Essay Questions
1. Consider the pros and cons of modularity and the brain. Are there any circumstances in which you think that a non-modular structure might be more effective?
Key Points:
- Point out that many aspects of cognitive functioning may be subserved by specialized modules (for example, in the visual system). This high level of specialization means that damage restricted to particular cortical regions can have very precise and selective effects.
- Development of the brain becomes much easier with a modular arrangement. For example, one can simply add more columns, or ‘bolt on’ more modules, rather like plugging in a new component on your computer.
- The brain can solve immensely difficult computational problems – for example, we can judge distances, identify objects and walk through complex environments relying solely on vision to guide us.
- There might also be an evolutionary explanation for modularity in the brain. To add a new perceptual analysis feature to our existing perceptual analysis systems, the simplest route would be to leave the existing analysis systems unchanged and simply ‘bolt on’ a new feature.
- Identify the problems posed by a computational stratagem like that mentioned above. For example, the brain does not process information as quickly as many silicon-based systems, there needs to be some way of ensuring that the different aspects of a stimulus, although processed separately, are none the less related to each other. This could present a problem if very rapid synthesis of information is required (e.g. leading to ‘illusory conjunctions’ and/or separation of perceptual features – students should receive considerable extra credit if they have read this widely).
- Credit awarded for the students’ acknowledgement that the nervous system has evolved to be flexible but that the prices for this modular flexibility are (occasionally) erroneous perceptions (e.g. ‘seeing things’ or ‘hearing things’ that aren’t actually present) and relatively slow processing speed compared with, say, the digital computer (which can, for example, ‘crunch numbers’ much faster than people can).
