A method for identifying eggs laid by individual birds

A method for identifying eggs laid by different subsections or individual members of groups of domestic hens is described. Fat-soluble dyes are placed in gelatin capsules and fed to selected birds. These dyes produce discrete colored bands in the yolks of eggs laid by those birds. The presence of dye in eggs can be detected through the shell, and different patterns of rings can be distinguished by boiling and sectioning eggs. Application of the method to other species and other circumstances is considered.     

A method for combining occurrence and nonoccurrence interobserver agreement scores

Various statistics have been proposed as standard methods for calculating and reporting interobserver agreement scores. The advantages and disadvantages of each have been discussed in this journal recently but without resolution. A formula is presented that combines separate measures of occurrence and nonoccurrence percentages of agreement, with weight assigned to each measure, varying according to the observed rate of behavior. This formula, which is a modification of a formula proposed by Clement (1976), appears to reduce distortions due to "chance" agreement encountered with very high or low observed rates of behavior while maintaining the mathematical and conceptual simplicity of the conventional method for calculating occurrence and nonoccurrence agreement.     

Reaction time as a function of the intensity and probability of occurrence of vibrotactile signals

Three Ss made judgments of the presence or absence of a burst of 60-cps vibration onthe index fingertip.The probability of S’s reporting the presence of a signal was found to be influenced by signal probability and signal intensity. Mean reaction time for reporting the presence of a signal decreased as a function of signal intensity and signal probability whereas mean reaction time for reporting the absence of a signal increased as a function of signal intensity and signal probability. On trials where no signal was presented mean R T for reporting a signal decreased with increases in the signal probability whereas mean RT for reporting the absence of a signal increased with increases in signal probability. The results were interpreted as support for the hypothesis that S’s decision time was longer the closer on the sensory continuum a particular observation was to his criterion.     

A method for increasing empirical discriminability and eliminating top‐row preference in photo arrays

It is important to consider the two parameters of signal detection theory, discriminability and response bias, when evaluating eyewitness identification from simultaneous lineups. On the basis of the diagnostic feature‐detection hypothesis, we tested a method for increasing discriminability that encourages eyewitnesses to carefully rank each lineup member based on match to their memory for a perpetrator. This procedure increased empirical discriminability and also eliminated a response bias that is largely overlooked in the literature: Participants were biased to choose from the top row of the six‐pack (2 × 3) lineup commonly used in the United States. We argue that suspect position in the simultaneous lineup is an important variable to consider for researchers and the criminal justice system. We also encourage researchers to test the ranking procedure to determine if such a simple set of instructions could be utilized by police to help eyewitnesses correctly sort innocent versus guilty suspects.     

Contour deletion as a method for identifying the weights of features underlying object recognition

A prerequisite for comparative work on object recognition is a method for identifying the features actually extracted from the form. The method introduced here with pigeons is discrimination training between two simple line drawings, followed by a generalization test in which contour is deleted from the reinforced drawing. In Condition 1, the line drawings were a square (S+) versus a triangle (S-); for Condition 2, the line drawings were planar projections of a cube (S+) versus a truncated pyramid (S-). The generalization decrement between responses to S+ and responses to test stimuli provides a quantitative index of the weight assigned to each feature. Contour deletion at either vertices or midsegments produced a decrement in the rate of responding, showing that each contour was represented as a feature. The generalization decrement to forms containing vertices with midsegments deleted was larger than the generalization decrement to forms containing midsegments with vertices deleted. Therefore, it appears that midsegments are weighted more strongly as features than vertices. Contour deletion provides a direct method for identifying the visual features underlying object recognition and lays a foundation for the development of comparative theories of object recognition.     

Developmental patterns of aggressive and withdrawn behavior in childhood: A possible method for identifying preschizophrenics

The generality of results from high-risk studies of the children of schizophrenics may be limited. Studies of preschizophrenics suggest that an alternative approach to the identification of populations at risk involves the selection of children high on aggression and withdrawal. Aggressive children, withdrawn children, aggressive-withdrawn children, and nondeviant controls were identified by peer ratings of 4,110 children in grades 1, 4, and 7. The probability of identifying aggressive-withdrawn subjects decreased as grade level increased, while the probability of identifying aggressive subjects and withdrawn subjects increased with age. Peerrated likability of the aggressive-withdrawn group decreased systematically as grade level increased, in contrast to likability scores for other groups. Teachers rated the aggressive-withdrawn group as more deviant on scales of external reliance, inattention-withdrawal, unable to change tasks easily, and slow to complete work. Mothers described this group as more deviant on scales of distractibility, pathological use of senses, and need for adult contact. These results suggest that, especially at older ages, children who are both aggressive and withdrawn represent a less mature, less socially skilled group that is potentially at risk for poor adjustment later in life.The research described here was supported by Quebec Ministry of Social Affairs Grant RS281 to Jane Ledingham and Alex Schwartzman. An earlier version of this paper was presented at the Annual Meeting of the Canadian Psychological Association in Ottawa, June 1978. The author would like to thank Lisa Serbin, Anna Beth Doyle, and Alex Schwartzman for their valuable comments on a draft of this paper, and the Commission des Ecoles Catholiques de Montréal for their continuing cooperation in this project.     

