Imtiaj Ahmed | East West University (original) (raw)

Papers by Imtiaj Ahmed

This thesis explores interaction paradigms for virtual 3D models on large displays. We explored t... more This thesis explores interaction paradigms for virtual 3D models on large displays. We explored three distant freehand interaction paradigms and for each paradigm we implemented a prototype system. Among these paradigms, it has been found that pointing by hand/eye with selection gesture is the ideal technique to interact with such interfaces. In the pointing technique we reduced the 3D interaction into 2D interaction to explore the 3D contents presented on the large displays. We propose a pinch gesture to select items effortlessly: a gesture of touching index finger with the thumb. Also we found a user-friendly way to present content meta-information of the virtual 3D models and its interactive units during interaction

Symbiotic Interaction, 2017

Affective symbiosis for human-computer interaction refers to the dynamic relationship between the... more Affective symbiosis for human-computer interaction refers to the dynamic relationship between the user and affective virtual agents. In order to facilitate a true, immersive experience, we believe that it is necessary to adapt the presentation of an affective agent to the user's affective state. Investigating the experience, behavior, and physiological correlates of affective events, such as winning and losing during a competitive game, therefore might be used to adapt the agent's emotional states and system events. An experimental virtual reality game environment was designed as a stepping stone toward a system to demonstrate affective symbiosis. Users were invited to play a game of air hockey with affective agents in virtual reality. We collected the electrocardiography, electrodermal activity, and postural data, as well as self-reports, to investigate how emotional events affected physiology, behavior, and experience. The users were found to be engaged in the competition strongly while only paying limited attention to their adversaries' emotional expressions. We discuss how game events are much stronger causes for affective responses, with the physiological effects of winning and losing becoming more enhanced as the game progresses. We discuss how an affective, symbiotic system could implement both game events and dynamic, affective agents to create a system for total immersion.

Social Cognitive and Affective Neuroscience, 2021

The tendency to simulate the pain of others within our own sensorimotor systems is a vital compon... more The tendency to simulate the pain of others within our own sensorimotor systems is a vital component of empathy. However, this sensorimotor resonance is modulated by a multitude of social factors including similarity in bodily appearance, e.g. skin colour. The current study investigated whether increasing self–other similarity via virtual transfer to another colour body reduced ingroup bias in sensorimotor resonance. A sample of 58 white participants was momentarily transferred to either a black or a white body using virtual reality technology. We then employed electroencephalography to examine event-related desynchronization (ERD) in the sensorimotor beta (13–23 Hz) oscillations while they viewed black, white and violet photorealistic virtual agents being touched with a noxious or soft object. While the noxious treatment of a violet agent did not increase beta ERD, amplified beta ERD in response to black agent’s noxious vs soft treatment was found in perceivers transferred to a bla...

IEEE Transactions on Affective Computing, 2020

Interpersonal touch is critical for social-emotional development and presents a powerful modality... more Interpersonal touch is critical for social-emotional development and presents a powerful modality for communicating emotions. Virtual agents of the future could capitalize on touch to establish social bonds with humans and facilitate cooperation in virtual reality (VR). We studied whether the emotional expression of a virtual agent would affect the way humans touch the agent. Participants were asked to hold a pressure-sensing tube presented as the agent's arm in VR. Upon seeing the agent's emotional expression change, participants briefly squeezed the arm. The effect of emotional expressions on affective state was measured using self-reported valence and arousal as well as physiology-based indices. Onset, duration, and intensity of the squeeze were recorded to examine the haptic responses. Emotional expression of agents affected squeeze intensity and duration through changes in emotional perception and experience. Haptic responses may thus provide an implicit measure of persons' experience towards their virtual companion.

