Tim Martin

From In-Session Behaviors to Drinking Outcomes: A Causal Chain for Motivational Interviewing

Client speech in favor of change within motivational interviewing sessions has been linked to treatment outcomes, but a causal chain has not yet been demonstrated. Using a sequential behavioral coding system for client speech, the authors found that, at both the session and utterance levels, specific therapist behaviors predict client change talk. Further, a direct link from change talk to drinking outcomes was observed, and support was found for a mediational role for change talk between therapist behavior and client drinking outcomes. These data provide preliminary support for the proposed causal chain indicating that client speech within treatment sessions can be influenced by therapists, who can employ this influence to improve outcomes. Selective eliciting and reinforcement of change talk is proposed as a specific active ingredient of motivational interviewing.

ASSESSING THE INTEGRITY OF MOTIVATIONAL INTERVIEWING INTERVENTIONS: RELIABILITY OF THE MOTIVATIONAL INTERVIEWING SKILLS CODE

The motivational interviewing skills code (MISC) was used to review 86 audiotaped interactions between clinicians and patients participating in a smoking cessation intervention. Intraclass correlations (ICCs) were completed for two of the MISC elements: global evaluations and behavior counts. Results indicate 75% of the global ratings yielded ICCs in the good to excellent range, while only 44% of the behavior counts yielded this level of accuracy. Adherence scores were created to form overall ratings of clinician adherence to using motivational interviewing and 80% of these competence measures yielded ICCs in the good to excellent range. Specific recommendations regarding modifications for the MISC are suggested based on the data presented.

Perceptual relearning of complex visual motion after V1 damage in humans

Damage to the adult, primary visual cortex (V1) causes severe visual impairment that was previously thought to be permanent, yet several visual pathways survive V1 damage, mediating residual, often unconscious functions known as “blindsight.” Because some of these pathways normally mediate complex visual motion perception, we asked whether specific training in the blind field could improve not just simple but also complex visual motion discriminations in humans with long-standing V1 damage. Global direction discrimination training was administered to the blind field of five adults with unilateral cortical blindness. Training returned direction integration thresholds to normal at the trained locations. Although retinotopically localized to trained locations, training effects transferred to multiple stimulus and task conditions, improving the detection of luminance increments, contrast sensitivity for drifting gratings, and the extraction of motion signal from noise. Thus, perceptual relearning of complex visual motion processing is possible without an intact V1 but only when specific training is administered in the blind field. These findings indicate a much greater capacity for adult visual plasticity after V1 damage than previously thought. Most likely, basic mechanisms of visual learning must operate quite effectively in extrastriate visual cortex, providing new hope and direction for the development of principled rehabilitation strategies to treat visual deficits resulting from permanent visual cortical damage.

Dynamic neural activity recorded from human amygdala during fear conditioning using magnetoencephalography

Magnetoencephalography (MEG) was used to record the dynamics of amygdala neuronal population activity during fear conditioning in human participants. Activation during conditioning training was compared to habituation and extinction sessions. Conditioned stimuli (CS) were visually presented geometric figures, and unconditioned stimuli (US) were aversive white-noise bursts. The CS+ was paired with the US on 50% of presentations and the CS- was never paired. The precise temporal resolution of MEG allowed us to address the issue of whether the amygdala responds to the onset or offset of the CS+, and/or the expectation of the initiation or offset of the an omitted auditory US. Fear conditioning elicited differential amygdala activation for the unpaired CS+ compared to the CS-, extinction and habituation. This was especially robust in the right hemisphere at CS onset. The strongest peaks of amygdala activity occurred at an average of 270 ms in the right and 306 ms in the left hemisphere following unpaired CS+ onset, and following offset at 21 ms in the left and 161 ms in the right (corresponding to an interval of 108 ms and 248 ms after the anticipated onset of the US, respectively). However, the earliest peaks in this epoch preceded US onset in most subjects. Thus, the activity dynamics suggest that the amygdala both differentially responds to stimuli and anticipates the arrival of stimuli based on prior learning of contingencies. The amygdala also shows stimulus omission-related activation that could potentially provide feedback about experienced stimulus contingencies to modify future responding during learning and extinction.

Visually-guided behavior of homonymous hemianopes in a naturalistic task

The gaze behavior of homonymous hemianopes differs from that of visually intact observers when performing simple laboratory tasks. To test whether such compensatory behavior is also evident during naturalistic tasks, we analyzed the gaze patterns of three long-standing hemianopes and four visually intact controls while they assembled wooden models. No significant differences in task performance, saccade dynamics or spatial distribution of gaze were observed. Hemianopes made more look-ahead fixations than controls and their gaze sequences were less predictable. Thus hemianopes displayed none of the compensatory gaze strategies seen in laboratory tasks. Instead, their gaze patterns suggest greater updating of, and greater reliance on a spatial representation.

MEG reveals different contributions of somatomotor cortex and cerebellum to simple reaction time after temporally structured cues

Magnetoencephalography (MEG) was used to measure brain activity while participants performed a simple reaction to targets after either a random interval (uncued targets) or a series of isochronous warning stimuli with 200‐ms intervals that acted as a countdown. Targets could arrive “on time” or “early” relative to the preceding warning stimuli. Cerebellar activity before any stimulus onset predicted uncued simple reaction time. Onset of activity in somatomotor cortex relative to the target predicted reaction time after two warning stimuli when the target arrived on time or early. After three warning stimuli, when the target arrived on time and was certain to occur, prestimulus cerebellar activity and somatomotor onset were significant predictors of reaction time. When the target arrived early after three warning stimuli, prestimulus cerebellar and cingulate activity were predictive. The cerebellar results may reflect a number of possible factors, including a role in timing, response readiness, prediction and attention. Hum. Brain Mapping 2005.

