Experimental assessment of skull aberration and transmission loss at 270 kHz for focused ultrasound stimulation of the primary visual cortex

Transcranial focused ultrasound is a rapidly emerging method for non-invasive neuromodulation and stimulation. However, the skull causes a significant acoustic barrier and can reduce the focal intensity and alter the position and shape of the focus compared to free-field. In this study, the insertion loss and focal distortion due to the skull bone were quantified using three ex vivo human skulls and a focused ultrasound transducer operating at 270 kHz targeted on the approximate positions of the left and right primary visual cortex. Compared to free-field, the average insertion loss was -9.8 dB (± 2.2 dB), while the average focal shift was 1.7 mm (± 0.56 mm) in the lateral direction and 2.8 mm (±4.2 mm) in the axial direction. Overall, the acoustic aberrations were small compared to the size of the focal volume, meaning effective stimulation at this frequency can likely be achieved without patient-specific targeting. However, the insertion loss was significant and should be considered when selecting the target focal intensity for human studies

Peer assessment of individual contribution in group work: a student perspective

With group work increasing in popularity at universities, students no longer feel it is acceptable to be awarded the same group mark. This presents a significant challenge in awarding an individual mark which reflects unequivocally the time and effort a student has invested in a group project. To address this challenge, a tool to evaluate individual peer assessed contribution (IPAC) has been developed at University College London (UCL). The aim of this paper is to report on the perceptions of students regarding their experience of peer assessment in group work, since these perceptions are key to ensuring that a tool, such as IPAC, is accepted and used effectively by staff and students alike. The views of 133 students were acquired through anonymous surveys and focus groups ranging from first year undergraduate to doctoral students across 12 different departments. Results showed that 92% of students are in favour of peer assessment with a positive trend to using the IPAC tool. Receiving constructive feedback was considered imperative amongst respondents, which in turn should identify clearly the points of error; highlight explicitly the areas for improvement; and thus reflect accurately the mark being awarded. The attributes that students valued to be important when assessing their teammates were, in decreasing order of priority, attendance at meetings, listening and communication, actual contribution to the project deliverables, quality of the work produced, personal circumstances, and finally time management and organization skills. The detailed analysis and conclusions drawn from this study are the focus of this paper

Peer assessing individual contributions in a group project

Graduates are expected to have good academic knowledge but also the professional skills required in the workplace. One such ‘soft’ skill is the ability to give constructive criticism and provide meaningful but professional feedback. This is particularly relevant when working in a team within industry, where peers need to influence each other to improve their project outcomes and chances of success. The development of student’s skills to generate such feedback should be supported within higher education. Specifically the IPAC Consortium investigates the use of Individual Peer Assessed Contribution to group work. In this context, students create an output directed to their own peers (i.e. a form of external-facing assessment), and prepares students for similar practices in industry. This paper, linked to the roundtable session on external-facing assessments proposed by Grindle and Tong, investigates staff and student perceptions on such practice. Insights gained to this date are presented