A second testing of paranoid schizophrenics on a dichotic listening task

Data from 15 adult institutionalized Ss tested twice over a 1-yr period show a slight deterioration in organizational abilities for short-term memory task performance over the succeeding times of measurement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of paranoid schizophrenics on a dichotic listening task.

Used 15 adult normals and 15 institutionalized paranoid schizophrenics in a dichotic listening task within a 2 (Groups) * 2 (Associated or Unassociated Word List) * 2 (Presentation Rate) design, with repeated measures on the last 2 variables. Presentation rates were either 1 or 3 sec. Dependent variables were word recall, intrusion errors, and strategy use and accuracy. Normals recalled significantly more information than paranoid schizophrenics under all memory conditions and had significantly fewer total intrusion errors. For both groups, information recall was significantly better under the associative conditions (particularly associative structure, 3-sec presentation rate). Under the varying structure conditions, paranoid schizophrenics did not employ optimal strategies with the same frequency or degree of accuracy as normals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensation seeking and selective attention: Focused and divided attention on a dichotic listening task.

Differences in selective attention as a function of sensation seeking, extraversion, neuroticism, and psychoticism were examined in 108 undergraduates using a dichotic listening task. Dependent measures included shadowing performance, reaction time (RT) to a secondary light task, target detection, and recall. Results suggested that high sensation seekers have better focused attentions than low sensation seekers, and these effects were strongest on the 1st trials of the shadowing tasks. Higher sensation seekers did not attend differently than low sensation seekers to words related to their interests (sexual, violent, or drug related). Extraversion was associated with greater recall of these kinds of words, although there were no overall differences in selective attention as a function of Eysenck's dimensions. The role of arousal in personality and attention is discussed, particularly in regard to the response of sensation seekers to task novelty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification of emotion in a dichotic listening task: event-related brain potential and behavioral findings

The lateralization of emotion perception has been examined using stimuli in both auditory and visual modalities. Studies using dichotic stimuli have generally supported the hypothesis of right-hemisphere dominance for emotion perception, whereas studies of facial and verbal emotion perception have provided evidence for the right-hemisphere and valence hypotheses. A dichotic target detection task was developed to enable acquisition of event-related potentials (ERP) from subjects engaged in emotion detection. Nonsense syllables (e.g., ba, pa) stated in seven different emotional intonations were dichotically presented to 24 young adults, in a target detection task during four separate blocks (target emotions: happiness, interest, anger, or sadness). Accuracy and reaction time and ERP measures were also collected. ERPs were recorded from 14 scalp electrodes with a nose reference and quantified for N100, sustained negativity, late positivity, and slow wave. Significantly greater left- than right-ear accuracy was obtained for the identification of target prosodic emotion. Hemispheric asymmetries of N100 and sustained negativity were found, with left-hemisphere amplitudes greater than right-hemisphere amplitudes. These ERP asymmetries were not significantly correlated with the left-ear dichotic advantage and may be related more to early phonetic processing than to emotion perception. Since the behavioral evidence supports the right-hemisphere hypothesis for emotion perception, behavioral and ERP asymmetries evident in this task reflect separable patterns of brain lateralization.     

The effects of handedness, family history and sex on the performance of a dichotic listening task

The action of some drugs on the eye may lead to the occurrence of unforeseen ocular and extraocular reactions. Vincaleukoblastin (Velbe) provokes serious corneal lesions with a healing time of two weeks and a half. The local application of Neo-Synephrine eye drops (10%) and Mydrial-Atropine ointment may lead in the case of a pharmacogenetic disposition to disagreeable systemic effects. In one case of preparation for a cataract operation by akinesis and retrobulbar injection, Novocain was changed by mistake with Pilocarpinum hydrochloricum by the error of a pharmaceutical firm. This led to severe complications, which could by successfully treated with Chlorpromazine (Largactil). The knowledge of these clinical observations may be of greater usefulness in the preventation of untoward drug reactions.     

The effects of method of recall on performance in the dichotic listening task.

Reports 2 experiments with 100 undergraduates in which Ss were required to recall dichotically presented digits (3/1/2-span) either vocally or in writing. It was found that items in the 1/2-span reported 2nd were recalled significantly more accurately with written as compared with vocal recall. Data suggest that the differential accuracy of recall of the items in the 2 1/2-spans, which is normally reported, is attributable, partially at least, to interference at output produced by the vocalization of items in the 1st 1/2-span. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lateralization of receptive language in preschoolers: Test–retest reliability in a dichotic listening task.

