A pinboard by
Subrata Tikadar

PhD Research Scholar, Indian Institute of Technology Guwahati


Affective Computing in HCI

Affect and emotion play an important role to make a system natural. If a system is able to detect the emotional state of its user and can serve accordingly, usability and user experience will be increased in a large scale. The foremost step of designing such an affective system to identify the user emotion. In this work, we have proposed a model to identify the emotional state of user from her/his touch pattern while interacting with the touchscreen device like smartphone/tablet. Minimum number of features have been used to make the model inexpensive in terms of computation. Moreover, our approach does not require any extra/expensive hardware/wire/sensor to capture the emotional data. The embedded sensors and processor of low-end smartphone (of price ~10,000 INR equivalent to 156 USD approximately) is sufficient to capture and process the emotional data to predict the emotional state of a user.


Upregulating the positive affect system in anxiety and depression: Outcomes of a positive activity intervention.

Abstract: Research suggests that the positive affect system may be an important yet underexplored treatment target in anxiety and depression. Existing interventions primarily target the negative affect system, yielding modest effects on measures of positive emotions and associated outcomes (e.g., psychological well-being). The objective of the present pilot study was to evaluate the efficacy of a new transdiagnostic positive activity intervention (PAI) for anxiety and depression.Twenty-nine treatment-seeking individuals presenting with clinically impairing symptoms of anxiety and/or depression were randomly allocated to a 10-session protocol comprised of PAIs previously shown in nonclinical samples to improve positive thinking, emotions, and behaviors (e.g., gratitude, acts of kindness, optimism; n = 16) or a waitlist (WL) condition (n = 13). Participants were assessed at pre- and posttreatment, as well as 3- and 6-month follow-up, on measures of positive and negative affect, symptoms, and psychological well-being. ClinicalTrials.gov Identifier: NCT02330627 RESULTS: The PAI group displayed significantly larger improvements in positive affect and psychological well-being from pre- to posttreatment compared to WL. Posttreatment and follow-up scores in the PAI group were comparable to general population norms. The PAI regimen also resulted in significantly larger reductions in negative affect, as well as anxiety and depression symptoms, compared to WL. Improvements across all outcomes were large in magnitude and maintained over a 6-month follow-up period.Targeting the positive affect system through a multicomponent PAI regimen may be beneficial for generating improvements in positive emotions and well-being, as well as reducing negative affect and symptoms, in individuals with clinically impairing anxiety or depression.

Pub.: 07 Jan '17, Pinned: 25 Aug '17

Brain activation during fear extinction predicts exposure success

Abstract: Exposure therapy, a gold-standard treatment for anxiety disorders, is assumed to work via extinction learning, but this has never been tested. Anxious individuals demonstrate extinction learning deficits, likely related to less ventromedial prefrontal cortex (vmPFC) and more amygdala activation, but the relationship between these deficits and exposure outcome is unknown. We tested whether anxious individuals who demonstrate better extinction learning report greater anxiety reduction following brief exposure.Twenty-four adults with public speaking anxiety completed (1) functional magnetic resonance imaging during a conditioning paradigm, (2) a speech exposure session, and (3) anxiety questionnaires before and two weeks postexposure. Extinction learning was assessed by comparing ratings to a conditioned stimulus (neutral image) that was previously paired with an aversive noise against a stimulus that had never been paired. Robust regression analyses examined whether brain activation during extinction learning predicted anxiety reduction two weeks postexposure.On average, the conditioning paradigm resulted in acquisition and extinction effects on stimulus ratings, and the exposure session resulted in reduced anxiety two weeks post-exposure. Consistent with our hypothesis, individuals with better extinction learning (less negative stimulus ratings), greater activation in vmPFC, and less activation in amygdala, insula, and periaqueductal gray reported greater anxiety reduction two weeks postexposure.To our knowledge, this is the first time that the theoretical link between extinction learning and exposure outcome has been demonstrated. Future work should examine whether extinction learning can be used as a prognostic test to determine who is most likely to benefit from exposure therapy.

Pub.: 06 Dec '16, Pinned: 25 Aug '17

What good are positive emotions for treatment? Trait positive emotionality predicts response to Cognitive Behavioral Therapy for anxiety.

Abstract: Cognitive behavioral therapy (CBT) is empirically supported for the treatment of anxiety disorders; however, not all individuals achieve recovery following CBT. Positive emotions serve a number of functions that theoretically should facilitate response to CBT - they promote flexible patterns of information processing and assimilation of new information, encourage approach-oriented behavior, and speed physiological recovery from negative emotions. We conducted a secondary analysis of an existing clinical trial dataset to test the a priori hypothesis that individual differences in trait positive emotions would predict CBT response for anxiety.Participants meeting diagnostic criteria for panic disorder (n = 28) or generalized anxiety disorder (n = 31) completed 10 weekly individual CBT sessions. Trait positive emotionality was assessed at pre-treatment, and severity of anxiety symptoms and associated impairment was assessed throughout treatment.Participants who reported a greater propensity to experience positive emotions at pre-treatment displayed the largest reduction in anxiety symptoms as well as fewer symptoms following treatment. Positive emotions remained a robust predictor of change in symptoms when controlling for baseline depression severity.Initial evidence supports the predictive value of trait positive emotions as a prognostic indicator for CBT outcome in a GAD and PD sample.

Pub.: 28 Mar '17, Pinned: 25 Aug '17