Journal of the Faculty of Agriculture, Kyushu University, 2016

Hypsizygus marmoreus is an edible and medicinal mushroom belongs to Basidiomycetes. The optimal c... more Hypsizygus marmoreus is an edible and medicinal mushroom belongs to Basidiomycetes. The optimal culture conditions for the vegetative growth of brown and white strains of H. marmoreus were investigated to obtain suitable farming condition. Temperature suitable and unsuitable for vegetative growth was obtained at 20 and 35°C, respectively. The both strains of H. mermoreus love medium temperature and the mycelial growth was well developed at 20-25°C. This mushroom prefer pH ranging 6-8 for mycelial growth. The highest and lowest mycelial growth was found at pH 7 and 5 of both strains, respectively. Among 5 different carbon sources, sucrose was the best, whereas, maltose and lactose were the worst. The most suitable nitrogen sources were CaNO 3 (in brown strain 65.6 mm and in white strain 56.3 mm) and the most unsuitable was NH 4 H 2 PO 4 (in brown strain 44.02 mm and in white strain 40.2 mm). Five different culture media were used to screen the optimal mycelial growth of H. marmoreus. PDA and YM (yeast-malt extract) were the most suitable and Czapek dox and Hennerberg were the most unfavorable for vegetative growth, whereas, glucose peptone was moderately suitable. The highest and lowest vegetative growth was observed in media prepared with mango (Mangifera indica) and koroi (Albizia procera) sawdust, respectively. However, for both strains, 3 weeks were required to complete mycelium running in mango sawdust, whereas, 4 weeks were spent to get 100% mycelium running in mahagoni (Swietenia mahagoni) and koroi sawdust. The premordia and fruiting bodies of H. marmoreus were formed in the mango sawdust medium sooner. The fruiting bodies of brown strain were formed earlier than white strain after occurrence of primordia. In case of limiting ventilation, the stem development was found to be good but no cap was seen to be formed. Ventilation influenced the growth and development of fruit body of H. marmoreus. Therefore, it could be said that physiochemical requirement for the vegetative growth is strictly considerable and results focused in this paper could be followed by farmers to scale up farming of H. marmoreus in Bangladesh.

American Journal of Biomedical and Life Sciences, 2020

In current study, an attempt was taken to investigate into the scenarios of otomycosis disease in... more In current study, an attempt was taken to investigate into the scenarios of otomycosis disease in Rajshahi metropolitan city of Bangladesh. There were 237 otomycosis patients found among 3875 ear patients during the studied period. Habit, habitat, life style, personal hygiene and food or nutritional status were found to be crucial factors which were largely responsible for the onset of otomycosis. Among 237 otomycosis patients, 125 and 112 sufferers were from rural and urban regions, respectively. In rural, male was more sufferer than female whereas, in urban, result was opposite to rural. Among 3 consecutive seasonal periods, the incidence of otomycosis patients was the highest in humid/rainy season (50.6%), intermediate level in winter season (35.4%) and the lowest level in dry seasons (14.0%). No significant variation was found between male (50.2%) and female (49.8%) patients for the onset of otomycosis. Age group was also potential for the onset of studied disease. The occurrences of over age (61 to above), baby (up to 10) and juvenile (11 to 20) group were 30.4%, 27.8% and 27.4%, respectively which were high. Whereas, the incidence was found to be low in early youth (5.1%) and late youth (9.3%) groups.

Journal of Bio-Science, 2019

Otomycosis is a chronic ear disease of external auditory canal and it is more prevalent in warm, ... more Otomycosis is a chronic ear disease of external auditory canal and it is more prevalent in warm, humid and dusty environment, although it is now found throughout the world. The most commonly found causative agents as of fungal species are Aspergillus and Candida along with preponderance of various fungal and bacterial species has also been reported. The aim of this review is to focus on the prevalence of causal agents of otomycosis in the global context and its clinical management. A total of 63 research articles have been reviewed, which deals prevalence of otomycosis. Its clinicomycological studies both separately and altogether with folk medicine in relation to treatment of otomycosis were also reviewed. Findings of various reports revealed that the Aspergillus and Candida species are the main causal agents of otomycosis. But many reports indicate that a few of other fungal species along with bacteria particularly Staplylococcus aureus and Pseudomonas aeruginosa are also responsi...

Mycobiology, 2004

This study was carried out to develop new mushroom strains with medicinal effects. Cultural chara... more This study was carried out to develop new mushroom strains with medicinal effects. Cultural characteristics and genetic relationships of 16 strains in Ganoderma applanata were examined. Three strains showing good qualities and fruitbody yield were selected as parental strains for breeding purpose. The spores collected from fruitbody should be immediately placed on the medium for the germination. The optimum temperatures of spore germination were 35 o C. The isolated monokaryons were observed their cultural characteristics. The sexuality of G. applanata was tetrapolarity. Thirty-three strains were developed by mono-mono crossing within ASI 18004 monokaryons. And eight monokaryons derived from each selected strains were mated with 16 dikaryons, that is di-mono mating, to release 128 strains. They were cultivated in the bottle and showed a big variation in their fruitbody yield.