Post-DSAEK optical changes: a comprehensive prospective analysis on the role of ocular wavefront aberrations, haze, and corneal thickness.

Purpose: The aim was to assess the visual impact of ocular wavefront aberrations, corneal thickness, and corneal light scatter prospectively after performing a Descemet stripping automated endothelial keratoplasty (DSAEK) in humans. Methods: Data were obtained prospectively from 20 eyes preoperatively and at 1, 3, 6, and 12 months post-DSAEK. At each visit, the best spectacle-corrected visual acuity and visual acuity with glare (brightness acuity testing) were recorded, and ocular wavefront measurements and corneal optical coherence tomography (OCT) were performed. The magnitude and the sign of individual Zernike terms [higher-order aberrations (HOAs)] were determined. Epithelial, host stromal, donor stromal, and total corneal thicknesses were quantified. The brightness and intensity profiles of OCT images were generated to quantify light scatter in the whole cornea, subepithelial region, anterior and posterior host stroma, interface, and donor stroma. Results: The mean best spectacle-corrected visual acuity and glare disability at low light levels improved from 1 to 12 months post-DSAEK. All corneal thicknesses and ocular lower-order aberrations and HOAs were found to be stable from 1 to 12 months, whereas total corneal, host stromal, and interface brightness intensities decreased significantly over the same period. A repeated measures analysis of variance performed across the follow-up period revealed that the change in scatter, but not the change in the HOAs, could account for the variability occurring in the acuity from 1 to 12 months post-DSAEK. Conclusions: Although ocular HOAs and scatter are both elevated over normal values post-DSAEK, our results demonstrate that the improvements in visual performance occurring over the first year post-DSAEK are associated with decreasing light scatter. In contrast, there were no significant changes in the ocular HOAs during this time. Because corneal light scatter decreased between 1 and 12 months despite there being stable corneal thicknesses over the same period, we conclude that factors that induced light scatter, other than tissue thickness or swelling (corneal edema), significantly impacted the visual improvements that occurred over time post-DSAEK. A better understanding of the cellular and extracellular matrix changes of the subepithelial region and interface, incurred by the surgical creation of a lamellar host–graft interface, and the subsequent healing of these tissues, is warranted.

The structure of client language and drinking outcomes in project match.

Client language during Motivational Interviewing interventions is an important predictor of drinking outcomes, but there are inconsistencies in the literature regarding what aspects of client language are most predictive. We characterized the structure of client language by factor analyzing frequency counts of several categories of client speech. The results provide limited support for a model proposed by Miller et al. (2006) and Amrhein et al. (2003) but with some important differences. While Amrhein et al. (2003) found that only increasing strength in client commitment language predicted behavior change, the current study revealed that client language preparatory to commitment predicted drinking outcomes.

Phase shift detection in thalamocortical oscillations using magnetoencephalography in humans

Magnetoencephalography was used to investigate exogenously stimulated oscillatory activity between cortex and thalamus resulting from clicks presented binaurally at the rate of 40 Hz. Analysis of the responses demonstrated activation of left and right auditory cortex, medial parietal cortex, thalamus, and cerebellum. Cross-correlations of the source waveforms revealed synchronicity between the auditory cortex sources (r > 0.9), auditory cortex and thalamic sources (r > 0.7), and thalamic and parietal sources (r > 0.7). The 40 Hz response in auditory cortex occurred 6 ms after thalamic activation. Supporting earlier findings, the results demonstrate the networks involved in the maintenance of 40 Hz auditory steady-state response and will prove useful for the interrogation of dysfunction in disorders demonstrating thalamocortical dysrhythmia, such as schizophrenia, Parkinsons disease, and depression.

Comparison of optical quality metrics to predict subjective quality of vision after laser in situ keratomileusis.

PURPOSE: To compare wavefront‐derived metrics to predict subjective quality of vision after laser in situ keratomileusis (LASIK) for myopia. SETTING: Department of Ophthalmology, Goethe University, Frankfurt am Main, Germany. METHODS: One month postoperatively, wavefront sensing was performed and overall subjective quality of vision assessed under 3 lighting conditions (photopic, high mesopic, low mesopic) with a questionnaire. Four wavefront‐error representations were computed for a pupil diameter of 6.0 mm and individual physiological pupil diameters at 0.4 lux: (1) the visual Strehl ratio based on optical transfer function (VSOTF), (2) the root‐mean‐square (RMS) value of Zernike orders 2 to 5 (total RMS), (3) higher‐order aberration (HOA) RMS, and (4) a wavefront‐error breakdown into the RMS of lower‐order aberrations, coma, spherical aberration, and remaining HOA. The impact of the postoperative wavefront error on subjective quality of vision was calculated using linear regression analysis. RESULTS: Fifty‐six eyes (29 patients) were included. The ability of wavefront error–derived metrics to predict subjective quality of vision was limited. The VSOTF, calculated for the best‐corrected eye, showed the highest predictability. Calculation of wavefront error for individual physiological pupil diameters did not improve predictive ability of the metrics. Eyes with a high theoretical retinal‐image quality had a high subjective quality of vision, and eyes with a low subjective quality of vision had a low theoretical image quality. CONCLUSIONS: Postoperative wavefront error had limited influence on the subjective quality of vision. Postoperative retinal image quality should be kept as high as possible to provide good subjective quality of vision.