Visual comparison of rotated and reflected random-dot patterns as a function of their positional symmetry and separation in the field

Subjects viewed pairs of random-dot patterns which were presented in a number of arrangements varying in the transformations applied to the patterns, in the distance between the patterns, and in the symmetry of the pattern positions with respect to the point of fixation. The task was to judge whether the patterns were “the same” taking into account possible rotations or reflections, or “different”. It was found that correct judgements for identical patterns were most affected by the distance between the two patterns, whereas correct judgements for patterns where one had been rotated through 180° or reflected were most affected by the symmetry of the pattern positions. A scheme modelling the visual recognition of transformed patterns, sufficient to explain the results, is presented.     

Is Human Learning Rational?

We can predict and control events in the world via associative learning. Such learning is rational if we come to believe that an associative relationship exists between a pair of events only when it truly does. The statistical metric ΔP, the difference between the probability of an outcome event in the presence of the predictor and its probability in the absence of the predictor tells us when and to what extent events are indeed related. Contrary to what is often claimed, humans' associative judgements compare very favourably with the ΔP metric, even in situations where multiple predictive cues are in competition for association with the outcome. How do humans achieve this judgemental accuracy? I argue that it is not via the application of an explicit mental version of the ΔP rule. Instead, accurate judgements are an emergent property of an associationist learning process of the sort that has become common in adaptive network models of cognition. Such an associationist mechanism is the “means” to a normative or statistical “end”.     

A comparison of body perceptions in relation to measured body composition in young Japanese males and females

The body composition of 139 Japanese females and 84 Japanese males (aged 18–30 years) was measured using anthropometry to assess gender differences in body perceptions in relation to their measured values. Participants were asked to rate perceptions of their own “heaviness” and “fatness” and these were compared to their BMI and percent body fat (%BF). Japanese females showed a significantly greater desire to lose body weight (−4.20 ± 0.6 kg) compared to males (0.27 ± 1.4 kg). Females also showed poor understanding of their “heaviness” and “fatness” in relation to actual body composition compared to males. The results confirmed distinct gender differences in body perception in relation to actual body composition and attitudes to weight management. Further promotion of “healthy” body image is recommended for the Japanese population.     

On varying the span of visual attention: Evidence for two modes of spatial attention

Three experiments investigated whether subjects could selectively attend to a target item presented in close spatial proximity to a distractor element. Typically, the display consisted of two curved lines, one a target and the other a distractor. The task was to judge the direction of curvature of the target. When subjects attended to a target away from fixation, performance was affected by the presence of a distractor within an area of 1° around the target. In contrast, the distractor did not influence target processing when subjects fixated on the target location. Two modes of visual attention are proposed. When a target is located away from fixation, a “wide” attentional span is employed. With the present stimuli, this led to the detailed processing of items within 1° of the attended position. However, when targets are at fixation a “narrow” span can be adopted, with the result that there is differential processing of attended items even within the formerly critical area.     

Reading abilities of school-age stutterers

The reading abilities of 20 school-age stutterers and their matched normally fluent controls were assessed by means of the Woodcock Reading Mastery Tests. Results indicate that the reading abilities of school-age stutterers are not significantly different from those of school-age normals. Similarly, knowing whether a subject was classified as a stutterer or normally fluent speaker was of minimal assistance in predicting the subject's reading performance. These findings suggest that school-age stutterers' reading abilities are within normal limits. An individual stutterer, just like an individual normally fluent speaker, may exhibit “reading problems”; however, caution should be employed in extrapolating from one individual stutterer's reading performance to the reading abilities of all stutterers.     

Acoustic factors in visual search

Previous work has shown that in searching for existing or absent “e.s” in printed prose, the presence or absence of silent “e.s” was less likely to be detected than that of pronounced “e.s.” It was suggested that the acoustic or kinaesthetic “image” was searched for evidence of an “e” in addition to the visual stimulus and that evidence from both sources was considered in making the appropriate response.

The present experiment employs mainly substitutive errors within words, which may or may not change their pronunciation. The results suggest that the form of the acoustic correlates has no bearing upon whether the words are detected as wrongly spelt, but that the presence or absence of an acoustic event corresponding in time to the spatial location of the error is important.     

Phenomenal causation at a distance

The aim of this research was to study the finding by Michotte, that a moving object A can apparently produce movement in a projectile B without making contact with it.

The experiments confirm the existence of a causal impression of “pushing at a distance,” but they demonstrate that the greater the distance the smaller the chance that this impression will occur.

When it does, in fact, occur, it has the same characteristics, and is associated with the same experimental conditions, as the impression of “pushing with contact.”

