Sparing of semantic memory in Alzheimer's disease.

A number of investigators have suggested that unlike the normal elderly population, patients with Alzheimer's disease have a severe semantic-memory deficit. However, the semantic-memory tasks used in previous studies have been confounded by the heavy demands they placed on effortful processing. In the present study, 20 demented (mean age 71 yrs) and 20 normal (mean age 69.8 yrs) elderly Ss were given a battery of episodic-memory tasks and 3 tasks that examined how intact and accessible their semantic memory was under conditions that did not require effortful processing. Although the demented Ss were greatly inferior to the normal Ss on the episodic-memory tests, they performed equally well on the semantic-memory test: The naming latency of both groups was equally facilitated by a semantic prime, the recall accuracy of both normal and demented elderly for a string of letters was similarly affected by the degree to which the string approximated English orthography, and recall accuracy for a string of words was affected equally in the 2 groups by the degree to which the word string obeyed syntactic and semantic rules. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Manipulation of avoidance behavior as a function of increased or decreased demand on repeated behavioral tests.

5 groups of 15 female undergraduates reporting fear of snakes participated in 2 behavioral avoidance tests employing a snake as the target object. 4 groups were first tested under low demand for approach and then under the same conditions or under 1 of 3 conditions of demand increase, mediated by instructions, mode of administration, or both. The 5th group was tested under high, then low demand. Ss first tested under low demand showed significantly more fear than those first tested under high demand. In addition, Ss in the demand-increase groups showed significant increases in approach at the 2nd behavior avoidance test, while Ss in the demand-decrease group showed a significant reduction in approach. Ss in the repeated-measure control group showed no significant changes. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relation between latency and redundancy-associated deficit in schizophrenic reaction time performance.

Evaluated the independence of 2 well-established measures of information-processing difficulties in process schizophrenics, namely, reaction time measures of latency and redundancy-associated deficit. Training exercises were designed to improve the speed of reaction time performance in 16 male Ss (average age 32.5 yrs). These exercises were successful in reducing latency over the course of training and from pre- to posttraining assessments to levels falling around the range of performance expected of normals. Redundancy-associated deficit, however, did not change from pre- to postassessment, indicating that this index is not a simple reflection of latency and is not responsive to training procedures involving positive motivation. Intercorrelations of the 2 indexes also showed that these measures were independent, at least within the process end of the schizophrenic spectrum. Furthermore, the 2 measures correlated with different types of S factors. Latency measures correlated with measures of chronicity, and the redundancy-deficit measure was correlated with prognosis. Findings help to clarify the utility of reaction time indexes as markers of various aspects of schizophrenic pathology. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Absolute judgment of colors in the Federal Standards System.

3 experiments were conducted to: (1) determine the number of Federal Standards colors which normal and deuteranopic Ss can identify absolutely under a variety of viewing conditions, and (2) identify optimum subsets of these colors for information coding under various operational circumstances. Results suggest that under optimal circumstances Ss can identify 24 Federal Standards colors, a number far in excess of most earlier estimates. Furthermore, careful selection can provide a 10-color subset identifiable under even marginal lighting conditions by normal Ss, and an 8-color subset identifiable even by deuteranopes. Discrepancies between these and earlier findings are explained primarily on the basis of insufficient color-label training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of biological and social motivation on schizophrenic reaction time.

Reaction times of schizophrenic and normal Ss were determined under instructions to respond as fast as possible to a buzzer signal. Half of the Ss were retested immediately under the same conditions, while the other half were shocked on the responding finger simultaneously with the buzzer. Schizophrenics' RTs improved significantly under shock conditions. Disturbances in schizophrenic RT are "partially accounted for by defective social motivation and… a biological deficit may be involved in the reactions of more chronic schizophrenics." 21 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in recognition memory and frequency judgments for planned versus performed activities.

