Effects of Neurofeedback and Transcranial Pulse Stimulation on Attention

The Conners' Continuous Performance Test (CPT) measures inattentiveness, impulsivity, sustained attention, and vigilance. Participants are required to push the spacebar when any letter, except "X", appears. Performances are measured in raw scores and standardized T scores. T scores between 45-54 indicate average performance, higher or lower scores indicate atypical performance.

The GradCPT is a continuous performance test to measure sustained attention. It has been shown to reliably indicate attentional fluctuation over time. Participants are required to respond to frequently presented city scene and inhibit responses to infrequently presented mountain scene. The sequence of visual stimuli is presented with gradual transitions to minimize involuntary attention capture by abrupt stimulus onset and offset. The main outcome of interest is reaction times variability, with higher variability indicating poorer sustained attention.

The Victoria version of the Stroop task is a validated means of measuring the ability to inhibit cognitive interference. Over three tasks of increasing difficulty level, participants are asked to identify colors as they appear on stimulus flash cards. These colors are randomly ordered either as dots, noncolor words, or noncorresponding color words. Performance is measured by reaction times and accuracy. Shorter reaction times and higher accuracy indicate better ability to inhibit cognitive interference.

The General Health Questionnaire (GHQ) measures psychological well-being. It comprises 12 self-report questions, each assessing the severity of a mental problem over the past few weeks. Total scores range from 0 to 36 with a higher score indicating poorer psychological states.

The Goal Orientation Scale measures how individuals interpret and respond to achievement situations. It comprises three subscales. The present study uses only the learning goal orientation subscale which consists of 5 self-report items measuring the desire to develop the self by acquiring new skills, mastering new situations, and improving one's competence. Total scores range from 5 to 35 with higher scores indicating greater learning goal orientation.

The N-back task measures working memory function. Participants are presented a sequence of numbers ranging from 0 to 9 one-by-one. For each, they are required to decide whether the current stimulus is the same as the one presented two trials ago. Performance is measured by reaction times and accuracy. Shorter reaction times and higher accuracy indicate better working memory.

The Color Trails Test (CTT) is used to assess attention shifting (i.e., the ability to alternate attention between two goals) and processing speed (i.e., the speed with which a cognitive operation is carried out). The test comprises two parts: CTT1 requires participants to connect a series of numbered circles that are randomly printed on a sheet of paper and CTT2 requires participants to connect numbered circles from 1 to 25 alternating between two colors (pink and yellow). Performance is measured by reaction times with faster reaction times indicating better flexibility and speed.

The Attentional Control Scale is a self-report measure of attentional control. It consists of two subscales which measure selective attention and attention shifting respectively. Total scores range from 20 to 80 with higher scores indicating better attentional control.

The Rosenberg Self-Esteem Scale is a 10-item self-report questionnaire which measures global self-esteem by measuring both positive and negative feeling about the self. Scores range from 10 to 40 with higher scores reflecting higher self-esteem.

The Social Connectedness Scale comprises 8 self-report items measuring three aspects of belongingness: connectedness, affiliation, and companionship. Total scores range from 8 to 48 with higher scores indicating higher sense of social connectedness.

The Hospital Anxiety and Depression Scale (HADS) is a 14-item self-report questionnaire comprising two subscales which assess levels of anxiety and depression respectively. Total scores for each subscale range from 0 to 21 with higher scores indicating higher levels of anxiety or depression.