Temporal continuity must obtain between the stopping of the moving object and the starting of the projectile; this refutes any theory positing that there is a “passage” of movement from one object to the other. The effects of differences in speed of movement, whether absolute or relative, are similar in both instances.

In general, however, it appears that distance slightly accentuates the segregation of the movements and that the temporal and kinematic conditions of integration require to be more favourable in the case of distance, if an impression of pushing is to be given which is as satisfying as that found in the case of direct contact.

The size of the Radius of Action, that is, the extent of the passive phase of the projectile, is of the same order in the two cases.

The results bring out the fundamentally temporal-kinematic nature of the perceptual pattern of pushing. They appear difficult to reconcile with an interpretation based on past experience, but tally with the theory of “Ampliation of Movement” put forward by Michotte. According to this theory the essential point lies in the phenomenal transitory belonging to A (the moving object) of the movement performed by B (the projectile).     

"They" as a gender-unspecified singular pronoun: eye tracking reveals a processing cost

The plural pronouns they and them are used to refer to individuals with unknown gender and when a random allocation of gender is undesirable. Despite this apparently felicitous usage, “singular they/them” should raise processing problems under the theory that pronouns seek gender- and number-matched antecedents. Using eye-tracking, we investigated whether there was any processing cost associated with using singular they/them. There was a clear cost of number incompatibility for they/them. Thus, although singular they/them is in current usage, it does not appear that they/them is immediately tolerant of a plural antecedent, though such may be rapidly accommodated. The data are consistent with the search account of pronoun resolution and preserve the semantics of they/them as denoting plurality.     

Payoff: A neglected factor in reaction time measurement

The aim of this paper is to point out some implications of implicit or explicit payoffs in reaction time experiments. In any psychophysical task the subject is given a set of instructions which define the desired performance, as it were the rules of the game. Instructions may be supplemented by knowledge of results which further define the required performance. When performance admits of being “good” or “bad,” however wide these limits, the instructions may be said to define, explicitly or implicitly, a system of payoffs. In reaction time experiments the subject is instructed, amongst other things, to respond as soon as possible after the stimulus but never before it. These instructions could equally well be represented by a system of payoffs and Figure 1 illustrates the kind of payoff system normally implied in these instructions. If S represents the time at which the physical stimulus occurs the graph shows a fixed penalty for anticipations (response before S), maximum positive score for responses immediately following S declining at an arbitrary rate as a function of elapsed time between S and the response until an unacceptably long time involves a constant maximum penalty. Some experimenters choose to treat very short RT's as anticipations. This is represented by the dashed line in Figure 1, but it should be clear that payoff values are, to a certain extent, arbitrary.     

Shorter articles and notes the interpretation of the passive voice

It was hypothesized that sentences in the passive voice emphasize the importance of the things referred to by their grammatical subjects to a greater extent than sentences in the active voice. Each subject had to produce simple diagrams to represent two sentences, one active and one passive, and it was assumed that the size of areas in these diagrams could be taken as an index of importance. In Group EQ, the sentences specified an equivalent arrangement of colours, e.g. “Red follows Blue,” “Blue is followed by Red”; in Group CO, they specified converse arrangements, e.g. “Red follows Blue,” “Red is followed by Blue.” The predictions, that (i) the subjects of all sentences would tend to be represented as larger than the objects, and that (ii) the subjects of passives would be represented as larger than those of actives, were confirmed.     

Memory of a speaker's voice: Reaction time to same- or different-voiced letters

Subjects were presented with a sequence of two letters, each letter spoken in either a male or female voice. On each trial, the subject was required to indicate, as quickly as possible, whether the two letters had the same name. Reaction times (RTs) were faster for letters spoken in the same voice for both “same” and “different” responses, even when letters were separated by 8 s. These results are incompatible with the notion of physical and name codes in auditory memory since a “different” response should always be based on a comparison of letter names and should not be influenced by voice quality. It was also found that RTs were not influenced by the phonemic distinctive feature similarity of the letters.     

S-R compatibilities depend on eccentricity of responding hand

Bauer and Miller (1982) demonstrated that when responding on the body midline with the right hand, subjects react faster when the pairing between horizontally oriented stimuli (an X to the left or right of fixation) and vertically oriented responses (an up or down finger movement) is left-down, right-up (“anti-clockwise”) but when responding with the left hand, the converse pairing was faster. The present experiments tested whether those preferences held for responses other than on the body midline. Unimanual reaction times for clockwise and anti-clockwise S-R pairings were determined for both hands at the midline and 30 and 60 cm to the left or right. Hand position determined both the direction and extent of the compatibility preference; at eccentric positions the right hand preferred clockwise pairings and the left anticlockwise, the converse of that found by Bauer and Miller. The results extend Bauer and Miller's finding, raise problems for theories of S-R compatibility, and further reveal that the state of the action system “sets up” perception.     