On 2 occasions dichotic digit tapes were presented to 29 right-handed children (aged 33–65 mo). Results indicate that the dichotic listening tasks yielded measures with sufficient test–retest stability to permit reliable group comparisons, but that such indices may differ in terms of their contamination by sample-specific distributions of ability levels. It is suggested that conclusions not be drawn from such measures unless different indices of laterality show converging results and that when groups are compared, investigators include tabulations of both the difference and accuracy scores in their results. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing capacity and switching attention in dichotic listening.

Describes 4 experiments with 82 undergraduates which indicate that (a) switching attention in a dichotic listening task requires processing capacity, and (b) increasing encoding difficulty reduces the amount of switching in a free recall dichotic listening task. Results are discussed in terms of a limited capacity processor model which contends that switching attention, encoding, and sustaining material all require processing capacity and that the S's strategy regarding switching attention is determined by the capacity available after capacity requirements for encoding are met. (French summary) (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychopathy and perceptual asymmetry during verbal dichotic listening.

Administered a verbal dichotic listening (divided attention) task to 146 male prison inmates (mean age 30 yrs) and 159 male noncriminals (mean age 27.5 yrs). The inmates were divided into psychopathic (P), nonpsychopathic (NP), and mixed (M) groups on the basis of a psychopathy checklist and the DSM-III criteria for antisocial personality disorder. Group P exhibited a significantly smaller right-ear advantage (less lateralized performance) than did either Group NP or the noncriminals. When the task was administered to 48 inmates under instructions to focus attention on 1 ear at a time, the performance of Group P was again less lateralized than was that of Group NP. The possibility that language processes are not strongly lateralized in psychopaths and that psychopaths are characterized by asymmetric low left-hemisphere arousal is discussed. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrieval tags and order of report in dichotic listening.

To explain the effects of varying the rate of presentation on order of report in dichotic listening, a retrieval tag model must consider 2 kinds of tag, side and temporal position, and must include a mechanism sensitive to the rate manipulation to alter the relative usefulness of the 2 tags. 2 absolute judgment experiments with undergraduates (N = 32) yielded no evidence that the relative usefulness of the tags is altered passively by a rate manipulation. Results are interpreted as evidence against a model which considers only retrieval operations, and an alternate model encorporating both attention operations and retrieval operations is suggested. (French summary) (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endogenous and exogenous control of attention in dichotic listening.

Dichotic listening to verbal stimuli results in a right ear advantage (REA), indicating a left hemisphere processing superiority. The magnitude of the REA can be modulated by instructions to direct attention to the left or right ear stimulus. A previous study from our laboratory showed that presenting a prime syllable before the presentation of the dichotic syllables increases reports of the nonprimed syllable, apparently a negative priming effect that inhibits attention to the distracting prime representation. The present study combined attention instruction and priming, making up a 3 × 3 factorial design. The prime stimulus was a single consonant-vowel syllable presented binaurally just before onset of the dichotic consonant-vowel syllables. Results showed that both instructions and priming manipulations had an effect on which dichotic stimulus was selected. There was also a significant interaction between attention instruction and priming manipulation, indicating that the mechanism for instructed attention and the mechanism for negative priming work on the same level of processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the perception of sarcasm in dichotic listening.

The purpose of the present study was to investigate the processing of sincere and sarcastic statements by the cerebral hemispheres. Forty right-handed students were asked to localize sincere and sarcastic statements presented dichotically. Participants either indicated the ear that perceived the sarcastic statement or the ear that perceived the sincere statement in counterbalanced blocks of trials. As expected, results revealed a left ear advantage for sarcastic statements and a right ear advantage for sincere statements. In addition, participants showed faster response time when localizing targets (both sarcastic and sincere) to the left ear compared to the right. Finally, a significant negative correlation between laterality effects in the two tasks provided support for causal hemispheric complementarity. Results are discussed with reference to the contribution of the right and left hemispheres to language processing. Their implications for models of sarcasm perception are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sentence production by aphasic patients in a constrained task

Sixty aphasic patients and 55 normal control subjects were tested on a sentence production protocol that required subjects to produce specific sentence types from semantic representations. Normal subjects produced the expected targets with great reliability. Analysis of the patients' performance indicated that patients had difficulty producing both grammatical forms and thematic roles. Patients had more trouble producing grammatical elements than content words, and showed differential difficulty on sentence types that had more grammatical elements and in which the order of thematic roles was non-canonical. The results provide evidence regarding the processing load imposed by different components of the sentence production process.     

Laterality effects for musical structure processing: A dichotic listening study.

