
Editorial
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Two experiments tested the hypothesis that children at the left of the distribution of right minus left (R-L) hand skill are at risk for poor phonological processing. In the first experiment, individual assessments of spoken rhyme awareness were made in 5- to 8-year-olds. In the second experiment, a group test of word order memory for spoken confusable and nonconfusable items was given to 9- to 11-year-olds. Evidence of poorer phonological processing in those at the left of the R-L distribution was found in both experiments. Rhyme judgements and word order memory were both associated with reading ability, but reading did not interact with effects for hand skill. A group test of homophone comprehension was given to the same children tested for word order memory. Homophone errors did not differ between hand skill groups, showing a dissociation between the two tasks for R-L hand difference. The findings suggest that some risks for phonological processing could be due to normal genetic variation associated with the hypothesized rs + gene (Annett, 1972, 1978).
The investigation of a patient with a selective impairment of phonological short-term memory has recently provided evidence that this system may be involved in long-term learning of novel words, for which a pre-existing semantic representation is not available (Baddeley, Papagno, & Vallar, 1988). The present series of experiments in normal subjects explored this hypothesis. We assessed the effects of phonological similarity and item length, which reflect the operation of the phonological short-term store and the rehearsal component of verbal memory, upon paired associate long-term learning of auditorily presented words and non-words. Phonological similarity affected the learning of novel words more than known words (Experiment 1); when a delay was interposed between presentation and recall, the disruptive effect was confined to novel words (Experiment 2). Also word length disrupted the learning of novel words, but not of known words (Experiment 3). These results tie in with neuropsychological evidence to suggest a role for phonological short-term memory in the learning of new words, and they have developmental implications for the study of language acquisition.
Five experiments examine the combined effects of spatial and non-spatial cues on the latency of an orientation judgement. In Experiment 1 an interaction between position and form expectancies is observed: There is an unusual delay in response time (RT) when expectancies mismatch—that is, when an unexpected (uncued) form appears at an expected (cued) position or an expected (cued) form appears at an unexpected (uncued) position. This interaction is inconsistent with the spatial spotlight model's prediction that position and form expectancy effects will be additive. The position-form interaction is eliminated when target position discriminability is made difficult by adding a distractor item at the location not containing a target (Experiment 2) or by decreasing the validity of the positional cue (Experiment 3). Decreasing the validity of the form cue has no effect on the interaction. The mismatching expectancy interaction is not unique to combinations of position and form—it is also observed when temporal (Experiment 4) and colour (Experiment 5) expectancies are combined with form expectancies. The effects of advance knowledge of position therefore suggest no special status for location compared to other stimulus attributes. Thus, at least for combined expectancies, the notion of a uniquely spatial mental spotlight seems unjustified. It is hypothesized that expectancy interactions may reflect a hierarchical crosstalk relation between dimensions of encoding.
Even though it can be shown that verbal knowledge of results (KR) is redundant with sensory feedback for learning certain motor skills, such findings do not eliminate the possibility that when KR is available it influences underlying learning processes. In order to examine the function of KR more closely, two experiments were designed in which the subjects received conflicting information about their own sensory feedback and the KR presented by the experimenter. In Experiment 1, two erroneous-KR groups, a correct-KR group, and a no-KR group performed 150 practice trials on a simple anticipation timing task and then performed three no-KR retention tests of 30 trials each following intervals of 10 minutes, 1 week, and 1 month. The results supported previous findings that providing correct KR is redundant in anticipation tasks. However, learning was influenced by KR as subjects performed according to the erroneous KR information, thereby ignoring their sensory feedback even after a 1-month interval. In Experiment 2, subjects practised a more complex striking response for the anticipation task for 75 trials and then performed no-KR retention trials either immediately, or 1 day or 1 week later. One of the groups received erroneous KR after 50 practice trials with correct KR. The results confirmed and extended those from Experiment 1, as erroneous KR, even after initial practice with correct KR, influenced retention performance. These results indicate that although KR provides information that is not needed to learn anticipation timing skills, this augmented verbal information is a dominant source of information that influences underlying cognitive processes involved in learning motor skills.
The effects of alcohol (1.0 ml/kg body weight) and practice (2 sessions) were investigated in 2-, 4-, and 8-choice reaction time (RT) tasks with 24 male subjects. The number of errors increased with alcohol, practice, and increasing task complexity (choice). Mean RT decreased with practice, but increased with alcohol and complexity. Both the alcohol and practice effects on mean RT increased as complexity increased. The effects of alcohol, practice, and complexity were all larger for the higher percentiles of the RT distributions than for the lower percentiles. RT distributions were further analysed at each level of choice by plotting percentiles (5th, 10th, …, 95th) for alcohol conditions against corresponding percentiles for no-alcohol conditions, and percentiles obtained early in practice (Session 1) against those obtained later in practice (Session 2). These plots revealed that whereas at all levels of choice the effect of alcohol could be expressed as a simple linear transformation of all RTs, the effect of practice required a more complex curvilinear transformation. Thus, alcohol produces a general slowing of all RTs, whereas practice produces a disproportionate improvement at the slower end of the RT distribution.
Despite the absence of “conscious”, overt identification, some patients with face recognition impairments continue covertly to process information regarding face familiarity. The fact that by no means all patients show these covert effects has led to the suggestion that indirect recogntion tasks may help in identifying different types of face recognition impairment. The present report describes a number of experiments with the patient NR, who, after a closed head injury, has been severely impaired at recognizing familiar faces. Investigations mostly failed to show overt or covert face recognition, but NR performed at an above-chance level in selecting the familiar face on a task requiring a forced-choice between a familiar and an unfamiliar face. This discrepancy between a degree of rudimentary overt recognition and absence of covert effects on most indirect tests was addressed using a cross-domaim identity priming paradigm. This examined separately the possibility of preserved recognition for faces that NR consistently chose correctly in a forced-choice familiarity decision and those on which he performed at chance level. Priming effects were apparent only for the faces that were consistently chosen as “familiar” in forced-choice. We suggest that NR's stored representations of familiar faces are degraded, so that face recognition is possible only via a limited set of relatively preserved representations able to support a rudimentary form of overt recognition and to facilitate performance in matching and priming tasks.


