Effects of variations in the preparatory interval on the reaction time of retardates and normals.

Conducted 2 studies to evaluate the effects, on simple RTs, of warning signal duration (WSD) and preparatory interval (PI) with normal and mentally retarded Ss. In Exp. I PIs of 2, 4, 8, and 12 sec. were presented in an unpredictable sequence. For 1/2 of the Ss the warning signal remained on throughout the entire PI (filled condition) and for the remainder of the Ss, the warning signal was present for only 1.5 sec. of the PI. Significant effects of intelligence, PI, and WSD were found. The interaction Intelligence * PI was also significant. The unfilled condition resulted from produced faster RTs for both normals and retardates. The interaction resulted from the particularly poor performance of the retardates at the short PIs. Exp. II employed a 1.5 sec WSD with PIs of 2, 4, 8, 16, and 32 sec. An interaction was found involving intelligence and PI. Results are discussed in terms of temporal uncertainty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of IQ and mental age on hypothesis behavior in normal and retarded children.

156 mental-age-matched normal and retarded Ss at mental-age (MA) levels of 5.5, 7.5, and 9.5 yrs received blank-trial discrimination problems designed to expose hypothesis behavior. There was evidence that Ss at all MA levels used hypotheses. Use of feedback indicating that a response was wrong increased significantly with MA, while use of feedback indicating that a response was right increased significantly with IQ. On simple problems involving 2 stimulus dimensions, retarded and normal groups used about equal numbers of hypotheses, but on 4-dimensional problems the retarded used fewer hypotheses than normals. It is suggested that this IQ Level * Problem Complexity interaction may explain contradictions among previous findings regarding IQ effects on learning. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental changes in concept utilization among normal and retarded children.

Examined the concepts employed by 100 normal children in kindergarten-Grade 4 (Study 1), and by 48 retarded vs 48 normal children matched for mental ages ranging from 5 to 11 yrs (Study 2). Ss were required to select pairs of pictures from a large array of pictures depicting common objects and to explain the basis for their pairing responses. Factor analysis of the conceptual responses of normal Ss revealed factors for abstraction (nominal and functional concepts as opposed to perceptible concepts) and complimentarity ("go together" responses as opposed to similarity responses). Retarded Ss differed from normals primarily in their use of more complimentary and fewer similarity concepts. The developmental course of concept utilization for normals was characterized as a change from perceptible to nominal and functional concepts, while that for retarded Ss was characterized as a change from complimentary to similarity concepts. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of external cues on the thinking behavior of obese and normal subjects.

Hypothesized that the thinking behavior of obese Ss is externally controlled to a greater extent than that of normals. 36 normal weight and 36 obese male undergraduates served as Ss. It was predicted that obese Ss would spend more time than normals thinking about an assigned topic of thought if there were topic-relevant external cues available, and less time than normals if there were no topic-relevant external cues available. With thinking measured directly by self-report and indirectly by distraction from pain, these predictions were confirmed. It is concluded that differences in eating behavior between obese and normal Ss can be explained by differences in thinking behavior. Therapeutic implications of the cognitive style of the obese are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distractibility in the conceptual performance of schizophrenics.

This study explores the role of interfering factors in the conceptual performance of schizophrenics. 40 schizophrenic patients at the Downey Hospital and 25 normals were used as Ss. They were required to sort cards containing 4 figures with 3 four-figured standard cards. One figure on each standard card was arbitrarily designated as correct for sorting. More of the schizophrenics than the normals used the incorrect "distracter" as a basis for sorting, even when conceptual sorting was required. The results support the hypothesis that schizophrenics fail conceptual tests because response to distracters prevents the demonstration of his concept-forming ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive controls and mental retardation.

