Eyeing ambiguity: Pupillary reactivity during early automatic interpretations in major depressive disorder.

Automatic interpretation biases (AIB) are theorized to be a risk factor for depression. However, documenting AIB in depressed persons has been challenging and the source (affective vs cognitive) of AIB remains unclear. We conducted a psychophysiological investigation of AIB in a sample of 25 clinical interview assessed individuals experiencing a current major depressive episode and 28 never-depressed control individuals. Participants completed the Word Sentence Association Paradigm for Depression while their pupil size was recorded. Repeated measures ANOVAs were used to examine behavioral response data and multilevel modeling was used to examine pupillary reactivity (change from trial baseline). Compared to controls, the depressed group was both more likely to endorse negative AIB (p = .001, d = 1.01) and less likely to endorse benign AIB (p = .011, d = 0.72). Further, the depressed group exhibited significantly increased pupil size while processing negative words when they endorsed a negative interpretation compared with controls (ps = .010-.037, ds = 0.69-0.87), but did not differ during other AIB trial types. Within group comparisons revealed greater differentiation between interpretations in the healthy control group in both reaction time and pupillary reactivity AIB measures. This depression-related pupillary reactivity pattern fits with an emotional salience-based explanation better than a cognitive effort-based hypothesis of negative AIB, while pupillary reactivity pattern within the control group is consistent with a benign bias. People with depression lack benign AIB and may be more emotionally engaged during negative AIB than healthy controls.

Comparison of a Silicon Skin Pad and a Tea Towel as Models for Learning a Simple Interrupted Suture.

There has been rapid growth in the range of models available for teaching veterinary clinical skills. To promote further uptake, particularly in lower-income settings and for students to practice at home, factors to consider include cost, availability of materials and ease of construction of the model. Two models were developed to teach suturing: a silicon skin pad, and a tea towel (with a check pattern) folded and stapled to represent an incision. The models were reviewed by seven veterinarians, all of whom considered both suitable for teaching, with silicon rated as more realistic. The learning outcome of each model was compared after students trained to perform a simple interrupted suture. Thirty-two second-year veterinary students with no prior suturing experience were randomly assigned to three training groups: silicon skin pad or tea towel (both self-directed with an instruction booklet), or watching a video. Following training, all students undertook an Objective Structured Clinical Examination (OSCE), placing a simple interrupted suture in piglet cadaver skin. The OSCE pass rates of the three groups were silicon skin pad, 10/11; tea towel, 9/10; and video, 1/11. There was no significant difference between the model groups, but the model groups were significantly different from the video group (p < .017). In conclusion, the tea towel was as effective as the silicon skin pad, but it was cheaper, simpler to make, and the materials were more readily available. In addition, both models were used effectively with an instruction booklet illustrating the value of self-directed learning to complement taught classes.