John D. Bain

Construct validity of eight tests of attention: Comparison of normal and closed head injured samples

Abstract Attentional problems are common symptoms of brain impairment and are generally assessed by a number of psychological tests. However, clinicians do not always agree on the processes measured by these tests and validation of the tests is often inadequate. The present study used factor-analytic techniques to examine the construct validity of eight attention tests (Letter Cancellation, Serial Subtraction, Digit Span, Digit Symbol, Stroop Colour-Word, Trail Making, Symbol Digit Modality, and Knox Cube). These tests were administered to 125 university controls, 45 normal controls from the community, and 37 closed-head-injured patients. Each of the 13 measures from the eight tests were found to load on one of three components/factors (identified as visuo-motor scanning, sustained selective processing, and visual/auditory spanning) for the normal as well as the patient group. Comparison of the mean performances of the patients and their matched controls suggested that: (a) severe short-term patients were...

Recognition memory: A cue and information analysis

Recall and recognition are operationally distinct procedures, yet there is increasing evidence for the involvement of recall in recognition decisions. Although this observation is not generally disputed, there has been no agreement about the appropriate level of theoretical analysis. Our contention in this paper is that the most fundamental level of analysis is in terms of the cues used, with the next level referring to the nature of the information employed as evidence. We compare at length two dual-information models to demonstrate important differences in their cuing assumptions and the difficulty of establishing that anything more than a cue analysis is required. We conclude tentatively in support of an information distinction and devote the final section to determining whether item information is contextually descriptive or is a strength variable that merely correlates with occurrence in the experiment.

Information-Processing Demands of Transitive Inference

The information-processing demands of transitive inference problems were investigated with a probe reaction-time (RT) secondary task. Two versions of a primary task were used: the standard three-term inference problem and a matched verification task that did not require premise integration. In the first two experiments the premise and target-matching components of the primary task were presented sequentially. For the transitive inference task, probe RT was especially slow when the probe occurred during the second premise phase, but no such effect was found with the matched verification task. This implies that premise integration imposed an increased load on processing resources. A third experiment showed that the processing demand associated with premise integration also occurred with simultaneous presentation. Other variations in problem form (e.g., premise markedness, negation, and pivot search) did not influence probe RT, although they are known to affect solution time. Thus, solution time and measures of processing load may be independent.

Global matching: A comparison of the SAM, Minerva II, Matrix, and TODAM models.

The pair recognition paradigm was chosen as a means to evaluate and compare different ways to implement a global matching process in which the matches with all list items are combined into a single value. Simplified versions of the SAM, Minerva II, Matrix, and TODAM models are shown to be specific instances of a more general model and are shown to share a parameter-free prediction. This prediction is then shown to be unaffected by the inclusion of additional processes into the models such as variable encoding, cue weights, forgetting, single item matches, context, and background memories. Furthermore, it is only slightly affected by the formation of interpair associations. A test of the prediction using word pairs was inconclusive due either to the use of a recall strategy or to a low level of interitem similarity. Ways to differentiate between the different models and to test the global matching assumption rigorously are discussed.

Effects of closed-head injury on attentional processes: An information-processing stage analysis

The present study, based on Sternbergs (1969) additive-factor method, examined attentional processes in terms of four information-processing stages (feature extraction, identification, response selection, and motor adjustment). Four task variables were used to operationally define the stages (signal quality, signal similarity, signal-response compatibility, and foreperiod uncertainty). In two studies, a visuo-spatial reaction-time task was undertaken by a group of university subjects (Experiment 1) and by three groups of closed-head-injured patients (severe short-term, severe long-term, and mild short-term) and their corresponding matched controls (Experiment 2). The results indicated that both patients and normals exhibited a similar mode of linear information processing. In addition, it was found that the severe short-term group was impaired on the response-selection stage and response selection stage; the severe long-term group was impaired only on the response-selection; and no evidence of impairment was found for the mild short-term patients. The implications of these findings with reference to the study of attentional processes in closed-head injured patients and to neuropsychological assessment and rehabilitation are discussed.

Set-size effects in primary memory: an age-related capacity limitation?

Set size was varied as a factor in the primary memory paradigm developed by Wickens and colleagues (Wickens, Moody, & Dow, 1981; Wickens, Moody, & Vidulich, 1985). In Experiment 1, using adults and teenagers, no proactive interference (PI) was observed at set size 4, consistent with previous research, but PI was observed at set size 10. In Experiment 2, with adults, PI was observed at set sizes 6, 8, and 10, but not at set size 4. These results are consistent with the hypothesis that sets of more than 4 items overload primary memory, so that some items have to be retrieved from secondary memory. In Experiment 3, 8- to 9-year-olds were used with set sizes of 2 and 4. Proactive interference was observed with the larger, but not with the smaller, set. This suggests that primary memory was overloaded by 4 items at this age, indicating that its capacity increases with age.

Consistency in learning strategies

This article examines the reported use of surface and deep level learning strategies by first-year student teachers at an Australian College of Advanced Education. Students responded to a brief questionnaire measuring the learning strategies they adopted in different assessment situations. The article describes the development of this questionnaire, its factorial structure, and the predictive validity of its factors. High levels of achievement, on both objective tests and essay assessments, were found to be associated with the reported use of deep strategies. Three-mode factor analyses revealed high levels of consistency in the strategies reported for various learning contexts, implying that these were stylistic behaviours rather than strategic approaches to learning which were situation specific. The notion of consistency in learning strategies was considered in light of recent literature suggesting a greater extent of cognitive flexibility.

Associative interference effects in recognition and recall

The results of three studies testing whether associative interference occurs in recognition as it does in recall are reported.

Lexical Decision as an Indirect Test of Memory: Repetition Priming and List-Wide Priming as a Function of Type of Encoding

Two experiments examined priming in the lexical decision task, an indirect test of memory. Experiment 1 manipulated type of processing during study of unrelated word pairs. Recognition of individual words benefited more from semantic than from nonsemantic processing. Repetition priming in lexical decision depended on the context in which the target appeared. Targets preceded at test by unstudied primes showed greater repetition priming if processed nonsemantically during study; targets preceded at test by studied primes were not affected by type of processing at study. Interestingly, studied targets were facilitated more by studied than by unstudied primes regardless of whether the prime came from the same pair as the target. This list-wide episodic priming occurred under all four processing conditions in Experiment 1 (consonant counting, rote rehearsal, pleasantness rating, and sentence generation) with a 250-ms stimulus onset asynchrony. Experiment 2 showed that this list-wide episodic priming disappeared by 1,000 ms, suggesting that it had resulted from relatively transient activation.

Does a concurrent memory load interfere with reasoning

Adult participants were required to solve algebraic problems involving identification of unknown operations while they held a concurrent load in short-term memory. The load was varied in relation to participants’ previously measured spans for the same materials. The algebra problems were at two levels of difficulty, Level 2 or Level 3, as defined by Halford and Wilson (1980). An interaction was found between difficulty of the algebra problem and concurrent memory load, but the point at which interference occurred was at or above span. These results support the contentions of Baddeley and Hitch (1974) and refute those of Evans and Brooks (1981). Several findings from the literature on concurrent memory and reasoning tasks are considered, and it is argued that competition between reasoning and memory occurs only when the memory task entails some form of active processing (such as encoding or rehearsal) that occurs simultaneously with reasoning. Simple storage of a concurrent memory load, or rehearsal that can be alternated with reasoning, does not interfere. It is also suggested that future studies of this problem should take care to adjust memory loads in relation to spans and to analyze the basis of the task difficulty manipulation they employ.