Devised a color-digit interference task and 2 sorting tasks as variants of the Stroop Color-Word Test and R. Gardner, et al. (see record 1961-02266-001) sorting tasks, respectively. These tasks proved applicable to a mentally retarded sample (n = 39) and provided reliable measures of 2 cognitive control dimensions (constricted-flexible control and equivalence range). As predicted, the main test scores were significantly more variable in retarded Ss than in normals (n = 32). Analyses of performance on the color-digit interference task indicated that retarded Ss were significantly slower than the normals on all parts of the task, particularly under conditions of distraction (whether inherent in the task or externally imposed). Low IQ retarded Ss were significantly slower than high IQ retarded Ss on all parts of the task. The extreme cognitive control test scores of the retarded Ss, the nature of the attentional deficit among these Ss, and the relevance of a cognitive control approach for the training of retarded persons are discussed. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Abstract thinking and social behavior in schizophrenia.

20 normal and 24 schizophrenic Ss were presented a series of cards, each bearing a stimulus word and 2 response words variously related in meaning to the stimulus. The Ss were asked to select the response word which they felt to be "closer in meaning" to the stimulus word. The results confirmed, at the .01 level, the hypotheses that (a) normals will exceed schizophrenics in the ability to select, as most similar in meaning to a given word, that word which is related to it in an essential abstract way; and (b) within a schizophrenic group, the above ability will be positively correlated with adequacy of everyday social interaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cue and response-choice acquisition and reversal after exposure to uncontrollable shock: Induction of response perseveration.

Evaluated the effects of inescapable shock in shock-motivated cue, response-choice (RC), and RC/positional Y-maze discrimination tasks. Ss were 253 male CD-1 mice. In the RC paradigm, Ss were required to turn in a predetermined direction to escape, whereas in the RC/positional task, Ss were required to enter the arm to the right of the start arm on any given trial. Although inescapable shock retarded escape performance, this was dependent on task difficulty and on the compatibility between response tendencies and the response requirement of the task. Irrespective of the task, exposure to inescapable shock did not influence accuracy of discrimination responding (acquisition or performance of a previously established discrimination). Likewise, discrimination reversal performance was unaffected by inescapable shock in either the cue or the RC paradigm. In contrast, acquisition of the RC/positional reversal was retarded by inescapable but not escapable shock. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of praise and censure on the performance of schizophrenics.

Ss were 36 normals, 36 good, and 36 poor premorbid schizophrenics. Poor premorbids were shown to be primarily motivated to avoid censure and good premorbids to be relatively more sensitive to praise. It was demonstrated that when censure was used on a task with only 2 possible responses, poor premorbids performed better than good premorbids. The opposite relationship was demonstrated for the effects of praise, to which the good premorbids were more responsive. On a task with many responses, the praise or censure gave little information as to the correct response. On this task, censure was demonstrated to be relatively more disruptive to the poor premorbids than praise, but the opposite held for the good premorbids. Comparisons with neutral conditions and normal Ss were also made. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of psychological content in the communications of suicidal individuals.

Tested and supported the general hypothesis that the psychological content of communications of Ss who commit suicide differs from that of nonsuicidal normal Ss. A comparison was also made of 31 suicide-threatening outpatients with 40 suicide committers and 40 nonsuicidal normals. Ss were American-born, white, adult males matched for age and occupational level. The content of communications of suicide committers (suicide note) reflected heightened dependency needs, difficulty maintaining interpersonal relationships, a high degree of activity, and an expressive style of veiled aggression which includes hurting the self in order to hurt and manipulate others. Suicide threateners were predictably in some ways like suicide committers and in certain other ways more like nonsuicidal normals. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time estimation in process-reactive schizophrenia.

