Reward responsivity and habit formation in the co-occurrence of restrictive eating and nonsuicidal self-injury.

Dysfunctions in reward and/or habit formation have been proposed as factors contributing individually to the maintenance of restrictive eating and nonsuicidal self-injury (NSSI). However, despite the high comorbidity between these behaviors, the associations between reward and habit formation in their co-occurrence remains unclear. This study examined self-reported reward responsivity and habit strength among individuals with co-occurring restrictive eating and NSSI (Comorbid group; n = 108) and those with one behavior only (One-behavior group; n = 113). Hierarchical logistic regression analyses assessed the association between reward and habit features and the co-occurrence of restrictive eating and NSSI, accounting for the effects of impulsivity (a characteristic commonly considered to underlie co-occurring disordered eating and NSSI). Partial correlations examined the relationships between these features and the severity of eating disorder and NSSI symptoms, also controlling for impulsivity. Lower reward responsivity was associated with the co-occurrence of restrictive eating and NSSI, even after accounting for impulsivity (p = 0.017). In exploratory analyses, this relationship was no longer significant after accounting for self-reported depression. No significant associations were found regarding habit formation and restrictive eating and NSSI co-occurrence. Lower reward responsivity was linked to increased NSSI frequency and versatility in both groups and associated with severity of eating pathology in the Comorbid group (ps < 0.05). Our findings suggest that blunted reward responsivity may relate to the co-occurrence of restrictive eating, NSSI, and depressive symptoms, as well as the severity of restrictive eating and NSSI. Reward disturbances may serve as a crucial target in the treatment of multiple self-destructive behaviors.

Decreased gray matter volume in regions associated with affective pain processing in unmedicated individuals with nonsuicidal self-injury.

Nonsuicidal self-injury (NSSI) has been consistently associated with a reduced aversion to physical pain. Yet, little research has been done to investigate the brain structures related to pain in individuals with NSSI. This study examined gray matter volume patterns of pain processing regions in participants engaging in NSSI (n = 63) and age-, sex-, and handedness-matched healthy controls (n = 63). Voxel-based morphometry was performed to explore gray matter volume in regions of interest (ROIs) and partial correlation analyses were conducted to identify their associations with the frequency, versatility, duration, functions, and pain intensity of self-injury. As a result, significant volume decreases were found in the right anterior insula, bilateral secondary somatosensory cortex (SII), and left inferior frontal gyrus. Moreover, individuals with smaller anterior insula and SII volume showed a higher likelihood of endorsing affect-regulation and sensation-seeking functions of NSSI, as well as engaging in self-injury with a greater perceived intensity of pain. Our results provide the first empirical evidence that individuals with NSSI may exhibit distinct characteristics in brain regions associated with the affective component of pain processing. These neurobiological changes may be associated with their maladaptive response to noxious and painful NSSI experiences.

Effects of age, working memory, and word order on passive-sentence comprehension: evidence from a verb-final language.

BACKGROUND: The purpose of the current study was to investigate the effects of working-memory (WM) capacity on age-related changes in abilities to comprehend passive sentences when the word order was systematically manipulated. METHODS: A total of 134 individuals participated in the study. The sentence-comprehension task consisted of the canonical and non-canonical word-order conditions. A composite measure of WM scores was used as an index of WM capacity. RESULTS: Participants exhibited worse performance on sentences with non-canonical word order than canonical word order. The two-way interaction between age and WM was significant, suggesting that WM effects were greater than age effects on the task. CONCLUSIONS: WM capacity effects on passive-sentence comprehension increased dramatically as people aged, suggesting that those who have larger WM capacity are less vulnerable to age-related changes in sentence-comprehension abilities. WM capacity may serve as a cognitive reserve associated with sentence-comprehension abilities for elderly adults.

Cross-Linguistic Differences in a Picture-Description Task Between Korean- and English-Speaking Individuals With Aphasia.

Purpose: The purpose of the study was to examine cross-linguistic differences in a picture-description task between Korean- and English-speaking individuals with Broca's and anomic aphasia to determine whether a variation exists in the use of verbs and nouns across the language and aphasia groups. Method: Forty-eight individuals (male = 29; female = 19) participated in the study (n = 28 for aphasic group and n = 20 healthy controls). Data for English speakers were obtained from the Aphasia Bank Project. We used the picture-description task to obtain connected speech samples and analyzed noun- and verb-related linguistic variables. Results: Korean speakers with aphasia produced more verbs per utterance and a lower noun-to-verb ratio than English speakers with aphasia, whereas English speakers produced more nouns than Korean speakers. The Korean anomic group produced more verbs than Korean speakers with Broca's aphasia, whereas no effects were significant for English speakers with aphasia depending on the type of aphasia. Conclusions: Aphasia symptoms vary as a function of linguistic features of languages that individuals with aphasia used premorbidly. Furthermore, the linguistic characteristics of the individual's language influenced aphasia symptoms more strongly than the type of aphasia. It is theoretically and clinically important that this cross-linguistic study provides different perspectives, and that noun-verb deficits may vary depending on linguistic features.

Impact of time interval between remifentanil and propofol on propofol injection pain.

STUDY OBJECTIVE: To determine the most effective time interval between remifentanil and propofol (TimeRP) for the prevention of propofol injection pain in association with remifentanil dosage. DESIGN: Prospective randomized study. SETTING: Operating room of a university hospital. PATIENTS: Sixty American Society of Anesthesiologists physical status 1 and 2 patients scheduled for elective surgery under general anesthesia. INTERVENTIONS: Patients were randomly assigned to 1 of 3 groups to receive remifentanil at dosages of 0.25, 0.5, or 0.75 µg/kg over 30 seconds before the injection of 1% propofol 2 mg/kg. TimeRP was defined as the time interval from the initiation of the remifentanil injection to the initiation of the propofol injection. TimeRP for each subsequent patient was determined by the response of the previous patient using an up-and-down sequential allocation method. Injection pain caused by propofol was evaluated using a 4-point scale during the propofol injection. MEASUREMENTS: TimeRP50 was defined as the TimeRP at which propofol injection pain was absent in 50% of patients, and it was estimated using isotonic regression for each dose group. MAIN RESULTS: TimeRP50 was significantly lower in the remifentanil 0.75 µg/kg group (38.6 seconds, 83% confidence interval [CI], 35.6-45.0) than in the 0.5 µg/kg group (65.0 seconds; 83% CI, 52.5-75.0) or the 0.25 µg/kg group (66.6 seconds; 83% CI, 57.1-76.5). CONCLUSIONS: The efficacy of remifentanil pretreatment for preventing propofol injection pain can be influenced by the time interval between remifentanil and propofol as well as the remifentanil dose.