Supplementary WMS-III tables for determining primary subtest strengths and weaknesses

It is common practice to evaluate the age-adjusted subtest scores from the Wechsler intelligence scales to determine strengths and weaknesses within a profile. The Wechsler Memory Scale-III (WMS-III; D. Wechsler, 1997a) represents a significant improvement over its predecessors and, for the first time, provides age-adjusted subtest scores for interpretation, just as the Wechsler intelligence scales have done for 60 years. It is reasonable to assume that examiners will evaluate the WMS-III subtest profiles for strengths and weaknesses. However, the WMS-III Administration and Scoring Manual and the WAIS-III-WMS-III Technical Manual (The Psychological Corporation, 1997) provide no assistance for accomplishing this goal. Data from the WMS-III standardization sample, as described in the WAIS-III-WMS-III Technical Manual, were used to develop tables for determining both confidence levels and infrequency of differences between individual subtest scores and the means of 5 subtest combinations that may be clinically relevant for individual cases.     

Preferred tempo in the learning of a gross cyclical action

Seventy-five subjects, randomly assigned to one of five training conditions, were required to learn to make large-amplitude, high-tempo, fluent movements on a so-called ski-simulator over a period of four days. Subjects trained under different tempo conditions. In four of the conditions the tempo was prescribed (“preferred”, high, low, or increasing), augmented feedback being provided to enable subjects to stay on “target”. “Preferred” tempo was based on the weight of the subject and was derived from a regression equation based on previous empirical research. In a fifth condition, subjects trained on “discovery learning” principles, i.e. without the tempo being prescribed. The results obtained on the three parameters (amplitude, frequency, and fluency) during the daily test sessions (in which the tempo was not prescribed) formed the data for the analyses.

A learning effect was apparent on all three parameters over the four-day training period. Subjects who trained under the high or the low prescribed tempos, however, were shown to produce significantly smaller amplitude movements than subjects who trained under the other three conditions. Training under the low-tempo condition was also shown to have disadvantageous effects on the parameters tempo and fluency. It was concluded that, for these kinds of action, training at a high or a low tempo—and particularly the latter—has undesirable effects. Such disadvantageous effects, however, were shown to be avoidable if training is begun with the “preferred” tempo of the subject and increased successively by 7% over days.     

Experimental finger dyspraxia

Subjects were required to perform discrete finger movements in accordance with a pre-arranged sequence of instructions. In all cases, any movement made by any finger was recorded by means of a constant-speed kymograph equipped with levers designed to record separately the movements of the individual fingers. This experiment was carried out under three conditions: (a) with no vision of the hand; (b) with direct vision of the hand; and (c) with the hand presented in mirror-image. It was found that, whereas deprivation of visual control was without effect on the efficiency of finger movements, presentation of the hand in mirror-image gave rise to significant increases in reaction time of three fingers and to an increase in the percentages of prior and substitute movements of other digits. Phenomena akin to depersonalisation were reported in some cases. It was also found that the rank order of mean reaction times of the five digits was approximately constant under all conditions and that the two fingers with the shortest reaction times were preceded by the fewest movements of other digits. These two digits were also the most frequently moved in advance when movements of other digits were requested and it is suggested that they have a certain “signpost function” in guiding identification of the remaining fingers. Some implications of these results for an understanding of “finger agnosia” are briefly indicated in an Appendix.     

Saccadic Eye Movements in Parkinson's Disease: I. Delayed Saccades

The saccadic eye movements of nine patients with Parkinson's disease were compared to those of nine age-matched controls in two paradigms generating volitional saccades. In both paradigms, subjects had to make delayed saccades to peripheral LED targets: a peripheral target appeared 700 msec before a buzzer sounded, the buzzer being the signal to make a saccade to the target. In the first paradigm (“centre-off”), the fixation target was extinguished simultaneously with buzzer onset. In the second (“centre-remain”) it was not extinguished until 1000 msec later. The results showed that for outward saccades in both paradigms, there was no difference between Parkinsonian patients and controls, but saccadic latencies were significantly shorter in the “centre-remain” paradigm. The initial outward saccades were indistinguishable from the normal, reflex saccades of the same subjects. However, saccades returning to the centre (a type of remembered target saccade) were hypometric and showed multistepping. Both effects were more pronounced in patients with Parkinson's disease. The significance of these findings in terms of current hypotheses about the nature of the Parkinsonian saccadic deficit is discussed.     

