Effect of the Group-based Paro Intervention on Physiological and Psychological Outcomes

Blood samples for the oxytocin assay will collected from the antecubital vein into pre-chilled 5 ml EDTA tubes with 250 KIU of apoprotinin, and refrigerated until processing.

The FTT consists of tapping with the index finger on a computer mouse as many times as possible within 60 second.

It collects in this study using the Wireless Physiological Feedback System (Model NeXus 4) manufactured by Mind Media in the Netherlands. This device sets 400 signal acquisitions per minute and regularly corrects the device to maintain good reliability. Signal acquisition is managed, corrected, and heart rate frequency calculated by BioTrace+ software (Mind Media). Autonomic neuro physiological status reflect by the amplitude of high-frequency (HF) and low-frequency (LF) waveforms that were analyzed with the LF/HF ratio.

The MMSE is a widely used tool that screens for levels of cognitive impairment, using the concepts of orientation, registration, attention and calculation, recall, and language. The MMSE score ranges from 0 to 30. In general, a cut-off point higher than 24 indicates normal cognition; 20-23 mild cognitive impairment; 10-19 moderate cognitive impairment; and 0-9 severe cognitive impairment.

The two core executive functions, WM and inhibition, were assessed using computerized tasks. Working memory was assessed using verbal WM and visuo-spatial WM tasks. Response inhibition was assessed using CWS, SS and GNG tasks.

Verbal WM task: These are powerpoint slides. Each slide has different numbers of red circles with squares as distracters. The task is to count the total number of red circles in each slide, keep the total in memory and recall the numbers in the correct order. The test starts with a length of memory recall (span) of two, that is, the participant had to recall two slides first. Each level of memory recall consists of three trials and the test is concluded when the participant failed two trials out of three at that same length of recall. If the participant is successful in 2 out of three trials, he/ she is allowed to go to the next span. A total score is calculated after adding a mark for each correct recall.

Visuo-spatial WM task: A 4 × 4 matrix with 16 squares is displayed on the computer screen as a pig house with a pig appearing in each window one at a time. The task is to recall in reverse order the locations where each target (pig) has appeared. The test start with a span length of two, that is, two pigs appear one after another. Each span consist of two trials and the test is concluded when the participant failed both trials at that same span length. Each correct location is given one point with a maximum score of 88. The score is taken as the measure of Visuo-spatial WM. At the end of the test, obtain score is automatically displayed on the computer screen.

Color word Stroop task: In this task different colour words will appear on the computer screen one at a time. The task is to name the color the word is printed, disregarding what the color word reads. The colour of the word printed is in the same color as the meaning of the word (congruent trials, eg; "red" is printed in red colour), or it is different from the meaning (incongruent trials, eg; word "green" is printed in blue colour). There are 75 congruent trials and 25 incongruent trials for one test session. Incorrect responses on incongruent trials are taken to assess the level of inhibitory control. The higher the errors the lower the interference control is.

Stop signal task: It assess the ability to inhibit ongoing responses. This is like a car game where a car appears on the computer screen. Every time the car appear, the participant is supposed to press a designated key as fast as possible to drive the car away. But when a stop-sign board appeared next to the car, participants has to refrain from pressing for the car to stand still. Each session in this task consist of 24 trials with six stop-signs-trials. Number of incorrect presses in stop sign (commission errors) is considered as the measure of inhibition and it is automatically displayed on the screen at the end of the task.

Go/no-go task (two versions: colour and shape): It assess ability to inhibit pre potent responses. The subject is presented with four different stimuli on the screen, one at a time in random order. There are two squares and two circles in blue and red. In the first session, the subject is instructed to respond by pressing a key each time when a blue figure appeared (go-trials) regardless of the shape, and not to respond when a red figure appear. In the second session, the subject is instructed to respond each time when a square appear, regardless of the color, and not to respond when a circle appear. Together the two consecutive sessions include 60 stimuli with 77% go-trials. The number of incorrect responses (commission errors) is used as a measure of inhibition and it is automatically displayed on the screen at the end of the task.

The GDS-SF consists of 15 items with 10 positive items and 5 negative items and has been found to be a useful tool to detect depressive symptoms in older populations. The scores range from 0-21 and a cut-off point of 6 or more indicates the presence of depression.

The UCLA loneliness is used to measure a person's subjective feelings of loneliness and feelings of isolation. Each item on the scale is rated from 1 (Never) to 4 (Often) with a total score ranging from 20 to 80. The scale does not identify a cut-off score that defines loneliness. The higher the score, the more severe a person's feelings of loneliness.

The WEMWBS scale was developed by researchers at the Universities of Warwick and Edinburgh (2006), including 14 items of mental well-being covering subjective well-being and psychological functioning. The scale is scored by summing responses to each item answered on a 5 points Likert scale and the scores range from 14 - 70. The higher the score, the better the mental well-being.

The Chinese version of the group climate questionnaire, 12 items, was developed by Zhong et al. (2013). This questionnaire consists three main dimensions including engagement (5 items), conflict (3 items), and avoidance (4 items). Each item on the scale is rated from 1 (Never) to 4 (Often) with a total score ranging from 12 to 48. The scale does not identify a cut-off score that defines good or bad group climate. The higher the score, the more better group atmosphere participant perceived.

The group satisfaction scale was developed Keyton (1991). The Chinese version of group satisfaction scale, which consists 14 items, was translated and modified by Lin. This questionnaire consists five main dimensions including group process feelings, attitudes of leaders, attitudes of group members, group acceptance, group equality. Each item on the scale is rated from 1 (very satisfied) to 5 (very dissatisfied) with a total score ranging from 14 to 70.The higher the score, the more dissatisfied the group is.