New interactive verbal dichotic listening test

INTRODUCTION AND OBJECTIVE: From the multimedia technology and of the digital recording of the voice, we have redesigned the verbal dichotic listening test. The recognition of 15 monosyllabic word pairs offered though some earphones is presented in an interactive program. METHODS: Using the mouse button, the subject decides the moment in which each stimuli coupe will take place. Likewise, the screen displays 10 words, among which you have to recognize the words supplied by the earphones. Finally, the program results in complete right answers and right answers cross or referred to the opposite ear. RESULTS: Applied the test to a sample of 92 subjects, apparently normal, with a middle and high cultural level, from among 19 and 60 years (44 females and 48 males), the test resulted in a predominance of rights answers in the right ear (p < 0.0064). Separated the sample in in left-handed and right-handed men (67 right handed and 25 left-handed), it hasn't been found meaningful differences among their averages. Separated the sample by sex, the differences among the slightly meaningful averages (p < 0.04, according to the Student's t test). CONCLUSIONS: The test is offered as a resource appropriate for laterality studies, and for differential disorder study of gnosias and praxias of the dyslexias of aphasias, hearing aids, multiple sclerosis, and aptitudes studies.     

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)     

Attentional strategies in dichotic listening.

Describes 2 experiments in which a total of 48 college students heard series of 3 dichotic word-digit pairs and were instructed to recall them either by ears or by types. Recall instructions were given before each block of 12 series, before each individual series, or after each series. With preinstruction, serial position effects were rather flat for the 1st-reported channel but showed a marked recency effect for the 2nd-reported channel, suggesting that the Ss attended mainly to the lst channel. With postinstruction, serial position effects were parallel for the 2 channels. Results were practically the same whether channels represented ears or types, suggesting that attention played the same role in each case. (French summary) (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)     

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)     

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)     

Developmental changes in dichotic listening with categorized word lists.

Two experiments examined the effects of blocking of word lists (grouped by semantic category membership or randomly ordered) on the dichotic listening performances of 48 2nd and 48 5th graders. For Exp I, shadowing and retention scores were obtained for groups of Ss representing the 4 combinations of blocked and random word lists for targets and distractors. Blocking of distractor lists led to better shadowing scores for 2nd graders. When word pairs were matched by categories in Exp II, 2nd graders who heard blocked lists recognized fewer target words (in retention tests) than did those who heard randomly ordered word lists. Results are interpreted in the context of variables that affect the shadowing performances of younger children and developmental differences in encoding strategies. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Baseline asymmetries in brain electrical activity predict dichotic listening performance.

Forty-four right-handed participants were assessed on 2 occasions 6 weeks apart on electrophysiological measures of activation asymmetry derived from spectral estimates of electroencephalogram (EEG) alpha power in homologous scalp electrodes. Approximately 4 months following the final EEG assessment. participants were administered a dichotic listening CV-syllables task. Overall, participants exhibited a highly significant right-ear advantage. Differences among individuals in ear asymmetry were predicted by the earlier recorded electrophysiological data. Participants with greater activation in left-sided posterior temporal and parietal regions showed a larger right-ear advantage. In addition, a larger right-ear advantage was predicted by right-sided prefrontal activation. These data indicate that some of the variance in dichotic listening performance can be explained by dispositional activation asymmetries and is associated with a complex pattern of posterior and anterior activation asymmetries. (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)     

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)     

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)     

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)     

Effects of sex and sex role attributions on the ear advantage in dichotic listening.

The Bem Sex Role Inventory (BSRI) and a dichotic listening task were administered to 30 participants in order to investigate the effect of polar sex (male, female) and spectral sex (masculinity, femininity) on hemispheric interactions. The dichotic pairs consisted of the consonant-vowel syllables Bee, Dee, Gee, Pee, Tee, and Kee. Although overall performance was the same across groups, women demonstrated smaller right ear advantages than men, due primarily to smaller right ear scores. Less masculine men also had smaller right ear advantages than more masculine men, but this difference was due primarily to greater left ear scores. These results were interpreted both in terms of the callosal relay and direct access models of hemispheric processing. Based on these interpretations, it was suggested that sex and sex role attribution have similar, but not identical effects on interhemispheric relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Controlling for stimulus dominance in dichotic listening tests: A modification of !l.

