TY  - JOUR
A1  - Herbert, Cornelia
A1  - Kübler, Andrea
T1  - Dogs Cannot Bark: Event-Related Brain Responses to True and False Negated Statements as Indicators of Higher-Order Conscious Processing
JF  - PLoS ONE
N2  - The present study investigated event-related brain potentials elicited by true and false negated statements to evaluate if discrimination of the truth value of negated information relies on conscious processing and requires higher-order cognitive processing in healthy subjects across different levels of stimulus complexity. The stimulus material consisted of true and false negated sentences (sentence level) and prime-target expressions (word level). Stimuli were presented acoustically and no overt behavioral response of the participants was required. Event-related brain potentials to target words preceded by true and false negated expressions were analyzed both within group and at the single subject level. Across the different processing conditions (word pairs and sentences), target words elicited a frontal negativity and a late positivity in the time window from 600-1000 msec post target word onset. Amplitudes of both brain potentials varied as a function of the truth value of the negated expressions. Results were confirmed at the single-subject level. In sum, our results support recent suggestions according to which evaluation of the truth value of a negated expression is a time-and cognitively demanding process that cannot be solved automatically, and thus requires conscious processing. Our paradigm provides insight into higher-order processing related to language comprehension and reasoning in healthy subjects. Future studies are needed to evaluate if our paradigm also proves sensitive for the detection of consciousness in non-responsive patients.
KW  - Locked-in syndrome
KW  - Vegetative state
KW  - Own-name
KW  - Language comprehension
KW  - Sentence comprehension
KW  - Text information
KW  - Time-course
KW  - Verification
KW  - Potentials
KW  - Activation
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135165
VL  - 6
IS  - 10
ER  - 
TY  - JOUR
A1  - Kohnen, Ralf
A1  - Krüger, Hans-Peter
T1  - Tranquillizer effects in an experimental analog of verbal examinations
N2  - In an experimental analog of verbal examinations, the call-up situation, the effects of two dosages of a tranquillizing agent (lopirazepam) are compared to placebo treatment. 72 male and female, healthy, young volunteers have been randomly assigned to 12 groups of 6 subjects each. Pulse frequency and performance were registered. The results indicated differential drug effects which were interpreted according to the hypotheses of "differential effects of social stressors". If a situation was highly challenging for a subject, the application of a tranquillizer in an adequately high dosage enabled him to perform well in spite of or because of strong increases in pulse frequency.
KW  - Tranquillizer
KW  - Social stress
KW  - Examination
KW  - Healthy subjects
KW  - Differential effects of stressors
KW  - Telemetry
KW  - Activation
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41617
ER  -