Margaret C. McKinnon

The Toronto Empathy Questionnaire: Scale development and initial validation of a factor-analytic solution to multiple empathy measures

To formulate a parsimonious tool to assess empathy, we used factor analysis on a combination of self-report measures to examine consensus and developed a brief self-report measure of this common factor. The Toronto Empathy Questionnaire (TEQ) represents empathy as a primarily emotional process. In 3 studies, the TEQ demonstrated strong convergent validity, correlating positively with behavioral measures of social decoding, self-report measures of empathy, and negatively with a measure of Autism symptomatology. Moreover, it exhibited good internal consistency and high test–retest reliability. The TEQ is a brief, reliable, and valid instrument for the assessment of empathy.

Bilateral Hippocampal Volume Increase in Patients with Bipolar Disorder and Short-term Lithium Treatment

Most previous magnetic resonance imaging (MRI) studies of patients with bipolar disorder (BD) report similar hippocampus (HC) volumes across patients and controls, but because patients studied were heterogeneous with respect to course of illness variables and medication status, the conclusions of these studies remain equivocal. Lithium (Li) is the reference-standard drug for BD and its role as an important agent in neuroprotection and neurogenesis has been documented in human and in animal studies. We compared the volume of the HC, hippocampal head (Hh), and body/tail (Hbt) in three groups with no history of medication use before entry into this study: (a) a group of patients treated with Li for 1–8 weeks and then scanned; (b) a group comprised of patients who were unmedicated at the time of scan; and (c) a group of patients treated with either valproic acid or lamotrigine. Healthy age- and sex-matched comparison subjects were also scanned. HC volumes did not differ between the unmedicated and healthy comparison groups. There was a bilateral increase in volumes of HC and Hh in the Li-treated group compared to the unmedicated group, an effect that was apparent even over a brief treatment period. Our study provides further confirmation that Li can exert structural effects on the HC, which are detectable in vivo. The study emphasizes the need to control for even brief exposure to medication in volumetric studies of the HC.

Successful computer-assisted cognitive remediation therapy in patients with unipolar depression: a proof of principle study

BACKGROUND Despite increasing awareness of the extent and severity of cognitive deficits in major depressive disorder (MDD), trials of cognitive remediation have not been conducted. We conducted a 10-week course of cognitive remediation in patients with long-term MDD to probe whether deficits in four targeted cognitive domains, (i) memory, (ii) attention, (iii) executive functioning and (iv) psychomotor speed, could be improved by this intervention. METHOD We administered a computerized cognitive retraining package (PSSCogReHab) with demonstrated efficacy to 12 stable patients with recurrent MDD. Twelve matched patients with MDD and a group of healthy control participants were included for comparison; neither comparator group received the intervention that involved stimulation of cognitive functions through targeted, repetitive exercises in each domain. RESULTS Patients who received cognitive training improved on a range of neuropsychological tests targeting attention, verbal learning and memory, psychomotor speed and executive function. This improvement exceeded that observed over the same time period in a group of matched comparisons. There was no change in depressive symptom scores over the course of the trial, thus improvement in cognitive performance occurred independent of other illness variables. CONCLUSIONS These results provide preliminary evidence that improvement of cognitive functions through targeted, repetitive exercises is a viable method of cognitive remediation in patients with recurrent MDD.

Name that tune: identifying popular recordings from brief excerpts.

We tested listeners’ ability to identify brief excerpts from popular recordings. Listeners were required to match 200- or 100-msec excerpts with the song titles and artists. Performance was well above chance levels for 200-msec excerpts and poorer but still better than chance for 100-msec excerpts. Performance fell to chance levels when dynamic (time-varying) information was disrupted by playing the 100-msec excerpts backward and when high-frequency information was omitted from the 100-msec excerpts; performance was unaffected by the removal of low-frequency information. In sum, successful identification required the presence of dynamic, high-frequency spectral information.

