Selective attention to words and colours

In the Stroop test it is found that the presence of words interferes with the task of naming colours. The usual account of this phenomenon is that the names of words are more readily obtained than are the names of colours and that the production of the latter is interfered with by the spontaneous occurrence of the former. Treisman and Fearnley (1969) have suggested a modification of the usual account such that stress is laid on the correspondence between the nature of the response (“verbal”) and that feature of a stimulus which will dominate. The present experiments seem to demonstrate that the data which Treisman and Fearnley use in support of their claim can be attributed to the strategy which their subjects adopted in their task. Some further observations are made concerning the different levels at which comparisons can be made between two stimuli.     

Two mechanisms in the stimulus suffix effect

The stimulus suffix is a redundant item presented immediately after a stimulus list. Its effect is the selective impairment of recall of the final items in a serially recalled, auditorily presented list of unconnected items. Two experiments indicate that there was no difference between the effects of suffixes .5 and 1.0 sec after the end of a digit list presented at a rate of one digit/sec. This suggests that the effect of the suffix, in this case the vowel sound "ah," is not a simple function of its time of arrival after the final digit, as has been thought. The possibility of more complex factors was supported in a further experiment which showed a slight reduction in the size of the suffix effect by repeating the suffix three times.     

Further findings on assaultiveness and alcohol use in interpersonal disputes

In a previous study uniform observational data were collected regarding family disputes managed by police officers; those data contradicted views commonly held by social scientists and by police about the roles of assaultiveness and alcohol use in these events. In the present study police officers employed systematic naturalistic observation during their interventions as third parties in disputes between nonfamily members as well as those between family members. Tentative conclusions about assaultiveness, based on the data of both studies, are that it: does not usually precede the arrival of police in such disputes; is associated with interpersonal closeness of the disputants; is associated with poverty rather than race; and is as likely in a middle-class small city as in a poor inner-city area. Tentative conclusions about the use of alcohol in police-managed interpersonal disputes are: that these disputes are not usually influenced by alcohol use; and that assaultiveness is not related to alcohol use in such disputes.     

General systems theory: Practical and theoretical implications for group intervention

General systems theory (GST) principles have particular relevance for the practice of group psychotherapy. The present paper involves an integration of the abstract conceptual principles of GST with more practical issues in the fields of group dynamics and group psychotherapy. The specific focus is upon a hierarchical array of boundary subsystems having object relations characteristics, any one of which may become the target system for the leader's group intervention.     

Aspects of suicidal behavior, depression, and treatment in college students: results from the spring 2000 national college health assessment survey

The National College Health Assessment Survey (NCHA), sponsored by the American College Health Association, measured depression, suicidal ideation, and suicide attempts among 15,977 college students in the academic year 1999-2000. Similar to the National College Health Risk Behavior Survey, conducted by the Centers for Disease Control and Prevention in 1995, 9.5% of students reported that they had seriously considered attempting suicide and 1.5% of students reported that they had attempted suicide within the last school year. The NCHA findings show a relationship between suicidal behavior and depressed mood. Depressed mood, difficulties of sexual identity, and problematic relationships all increase the likelihood of vulnerability to suicidal behavior. Less than 20% of students reporting suicidal ideation or attempts were receiving treatment.     

Blind children recognizing tactile pictures respond like sighted children given guidance in exploration

Theory of tactile pictures argues that untrained blind subjects can recognize raised, outline pictures. It contends the blind person’s knowledge of the shapes of common objects is like that of the sighted, and the blind person’s pictorial abilities use the same principles as the sighted person’s. To test this theory, blind children (aged 8–13) and blindfolded age-matched sighted children were asked to identify raised-line drawings of common objects. Their performances were correlated. In addition, the blind children identified more than sighted children exploring the pictures actively, but the same number of pictures as sighted children who were given passive, guided exploration. We argue blind and sighted children use the same principles to identify the pictures, but the blind have superior exploration skills. The differences in the effects of exploration skills on recognition scores are minimized when the sighted children are given guidance, since the sighted children then have efficient contact with the displays, and the performance of the sighted and the blind is then governed by the same principles, without one group benefitting from advantages in exploration skills.     

Comparisons of some learning models for response bias in signal detection

The effects of variations in signal probability and varying degrees of correct feedback on response bias were studied in a yes-no auditory signal detection task. The main finding was that the bias towards saying yes was an increasing function of the frequency of signal feedback events, but did not depend on the correctness of the feedback. Several learning models coupled with a simple psychophysical and decision model yielded predictions about overall biases and certain sequential statistics. Only one model, which can be decribed as an “informational” model, gave a good account of both observed overall biases and sequential statistics. This model assumes the observer’s response bias is strengthened for the feedback-reinforced response when the observer’s sensory information is ambiguous or is contradicted by the feedback information.     

Stimulus aspects of aversive controls: stimulus generalization of conditioned suppression following discrimination training

A tone ending with unavoidable electrical shock was periodically presented to pigeons while they pecked a key for food. A second group of birds was exposed to these tone-shock contingencies and also to a second tone which never ended with shock. The gradient of stimulus generalization following training to a single stimulus was symmetrical, whereas the gradient following discrimination training was asymmetrical, but there was no evidence of peak shift. During testing, suppression to all tones gradually extinguished and in both groups the slope of the gradient increased markedly. A second experiment with the discrimination birds revealed that free shock caused a recovery of the gradient, but the asymmetry persisted.     

LESS SKILLED READERS HAVE LESS EFFICIENT SUPPRESSION MECHANISMS

Abstract— One approach to understanding the component processes and mechanisms underlying adult reading skill is to compare the performance of more skilled and less skilled readers on laboratory experiments. The results of some recent experiments employing this approach demonstrate that less skilled adult readers suppress less efficiently the inappropriate meanings of ambiguous words (e.g., the playing card vs. garden tool meanings of subject the incorrect forms of homophones (e.g., patients vs . patience), the typical-but-absent members of scenes (e.g., a tractor in a farm scene), and words superimposed on pictures. Less skilled readers are not less efficient in activating contextually appropriate information; in fact, they activate contextually appropriate information more strongly than more skilled readers do. Therefore, one conclusion that can be drawn from these experiments is that less skilled adult readers suffer from less efficient suppression mechanisms.     

Influence of visual guidance on braille recognition: Low lighting also helps touch

This study was an attempt to clarify the mechanisms responsible for the benefits of visual guidance in tactual braille recognition. Subjects touched +90° tilted braille under normal room lighting, or with low lighting, with or without visual guidance. Both visual information about finger angle and spatial reference information were manipulated with stained glass and light-emitting diodes. The provision of visual information about finger angle alone was no help to braille recognition, and performance was low. Adding visual spatial reference information to vision of finger angle raised performance. However, recognition accuracy was also substantially improved by low lighting. The benefits of darkness for haptics did not generalize to the reading of upright, two-letter braille words. It was proposed that extraneous visual information may distract sighted subjects in haptic tasks that require mental rotation of visual images.