24 young (18.25–27.92 yrs old) and 24 elderly (62.75–80.42 yrs old) adults received a series of tasks (e.g., card sorting, arithmetic) that were planned for performance and subsequently performed with varying frequencies under intentional- and incidental-memory conditions to investigate age differences in active memory. Following the series of tasks, Ss estimated the frequencies with which task activities had been both performed and planned. Recognition-memory scores derived from performance-judgment scores revealed a significant age deficit in Ss' identification of those activities that had been performed earlier. However, memory was unaffected by intentionality at each age level. Results imply a modest age deficit for encoding rehearsal-independent, episodic events, but no age differences were found for reality monitoring: Elderly Ss were as proficient as young Ss in discriminating between planning and performance of an activity in terms of absolute frequency-judgment scores. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anxiety, induced muscular tension, and the statistical structure of binary response sequences.

60 high school age boys generated binary response sequences under 2 conditions—with induced muscular tension and without tension. ? the Ss scored high on the Taylor Manifest Anxiety (MA) scale, ? the Ss scored low on the Taylor MA scale. Each response sequence was subjected to a sequential redundancy analysis. The results indicate that highly anxious Ss tend to generate more random sequences than nonanxious Ss in the nontension condition. Tension tends to decrease the randomness of the sequences of the high-anxiety Ss and has little effect on the sequences of the low-anxiety Ss. These results are taken to support the hypothesis that anxiety response variability in a situation in which the set of responses elicited is relatively equal in response strength. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Schizophrenic short-term memory: A deficit in subjective organization.

24 schizophrenic and 24 normal Ss received 3 trials on each of 2 lists of trigrams, 1 being for recognition and the other for recall. 1/2 of the Ss received special instructions for alphabetical ordering of the recall terms, while the other 1/2 was asked to do their best. Special instructions facilitated recall of normal Ss, but not of schizophrenics. Instructions had no significant effect upon the recognition scores. The effect of trials was to increase schizophrenic recall, but not recognition, while normals showed gains both in recall and recognition. It is concluded that the schizophrenic recall deficit results, in part, from an inability to subjectively organize memory store. (French summary) (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of a metacontrast and a paracontrast procedure to assess the visual information processing of hypothetically schizotypic college students.

Compared the metacontrast and paracontrast performance of 2 groups of hypothetically schizotypic college students with that of a psychiatric control group and normal control group. There were 12 undergraduate Ss in each group. Ss were defined by 2 sets of criteria: (1) the 2-7-8 Minnesota Multiphasic Personality Inventory (MMPI) profile and (2) the 8-9 MMPI profile. The quality of the short-term visual store (STVS) was evaluated through the use of a critical stimulus duration (CSD) procedure. Speed of information transfer from the STVS into short-term memory was assessed in the metacontrast condition. Schizotypics demonstrated impaired speed of information transfer in comparison with controls. However, as expected, no group differences in paracontrast effects were found. Ss in the 2-7-8 group (showing vulnerability to schizophrenia) evidenced a significant CSD deficit when compared with the other 3 groups. Results suggest that vulnerability to backward masking may be a trait marker of schizophrenia. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of social and nonsocial censure on stimulus generalization in neurotics and schizophrenics.

36 schizophrenic and 36 neurotic depressive Ss were given a visual-spatial generalization task under either social or nonsocial (impersonal) censure conditions. The following hypotheses derived from previous investigations were tested: (1) schizophrenics would show higher gradients of generalization than neurotic depressives, and (2) generalization gradients would be higher under conditions of social as opposed to nonsocial censure, especially in schizophrenics. The data supported Hypothesis 1 but not Hypothesis 2. There was no evidence for differential responding between these 2 groups with respect to either stimulus generalization or response to censure. It was suggested that hypotheses concerning the schizophrenic's performance in these 2 situations have been biased and oversimplified by use of normal, rather than patient, control groups in previous investigations. (22 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Olfactory regulation of maternal behavior in rats: I. Effects of olfactory bulb removal in experienced and inexperienced lactating and cycling females.

