This focus idea is explored through:
Contrasting student and scientific views
Student everyday experiences
Students take their senses for granted and often do not realise how they work together in providing different types of information about our immediate environment. This information allows us to respond to changes in our environment.
Since students rarely lose one of their senses, they do not appreciate that they work in combination. In situations when students may experience temporary loss or masking of one sense, such as losing their sense of taste when they have a cold, losing their sense of sight when walking from a well-lit room into a dark room, or losing their general sense of hearing when using an MP3 player and personal ear phones, they may become more aware of having to use other senses to provide information from their environment.
Students rarely have first hand experience of how people with a sensory loss obtain needed information about the environment by using other senses.
The five senses - sight, taste, touch, hearing and smell – collect information about our environment that are interpreted by the brain. We make sense of this information based on previous experience (and subsequent learning) and by the combination of the information from each of the senses.
We respond almost automatically to most sensory information. Such response is important for survival in our environment.
Critical teaching ideas
- We use our senses to gather and respond to information about our environment, which aids our survival.
- Each sense provides different information which is combined and interpreted by our brain.
- Which sense is dominant varies between different animals, as well as which is the most sensitive. Our dominant sense is sight and hearing is our most sensitive (due to the range of ‘loudness’ over which hearing operates).
- Advancements in science have enhanced the quality of life for many people with sensory disabilities by providing such things as alternative methods of communication, increased mobility, additional educational tools, and technology designed for sensory enhancement, such as cochlear implants.
Explore the relationships between ideas about the operation and role of the senses in the
Concept Development Maps: Cells and Organs
At this level, learning experiences which encourage students to find out more about themselves and other animals are important. Initially it is important to explicitly identify the five senses and the
organ(s) associated with each sense. Then, with the intention of moving towards an understanding of ‘systems,’ it is also important to provide opportunities for students to experience the ways that each sense provides information which helps and supports the other senses and the organism as a whole.
Learning experiences should allow students to consider everyday difficulties that may be experienced by people whose sensory input is disrupted or unreliable. Encourage students to identify items or systems that have been developed to enhance sensory input. These could include: Braille, bells at railway crossings, audible, vibrating and tactile pedestrian signals, hearing aids, guide dogs, talking clocks, walking canes, etc.
Bring out students’ existing ideas and open discussion via shared experiences
Introduce the topic by providing a variety of experiences which can be built upon to explore each sense in detail. Use ‘feely bags’, secret packages, taped sounds and taste tests of bitter, sweet, salty and sour-tasting foods to create learning experiences which rely on one sense collecting information. Explore each sense in detail: for example, explore whether different tastes have the same effect on different parts of the tongue.
Promote, reflect on and clarify existing ideas
Provide an opportunity for students to be aware that they use more than one sense to gather information about their environment.Students could collect a variety of objects according to certain criteria (for example, something that is blue; that is heavy; that makes a noise; with a rough texture; with an odour.) They should examine all the objects collected and consider if there are some which would fit into another, different category from the one for which it was collected. Students should be made aware that they used input from at least two senses to determine their answer.
Collect evidence/data for analysis
Build on the previous activity by exploring how senses work together.Determine the success of our ability to correctly identify samples of food when sensory input is limited. Food samples may include: pieces of orange, carrot, celery, cantaloupe, potato, apple, pear, banana, etc. Place each sample in a paper bag. Organise students into three groups and blindfold two of the groups. One of these blindfolded groups must try to identify the wrapped food samples using only their sense of smell. The other blindfolded group may use only touch; their sense of smell is blocked (they should pinch their nose or put cotton wool in their nostrils). The final group is not blindfolded and may use touch, smell and appearance to identify the food samples. Students can record their observations using science journals and present their results using graphs and tables.
Help students work out some of the ‘scientific’ explanation for themselves
From data collected above students make generalisations about our ability to gather information and make sense of the world around us when sensory input is restricted as compared to when senses work together.
Clarify and consolidate ideas
Provide a shared experience to demonstrate the application of this idea in everyday life. Make popcorn with the class and list under each sense how we were able to observe the changes that took place throughout the process. For example, students might observe that at the beginning the popcorn was small and hard (using sight and touch), then the popcorn began to move (using sight and hearing) and then it popped (using hearing) and then the smell of cooking appeared (using smell) and then it was eaten (using taste).
Consolidate and extend application of ideas
Compare and contrast human senses with those of animals. Explore examples of how animals sense the outside world and the anatomical structures that allow them to do so. For example:
- bees have chemoreceptors (taste receptors) on their jaws, forelimbs and antennae
- the eyes of the chameleon can move independently - it can see in two different directions at the same time
- crickets hear using their legs when sound waves vibrate a thin membrane on the cricket's front legs
- falcons can detect a 10 cm object from a distance of 1.5 km
- dolphins and whales use some high pitched ‘whistles’ and ‘clicks’ beyond the range of human hearing to communicate.
Discuss why these senses are important for each animal.