Perceptual latency priming by masked and unmasked stimuli: evidence for an attentional interpretation

Four experiments investigated the influence of a metacontrast-masked prime on temporal order judgments. The main results were (1) that a masked prime reduced the latency of the mask's conscious perception (perceptual latency priming), (2) that this effect was independent of whether the prime suffered strong or weak masking, (3) that it was unaffected by the degree of visual similarity between the prime and the mask, and that (4) there was no difference between congruent and incongruent primes. Finding (1) suggests that location cueing affects not only response times but also the latency of conscious perception. (2) The finding that priming was unaffected by the prime's detectability argues against a response bias interpretation of this effect. (3) Since visual similarity had no effect on the prime's efficiency, it is unlikely that sensory priming was involved. (4) The lack of a divergence between the effects of congruent and incongruent primes implies a functional difference between the judgments in the temporal order judgment task and speeded responses that have demonstrated differential effects of congruent and incongruent primes (e.g., Klotz & Neumann, 1999). These results can best be interpreted by assuming that the prime affects perceptual latency by initiating a shift of attention, as suggested by the Asynchronous Updating Model (AUM; Neumann 1978, 1982).     

Encoding and the rea for speech signals

A number of different possible explanations are distinguished for the findings on the right ear advantage (REA) for speech signals varied in their acoustic and phonetic properties. Two experiments are reported, using synthesized semivowels and vowels in monosyllable word frames. Both show REA. The detailed results of both experiments support the idea that a complicated “encoded” relationship between the acoustical stimulus and the response phoneme is a necessary condition for the REA, but that the encoding need only be signalled by an acoustical “trigger feature” in the stimulus; a task requiring a perceptual decoding is not necessary for REA to occur.     

Signal evaluation environment: a new method for the design of peripheral in-vehicle warning signals

An evaluation method called the Signal Evaluation Environment (SEE) was developed for use in the early stages of the design process of peripheral warning signals while driving. Accident analyses have shown that with complex driving situations such as intersections, the visual scan strategies of the driver contribute to overlooking other road users who have the right of way. Salient peripheral warning signals could disrupt these strategies and direct drivers’ attention towards these road users. To select effective warning signals, the SEE was developed as a laboratory task requiring visual–cognitive processes similar to those used at intersections. For validation of the SEE, four experiments were conducted using different stimulus characteristics (size, colour contrast, shape, flashing) that influence peripheral vision. The results confirm that the SEE is able to differentiate between the selected stimulus characteristics. The SEE is a useful initial tool for designing peripheral signals, allowing quick and efficient preselection of beneficial signals.     

Structure of the visual array and saccadic latency: implications for oculomotor control

Subjects were required to look saccadically at single targets selected from one- or two-dimensional arrays of different numbers of possible alternative targets. Saccadic latencies varied with the direction but not the distance of the target, with practice and with individual subject. The effect of number of alternatives was complex, and it is suggested that an important factor influencing saccadic latency is not the number of targets per se but the number of possible directions in which a saccade may have to go.     

Comparison of perceptual dimensions uncovered from infant-cry signals using the method of pair-comparisons and the semantic differential

Since infant cry sounds may provide caregivers with information concerning an infant's needs, several studies have examined the perceptual features of cry signals. This tradition is followed in the present study, which utilises two techniques; the method of pair-comparisons (coupled to INDSCAL) and the Semantic Differential (SD). In each case 24 infant cries (six each of pain, hunger, pleasure and birth) are used as stimuli. Data were collected from mothers; 39 rated each cry on 50 SD scales, and 26 provided ratings of similarity for every possible pairwise combination of cries. The similarity of the perceptual spaces described by the two techniques is demonstrated by a canonical analysis which compared the SD factor matrix with the INDSCAL dimension-weight matrix. Two of three possible common dimensions were uncovered. This similarity is also indicated by a standard multiple regression analysis by which the INDSCAL dimensions were described in terms of the SD scales. However, it appears the SD emphasised emotional characteristics of the cry signals whereas INDSCAL emphasised physical attributes.     

A minicomputer program for the resolution of response frequency and latency in classical conditioning preparations

This classical conditioning program is capable of controlling stimulus events and recording response data in experiments using the rabbit’s nictitating membrane and/or iaw-movement responses. The main features of the program, implemented on the PDP·12 computer, are the ability to resolve response latency within a 1 msec error range and to display the response topography on the computer’s cathode ray tube. The extreme accuracy in latency measurement cannot be duplicated either by conventional hand-scoring methods involving oscillographic records or by other minicomputer conditioning programs.     

Short-term memory for the timing of auditory and visual signals.