Computers in Human Behavior, 2018

Receiving a touch or smile increases compliance in natural face-to-face settings. It has been unc... more Receiving a touch or smile increases compliance in natural face-to-face settings. It has been unclear, however, whether a virtual agent's touch and smile also promote compliance or whether there are individual differences in proneness to nonverbal persuasion. Utilizing a multimodal virtual reality, we investigated whether touch and smile promoted compliance to a virtual agent's requests and whether receiver's personality modulated the effects. Compliance was measured using the ultimatum game, in which participants were asked to either reject or accept an agent's monetary offers. Decision-making data were accompanied by offer-related cardiac responses, both of which were analyzed as a function of expression (anger, neutral, and happiness), touch (visuo-tactile, visual, no touch), and three personality traits: behavioral inhibition/activation system sensitivity (BIS/BAS) and justice sensitivity. People accepted unfair offers more often if the agents smiled or touched them. The effect of touch was more enhanced in those with low justice sensitivity and BAS, whereas facial expressions affected those with high BIS the most. Unfair offers amplified the cardiac response, but this effect was not dependent on nonverbal cues. Together, the results suggest that virtual nonverbal behaviors of virtual agents increase compliance and that there is substantial interindividual variation in proneness to persuasion.

Nonverbal communication determines much of how we perceive explicit, verbal messages. Facial expr... more Nonverbal communication determines much of how we perceive explicit, verbal messages. Facial expressions and social touch, for example, influence affinity and conformity. To understand the interaction between non-verbal and verbal information, we studied how the psychophysiological time-course of decoding the meaning of a message – the semiotics – is altered by facial expressions and touch. A virtual reality-based economic decision-making game of Ultimatum was used to investigate how participants perceived, and responded to, financial offers of variable levels of fairness. In line with previous studies, unfair offers evoked medial frontal negativity (MFN) within the N2 time window, which has been interpreted as reflecting an emotional reaction to violated social norms. Contrary to this emotional interpretation of the MFN, however, nonverbal signals did not modulate the early N2 component, only affecting fairness perception during the P3 component. This suggests that the non-verbal c...

Personality and Individual Differences, 2017

Receiving a tender caress from a caregiver or spouse reduces stress and promotes emotional wellbe... more Receiving a tender caress from a caregiver or spouse reduces stress and promotes emotional wellbeing, but receiving the same caress from a stranger makes us feel uncomfortable. According to recent neurophysiological findings, we not only react differently to the invited versus uninvited touch but also perceive the touch differently depending on context. A virtual reality experiment was conducted to investigate whether individual differences regarding behavioral inhibition system (BIS) and gender contribute to this affective touch perception. Touch perception was measured directly using self-reports and indirectly using the touch-related orienting response. The results showed that touch perception depended on the emotional expression of the virtual agents. High-arousal approach-related (happiness, anger) and avoidance-related (fear) expressions increased self-reported touch intensity, while happiness reduced the orienting response to touch. Moreover, interpersonal differences in behavioral inhibition and gender played distinct roles: BIS sensitivity in males was associated with stronger affective touch perception, particularly with high-arousal emotions whereas in females BIS sensitivity did not affect touch perception. The results suggest that individual differences that are related to preferences regarding tactile communication also determine how touch is perceived.

Frontiers in human neuroscience, 2017

Earlier studies have revealed cross-modal visuo-tactile interactions in endogenous spatial attent... more Earlier studies have revealed cross-modal visuo-tactile interactions in endogenous spatial attention. The current research used event-related potentials (ERPs) and virtual reality (VR) to identify how the visual cues of the perceiver's body affect visuo-tactile interaction in endogenous spatial attention and at what point in time the effect takes place. A bimodal oddball task with lateralized tactile and visual stimuli was presented in two VR conditions, one with and one without visible hands, and one VR-free control with hands in view. Participants were required to silently count one type of stimulus and ignore all other stimuli presented in irrelevant modality or location. The presence of hands was found to modulate early and late components of somatosensory and visual evoked potentials. For sensory-perceptual stages, the presence of virtual or real hands was found to amplify attention-related negativity on the somatosensory N140 and cross-modal interaction in somatosensory an...

Scientific reports, Jan 12, 2017

Although the previous studies have shown that an emotional context may alter touch processing, it... more Although the previous studies have shown that an emotional context may alter touch processing, it is not clear how visual contextual information modulates the sensory signals, and at what levels does this modulation take place. Therefore, we investigated how a toucher's emotional expressions (anger, happiness, fear, and sadness) modulate touchee's somatosensory-evoked potentials (SEPs) in different temporal ranges. Participants were presented with tactile stimulation appearing to originate from expressive characters in virtual reality. Touch processing was indexed using SEPs, and self-reports of touch experience were collected. Early potentials were found to be amplified after angry, happy and sad facial expressions, while late potentials were amplified after anger but attenuated after happiness. These effects were related to two stages of emotional modulation of tactile perception: anticipation and interpretation. The findings show that not only does touch affect emotion, b...

