy and hard problems that were tailored to the participants' own ability levels, thereby eliminating aptitude group differences in effort requirements. Contrary to previous results, high aptitude was associated with high cortical glucose use. Average aptitude participants showed diminished glucose use in the hard condition. A significant Group X Condition X Hemisphere Effect was also noted, with greater right hemisphere activation in the hard condition for the high-aptitude group. These results demonstrate that the relation of cerebral glucose use and cognitive ability is sensitive to participant and task selection.     

Prediction of mood and risk appraisals from trait measures: Two studies of simulated driving

Two contrasting hypotheses concerning the relationship between personality and mood are distinguished. First, broad traits may relate to emotional temperament, and so predict mood across situations. Second, the interactionist approach to personality implies that narrow, context specific traits may sometimes be the most powerful predictors of mood within situations. This article reports correlations between mood and broad and narrow trait measures, the Eysenck Personality Inventory (EPI; Eysenck and Eysenck, 1964) and the Driving Behaviour Inventory (DBI; Gulian, Matthews, Glendon, Davies and Debney, 1989), within the context of vehicle driving. Mood was measured with the UWIST Mood Adjective Checklist (UMACL; Matthews, Jones and Chamberlain, 1990), in two samples before and after a simulated drive. One sample (N = 73) performed a ‘passive’ drive, in which little interaction with other traffic was required. The second sample (N = 93) performed an ‘active’ driving task, in which subjects had to decide when to overtake other vehicles. Results showed that the DBI traits were more strongly related to mood than EPI traits, particularly following the active drive. The DBI Dislike of Driving scale was the strongest single predictor of post-drive mood. Prior to the drive, subjects also rated accident risk, driving skill, and judgement, for themselves and for a ‘peer’ driver of similar age and sex. Analysis of these data in the combined sample (N = 166) showed that the DBI was the more consistent predictor of self-ratings of risk and driving competence, although some relationships between ratings and the EPI were found. Again, the DBI Dislike of Driving scale was the strongest single predictor of self-ratings. Drivers scoring high on this scale seem immune to drivers' general bias towards rating themselves as safer and more competent than their peers. It is concluded that narrow traits are more predictive than broad traits within the driving context. Data are consistent with the transactional model of driver stress, which proposes that dislike of driving is derived from negative secondary appraisals.