Dichotic listening procedures have been used to assess cerebral lateralization in normal Ss. One particularly useful technique is the use of stimuli that fuse into a single percept. Although this procedure has many advantages over other dichotic listening methods, it is particularly susceptible to stimulus dominance, which acts as noise in a S's response data, thus reducing the power of any statistical test of the ear advantage. It is proposed that the solution to this problem is a log-linear analysis of the response data to yield a λ-type index (λ*) that is a measure of ear dominance independent of stimulus dominance. Details of the analysis are provided, as well as a sample analysis of data collected from 104 right-handed and 30 left-handed Ss. Comparisons are drawn between the log-linear analysis and other methods that have been proposed to control for stimulus dominance in this single-response dichotic fusion procedure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory attention in hyperactive children: Effects of stimulant medication on dichotic listening performance.

Administered dichotic digit tasks requiring free report and selective listening, respectively, to 20 6–16 yr old hyperactive children. Ss received methylphenidate before 2 experimental sessions and a placebo before 2 control sessions. The stimulant did not improve free-report performance significantly; rather it facilitated or impaired performance, depending on how it affected the order in which stimuli were reported. Similarly, medication had no effect on overall selective-listening performance, but it increased the difficulty of switching attention from one ear to the other. Results demonstrate that stimulants may act to maintain selective attention and to inhibit channel switching. Listening asymmetry, that is, right-ear superiority, was influenced by task variables but not by stimulant medication. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotic dissociation, dichotic listening, and active versus passive modes of attention.

Describes 2 experiments with 75 high and low hypnotically susceptible Ss (Harvard Group Scale of Hypnotic Susceptibility). Detecting left-channel targets interfered less with the shadowing of right-channel prose when performance of the former task was posthypnotically dissociated from consciousness. However, this superiority over an ordinary divided-attention condition was not due to unconscious target detection by Ss. Rather, the suggestions for posthypnotic responsiveness with amnesia apparently engendered a passive mode of attention to the left-channel task, such that Ss did not actively listen for targets in order to hear them. In Exp II, explicit instructions to adopt a strategy of attentional passivity to the target-detection task proved to be far more effective in producing the reduced-interference effect than the posthypnotic suggestions had been. The posthypnotic suggestions seemed to induce attentional passivity as an indirect effect of amnesia for the posthypnotic suggestions and for previously detected targets. Study findings are interpreted in terms of E. R. Hilgard's (1973) neodissociation theory. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Binaural competition and division of attention as determinants of the laterality effect in dichotic listening.

In the normal dichotic listening procedure, there is competition between 2 inputs arriving simultaneously. Also, S must attend to both ears at the same time. In a series of 4 experiments, with over 80 undergraduates, these 2 factors were manipulated independently to assess their relative contributions to the laterality effect. In the 1st 3 experiments, conditions were employed in which the input was always monaurally presented, but the S did not know in advance where the material would arrive. In Exp. IV, the preinstruction condition provided a situation in which the S could direct his attention to a single channel. Results indicate that competition is both necessary and sufficient for a right-ear superiority to be observed. The necessity of attending to 2 channels at the same time does not seem to influence the laterality effect in any way. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric lateralization of perception and memory for emotional verbal stimuli in normal individuals.

The purposes of this study were to extend the literature on lateralization of perception of emotional verbal stimuli in normal individuals, including a test of both the right hemisphere and valence models, and to investigate predictions from these models regarding lateralization of memory for emotional verbal stimuli in normal individuals, an area that, to our knowledge, has not been investigated. Seventy-nine undergraduates were presented lateralized positive, negative, and neutral English words and nonwords. Participants were then asked to freely recall the presented words and, after a 20-min delay, to recognize the words. Recognition memory data provided strong support for the valence model. In addition, free-recall and perception data provided partial support for this model. The literature on the lateralization of processing emotional verbal and nonverbal material is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)