Image in Medical Education: Why, When and How to Use It? A Critical Review of the Literature

Citation: Dhouha B, Ghofrane T, Wael F, Mejri A, Lasaad G. Image in Medical Education: Why, When and How to Use It? A Critical Review of the Literature. Biomed J Sci & Tech Res 26(3)-2020. BJSTR. MS.ID.004343.


Introduction
The image is a visual representation of the reality or part of the reality (without being the reality itself) [1]. Since prehistory the image has preceded the text. It is at the origin of the development of all linguistic signs. Nowadays, the image is a polysemic word.
Indeed, it may have 2 or 3 dimensions. It can be fixed or animated, colored or not, digital or not, real or virtual. Moreover, the image will make clinical diagnosis without recourse to any doctor, thanks to artificial intelligence [2]. The image is a didactic tool widely (and logically) used in the teaching of medicine. The image in medical pedagogy can be figurative (related to resemblance) or being abstract (related to imagination). We consider an image to be a visual signal that illustrates a concept. It is, therefore, all "nontext". Apart some few narrative reviews reported in the literature, our study seems to be the first (to our knowledge) critical reviews that analyses the contribution of image in medicine. The aim of our work is to carry out a critical review of the literature concerning the interest of the image in the teaching of medicine. Through this review, we try to answer the following questions: Why? How? and when using image as a pedagogic tool in medicine.

Image in Medical Education: Why is this?
Image enhances all domains of learning which is divided into 3 categories: cognitive domain (knowledge), affective domain (attitudes) and psychomotor domain (skills) [3]. It improves the 3 stages in the memory process: encoding, storage and retrieval. These into a storable form so that it can be recalled later [4]. Furthermore, encoding via an image is better and faster than encoding via a word or text. That is why the displaying of auscultator data (visual coding) in cardiology, for example, is better in diagnostic than isolated auscultation (acoustic coding). The image makes, in this example, encoding through 2 ways (visual and acoustic). Indeed, interpreting an image aloud allows the brain to process information using visual and acoustic coding. Similarly, drawing an image while touching it (a bone in anatomy education, for example) is another example of double coding through visual and haptic paths.
On the other hand, long-term memory encodes new fact and information semantically for storage as demonstrated by Baddeley [5]. An image needs, therefore, to enter into visual working memory before being stored onto long-term memory. Moreover, pictures and images are more likely to be remembered than words and texts. That's what we call ''picture superiority effect'' which is demonstrated in various studies [6]. Thus, an image transmits a maximum of educational messages in a minimum of time and space.
The use of color-coding increases memory efficiency. Memory enhancement is achieved through repetition and active storage However, the superiority of a video compared to a still image is enhancing memory isn't yet demonstrated. Beyond memorization, the image is a useful tool to help both sequential learners who need to learn in steps (via sequential images) and global learners [7].
In addition to memorization, the image improves reasoning.
It is a process which inputs are specific information and outputs are consequent decision. When the input is an image, reasoning is called visual reasoning. This visual reasoning reinforces critical vision and meta-cognition through two strategies: Visual Thinking Strategies (VTS) and Art Thinking (AT) [8]. In VTS, the learner is asked to answer the following 3 questions: a) What's going on in this picture? b) What makes you say that?

c)
What else can you find?
AT is a method similar to VTS but is aimed at artworks, plays or films. The usefulness of AT in learning (affective domain) is demonstrated. Otherwise, The Eye Tracking method evaluates this visual reasoning. It is a quantitative process measuring either the point of gaze where one is looking or the motion of an eye relative to head [9]. Finally, the image is a tool appreciated by learners, especially if it is used through social networks.

Image in Medical Education: How Can it be Used?
The use of images is mandatory in several methods because it is the foundation on which they are based (CIAP (Clarification, Illustration, Application, Participation)-Mini Talk Chalk) [10].    Faced with a sequential image ( Figure 2) the learner can be led to: I. Iinterpret a sequence.
II. Arrange a sequence in disorder (in time or space).
III. Draw a missing image in a sequence (or lengthen a sequence).
Indeed, the sequential image allows teaching by analogy or concordance and promotes mental rotation.
In front of a video the learner can be led to: i. Interpret.
ii. Produce a video of a clinical case.
iii. Produce a video selfie, mirror effect.
Elsewhere, the image may be a symbol or a graphic (Figure 3).
The image is, thus, a mediator of action, co-action and interaction.
Action-coaction-interaction, indeed, improves learners' motivation and enables them to detect their errors in order to remedy them through feedback action. This trilogy (action-coaction-interaction) enables the image to meet the requirements of the different teaching methods (active pedagogy, participatory pedagogy, collaborative pedagogy). c) At the end of the course an image can be used to reframe the concept(s) taught (thanks to big picture).

Discussion
Like any teaching tool, the image has the above-mentioned advantages, but it also has its pitfalls.

Conclusion
In today's highly image-based world, the use of images in medical education is essential. Indeed, the image is a pedagogic tool highly recommended. However, the advantages and disadvantages of such a tool must be known by all teachers.