Objective: Our study investigated hemispheric lateralization for musical structure processing using a dichotic listening paradigm with music and speech. Method: Eight chord sequences and 8 spoken syllable sequences were simultaneously presented, each to 1 ear. For the musical sequences, the final chord was expected (i.e., tonic) or less expected (i.e., subdominant). In addition to tonal function, which was task irrelevant, we manipulated the final syllable and the final timbre of the sequences for the experimental task: Participants were asked to identify the final syllable (/di/, /du/) or the timbre of the final chord (Timbre A or B). Results: Our experiment revealed a left-ear advantage for the tonal function effect on spoken syllable identification. For syllables presented to the right ear, identification was faster when the final chord of the musical sequence was a tonic chord rather than a subdominant chord (i.e., musical sequences presented to the left ear). Conclusions: The present finding extends the effect of musical structure previously observed for sung and visual syllable processing to spoken syllable processing. It further suggests a right-hemispheric specialization for the processing of musical structures in healthy listeners, as previously reported for split-brain patients (Tramo & Bharucha, 1991). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal and music dichotic listening tasks reveal variations in functional cerebral asymmetry across the menstrual cycle that are phase and task dependent

BACKGROUND: One of the key factors in maintaining optimal cognitive performance in the high-G environment is the adequate delivery of oxygen to the cerebral tissue. As eye-level blood pressure is compromised at 22 mmHg x G(-1), perfusion to the peripheral cerebral tissues (cerebral cortex) may not be adequate to support the mental demands of flight. This study measured the effect of closed-loop flight simulations (3 min) on cerebral oxygen saturation changes (rSO2), arterial oxygen saturation (SAO2), and heart rate (HR), in both rested (8 h of rest) and sleepless (24 h without sleep) conditions. METHODS: Subjects (16; 8 males and 8 females) were subjected to G-exposures via closed-loop flight simulations in a series of four 3-min sorties flown by subjects on the Dynamic Environment Simulator (centrifuge) in either a rested or a sleepless state. Prior to the centrifuge flight, subjects were instrumented with sensors for measurement of arterial oxygen saturation (SAO2) and regional cerebral tissue oxygenation (rSO2). Subjects wore the standard flight suit, boots, CSU-13B/P anti-G suit, and the COMBAT EDGE positive-pressure breathing for G-protection system. RESULTS: Significant changes in cerebral and arterial oxygen saturation were observed within groups when comparing pretest baselines and minimum values during the test and pre- and post-G rSO2, SAO2, and HR in both the rested and sleepless state, (p # 0.01), respectively, for each group. Comparisons between groups showed women to have significantly smaller regional cerebral cortex oxygen decreases than men (p # 0.01). No significant changes in SAO2, however, were observed between groups. Both men and women showed a slow recovery of rSO2 values to the prebaseline levels. CONCLUSIONS: Sleeplessness had no effect on the rSO2, SAO2, and HR compared with the rested condition. During acceleration, regional cerebral tissue oxygen decreased 13% in men compared with 9% in women. The recovery of cerebral tissue oxygen levels to prebaseline values was retarded somewhat when compared with the recovery response of arterial oxygen saturation.     

Reliability and magnitude of perceptual asymmetries in a dichotic word recognition task.

The hypothesis that control of idiosyncratic attention deployment and retrieval strategies would improve the reliability and magnitude of laterality effects obtained in an auditory word recognition task was investigated. Sixty participants completed a dichotic word recognition task under 1 of 3 conditions. In free recall, they reported the 2 words presented on each trial (1 to each ear). In focused attention, they reported only the word presented to a prespecified ear. In target detection, they indicated whether a target word was presented to either ear on each trial. Results showed that the target-detection condition produced the largest and most reliable laterality effects compared with the other 2 conditions. The mechanisms likely to be responsible for these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemisphere-specific interference in dichotic listening: Task variables and individual differences.

In Exps I and II, 214 right-handed college students were required to identify dichotically presented CV syllables with either no concurrent memory (CM) load or with a CM load of 6 low-imagery nouns. Based on performance on their initial set of no-load trials, Ss were assigned to either a right-, left-, or no-ear advantage (REA, LEA, or NEA) group. Results for the REA group were similar to the results of previous studies of visual laterality and concurrent activity: Introducing a CM load of 6 words reduced recognition of right-ear CVs but not left-ear CVs. Furthermore, these effects persisted across 2 blocks of no-load and memory-load trials. This Memory Load?×?Ear interaction was weaker in the NEA group and tended to be reversed in the LEA group. About 10% of Ss showed a consistent LEA for CV recognition, and, for these Ss, introducing a CM load of 6 words reduced recognition of left-ear CVs but did not change the recognition of right-ear CVs. Again, these effects persisted across 2 blocks of no-load and memory load trials. Exp III (48 Ss) was similar to Exps I and II except that the CM task involved nonsense shapes that could probably be processed by either hemisphere. Introducing this concurrent nonverbal memory task did not reduce the recognition of either right- or left-ear CVs. Results indicate that the verbal nature of the concurrent task appears to be critical, as in previous visual laterality experiments. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)