Syllogistic inference

This paper reviews current psychological theories of syllogistic inference and establishes that despite their various merits they all contain deficiencies as theories of performance. It presents the results of two experiments, one using syllogisms and the other using three-term series problems, designed to elucidate how the arrangement of terms within the premises (the ‘figure’ of the premises) affects performance. These data are used in the construction of a theory based on the hypothesis that reasoners construct mental models of the premises, formulate informative conclusions about the relations in the model, and search for alternative models that are counterexamples to these conclusions. This theory, which has been implemented in several computer programs, predicts that two principal factors should affect performance: the figure of the premises, and the number of models that they call for. These predictions were confirmed by a third experiment.     

Auditory lateralization: An effect of rhythm

Recall of monaurally presented semantically anomalous sentences, which had either neutral or rhythmic timing, was tested at the right ear, at the left ear, and on transfer from one ear to the other. The component words, being computer stored digitized waveforms, had identical acoustic structure in the two conditions. In the rhythmic condition there was not only an overall advantage in the second half of the experiment but also an asymmetric transfer effect such that this advantage did not appear when the left ear was tested after the right. It is proposed that functional lateralization be viewed as an adaptive, dynamic, organizational factor.     

Developmental and acquired dyslexia: A comparison

Jorm (1979a) has drawn attention to similarities between developmental dyslexia and acquired deep dyslexia, an analogy which has been criticized by A. W. Ellis (1979). A series of three experiments compared the two syndromes, using the techniques applied by Patterson and Marcel (1977) to adult deep dyslexics, to study a group of 15 boys suffering from developmental dyslexia. Patterson and Marcel's patients were able to perform a lexical decision task but showed no evidence of phonemic encoding of nonwords; our dyslexic children performed this task very slowly and with reduced accuracy but showed clear evidence of phonemic coding of the nonword items. Patterson and Marcel observed that their patients could not read out orthographically regular nonwords; our dyslexic children were able to do this task, although more slowly and somewhat less accurately than their chronological age or reading age controls. Finally, Patterson and Marcel observed that highly imageable words were more likely to be read correctly than words of equal frequency but low imageability; we observed a similar effect in both our dyslexic group and in their reading age controls. This implies that the imageability effect may not be peculiar to dyslexics but may be characteristic of normal reading under certain conditions. It is concluded that developmental dyslexics differ from the patients studied by Patterson and Marcel in demonstrating a pattern of reading which, though slow, is qualitatively similar to the reading of normal readers of a younger age. As such, our results do not support Jorm's position.     

Rhythm and dominance

Subjects were tested by a short experimental procedure involving tapping of a rhythm with one limb with a simultaneous regular beat with another limb. Informal observations had suggested a rhythm dominance effect—that is was dramatically easier with some limb combinations. Notably it was easy when the right hand tapped the rhythm and the left hand the beat but almost impossible the other way round. Equally, both hands dominated both feet. Our tests revealed enormous individual differences, subjects separating neatly into three groups. Some people could not do the task at all, some could do it with any limb combination, the latter group including all the serious musicians tested. For the remainder the rhythm dominance effect was clear. However, the laterality effect was the same (right hand advantage) for a majority (60%) of left handers. We conclude, then, that this effect is linked to language dominance and not handedness. In addition it seems there is a task scheduler which imposes its own view in combining this laterality effect with the dominance of hands over feet.     

Remembering plurals: Unit of coding and form of coding during serial recall

Subjects were required to recall lists of six words which had been presented visually in sequence. One or two of the words might be plural nouns. A substantial number of errors occurred in which the plural form became detached from its original root. This is taken as evidence for a morpheme-based code as opposed to a unitary word code. A significantly high proportion of these errors maintained the form of the plural ( /S/, /Z/ or (ЪZ/) which is considered evidence for a primarily phonological coding of the plural morpheme. There is however a suggestion that on some occasions the plural is coded morphemically—i.e., in a way which does not distinguish between the various plural endings.     

What is right with “deep” dyslexic patients?