Process and reactive schizophrenics, and reactive schizophrenics and normals were compared as to their responses on a perceptual time-estimation task. Null hypotheses being tested were that groups would not differ in variability or accuracy of response. Schizophrenic (45) and normal (15) subjects were selected from the male patient population and hospital employees, respectively, of a Veteran's Administration hospital. Schizophrenics selected for the study were classified by means of the Abbreviated Becker Elgin Scale. Subjects were individually administered a time-estimation task consisting of seven stimulus cards which were tachistoscopically presented, with exposure speeds at 10, 20, and 30 seconds for each card. Judgments of exposure times were converted into scores based upon ratios of estimated time to actual time. Scores (three) for each card were totaled. Groups were then compared on each of the stimulus cards by means of two-tailed t tests. In accuracy of estimation, process schizophrenics demonstrated significantly less accuracy than did reactives on four of the seven cards; no differences were shown between reactives and normals in accuracy of estimation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies in efficiency: Semantic generalization in schizophrenia.

This study examined the hypothesis that schizophrenics would generalize a conditioned GSR response relatively more to the homonym of a CS and relatively less to the synonym than normals. The specific prediction was that the difference in the magnitude of response to synonyms and homonyms (RS - RH) would be greater for normals than for schizophrenics. The Ss were 16 normals and 16 chronic schizophrenics. The synonyms elicited a larger response than the homonyms with the majority of normal Ss. The opposite results were obtained with the schizophrenics. An analysis of variance clearly supported the hypothesized interaction between the "normal-schizophrenic" variable and generalization to synonyms and homonyms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Latent inhibition and stimulus generalization of the classically conditioned nictitating membrane response in rabbits (Oryctolagus cuniculus) following hippocampal ablation.

30 male and female New Zealand albino rabbits received 0 to 450 exposures of a tone CS prior to classical defensive conditioning of the nictitating membrane response based on an infraorbital eye shock UCS. Tone preexposure resulted in retarded conditioning in normal Ss, but was not present in Ss with bilateral dorsal hippocampectomy produced by aspiration. Controls with bilateral neocortical and callosal aspiration lesions demonstrated a latent inhibition effect similar to that shown by normal nonoperated Ss. The failure of CS preexposure to retard conditioning in hippocampal Ss was not due to differences in threshold of the conditioned response to the CS or to differences in response mechanisms as determined by tests of habituation and dishabituation of the UCR. A subsequent experiment with 24 Ss used combined-cue summation tests to confirm the fact that preexposure did not endow the tone with conditioned as well as latent inhibitory properties. Finally, tests of stimulus generalization along the auditory frequency dimension indicated flatter relative gradients for hippocampals than for nonoperated controls, with cortical controls in between. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Redundancy deficit in the reaction time of normal subjects under standard and meprobamate-impaired conditions.

Assessed latency and redundancy deficit, which reliably show impairment in process schizophrenics, using 20 normal Ss (mean age 30.4 yrs) with no psychiatric history. Ss were tested under standard/optimal and drug-impaired conditions to evaluate whether an expected increase in latency would be accompanied by a correlated increase in redundancy deficit. Ss completed RT trials in which they depressed and released a key in response to slides and a buzzer. Meprobamate was administered for the 2nd series of trials. In other research, the redundancy deficit index has been found to be independent of latency and has shown promise as a marker of schizophrenic information processing difficulty. The present findings confirm the independence of these 2 markers in that no increased redundancy deficit was observed despite a significant increase in latency. Findings also reveal a greater degree of redundancy deficit in normals under the optimal conditions than had been expected. A methodological problem with trial arrangements is discussed, and a review of studies that tested redundancy deficit in normal Ss is presented. (French abstract) (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrusion of associative responses into schizophrenic conceptual performance.

One normal and one schizophrenic group, each consisting of 32 adult males, were required to sort cards bearing the name of a common object with 3 guide-card words—one sharing a concept with the sorting-card word, one with an associate connection to it, and one which was irrelevant. The schizophrenics were expected to make more associative errors than the normals. The results indicated that both difficulty in forming concepts and susceptibility to associative distraction are in part responsible for the fact that schizophrenics show more associative intrusions than do normals. 23 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sucrose preferences of hungry and thirsty rats as a function of duration of stimulus presentation.

