Inverting the modality effect in serial recall

Differences in recall ability between immediate serial recall of auditorily and visually presented verbal material have traditionally been considered restricted to the end of to-be-recalled lists, the recency section of the serial position curve (e.g., Crowder & Morton, 1969). Later studies showed that--under certain circumstances--differences in recall between the two modalities can be observed across the whole of the list (Frankish, 1985). However in all these studies the advantage observed is for recall of material presented in the auditorily modality. Six separate conditions across four experiments demonstrate that a visual advantage can be obtained with serial recall if participants are required to recall the list in two distinct sections using serial recall. Judged on a list-wide basis, the visual advantage is of equivalent size to the auditory advantage of the classical modality effect. The results demonstrate that differences in representation of auditory and visual verbal material in short-term memory persist beyond lexical and phonological categorization and are problematic for current theories of the modality effect.     

Using direct and indirect measures to study perception without awareness

Many studies directed at demonstrating perception without awareness have relied on the dissociation paradigm. Although the logic underlying this paradigm is relatively straightforward, definitive results have been elusive in the absence of any general consensus as to what constitutes an adequate measure of awareness. We propose an alternative approach that involves comparisons of the relative sensitivity of comparable direct and indirect indexes of perception. The only assumption required by the proposed approach is that the sensitivity of direct discriminations to relevant conscious information is greater than or equal to the sensitivity of comparable indirect discriminations. The proposed approach is illustrated through an evaluation of Avant and Thieman’s (1985) recent claim that an indirect measure of perception based on judgments of apparent visual duration provides a more sensitive indicator of perception than does a direct measure based on forced-choice recognition. Contrary to this claim, when direct and indirect indexes are measured under comparable conditions, an indirect measure based on judgments of perceived duration provides a less sensitive index of perceptual processing than do comparable direct measures. The proposed approach provides a general conceptual/methodological framework for using the dissociation paradigm in studies directed at establishing unconscious processes.     

Group differences in intelligence and speed of information-processing

Three samples of different levels of mental ability, but each of average or above- average intelligence, were administered a battery of reaction time test which measure the speed with which persons can execute various elementary cognitive processes. Discriminant analyses revealed significant differences between the groups in reaction times and intraindividual standard deviations, and univariate analyses indicated that higher ability groups tended to obtain significantly faster mean reaction times and to show significantly less intraindividual variability than lower ability groups. Groups which differed the most in mental ability differed to the greatest extent on the more complex reaction time tests but this pattern was reversed for groups which were relatively close in mean IQ. Generally, the results support the hypothesis that speed- of-processing is an important factor unferlying intelligence, but a number of puzzling findings indicate the need for continued research in this area.