Two aphasic adults with a specific acquired dyslexia were given tests requiring the processing of written words and sentences. Despite the general severity of the patients' deficits, some aspects of such processing appear to be relatively well preserved. The patients have particular difficulty reading aloud function words and abstract words; yet in word/nonword discrimination tests, both patients showed normal recognition of function words and one showed normal performance with abstract words. The patients do have a deficit in comprehension of visually presented words and sentences; yet their performance on comprehension tests was considerable and, moreover, showed meaningful relationships with their ability to read aloud.     

Errors in children's subtraction

Many of the errors that occur in children' subtraction are due to the use of incorrect strategies rather than to the incorrect recall of number facts. A production system is presented for performing written subtraction which is consistent with an earlier analysis of the nature of such a cognitive skill. Most of the incorrect strategies used by schoolchildren can be accounted for in a principled way by simple changes in the production system, such as the omission of individual rules or the inclusion of rules appropriate to other arithmetical tasks. The production system model is evaluated against a corpus of over 1500 subtraction problems done by 10-year olds and is shown to account for about two-thirds of the (nonnumber fact) errors. It also provides an alternative, simpler interpretation of the subtraction errors analysed by Brown and Burton (1978). Some implications for teaching are discussed.     

The effects of S-R uncertainty in the PRP paradigm: A reply to Kantowitz

Karlin and Kestenbaum (1968) reported a series of apparently complex interactions between S-R uncertainty and RT in an experiment using the psychological refractory period paradigm. McLeod (1977) showed that these effects could be predicted by a parallel processing limited capacity model. Kantowitz (1978) criticised that paper on the grounds that it paid insufficient attention to the predictions of response conflict theory and made no mention of errors.It will be shown (a) that response conflict theory, as described by Kantowitz, fails to predict the effects found by Karlin and Kestenbaum (b) that the comments about errors miss the point of McLeod (1977) (c) that in his final section Kantowitz falls into an old trap which awaits the unwary analyser of PRP data.     

The height of handwriting

An experiment is described that examines the basis of the control of vertical amplitude (height) of handwriting. It is shown that changes in movement duration accompany changes in height whether the latter are associated with instructions to write larger than normal (between words) or because the letters to be written (e, l) differ in height (within words). The proportional differences in movement duration match the proportional differences in amplitude between words but not within words. It is concluded that two different time-based mechanisms are invoked for handwriting height control: interval adjustment for writing size changes between words and duration selection for letters differing in height within a word.     

The demonstration of capacity limitation

The study of divided attention has produced many apparent demonstrations of “capacity limitation.” Possible ambiguities in such demonstrations are considered for three major types of experimental situation: simultaneous inputs with separate responses; choice; and classification. Two issues emerge. First, demonstrations always rest on assumptions about process set, i.e., the set of internal processes by which the task actually is performed. Alternative process sets are considered for situations of each type. Second, a demonstration of capacity limitation is made either by increasing the number of simultaneous processes, or by changing the bias between them. In either case effects unrelated to capacity limitation may influence the results. If several processes contribute to a single response, some performance decrement must accompany an increase in their number, simply through the increased overall chance for error. If the subject is biased toward one alternative in a choice or classification situation, the benefits enjoyed by this alternative may reflect not a preferential allocation of attentional capacity, but simply a willingness to decide in favor of this alternative with relatively little evidence.     

The role of short-term working memory in mental arithmetic

A series of experiments explored the role of information storage in working memory in performing mental arithmetic. Experiment 1 assessed the strategies people report for solving auditorily presented multidigit problems such as 325 + 46. As expected, all subjects reported breaking down the problems into a series of elementary stages, though there were considerable individual differences with regard to the order of their execution. Strategies of this type necessitate both the temporary storage of information and the mobilization of long-term knowledge. Experiments 2 and 3 examined the effects of delaying the output of individual partial results on calculation accuracy and showed that interim information is forgotten if it is not utilized immediately. Experiment 4 showed that forgetting the initial information is also a source of error and suggested that forgetting increases as a function of the number of calculation stages intervening between initial presentation and subsequent utilization of information. Two simple quantitative models were derived from a general task analysis, one of which assumed a decay process in working storage and the other no decay. The decay model gave a reasonable fit to data from Experiments 2–4, and in doing so it coped appreciably well with the effects of a large variety of task variables (e.g., carrying, the provision of written notes, calculation strategy, output order). The decay model is a tractable analysis of a complex task, and it is suggested that similar analyses may prove fruitful for other problem-solving activities which involve the use of working memory.     