Anterior Cingulate Volumes in Never-Treated Patients with Major Depressive Disorder

The anterior cingulate cortex (ACC) is implicated in the cognitive and affective abnormalities observed in mood disorders. Bilateral ACC volume reductions have been reported in patients with major depressive disorder (MDD) when compared to healthy controls. We compared regional brain volumes in the subgenual prefrontal cortex (SGPFC; Brodmann area (BA) 24sg), subcallosal gyrus (BA25), and paracingulate gyrus (BA32) in 65 patients receiving a first course of treatment for MDD and 93 healthy control subjects. Patients with more than three episodes of untreated MDD had smaller subcallosal gyrus volumes than healthy controls, while those with three or fewer past untreated episodes did not differ from controls. We also found preliminary evidence that medication-exposed patients had smaller SGPFC volumes than patients with no exposure to medication and healthy controls. There was no evidence that these effects related to mood state, duration of untreated illness, or to patient age. No differences were apparent in paracingulate gyrus volumes between patients and controls. These findings confirm the presence of ACC volume reductions in untreated patients with MDD and suggest that illness burden and short-term medication exposure mediate this change.

Restoring large-scale brain networks in PTSD and related disorders: a proposal for neuroscientifically-informed treatment interventions

Background Three intrinsic connectivity networks in the brain, namely the central executive, salience, and default mode networks, have been identified as crucial to the understanding of higher cognitive functioning, and the functioning of these networks has been suggested to be impaired in psychopathology, including posttraumatic stress disorder (PTSD). Objective 1) To describe three main large-scale networks of the human brain; 2) to discuss the functioning of these neural networks in PTSD and related symptoms; and 3) to offer hypotheses for neuroscientifically-informed interventions based on treating the abnormalities observed in these neural networks in PTSD and related disorders. Method Literature relevant to this commentary was reviewed. Results Increasing evidence for altered functioning of the central executive, salience, and default mode networks in PTSD has been demonstrated. We suggest that each network is associated with specific clinical symptoms observed in PTSD, including cognitive dysfunction (central executive network), increased and decreased arousal/interoception (salience network), and an altered sense of self (default mode network). Specific testable neuroscientifically-informed treatments aimed to restore each of these neural networks and related clinical dysfunction are proposed. Conclusions Neuroscientifically-informed treatment interventions will be essential to future research agendas aimed at targeting specific PTSD and related symptoms.

Visual imagery deficits, impaired strategic retrieval, or memory loss: disentangling the nature of an amnesic person's autobiographical memory deficit

Conclusions about the duration of hippocampal contributions to our autobiographical record of personal episodes have come under intense scrutiny in recent years. Interpretation is complicated by such factors as extent and site of lesions as well as test sensitivity. We describe the case of an amnesic person, K.C., with large, bilateral hippocampal lesions who figured prominently in the development of theories of remote memory due to his severely impoverished autobiographical memory extending across his entire lifetime. However, the presence of lesions in higher-order visual cortex raises the possibility that K.C.s retrograde autobiographical amnesia is mediated by loss of long-term visual images, whereas widespread frontal lesions suggest that his impairment may relate to deficits in strategic retrieval rather than storage. Normal performance on an extensive battery of visual imagery tests refutes the imagery loss interpretation. To test for deficits in strategic retrieval, we used a more formal autobiographical memory test requiring generation of personal events under varying levels of retrieval support. However, even with rigorous contextual prompting, K.C. produced few pre-injury recollections; all were schematic, lacking the richness of detail produced by control participants, raising doubt that his deficit is one of retrieval. Findings are discussed in the context of theories concerning the duration of hippocampal-neocortical interactions in supporting autobiographical re-experiencing. The approach we used to investigate the effects of different lesions on memory provides a framework for dealing with other patients who present with an interesting functional deficit whose neuroanatomical source is difficult to specify due to widespread lesions.

