Routes to action in reaction time tasks

Summary Two-choice tactile RTs are no faster than 8-choice tasks, implying the existence of a direct route. However, simple tactile RTs are much faster than choice tactile RTs (Leonard, 1959). In Experiment I we show that this is not due to subjects anticipating the stimulus in simple tactile RT tasks. Increasing probability of stimulus occurrence at a particular time led to equally decreased tactile RTs for simple and choice tasks.We suggest that an alternative route is available for simple RTs which is faster than the direct route available for choice tactile RTs. This route is faster because (a) the response can be specified in advance, and (b) the stimulus does not need to be identified. The subject needs merely to register that it has occurred. In Experiment II we show that simple RTs to a visual stimulus are decreased by a simultaneous uninformative tactile stimulus even when this is to the wrong finger. This confirms that exact stimulus identification is not necessary in the fast route. In Experiment III we show that a secondary task slows down simple tactile RTs to the same level as choice tactile RTs while the latter are hardly affected. This suggests that focussed attention is not needed for the direct route, but it is needed for the fast route. We propose that a useful distinction can be made between action largely controlled by external stimuli (the direct route) and action largely controlled by internal intentions of will (the fast route).     

Comprehension in "hyperlexic" readers

Mentally retarded children who can read aloud written words better than one would expect from their Mental Age are often called hyperlexic. The reading comprehension thought to be impaired in such children was investigated in four experiments. Mentally retarded advanced decoders, including autistic and nonautistic children, were compared with younger nonretarded children matched for Mental Age and Reading Age. Experiment 1 established that mildly mentally retarded readers could match sentences to pictures as well as could be expected from their verbal ability. This was the same whether they read the sentences or heard them. Experiment 2 demonstrated that only the more able retarded subjects, but not the less able ones, used sentence context in a normal way in order to pronounce homographs. Experiments 3 and 4 showed that these same more able children could extract meaning at both sentence and story level, and their performance was indistinguishable from that of normal controls. Hence, it is doubtful whether these advanced decoders should be called hyperlexic. In contrast, the readers of relatively low verbal ability performed much worse than their normal controls. Although they could be induced under certain conditions to read sentence-by-sentence rather than word-by-word, they did not do so spontaneously. Furthermore, they did not make use of already existing general knowledge in order to answer questions about the stories they had read. The ability to comprehend in terms of large units of meaning seems to be specifically impaired in these low verbal ability fluent readers. We suggest that it is this impairment that marks true hyperlexia. Since there were no differences between autistic and nonautistic readers on any of our tasks, we conclude that hyperlexia is not an autism-specific phenomenon.     

Learning and reminiscence as a function of target predictability in a two-dimensional tracking task

Twenty subjects performed one of two types of a two-dimensional tracking task for two 5-min sessions, separated by a 10-min rest. In task I, both the horizontal and the vertical components of target movement were unpredictable. In task II, the horizontal component of target movement was predictable (sinusoidal), while the vertical movement was unpredictable. There was no change in level of performance throughout the 10 min of practice on task I. For task II's predictable component, there were marked within- and between-session improvements in performance; whereas for the unpredictable component there was only a between-session improvement. It is proposed that, in these tracking tasks, improvement with practice depends on the development of programmed sequences of movement which can only occur for predictable target movements. Only after a rest do these programmed sequences become automatic, releasing spare attentional capacity for improving the performance of any unpredictable components of the task.     

Improving the reliability of event-based laboratory tests of prospective memory

Laboratory tests of event-based prospective memory (ProM) require participants to perform actions in response to infrequent cues in a background task. We conducted three experiments to assess and improve the reliability of this popular procedure. In Experiment 1, we tested college students on 2 separate days and found that the alternate-forms reliability of ProM accuracy was quite low (r = .31), although general knowledge accuracy was more reliable (r= .89). In Experiment 2, a statistically significant difference in reliability emerged between conditions with a low (n = 6) versus a high (n = 30) number of ProM targets. Finally, lower ProM accuracy increased reliability in Experiment 3. Adopting these straightforward changes may enhance the search for individual differences in ProM.     

The role of sensorimotor impairments in dyslexia: a multiple case study of dyslexic children

This study attempts to investigate the role of sensorimotor impairments in the reading disability that characterizes dyslexia. Twenty-three children with dyslexia were compared to 22 control children, matched for age and non-verbal intelligence, on tasks assessing literacy as well as phonological, visual, auditory and motor abilities. The dyslexic group as a whole were significantly impaired on phonological, but not sensorimotor, tasks. Analysis of individual data suggests that the most common impairments were on phonological and visual stress tasks and the vast majority of dyslexics had one of these two impairments. Furthermore, phonological skill was able to account for variation in literacy skill, to the exclusion of all sensorimotor factors, while neither auditory nor motor skill predicted any variance in phonological skill. Visual stress seems to account for a small proportion of dyslexics, independently of the commonly reported phonological deficit. However, there is little evidence for a causal role of auditory, motor or other visual impairments.     

Instantiated features and the use of "rules."

Classification "rules" in expert and everyday discourse are usually deficient by formal standards, lacking explicit decision procedures and precise terms. The authors argue that a central function of such weak rules is to focus on perceptual learning rather than to provide definitions. In 5 experiments, transfer following learning of family resemblance categories was influenced more by familiar-appearing features than by novel-appearing features equally acceptable under the rule. This occurred both when rules were induced and when rules were given at the beginning of instruction. To model this and other phenomena in categorization, features must be represented on 2 levels: informational and instantiated. These 2 feature levels are crucial to provide broad generalization while reflecting the known peculiarities of a complex world.     

Implicit policies about relations between personality traits and behavioral effectiveness in situational judgment items

This paper develops the concept of implicit trait policy (ITP), which is a variant of the accentuation effect described by Tajfel (1957). ITPs are implicit beliefs about causal relations between personality traits and behavioral effectiveness. Studies reported here tested the hypotheses (a) that personality traits affect ITPs so that agreeable people, for instance, believe the relation between agreeableness and effectiveness is more strongly positive than disagreeable people do and (b) that ITPs can predict behavior that expresses associated personality traits. Two studies with undergraduate research participants supported the first hypothesis for traits of agreeableness and extraversion (the average correlation between traits and associated ITPs was .31 for agreeableness and .37 for extraversion) but not for conscientiousness. A 3rd study with student participants found that individual differences in ITPs for agreeableness predicted agreeable behavior (the average correlation was .33) in simulated work settings. These results suggest that ITPs may be useful for predicting work behavior that expresses personality traits even though ITPs may not be strongly correlated with the personality traits themselves.     

How similar is similar enough? Job profile similarity benchmarks using occupational information network data

Job comparison research is critical to many human resources initiatives, such as transporting validity evidence. Job analysis methods often focus on critical attribute (e.g., tasks, work behaviors) overlap when assessing similarity, but profile similarity metrics represent an alternative or complementary approach for job comparisons. This paper utilizes Occupational Information Network (O*NET) data to establish a distribution of job profile correlations across all job pairs for five attributes – generalized work activities, knowledge, skills, abilities, and work styles. These correlations represent effect sizes, or degree of shared variance between jobs. Practitioners may reference these correlational distributions as benchmarks for gauging the practical significance of the observed degree of similarity between two jobs of interest compared to the broader world of work.