Fig 1.
The questionary used to investigate students’ conceptions of the nervous system.
Fig 2.
The eight conceptual categories of neural circuit architecture represented by examples from the students’ answers (drawings) on question 3 (see Fig 1 for details on question 3).
Fig 3.
Bar graphs showing the percentage of students within each conceptual category of neural circuit architecture identified from their answers on question 3 (see Fig 1 for details on question 3).
Fig 4.
Stacked bar graphs showing the percentage of students within each conceptual category of neural circuit architecture identified from their answers on question 3 (Q3), and within each combination of answers on question 3 and 7 (Q3 + Q7).
Only the category CHAIN (OPEN) is specified for Q3, and only the category YES is specified for Q7. This is because they are the only relevant categories for the purpose of demonstrating the prevalence and persistence of the Open Chain conception.
Fig 5.
Bar graphs showing the percentage of students within each conceptual category of synaptic action identified from their answers on question 1 (see Fig 1 for details on question 1).
Fig 6.
Stacked bar graphs showing the percentage of students within each conceptual category of synaptic action identified from their answers on question 1 (Q1), within each combination of answers on question 1 and 4 (Q1 + Q4), and within each combination of answers to question 1, 4, and 6 (Q1 + Q4 + Q6).
Only the category EXCITATORY is specified for Q1, only the category YES is specified for Q4, and only the category NO is specified for Q6. This is because they are the only relevant categories for the purpose of demonstrating the prevalence and persistence of the Excitatory and the Exclusive Excitatory conception.
Table 1.
Examples from the coding of students’ answers to question 1: A nerve cell sends a strong nerve signal to another nerve cell.
What does the other nerve cell do with the signal (what happens to the signal)?.
Fig 7.
Bar graphs showing the percentage of students within each conceptual category of nerve signal origin identified from their answers on question 2 (see Fig 1 for details on question 2).
Fig 8.
Stacked bar graphs showing the percentage of students within each conceptual category of nerve signal origin identified from their answers on question 2 (Q2), and within each combination of answers on question 2 and 8 (Q2 + Q8).
Only the category BRAIN is specified for Q2, and only the category YES is specified for Q8. This is because they are relevant and sufficient for the purpose of demonstrating the prevalence and persistence of the BRAIN conception.
Fig 9.
Bar graphs showing the percentage of students within each response alternative on question 9 (see Fig 1 for details on question 9).
Table 2.
Relationships between students’ understanding of the system and their conceptions of the three basic aspects: 1) Neural circuit architecture, 2) Synaptic action, and 3) Nerve signal origin.