Used 57 Sprague-Dawley virgin female rats to study the effects of olfactory bulbectomy under various conditions. Bilateral bulbectomy induced either cannibalism or short latency maternal behavior in naive Ss. Following unilateral bulbectomy or 2-stage bilateral bulbectomy, short latency maternal behavior appeared but cannibalism did not. Pregnancy and parturition overcame cannibalism after bilateral bulbectomy in inexperienced Ss, but not in females exhibiting cannibalism as virgins. Experienced (2 days postpartum) bulbectomized Ss had shorter latencies for reinduction of maternal behavior than experienced intact Ss. Results suggest that olfactory bulbs have 2 functions in relation to maternal behavior: sensory (olfaction) and nonsensory. Female response to olfactory bulbectomy may be due to anosmia facilitating maternal behavior, or to removal of nonsensory influences resulting in cannibalism. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure of hippocampectomy to facilitate classical conditioning at an optimal interstimulus interval is not due to a "ceiling effect."

Examined the effects of amphetamine injection (2 mg/kg), hippocampal lesions, and cortical lesions in 30 naive New Zealand albino rabbits during classical conditioning of the rabbit nictitating membrane response. An optimal interstimulus interval (ISI) was employed. Whereas neocortical and hippocampal damage had no significant effect on the rate of acquisition, amphetamine treatment produced a marked facilitation. A control group of amphetamine-treated Ss receiving explicitly unpaired presentations of the conditioned stimulus/stimuli (CS) and unconditioned stimulus/stimuli (UCS) failed to exceed spontaneous response rates throughout training. The failure of hippocampectomy to accelerate conditioning under an optimal ISI does not appear to be due to a ceiling effect. Rather, it is suggested that the response system is predisposed to conditioned responses of a given latency. Optimal ISIs may fall within this range. Thus, in short or long intervals, temporal aspects of the motor response must be adjusted to conform to the stimulus configuration. It appears that the hippocampus is a likely source of response modulation. Thus, loss of hippocampal input accelerates conditioning under nonoptimal intervals at the expense of proper timing. Conditioning under an optimal interval would occur at normal rates because no modulation is required. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trance logic and cue structure as supplied by the hypnotist

Logically incongruous behavior was elicited in contexts that varied appreciably in the extent to which they cued Ss as to appropriate trance logic response. Independent sets of hypnotically responsive and unresponsive Ss were assigned to a real or simulating condition in application of the real-simulating model of hypnosis and tested under 1 of 2 cue conditions (high and low). These conditions either clearly communicated the hypnotist's intent regarding trance logic response (high cue) or did not (low cue). It was hypothesized that real and simulating Ss would be differentiated when optimal conditions for testing were maintained, that is, under the low-cue condition where intent was not communicated obviously. Data for 107 highly selected undergraduates challenge the validity of the double hallucination index as an adequate measure of trance logic but show high discriminative value for the transparency index. Detailed analysis of the behavior of both groups of Ss indicated distinctive properties of experience that highlighted the complex nature of hypnotic Ss' cognitive controls. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Collateral behaviors and the DRL deficit of rats with septal lesions.

Trained a total of 31 male Long-Evans hooded normal and septally-lesioned rats to lever press for food on a DRL 20-sec schedule in either a conventional operant chamber or 1 containing wood blocks and cardboard strips. The DRL behavior of normals trained in modified chambers was most efficient, and that of Ss with septal lesions trained in conventional chambers was least efficient. After 35 hr. of training, normals tested in conventional chambers and Ss with septal lesions tested in modified chambers did not differ significantly. Ss chewed the blocks and cardboard, and prevention of these collateral behaviors reduced DRL efficiency. Results show that colalteral behaviors facilitate the development of efficient DRL behavior and indicate that the DRL deficit of rats with septal lesions can be modified. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual closure in schizophrenia.

