Word association responses in normal adult subjects

A word association test was administered to a group of 316 undergraduate students. Word stimuli were balanced according to frequency of occurrence in written English language usage (frequent, infrequent), word length (short, long), abstraction level (low, medium, high), and grammatical class (noun, verb, adjective). Responses were analyzed according to a syntactic classification system. The factorial nature of the word list used enhances its value as a research tool.The authors wish to thank Professor Louis J. Gerstman, Department of Psychology, City College of CUNY, New York, for his assistance in preparing the statistical data in this study.     

The stability and control of conditioned noise aversion in the tilt cage

Twenty-six rats were used to study the development of stable conditioned responding to terminate white noise (100 or 105 db) in a tilt cage apparatus. Preliminary work, with one end of the cage consistently associated with silence, demonstrated stability at a high level of cumulative noise-off time per session. Time spent at the noise-off cage end was unaffected by lay-off and showed adaptation to reversal of the cage end functions. Variability in reversal acquisition, insensitivity to stimulus intensity changes and persistence in remaining at one end of the cage in the absence of noise-termination contingencies indicated the need for more precise behavioral control. A schedule programming several reversals of the no-noise end at variable intervals within each session was developed. Performance on the latter schedule was characterized by stability of high noise-off times and also proved more sensitive than the preliminary method to stimulus intensity changes (55, 70, 100 db) as measured by both cumulated noise-off time and cage crossing rates. The ease of training combined with sensitivity to stimulus change and the lack of highly specific motor response requirements make this technique promising for use with animals potentially debilitated by drugs or surgical after-effects.     

Melody recognition at fast and slow tempos: effects of age, experience, and familiarity

Eighty-one listeners defined by three age ranges (18-30, 31-59, and over 60 years) and three levels of musical experience performed an immediate recognition task requiring the detection of alterations in melodies. On each trial, a brief melody was presented, followed 5 sec later by a test stimulus that either was identical to the target or had two pitches changed, for a same-different judgment. Each melody pair was presented at 0.6 note/sec, 3.0 notes/sec, or 6.0 notes/sec. Performance was better with familiar melodies than with unfamiliar melodies. Overall performance declined slightly with age and improved substantially with increasing experience, in agreement with earlier results in an identification task. Tempo affected performance on familiar tunes (moderate was best), but not on unfamiliar tunes. We discuss these results in terms of theories of dynamic attending, cognitive slowing, and working memory in aging.     

Musical expertise has minimal impact on dual task performance

Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.     

Too much to count on: impaired very small numbers in corticobasal degeneration

Patients with corticobasal degeneration (CBD) have calculation impairments. This study examined whether impaired number knowledge depends on verbal mediation. We focused particularly on knowledge of very small numbers, where there is a precise relationship between a cardinality and its number concept, but little hypothesized role for verbal mediation. We evaluated accuracy and reaction time (RT) for matching dot arrays and Arabic numerals involving smaller (2-4) and larger (5-9) cardinalities in non-aphasic patients with CBD (n=16), frontotemporal dementia (FTD; n=23), and healthy controls (n=15). CBD were less accurate and slowed at judging smaller Arabic numeral-dot array stimuli compared to FTD patients and controls. Moreover, only CBD showed longer RTs judging successively larger number-dot array pairs among the smaller cardinalities. Difficulty judging very small numbers is impaired in CBD, suggesting degraded representation of precise number knowledge that does not depend on language functioning.     

Young handicapped children and their families: Patterns of interaction with human service institutions

The experiences of nine young handicapped children and their families with a variety of human service institutions are discussed. A retrospective account is presented from the parents' perspective of those aspects of their and their children's experience that have had a significant impact on their quality of life. Central among these experiences has been the interpersonal interaction with professionals. The parents' reported experiences regarding identification, the search for assistance, assessment, and their children's receipt of services suggest that there are problems in the areas of locating and acquiring an appropriate combination of services to meet family needs and in the quality of interpersonal relationships between parents and professionals. Recommendations are made to alleviate these and other problems.     

Word-association responses to time-altered stimuli by schizophrenic adults

This research addressed the relationship between the speed of presentation of stimuli through the auditory and visual modalities and the number of syntagmatic and paradigmatic word-association responses of 49 chronic undifferentiated schizophrenic adults. In word-association tests administered to subjects stimuli were balanced for frequency of occurrence in written English language (frequent, infrequent), word length (long, short), abstraction level (low, medium, high), and part of speech (noun, verb, adjective). The words were presented auditorily at normal speed (equivalent to 10 phonemes per second) and at half speed (equivalent to 5 phonemes per second) speech. Words were also presented visually, using a tachistoscope, at extended fixation speed (equivalent to 1,000 msec.) and at sweep speed (equivalent to 10 msec.). More paradigmatic responses occurred on word stimuli if nouns, long, and frequently occurring presented auditorily; and if concrete, nouns, and presented slowly and visually. Results were compared to previously reported data for aphasic and normal adults, and differentiating features and clinical implications were discussed.     

Taken by surprise: The paradox of the surprise test revisited

A teacher announced to his pupils that on exactly one of the days of the following school week (Monday through Friday) he would give them a test. But it would be a surprise test; on the evening before the test they would not know that the test would take place the next day. One of the brighter students in the class then argued that the teacher could never give them the test. It can't be Friday, she said, since in that case we'll expect it on Thurday evening. But then it can't be Thursday, since having already eliminated Friday we'll know Wednesday evening that it has to be Thursday. And by similar reasoning we can also eliminate Wednesday, Tuesday, and Monday. So there can't be a test!The students were somewhat baffled by the situation. The teacher was well-known to be truthful, so if he said there would be a test, then it was safe to assume that there would be one. On the other hand, he also said that the test would be a surprise. But it seemed that whenever he gave the test, it wouldn't be a surprise.Well, the teacher gave the test on Tuesday, and, sure enough, the students were surprised.