Auditory DUM neurons in a bush‐cricket: A filter bank for carrier frequency

In bush‐crickets the first stage of central auditory processing occurs in the prothoracic ganglion. About 15 to 50 different auditory dorsal unpaired median neurons (DUM neurons) exist but they have not been studied in any detail. These DUM neurons may be classified into seven different morphological types, although, there is only limited correlation between morphology and physiological responses. Ninety seven percent of the stained neurons were local, 3% were intersegmental. About 90% project nearly exclusively into the auditory neuropile, and 45% into restricted areas therein. Lateral extensions overlap with the axons of primary auditory sensory neurons close to their branching point. DUM neurons are typically tuned to frequencies covering the range between 2 and 50 kHz and thereby may establish a filter bank for carrier frequency. Less than 10% of DUM neurons have their branches in adjacent and more posterior regions of the auditory neuropile and are mostly tuned to low frequencies, less sensitive than the other types and respond to vibration. Thirty five percent of DUM show indications of inhibition, either through reduced responses at higher intensities, or by hyperpolarizing responses to sound. Most DUM neurons produce phasic spike responses preferably at higher intensities. Spikes may be elicited by intracellular current injection. Preliminary data suggest that auditory DUM neurons have GABA as transmitter and therefore may inhibit other auditory interneurons. From all known local auditory neurons, only DUM neurons have frequency specific responses which appear suited for local processing relevant for acoustic communication in bush crickets.     

Verbal Interventions in Significant Psychodynamic-Interpersonal and Cognitive-Behavioral Therapy Sessions

The interventions used by 13 psychodynamic-interpersonal (PI) and 18 cognitive-behavioral (CB) therapists in sessions representing client change were explored. The most frequently used verbal interventions by both orientations were Questions, Reflections, and Interpretations (defined broadly as the therapists providing their own perspective on the client's functioning). For the sessions as a whole, PI therapists made significantly more use of Reflection, and CB therapists more use of Advisements and Acknowledgments. During the specific portions of sessions judged by therapists as most closely tied to client change, both orientations used equivalent amounts of Questions and Interpretations, whereas CB therapists' were more likely to use Advisements, and PI therapists to use Reflection. In significant portions of sessions, CB therapists used more Interpretations, and fewer Questions and Acknowledgments than they did in less significant portions. In portions of sessions that PI therapists judged to be associated with change, they used more Reflections and Interpretations, and fewer Questions and Acknowledgments relative to the rest of the sessions. These findings are discussed in terms of similarities and differences in the change process as construed by therapists of the two orientations.