Studies in Spaced and Massed Learning: III. Paired-Associate and Serial Learning

An experiment on paired-associate learning was carried out to test Hovland's prediction that spaced practice should be more advantageous than massed if the order of presenting the pairs of nonsense syllables were fixed.

In the results, spaced and massed practice showed little difference in learning efficiency. Hovland's prediction was not confirmed.

In a previous experiment of this series of studies it had been found that spaced practice was more efficient than massed in serial learning when syllables of “low-meaningfulness” value were used; but that there was little difference in efficiency between the two forms of distribution when “high-meaningfulness” syllables were used. The results of the two experiments naturally suggested that, as regards the relative efficiency of spaced and massed practice, paired-associate learning of low-meaningfulness syllables differed from serial learning of similar syllables, but matched serial learning of high-meaningfulness syllables. It seems justifiable to draw the conclusion that the relative efficiency of spaced and massed practice is different in paired-associate and serial learning, not because remote associations can be formed in the one case and not in the other, as Hovland (1939a, 1939b) assumed; but because the organization of the material and the learning processes are different in the two forms of learning.     

Measuring lexical diversity in children who stutter: application of vocd

There is growing but equivocal evidence that the language abilities of young children who stutter (CWS) may be depressed when compared to those of their fluent peers. In particular, the lexical skills of CWS have variously been reported to be weaker or stronger than comparison children in a number of recent studies. One source for such disagreement may be the measures used to compute lexical characteristics of these children’s spoken conversations. In this study, we examined the concurrent validity of two measures of lexical diversity in spontaneous language samples, Type-Token Ratio (TTR) and the newly developed utility vocd (Malvern & Richards, 1997), using a standard test of expressive vocabulary as the comparison measure. Findings indicated that vocd values (“D”) correlated well with standardized measures of expressive vocabulary, while TTR values did not. In addition, both the standardized measure and vocd revealed significantly poorer expressive lexical skills of CWS, whereas TTR analyses did not evidence this difference. Results are discussed in relation to the relative strength of vocd over TTR as a method for describing lexical characteristics of the spontaneous language samples of this population.

Educational objectives: The reader will learn about and be able to (1) identify several common measures of conversational vocabulary and the strengths and weaknesses of each, and (2) compare the performance of the young CWS in this study to their normally fluent peers in terms of vocabulary performance on both formal and conversational measures of vocabulary.     

Are professors likely to report having “beliefs” about the intelligence and competence of students who stutter?

Some university students who stutter report that they avoid participating in class discussions and talking with professors because they believe that if their professors find out they stutter, the professors are likely to view the students as being less intelligent and/or competent than they otherwise would. The purpose of this study was to determine whether professors, as a group, are likely to report such beliefs. A random sample of 87 professors at Marquette University, Indiana University of Pennsylvania, and the State University of New York at Stonybrook rated “A Student Who Stutters” on each of 81 seven-point, bipolar semantic differential scales, including intelligent/unintelligent and competent/incompetent. Although there was considerable scatter in their ratings for the majority of the scales, 85 of the 87 rated the student at the center or “positive” end of the intelligent/unintelligent scale and 83 of the 87 did so on the competent/incompetent one. Assuming that the attitutes reported by the professors reflect their “real” ones, these data suggest that many—perhaps the majority—do not have negative attitudes about the intelligence and competence of their students who stutter.     

Remembering, Familiarity, and Source Monitoring

Two experiments investigated recollective experience in a source monitoring task. Subjects saw an array of objects and performed, watched, or imagined actions involving pairs of objects. In a subsequent recognition test, subjects indicated whether their recognition judgements were made on the basis of conscious recollective experience (“remember” responses), or on some other basis such as familiarity (“know” responses). The proportions of correct “remember” responses for both objects and actions decreased from performed, through watched, to imagined actions, whereas the proportions of correct “know” responses were uninfluenced by the source of the memories. In addition, the relationship between recollective experience and accuracy of source judgement varied across sources. Source accuracy for performed actions was obtained only in “remember” responses, whereas source accuracy for imagined actions was obtained only in “know” responses. Source accuracy for watched actions was obtained in both “remember” and “know” responses. The findings suggest that the types of memory attributes available at retrieval determine the quality of subsequent memory experience, and it is proposed that memories with strongly self-referential attributes (arising from performed actions) powerfully cue recollective experience during retrieval.