The concept of closure has been more frequently investigated using normal Ss than psychotic patients. The present study utilizes schizophrenics and compares their performance with a comparable group of hospitalized nonpsychotic Ss. Taylor's (1960) test of closure was used. Tendency to closure tended to be lower for the schizophrenics than for the nonschizophrenics, with schizophrenics on drugs (and, hence, manifesting a greater degree of personality disorganization than the other schizophrenic Ss) showing no tendency towards closure. The results are related to 2 theories of schizophrenia, one which involves a deficit in the energizing or arousal systems in the brain, and the other, an inability to maintain a set in the way normal Ss do. From Psyc Abstracts 36:04:4JQ31S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Focus of attention, chronic expectancy, and responses to a feared stimulus.

Tested an attentional model of fear-based behavior with 44 undergraduates. It was predicted that among Ss with moderate fear of snakes, heightened self-attention during an approach attempt would cause increased awareness of existing anxiety, followed by 1 of 2 courses of events: Ss who believed that they could do the behavior in spite of their fear were expected to redirect their attention to the behavior–goal comparison and exhibit no behavioral deficit. Ss who doubted their ability to do the behavior were expected to divert their attention from the behavior–goal comparison and to withdraw behaviorally from the approach attempt. Results support this reasoning and discussion centers on relationships between the proposed model and previous theory. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Within-subjects positive and negative contrast effects in rats.

Conducted 4 experiments, using a total of 47 Sprague-Dawley albino rats. Ss were given alternating 1-min access periods to 2 tubes containing either 32 or 4% sucrose solutions for daily 6-min test sessions. Lick rate for 32% was higher under comparison (32 vs 4) than noncomparison (32 vs 32) conditions; and lick rate for 4% was lower under comparison conditions (4 vs 32) than under noncomparison conditions (4 vs 4). All sucrose conditions were varied within Ss, and both positive and negative contrast were obtained with a small n. In addition to lick rate, intake and latency measures revealed contrast effects. Deprivation conditions altered latency but not lick rate measures of contrast. Reducing the test session to 3 min (alternating 30-sec access periods) did not greatly affect contrast. Additional experiments provided evidence for distinct within- and between-days contrast effects, as well as a between-groups contrast effect. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual sensitivity following inferotemporal and foveal prestriate lesions in the rhesus monkey.

Performed ablations of inferotemporal (2 Ss) and of foveal prestriate cortex (2 Ss) in rhesus monkeys, impairing their visual learning. In order to determine if a sensory loss was associated with either lesion, the detectability of a light flash under scoptopic conditions was measured with a signal-detection procedure with the monkeys and with 2 male undergraduates. Neither lesion produced a decrease in sensitivity, although both produced the usual visual-learning deficit. Sensitivity of the human Ss was well within the limits of unoperated animals. (27 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automaticity of word recognition under phonics and whole-word instruction.

38 undergraduates learned to read words spelled with novel letters under phonics or whole-word conditions. Training was carried through several overlearning trials, and vocalization latency of word recognition responses was measured. On initial overlearning trials, vocalizations of phonics Ss were faster than those of whole-word Ss. At no stage of overlearning were whole-word Ss faster than phonics Ss. Vocalization latencies declined as overlearning progressed at approximately equal rates for phonics and whole-word Ss but did not reach fully automated speeds. Correlations of vocalization latencies from overlearning trials and a baseline task indicated that whole-word instruction resulted in word recognition mechanisms similar to fully automated mechanisms but that phonics instruction did not. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suppressive and enhancing effects of footshock on food-reinforced operant responding following septal lesions in rats.

Measured effect of septal lesions on suppression of an intermittently food-reinforced lever press by contingent and noncontingent footshock, using a total of 48 experimentally naive male hooded Lister rats in 2 experiments. Ss with septal damage maintained higher response rates than did intact Ss under both contingent and noncontingent shock. Furthermore, the difference in suppression produced by the contingent and noncontingent conditions was approximately the same for the experimental Ss and controls. In Exp II performance was measured during counter-conditioning in which the correlation between contingent shock and positive reinforcement was varied. Ss with septal lesions responded at higher rates than did controls. When only reinforced responses were punished, this lesion-induced elevation represented an increase above baseline performance without punishment. This finding suggests that the effect of septal damage on appetitive instrumental performance cannot be due solely to a deficit in response inhibition. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)