Learning New Tricks: Exploring Brain Plasticity and Behavior Change
Early Language Development and the Critical Period Hypothesis
When we arrive in this world, we are dependent on our caregivers. We need to gain control and build up knowledge and understanding of the world. Infants are incredible “learning machines” during their first years of life. Language is an indispensable tool for learning, making sense of the world, and communicating with others. Prior to speech, children use gestures to engage with adults. Then, from the age of 18 months to four years old, children learn to say their first words and start to form sentences.
Language is the main facilitator of social interaction (Vygotsky). Therefore, if children are deprived of access to any type of language input prior to puberty, they will find it difficult to fully develop grammatical abilities later on. Lenneberg (1967) supported this idea with his hypothesis of a critical period for language development, remarking that this period was crucial to developing grammatical abilities. This was supported by case studies of wild or feral children.
Genie, who was discovered at the age of 13, was abused and neglected by her parents and was never exposed to language. Initially, she couldn’t speak at all, and although she had intensive speech therapy, she was never able to communicate in grammatically correct, complex sentences (Buddenhagen, 1971).
Challenging the Critical Period: Brain Plasticity and Language Acquisition
However, this hypothesis has been challenged recently. Current thinking suggests that language, like any skill, can be acquired at any time, providing circumstances are favorable and a person doesn’t have any barriers to learning in a typical manner, for example, a disability of some kind (Tomasello, 2000). Studies related to plasticity support Tomasello’s idea.
For example, sometimes we can lose abilities already learned, like language, due to a brain injury. Aphasia is a language impairment that occurs as a consequence of brain damage and often comes from a stroke. Typically, the lesions implicated in language are situated in the left hemisphere of the brain. Sir William Gowers (1887) and Henschen (1892) found that when that occurs, other parts of the brain may play a greater role in a particular cognitive function that would have been the function of the damaged region, i.e., the right hemisphere, which suggests that there may exist a “neural compensation system.”
However, it has been proven that age plays an important role when it comes to recovering from a brain injury. Individuals who have hemispherectomies (a surgical procedure that results in the removal of most of an entire hemisphere) in infancy have the capacity to develop speech and comprehension of speech regardless of which hemisphere is removed (Ogden, 1988). However, if damage to the left hemisphere occurs in adolescence or later, the right hemisphere’s ability to take on a role in speech production decreases dramatically. This suggests that the degree of brain plasticity relating to language function reduces as the brain matures (Gott, 1973).
Behavior Change: Attitudes and the Theory of Planned Behavior
So far, we have discussed how abilities can be acquired and also how we can lose them, pointing out that age is a crucial factor in their recovery. This next section will focus on behavior and how we may be able to change it. There is a belief that attitudes shape our behavior, which suggests that if it’s possible to modify a behavior, we may need to start looking at what lies behind this specific behavior and which attitudes or beliefs lead us to behave that way.
An attitude is an underlying tendency or disposition that is expressed in our thoughts, feelings, and actions. Attitudes also provide a basis for navigating our way in the world, guiding decisions and behavior, and communicating with others. There are two types: implicit and explicit attitudes.
- Implicit attitudes refer to spontaneous, non-verbal, unconscious responses to an attitude object.
- Explicit attitudes refer to conscious, verbal, or written claims as direct attitude indicators.
Fazio (1989) pointed out that even strong attitudes can contain inconsistencies. Evaluative conditioning enhances or changes the feeling towards a stimulus that carries a stronger or opposite response. This is better seen in the study by Hollands et al. (2011), which consisted of two groups of people watching slides of junk food. The first group watched the slides paired with a fat body, and the second group watched the slides paired with a blank screen. The results showed that the first group demonstrated a stronger preference for healthy food than the second group and that those who had a stronger preference for fast food before were the ones showing the strongest preference for healthy food afterward. This suggests that when attitudes are stronger, the effect of evaluating conditioning will also be stronger. The study also shows the importance of changing implicit attitudes to change behavior through cognitive associations, meaning then that implicit attitudes can be manipulated and therefore behavior too.
The Theory of Planned Behavior (TPB) by Ajzen (1991) explores how a behavior can be changed by control beliefs and perceived behavioral control and the influence of others’ opinions. For example, Calum’s beliefs about smoking are that it is bad, and his expectation is that giving up smoking will be better for his health. He can also see that the opinion of his family and friends is that giving up smoking is a good thing, and he cares about their opinion. So Calum eventually stops smoking. Identifying the behavioral, normative, and control beliefs that determine a behavior are then crucial to gain information about the kinds of beliefs that would have to be changed to effect and change intentions and behaviors (Fishbein & Ajzen, 2010).
Conclusion: Learning and Changing Throughout Life
The first part of the essay has focused on learning abilities like language. Some studies have demonstrated the importance of developing language skills before puberty and that recovering from a brain injury is more difficult as the brain is more mature. The second part has focused on behavior and theories that demonstrate the importance of knowing what beliefs and attitudes lie behind them so they can be changed. The different studies and theories have shown that it is possible to modify behaviors and learn new skills at any age, as long as there aren’t concrete factors that stop them, like a brain injury or a disability. Therefore, it is possible to teach an old dog new tricks.