Studied sucrose preference in 3 experiments with 6, 12, and 12 male Holtzman albino rats. With progressively shorter intervals of repeated stimulus presentation (continuous down to 10 sec/min) in 2-choice brief exposure tests, thirsty Ss dropped from 90-50% preference for 6 or 12% sucrose over water, and showed little preference for 12 over 6%. Hungry Ss maintained a 90% preference for sucrose over water at all intervals but showed a decrement for 12 over 6% sucrose. For thirsty Ss (a) sucrose preference was a joint function of amount of exposure time and time between exposures, and (b) presentation order of different exposure durations was important. Results are discussed in terms of approach "arousal" and "decay" as a function of concentration and type of deprivation. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of task complexity and practice on performance after loss of sleep.

An experiment was conducted to assess the effects of degrees of task complexity and practice on performance after loss of sleep. The Ss were automatically presented every 7 sec. for 23 min., with cards containing 6 symbols. A symbol had to be chosen on the basis of certain rules. Some cards required 1 rule, some 2, some 3, and some 4. Group 1 was practiced after normal sleep and tested after 22 and 46 hr. without sleep. Group 2 was tested without sleep and without previous practice. Group 3 was practiced and tested after normal sleep. Loss of sleep had a greater effect after practice, but no clear differences emerged between the different levels of task complexity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of perceived competence, motivational orientation, and anxiety in segregated and mainstreamed educable mentally retarded children.

Examined whether instruments designed to tap the self-system in normal IQ children could be used with retarded pupils. The Perceived Competence Scale for Children and scales assessing intrinsic vs extrinsic orientation in the classroom and school concerns were administered to 90 retarded children mainstreamed for socialization or academic purposes and to 36 retarded children who were taught in self-contained classrooms. All Ss were aged 9–12 yrs. For each measure, the 4- or 5-factor structure found for normal-IQ children was not obtained. However 2-factor solutions were revealed, leading to the identification of 6 constructs: General Competence, Popularity, Motivation for Hard Work, Autonomous Judgment, Concern About Evaluation, and Concern About Teacher Support. The failure to find differences between mainstreamed and self-contained Ss was related to the social comparison groups used. Mainstreamed Ss compared themselves with other mainstreamed retarded pupils, whereas self-contained Ss used other self-contained pupils as their comparison group. Findings highlight the need to revise instruments for use with the retarded and to obtain social comparison information. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reaction time in schizophrenic and normal subjects in relation to the sequence of series of regular preparatory intervals.

Earlier research (Huston et al, 1937) emphasized the inability of schizophrenic Ss, in comparison to normals, to maintain a given set over an extended period of time; this, again, was the focus of the present investigation. Reaction times in 7 schizophrenic and 11 nonschizophrenic Ss were reviewed in the context of situations which required varying amounts of preresponse times. The results confirm the unfavorable effect on the performance of schizophrenic Ss in situations requiring prolonged maintenance of a response set. Results are related to a psychophysical interpretation of schizophrenia. From Psyc Abstracts 36:04:4JQ61Z. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive factors in differential conditioning of the GSR: Use of a reaction time task as the UCS with normals and schizophrenics.

22 normals and 22 schizophrenics underwent differential conditioning of the GSR, using 8-sec tones of differing frequencies as the CSs, an 8-sec CS-UCS interval, and a UCS comprised of an RT task signaled by a low-intensity light. Both intertrial reports and postconditioning interviews were obtained. 12 Ss in the normal group verbalized the CS relations accurately, compared to 3 Ss in the schizophrenic group. The normal group showed significant GSR differentiation, though conditioning was limited to the group of accurately verbalizing Ss. No evidence for conditioning was obtained in the schizophrenic group. Normal Ss had faster RTs than schizophrenic Ss. The RT of accurately verbalizing normals was shorter than that of inaccurately verbalizing normals, and the degree of GSR differentiation was significantly correlated with RT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)