Post by Stephanie Williams
What's the science?
Human learning typically emerges from interactions with others. As online learning and e-lectures become more prevalent, it is important to understand how different social communication styles (eg. computer-mediated) can influence teaching effectiveness. Previous evidence has suggested that both communication style and prior knowledge states can affect how well students learn from their teachers. It is still unclear how the two factors interact, and how neural mechanisms contribute to differences in learning. This week in NeuroImage, Liu and colleagues used fNIRS-scanning to analyze how communication style and knowledge state affect how students learn.
How did they do it?
The authors measured the brain activity of 42 pairs of participants simultaneously, using a method called hyperscanning. The brain activity recordings were done using function near infrared spectroscopy (fNIRS), which employs lasers to noninvasively measure changes in deoxygenated and oxygenated hemoglobin in the brain. During the experiment, one participant of the pair acted as the ‘student’ and the other as the ‘teacher’. Teachers were asked to present material for approximately six minutes in two different communication modes: Face-to-face and via computer-mediated communication. In the face-to-face group, the teacher and student could see each other and could interact with nonverbal cues. In the computer-mediated communication mode, the participants sat with their backs to each other, and could only communicate via the computers.
Teachers presented two different types of material. One was a topic that the student already had prior knowledge about (“with prior knowledge” group), and one was a completely new topic (“without prior knowledge” group). In the prior knowledge group, teachers taught a Probability Theory formula (P(A|B) = P(A∩B)/P(B)) to students who had taken a formal course on Probability Theory. Material in the no prior knowledge group covered Option Theory (teachers taught the formula FV=Ae^nxr to calculate the price of a call option). Before they were allowed to interact with the students, the teachers underwent training and demonstrated that they could teach both types of materials.
The authors analyzed a) the participants’ responses to questionnaires (to understand how subjects the perceived teacher-student interaction), and b) the students’ scores on tests covering the material taught. The authors used these two types of behavioral measures to analyze the effect of interpersonal neural synchronization. They were interested in whether interpersonal neural synchronization mediated the relationship between the ratings of the teacher-student interaction, and the student subjects’ test scores. They were also interested in identifying the earliest time point in the experiment at which there was a correlation between the interpersonal neural synchronization and the teaching outcome. Finally, they assessed whether interpersonal neural synchronization in specific regions of the brain contributed to the relationship between the teacher-student interaction and the students’ test scores.
What did they find?
The authors found that the mode of communication had a significant effect on the perceived quality of the teacher-student interaction. Subjects tended to rate the perceived student-teacher interaction higher after face-to-face communication versus after computer-mediated communication. The prior knowledge state of the student did not affect the ratings of the student-teacher relationship. The authors found that both prior knowledge and communication mode had an effect on the students’ test scores: Students taught in the face-to-face mode scored higher on tests than students in computer-mediated communication mode, but only when they had already been exposed to the material and not when they had to learn new material. Students who rated their teacher-student interaction higher also tended to have higher test scores.
The authors found significant interpersonal neural synchronization in the left prefrontal cortex during the face-to-face teaching condition when students had prior knowledge. Early (within the first 25-35 seconds of teaching) prefrontal task-related interpersonal neural synchronization was correlated with teaching effectiveness. Differences between the fNIRS data collected during the two communication modes showed that task-related interpersonal neural synchronization was higher overall during face-to-face teaching than for the computer-mediated teaching. The authors concluded that interpersonal neural synchronization mediated the relationship between the perceived interaction and the students’ test scores. The authors did not see any signs of synchronization in the rTPJ, which had been previously found by other researchers during social interactions.
What's the impact?
The author’s findings suggest that fNIRS can be used to better understand dynamics between teachers and students, and to analyze teaching effectiveness. Further, teaching effectiveness is affected by the mode of communication (face-to-face vs. computer mediated) and this could be mediated in part by neural synchronization between student and teacher. This work advances our understanding of the interplay between knowledge state and communication mode in teacher-student interactions.
Liu et al. Interplay between prior knowledge and communication mode on teaching effectiveness: Interpersonal neural synchronization as a neural marker. Neuron (2019).Access the original scientific publication here.