Deliberate self-harm,clinical history and extreme scoring on the EPQ

Two hundred consecutive admissions to an inpatient psychiatric unit were assessed on the EPQ following recovery from the disturbance for which they were hospitalized. Case-history data was also checked for these patients and extended by using a clinical-history structured interview, also administered within 1 week of discharge. Results showed that for males, high P and high N was associated with a history of deliberate self-harm (DSH) by mutilation. High N was also associated with parental violence. In females, both low E and high N were associated with a history of self-mutilation. High N scores were also more likely to have appeared in court, and high P females were more likely to have a history of bedwetting and of parental violence.None of the associations between extreme scoring on the EPQ and self-mutilation were found for DSH by overdose.     

Evoked potential correlates of visual selective attention

Two experiments are reported in which the relationship is explored between the N1 and P2 components of the visual evoked potential and visual selective attention. In both experiments, channels were defined in terms of stimulus attributes (experiment 1 — intensity; experiment 2 — shape) with all stimuli being presented at a common spatial locus in order to preclude fixation shifts. Under these circumstances, P2 was found in both experiments to correlate with visual selective attention whereas N1 did not. It is concluded from the null result for N1 that a precortical gating mechanism for visual inputs within a single spatial channel is not a component of the visual system. The P2 correlate of visual selective attention, because of its long latency, is attributed to the differential post-perceptual processing inevitably received by task-relevant and task-irrelevant inputs.     

Intellectual realism in children's drawings of cubes

Ninety-six children copied simple line drawings of perspective views of cubes and similar designs unlikely to be seen as representing objects. The views of cubes were copied much less accurately than the non-object patterns, and the errors made in copying the cubes involved replacement of properties specific to the single perspective view by properties more appropriate to the object itself. Some copies were drawn with the child continually looking at the model and unable to see his own copy, others were drawn in the normal way. Copies made in the former way were more accurate, but even under these conditions cubes were copied less accurately than the non-object patterns. The disadvantage of object pictures, as far as literal copying accuracy is concerned, was still present at 9 1/2 years of age, but was less than at 7 1/2. Two possible explanations are discussed. One is in terms of computational complexity, the other in terms of graphic motor schema. On the basis of the drawings obtained a few suggestions are made about the content and development of the data-structures for cubes.     

The use of natural consequences and a make-up period to eliminate school phobic behavior: A case study

The school-phobic behavior of a seven-year-old male was modified through implementing a program characterized by maximum parental involvement, restructing of natural consequences, and the use of a make-up period. Full-time school attendance was achieved on the sixteenth day of the program. The advantages of using school personnel as monitors and not as disciplinarians of the school-phobic child's behavior are discussed.     

Autonomous processes in comprehension: A reply to Marslen-Wilson and Tyler

A criterion which has been proposed for distinguishing minds from computing systems is examined from the point of view of some current work on computer induction.     

Word shape,orthographic regularity,and contextual interactions in a reading task

In an investigation of the interaction between three sources of information about a printed word, skilled readers performed a simple naming task. The naming latency was observed as a function of case of presentation, orthographic regularity, and the congruency of context supplied in a previously presented sentence. Differences between regular and irregular words were observed for upper case presentations only, suggesting that lexical access can proceed via a direct visual route only when the distinctive features of the global word envelope are available. Incongruent sentences inhibited word naming, and congruent sentences facilitated naming, but this effect was more apparent for upper case than for lower case words. These results suggest an interaction of information during word recognition, with the removal of the word envelope leading to a greater dependence upon other intrinsic and extrinsic information.