Proceedings of the 18th ACM International Conference on Multimodal Interaction, 2016

Virtual reality presents an extraordinary platform for multimodal communication. Haptic technolog... more Virtual reality presents an extraordinary platform for multimodal communication. Haptic technologies have been shown to provide an important contribution to this by facilitating co-presence and allowing affective communication. However, the findings of the affective influences rely on studies that have used myriad different types of haptic technology, making it likely that some forms of tactile feedback are more efficient in communicating emotions than others. To find out whether this is true and which haptic technologies are most effective, we measured user experience during a communication scenario featuring an affective agent and interpersonal touch in virtual reality. Interpersonal touch was simulated using two types of vibrotactile actuators and two types of force feedback mechanisms. Self-reports of subjective experience of the agent’s touch and emotions were obtained. The results revealed that, regardless of the agent’s expression, force feedback actuators were rated as more natural and resulted in greater emotional interdependence and a stronger sense of co-presence than vibrotactile touch.

Proceedings of the 2016 ACM Conference on Designing Interactive Systems, 2016

Technological support for augmenting the relationship that people establish with remote places ha... more Technological support for augmenting the relationship that people establish with remote places has been studied fairly little as the primary focus in telepresence studies is the connection between people. This paper addresses the design challenge for supporting 'active place presence' at home. A prototype, Hole in Space, was created to explore the design challenge. A longitudinal study of how an urban couple appropriated the prototype was conducted over the duration of seven months. The paper elaborates on how the Webmediated design influenced place presence and outlines several aspects that need to be considered when designing for active place presence at home.

Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing, 2015

We propose the use of a single continuous gesture as a novel, intuitive, and efficient mechanism ... more We propose the use of a single continuous gesture as a novel, intuitive, and efficient mechanism to authenticate a secure communication channel. Our approach builds on a novel algorithm for encoding (at least 20-bits) authentication information as a single continuous gesture, referred to as a checksum gesture. By asking the user to perform the generated gesture, a secure channel can be authenticated. Results from a controlled user experiment (N = 13 participants, 1022 trials) demonstrate the feasibility of our technique, showing over 90% success rate in establishing a secure communication channel despite relying on complex gesture patterns. The authentication times of our method are over three-folds faster than with previous gesture-based solutions. The average execution time of a gesture is 5:7 seconds in our study, which is comparable to the input time of conventional text input based PIN authentication. Our approach is particularly well-suited for scenarios involving wearable devices that lack conventional input capabilities, e.g., pairing a smartwatch with an interactive display.

Lecture Notes in Computer Science, 2015

We describe a field prototyping project where open-ended prototype tools for web-connected tags a... more We describe a field prototyping project where open-ended prototype tools for web-connected tags are weekly co-designed and programmed with and by the user. We call this approach Extreme Co-design to denote how design is inscribed in Extreme Programming sessions with rapid cycles of use, design and development that allow extensive exploration and experiencing of appropriation scenarios. Such an approach is particularly suited for repurposing malleable technologies such as RFID/NFC, which can take a variety of affordances and be applied for many uses, in particular acknowledging trends such as composition at end-user level of web functionality. We analyse the results of a one-month field work highlighting how to document explored ideas, appropriation scenarios, use try-outs, developed features and gained insights. We discuss this successful approach as a design tactic for unfinished products to foster end-users’ creativity through situated use and show how Extreme Programming and in-situ deployment supported meaningful designer-user interactions that resulted in the advancement of the initial design.

Frontiers in psychology, 2015

Executive control refers to the ability to withstand interference in order to achieve task goals.... more Executive control refers to the ability to withstand interference in order to achieve task goals. The effect of conflict adaptation describes that after experiencing interference, subsequent conflict effects are weaker. However, changes in the source of conflict have been found to disrupt conflict adaptation. Previous studies indicated that this specificity is determined by the degree to which one source causes episodic retrieval of a previous source. A virtual reality version of the Simon task was employed to investigate whether changes in a visual representation of the self would similarly affect conflict adaptation. Participants engaged in a mediated Simon task via 3D "avatar" models that either mirrored the participants' movements, or were presented statically. A retrieval cue was implemented as the identity of the avatar: switching it from a male to a female avatar was expected to disrupt the conflict adaptation effect (CAE). The results show that only in static c...