#DICHOTIC LISTENING THEORY MANUAL#
#DICHOTIC LISTENING THEORY TRIAL#
#DICHOTIC LISTENING THEORY FREE#

Ignoring these design variables or leaving them uncontrolled introduces error variance to the obtained measures, affecting both the reliability of the obtained laterality measures and the efficiency of the paradigm.

#DICHOTIC LISTENING THEORY TRIAL#

Also, presenting multiple stimulus pairs per trial increases the working-memory load of the task by requiring the participant to keep the representation of multiple stimuli activated simultaneously, leading to a decreased right-ear advantage.

#DICHOTIC LISTENING THEORY FREE#

For example, it has been demonstrated that paradigms instructing participants to selectively attend to only one ear at a time are more difficult for participants to perform than paradigms allowing for a free selection. In fact, since the early conceptualization of dichotic listening more than six decades ago, a plethora of studies has accumulated a significant amount of evidence on how features of the experimental set-up (e.g., stimulus order, stimulus material) and task instructions lead to systematic response biases. At the same time, however, substantial differences in reliability estimates between paradigms suggest that certain design features systematically affect the consistency of an individual’s dichotic listening task performance. This shortcoming severely threatens the inferences that can be made using dichotic-listening measures, as the reliability of a test also sets the upper limit of its validity. However, many different versions of dichotic-listening paradigms have been suggested and the test-retest reliability of most dichotic paradigms–even of those used for diagnostic purposes–are far from optimal. This right-ear advantage is widely accepted to indicate left hemispheric dominance for speech processing and differences in the magnitude of this right-ear preferences have been related to interhemispheric auditory integration. Instructed to report the one of the two stimuli which was heard best, participants typically report the right-ear stimulus more frequently, more accurately, and more rapidly than the left-ear stimulus. That is, in its basic form, pairs of verbal stimuli (e.g., words or syllables) are presented via headphones, with one of the stimuli presented to the left ear and the other one, simultaneously, to the right ear. A significant advantage of dichotic compared with alternative paradigms (e.g., visual-half field techniques or neuroimaging approaches) is the simplicity of the testing procedure which can be easily understood and performed also by young children, elderly individuals, or patients with cognitive disabilities. Verbal dichotic-listening paradigms offer well-established behavioral tests for the assessment of latent hemispheric differences for language processing and are integral part of test procedures for the diagnosis of auditory processing disorders. These excellent reliability estimates suggest that the optimal paradigm may offer an effective and efficient alternative to currently used paradigms both in research and diagnostic.

#DICHOTIC LISTENING THEORY MANUAL#

Evaluating a verbal and manual response-format version of the paradigm in a sample of N = 50 healthy participants, we yielded test-retest intra-class correlations of r ICC =. To this end, the key design features of the paradigm were the use of stop-consonant vowel (CV) syllables as stimulus material, a single stimulus pair per trial presentation mode, and a free recall (single) response instruction. The main design principle was to minimize the relevance of higher cognitive functions on task performance in order to obtain stimulus-driven laterality estimates. Based on an extensive literature review, the paradigm was optimized to account for the main experimental variables which are known to systematically bias task performance or affect random error variance. Thus, the aim of the present work was to design and evaluate a novel, highly reliable dichotic-listening paradigm for the assessment of hemispheric differences. Despite its popularity in research and clinical settings, dichotic paradigms show comparatively low reliability, significantly threatening the validity of conclusions drawn from the results. Dichotic-listening paradigms are widely accepted as non-invasive tests of hemispheric dominance for language processing and represent a standard diagnostic tool for the assessment of developmental auditory and language disorders.

Dichotic listening theory