Inter-rater and test–retest reliability of quality assessments by novice student raters using the Jadad and Newcastle–Ottawa Scales

Introduction Quality assessment of included studies is an important component of systematic reviews. Objective The authors investigated inter-rater and test–retest reliability for quality assessments conducted by inexperienced student raters. Design Student raters received a training session on quality assessment using the Jadad Scale for randomised controlled trials and the Newcastle–Ottawa Scale (NOS) for observational studies. Raters were randomly assigned into five pairs and they each independently rated the quality of 13–20 articles. These articles were drawn from a pool of 78 papers examining cognitive impairment following electroconvulsive therapy to treat major depressive disorder. The articles were randomly distributed to the raters. Two months later, each rater re-assessed the quality of half of their assigned articles. Setting McMaster Integrative Neuroscience Discovery and Study Program. Participants 10 students taking McMaster Integrative Neuroscience Discovery and Study Program courses. Main outcome measures The authors measured inter-rater reliability using κ and the intraclass correlation coefficient type 2,1 or ICC(2,1). The authors measured test–retest reliability using ICC(2,1). Results Inter-rater reliability varied by scale question. For the six-item Jadad Scale, question-specific κs ranged from 0.13 (95% CI −0.11 to 0.37) to 0.56 (95% CI 0.29 to 0.83). The ranges were −0.14 (95% CI −0.28 to 0.00) to 0.39 (95% CI −0.02 to 0.81) for the NOS cohort and −0.20 (95% CI −0.49 to 0.09) to 1.00 (95% CI 1.00 to 1.00) for the NOS case–control. For overall scores on the six-item Jadad Scale, ICC(2,1)s for inter-rater and test–retest reliability (accounting for systematic differences between raters) were 0.32 (95% CI 0.08 to 0.52) and 0.55 (95% CI 0.41 to 0.67), respectively. Corresponding ICC(2,1)s for the NOS cohort were −0.19 (95% CI −0.67 to 0.35) and 0.62 (95% CI 0.25 to 0.83), and for the NOS case–control, the ICC(2,1)s were 0.46 (95% CI −0.13 to 0.92) and 0.83 (95% CI 0.48 to 0.95). Conclusions Inter-rater reliability was generally poor to fair and test–retest reliability was fair to excellent. A pilot rating phase following rater training may be one way to improve agreement.

The Dissociative Subtype of Posttraumatic Stress Disorder: Unique Resting-State Functional Connectivity of Basolateral and Centromedial Amygdala Complexes

Previous studies point towards differential connectivity patterns among basolateral (BLA) and centromedial (CMA) amygdala regions in patients with posttraumatic stress disorder (PTSD) as compared with controls. Here we describe the first study to compare directly connectivity patterns of the BLA and CMA complexes between PTSD patients with and without the dissociative subtype (PTSD+DS and PTSD−DS, respectively). Amygdala connectivity to regulatory prefrontal regions and parietal regions involved in consciousness and proprioception were expected to differ between these two groups based on differential limbic regulation and behavioral symptoms. PTSD patients (n=49) with (n=13) and without (n=36) the dissociative subtype and age-matched healthy controls (n=40) underwent resting-state fMRI. Bilateral BLA and CMA connectivity patterns were compared using a seed-based approach via SPM Anatomy Toolbox. Among patients with PTSD, the PTSD+DS group exhibited greater amygdala functional connectivity to prefrontal regions involved in emotion regulation (bilateral BLA and left CMA to the middle frontal gyrus and bilateral CMA to the medial frontal gyrus) as compared with the PTSD−DS group. In addition, the PTSD+DS group showed greater amygdala connectivity to regions involved in consciousness, awareness, and proprioception—implicated in depersonalization and derealization (left BLA to superior parietal lobe and cerebellar culmen; left CMA to dorsal posterior cingulate and precuneus). Differences in amygdala complex connectivity to specific brain regions parallel the unique symptom profiles of the PTSD subgroups and point towards unique biological markers of the dissociative subtype of PTSD.

Expectancy in Melody: Tests of Children and Adults

Melodic expectancies among children and adults were examined. In Experiment 1, adults, 11-year-olds, and 8-year-olds rated how well individual test tones continued fragments of melodies. In Experiment 2, 11-, 8-, and 5-year-olds sang continuations to 2-tone stimuli. Response patterns were analyzed using 2 models of melodic expectancy. Despite having fewer predictor variables, the 2-factor model (E. G. Schellenberg, 1997) equaled or surpassed the implication-realization model (E. Narmour, 1990) in predictive accuracy. Listeners of all ages expected the next tone in a melody to be proximate in pitch to the tone heard most recently. Older listeners also expected reversals of pitch direction, specifically for tones that changed direction after a disruption of proximity and for tones that formed symmetric patterns.