Hans Menning

Plastic changes in the auditory cortex induced by intensive frequency discrimination training

The slow auditory evoked (wave Nlm) and mismatch field (MMF) elicited by sequences of pure tones of 1000 Hz and deviant tones of 1050, 1010 and 1005 Hz were measured before, during and 3 weeks after subjects were trained at frequency discrimination for 15 sessions (over 3 weeks) using an odd-ball procedure. The task of the subject was to detect deviants differing by progressively smaller frequency shifts from the standard stimulus. Frequency discrimination improved rapidly in the first week and was followed by small but constant improvements thereafter. Nlm and MMF responses to the deviant stimuli increased in amplitude during training. This enhancement persisted until training was finished, but decreased 3 weeks later. The results suggest a plastic reorganization of the cortical representation for the trained frequencies.

Pre-attentive detection of syntactic and semantic errors.

This magnetoencephalographic study tested whether magnetic fields evoked by syntactic and semantic errors differ in their time course and magnitude from fields evoked by phonemic differences. An oddball design, using German sentences with embedded critical words was applied: The error condition (with the standard word RASEN, lawn, in 70% of the trials, and the syntactic and semantic errors ROSEN, roses and RIESEN, giant as deviants) wasx compared with a neutral, correct phonemic condition. Mismatch responses were significantly larger for syntactic and semantic errors as compared to mere phonemic deviations. The semantic error elicited higher mismatch responses than the syntactic error. This error-sensitive component is interpreted as a very early detector for semantic and syntactic errors.

Dresden PTSD treatment study: randomized controlled trial of motor vehicle accident survivors

BackgroundWe translated, modified, and extended a cognitive behavioral treatment (CBT) protocol by Blanchard and Hickling (2003) for the purpose of treating survivors of MVA with full or subsyndromal posttraumatic stress disorder (PTSD) whose native language is German. The treatment manual included some additional elements, e. g. cognitive procedures, imaginal reliving, and facilitating of posttraumatic growth. The current study was conducted in order to test the efficacy of the modified manual by administering randomized controlled trial in which a CBT was compared to a wait-list control condition.MethodsForty-two motor vehicle accident survivors with chronic or severe subsyndromal posttraumatic stress disorder (PTSD) completed the treatment trial with two or three detailed assessments (pre, post, and 3-month follow-up).ResultsCAPS-scores showed significantly greater improvement in the CBT condition as compared to the wait list condition (group × time interaction effect size d = 1.61). Intent-to-treat analysis supported the outcome (d = 1.34). Categorical diagnostic data indicated clinical recovery of 67% (post-treatment) and 76% (3 months FU) in the treatment group. Additionally, patients of the CBT condition showed significantly greater reductions in co-morbid major depression than the control condition. At follow-up the improvements were stable in the active treatment condition.ConclusionThe degree of improvement in our treatment group was comparable to that in previously reported treatment trials of PTSD with cognitive behavioral therapy.Trial registrationISRCTN66456536

Who is telling what from where? A functional magnetic resonance imaging study

The human central-auditory system exhibits distinct lateralization effects (speech, space) and encompasses different processing pathways (where, what, who). Using spatialized pseudoword utterances, attentional modulation of the networks bound to sound source localization (‘where’), voice recognition (‘who’), and the encoding of phonetic-linguistic information (‘what’) was evaluated by silent functional magnetic resonance imaging. The ‘where’-pathway was found to be restricted to posterior parts of the left superior temporal gyrus, speaker (‘auditory face’) identification exclusively activated temporal lobe structures, and the representation of the sound structure of the utterances was associated with hemodynamic activation of Brocas area. Speech perception in space, therefore, engages at least three distinct neural networks. Furthermore, the findings indicate that voice recognition may depend upon template matching within auditory association cortex whereas the sequencing of phonetic-linguistic information extends to frontal areas.

MEG responses to rippled noise and Huggins pitch reveal similar cortical representations.

The onset of pitch within an ongoing noise signal evokes a particular brain activity, the pitch onset response (POR). Using whole-head MEG, PORs to iterated rippled noise (IRN) and Huggins pitch (HP), representing prototypical pitch-in-noise signals, were measured in twenty subjects during a pitch identification task (333 Hz, 400 Hz, randomized). HP and IRN yielded similar responses, lateralized to the left hemisphere and peaking about 180 ms after pitch onset. The initial phase (140 ms) showed stronger activations to 400 than to 333 Hz whereas later stages (200–300 ms) showed target vs nontarget effects. These results suggest, first, that different pitches converge into a common cortical representation and, second, that the POR encompasses various successive processing stages.