Short-term memory for the timing of irregular sequences of signals has been said to be more accurate when the signals are auditory than when they are visual. No support for this contention was obtained when the signals were beeps versus flashes (Experiments 1 and 3) nor when they were sets of spoken versus typewritten digits (Experiments 4 and 5). On the other hand, support was obtained both for beeps versus flashes (Experiments 2 and 5) and for repetitions of a single spoken digit versus repetitions of a single typewritten digit (Experiment 6) when the subjects silently mouthed a nominally irrelevant item during sequence presentation. Also, the timing of sequences of auditory signals, whether verbal (Experiment 7) or nonverbal (Experiments 8 and 9), was more accurately remembered when the signals within each sequence were identical. The findings are considered from a functional perspective.     

Efficient visual search by category: Specifying the features that mark the difference between artifacts and animals in preattentive vision

In this report, we explored the features that support visual search for broadly inclusive natural categories. We used a paradigm in which subjects searched for a randomly selected target from one category (e.g., one of 32 line drawings of artifacts or animals in displays ranging from three to nine items) among a mixed set of distractors from the other. We found that search was surprisingly fast. Target-present slopes for animal targets among artifacts ranged from 10.8 to 16.0 msec/item, and slopes for artifact targets ranged from 5.5 to 6.2 msec/item. Experiments 2–5 tested factors that affect both the speed of the search and the search asymmetry favoring detection of artifacts among animals. They converge on the conclusion that target-distractor differences in global contour shape (e.g., rectilinearity/curvilinearity) and visual typicality of parts and form facilitate search by category. We argue that existing theories are helpful in understanding these findings but that they need to be supplemented to account for the specific features that specify categories and to account for subjects’ ability to quickly locate targets representing heterogeneous and formally complex categories.     

A multiple-observations model for response latency and the latencies of correct and incorrect responses in recognition memory

A model for response latency in recognition memory is described which is a strength model incorporating the notion of multiple observations and with the additional assumptions that the variance of the strength distributions increase with set size and that the observer attempts to keep his error rate at a constant level over set size. It is shown that the model can, without recourse to particular parameter values, predict a near linear RT set-size function and, since it is a (TSD) model in its decision aspects, can account for errors and hence error latencies in the recognition task. After the model is described, two experiments are performed which test the prediction that correct mean latency is generally shorter than incorrect mean latency. The prediction is confirmed and this feature is discussed in general, the model being compared with that of Juola, Fischler, Wood, and Atkinson (1971) in this respect. Some possible modifications to the latter model are also considered.     

Logical questions behind the lottery and preface paradoxes: lossy rules for uncertain inference

We reflect on lessons that the lottery and preface paradoxes provide for the logic of uncertain inference. One of these lessons is the unreliability of the rule of conjunction of conclusions in such contexts, whether the inferences are probabilistic or qualitative; this leads us to an examination of consequence relations without that rule, the study of other rules that may nevertheless be satisfied in its absence, and a partial rehabilitation of conjunction as a ??lossy?? rule. A second lesson is the possibility of rational inconsistent belief; this leads us to formulate criteria for deciding when an inconsistent set of beliefs may reasonably be retained.     

The functional independence of response latency and accuracy: Implications for the concept of conceptual tempo

Kagan (1965a) developed the concepts of impulsive and reflective cognitive styles (conceptual tempo) to add a new dimension to the understanding and assessment of human intelligence. Although latency (the principal component of conceptual tempo) is negatively correlated with academic performance, it may not be necessary to modify latency in order to modify accuracy. With 40 disadvantaged preschool children, it was found that reinforcing long latencies in choice tasks did not increase accuracy and vice versa, and that reinforcing both long latencies and accuracy was no more effective than reinforcing accuracy alone. These data were used to question the usefulness of the construct of conceptual tempo.This article is based on a master's thesis prepared by the first author under the supervision of the second author.     

Contingency theory and the effect of the duration of signals for noncontingent reinforcement

Rats learned to approach a light that signaled food when food occurred only after the signal, but did not approach the light when food was equally probable regardless of the signal. When food unpaired with the light was preceded by a 5-sec noise, little learning was evident as well, but when the unpaired food was preceded by a 15-sec noise, approach to the light conditioned stimulus readily occurred. These effects of signal duration are similar to those previously obtained with the effect of free food on free-operant behavior and challenge existing theories of contingency effects in Pavlovian conditioning.     

Short-term memory for simultaneously presented visual and auditory signals in the pigeon

A series of divided-attention experiments in which matching to the visual or auditory component of a tone-light compound was compared with matching to visual or auditory elements as sample stimuli were carried out. In 0-s delayed and simultaneous matching procedures, pigeons were able to match visual signals equally well when presented alone or with a tone; tones were matched at a substantially lower level of accuracy when presented with light signals than when presented as elements. In further experiments, it was demonstrated that the interfering effect of a signal light on tone matching was not related to the signaling value of the light, and that the prior presentation of light proactively interfered with auditory delayed matching. These findings indicate a divided attention process in which auditory processing is strongly inhibited in the presence of visual signals.