This paper presents a comprehensive review of symmetrically shaped antennas in terms of antenna size, dielectric materials, resonating band, peak gain, radiation pattern, simulating tools, and their applications. In this article, flower shape, leaf shape, tree shape, fan shape, Pi shape, butterfly shape, bat shape, wearable, multiband, monopole, and fractal antennas are discussed. Further, a survey of previously reported bandwidth enhancement techniques of microstrip patch antenna like introduction of thick and lower permittivity substrate, multilayer substrate, parasitic elements, slots and notches, shorting wall, shorting pin, defected ground structure, metamaterial-based split ring resonator structure, fractal geometry, and composite right-hand/left-handed transmission line approach is presented. The physics of these techniques has been discussed in detail which is supported by circuit theory model approach.

In two experiments, we examined the hypothesis that bilingual speakers modulate their cognitive control settings dynamically in the presence of different interlocutors, and this can be captured through performance on a non-linguistic attention task. We introduced Malayalam–English bilinguals to interlocutors with varying L2 dominance through a pre-experiment familiarisation and interaction phase. Later, participants did the Flanker task while the interlocutors appeared before each trial. While in experiment one participants did the Flanker task with equal distribution of trials, in experiment two we manipulated the monitoring demands by changing the frequency of trials. Results showed that high-L2 proficient bilinguals had lower conflict effect on the Flanker task in the presence of balanced interlocutors in both the experiments. The results provide strong evidence of dynamic adaptation of control settings in bilinguals with regard to different passively present interlocutors. The results further extend the predictions of the adaptive control hypothesis with novel manipulation.

Does a concurrent verbal working memory (WM) load constrain cross-linguistic activation? In a visual world study, participants listened to Hindi (L1) or English (L2) spoken words and viewed a display containing the phonological cohort of the translation equivalent (TE cohort) of the spoken word and 3 distractors. Experiment 1 was administered without a load. Participants then maintained two or four letters (Experiment 2) or two, six or eight letters (Experiment 3) in WM and were tested on backward sequence recognition after the visual world display. Greater looks towards TE cohorts were observed in both the language directions in Experiment 1. With a load, TE cohort activation was inhibited in the L2 – L1 direction and observed only in the early stages after word onset in the L1 – L2 direction suggesting a critical role of language direction. These results indicate that cross-linguistic activation as seen through eye movements depends on cognitive resources such as WM.

In two experiments with Telugu–English bilinguals, we examined if bilingual speakers are sensitive towards an interlocutor's (cartoon) relative language proficiency when they voluntarily selected a language for object naming. After familiarization with four different cartoons with varied L2 proficiency, participants did a voluntary naming task. In Experiment 1, participants explicitly indicated their choice of language before naming objects. In Experiment 2, participants named the objects directly. In both experiments, language choices and switchrates were thoroughly modulated by the participants’ perceived linguistic ability of the cartoon. However, awareness of perceived proficiency of the cartoons did not modulate naming latency. These results provide strong support for the adaptive control hypothesis, showing that bilingual speakers are sensitive to their interlocutor's language needs and this influences how they plan their language use. The results provide evidence of speakers taking into consideration the language proficiency of interlocutors, suggesting extreme adaptability of the bilingual mind.

In their keynote article, Dijkstra, Wahl, Buytenhuijs, van Halem, Al-jibouri, De Korte & Rekke (2018) propose a new model that aims to integrate and take care of the possible shortcomings of both the Revised Hierarchical Model (RHM, Kroll & Stewart, 1994) and Bilingual Interactive Activation model (BIA and several of its later versions, Dijkstra & Van Heuven, 1998). They begin their proposal by examining the objections/issues raised by Brysbaert and Duyck (2010) on RHM. It is well known that RHM is a developmental, production-based model which mostly predicted performance on translation-based tasks albeit with different predictions for translation recognition vs. production with regard to second language proficiency; BIA being a connectionist model of bilingual word recognition majorly emphasized on language non –selective selection and parallel language activation. Having been developed in and around Dutch (English as the second language), it took cognate status and orthographic similarity between words very seriously. Cognate status and orthographic similarity as factors won't count much as theoretical constructs around which a hypothesis could be developed if we look round the diverse types of orthographies and phonologies we find around the world.

Valian (2014) argues that current approaches in the study of bilingualism's beneficial effects on executive functions and cognition are at best methodologically weak. There is no unanimity on what constitutes executive function and which tasks measure it. I agree with her view that executive function is not a single phenomenon but a collection of processes. Different tasks measure different aspects of them. Performance on different executive function tasks is related to the particular cognitive demands of the tasks as well as the participants’ profile. It does not follow necessarily that negotiating two languages should lead to an enhancement of ability on that task. Therefore, no single task can capture the cognitive benefits of bilingualism. Valian proposes that factors such as education, socio-economic status, and even extracurricular skills involving sports and exercise could boost executive functioning independent of bilingualism.

Though many previous studies have reported enhanced cognitive control in bilinguals, few have investigated if such control is modulated by language proficiency. Here, we examined the inhibitory control of high and low proficient Hindi–English bilinguals on an oculomotor Stroop task. Subjects were asked to make a saccade as fast as possible towards the appropriate colour patch among competitors and distractors suppressing an eye movement evoked by the meaning of the word. High proficient bilinguals quickly oriented their attention towards the correct colour patch while effectively controlling the Stroop interference compared with low proficient subjects, on both colour and direction words. High proficient bilinguals also had fewer saccadic errors and demonstrated overall faster saccadic latency on all trial types. The results provide strong evidence for enhanced oculomotor control in proficient bilinguals compared with the less proficient ones.